malloc.c source code [glibc/malloc/malloc.c]

1	/ Malloc implementation for multiple threads without lock contention.*
2	Copyright (C) 1996-2017 Free Software Foundation, Inc.
3	This file is part of the GNU C Library.
4	Contributed by Wolfram Gloger <wg@malloc.de>
5	and Doug Lea <dl@cs.oswego.edu>, 2001.
6
7	The GNU C Library is free software; you can redistribute it and/or
8	modify it under the terms of the GNU Lesser General Public License as
9	published by the Free Software Foundation; either version 2.1 of the
10	License, or (at your option) any later version.
11
12	The GNU C Library is distributed in the hope that it will be useful,
13	but WITHOUT ANY WARRANTY; without even the implied warranty of
14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15	Lesser General Public License for more details.
16
17	You should have received a copy of the GNU Lesser General Public
18	License along with the GNU C Library; see the file COPYING.LIB. If
19	not, see <http://www.gnu.org/licenses/>. /*
20
21	/*
22	This is a version (aka ptmalloc2) of malloc/free/realloc written by
23	Doug Lea and adapted to multiple threads/arenas by Wolfram Gloger.
24
25	There have been substantial changes made after the integration into
26	glibc in all parts of the code. Do not look for much commonality
27	with the ptmalloc2 version.
28
29	* Version ptmalloc2-20011215
30	based on:
31	VERSION 2.7.0 Sun Mar 11 14:14:06 2001 Doug Lea (dl at gee)
32
33	* Quickstart
34
35	In order to compile this implementation, a Makefile is provided with
36	the ptmalloc2 distribution, which has pre-defined targets for some
37	popular systems (e.g. "make posix" for Posix threads). All that is
38	typically required with regard to compiler flags is the selection of
39	the thread package via defining one out of USE_PTHREADS, USE_THR or
40	USE_SPROC. Check the thread-m.h file for what effects this has.
41	Many/most systems will additionally require USE_TSD_DATA_HACK to be
42	defined, so this is the default for "make posix".
43
44	* Why use this malloc?
45
46	This is not the fastest, most space-conserving, most portable, or
47	most tunable malloc ever written. However it is among the fastest
48	while also being among the most space-conserving, portable and tunable.
49	Consistent balance across these factors results in a good general-purpose
50	allocator for malloc-intensive programs.
51
52	The main properties of the algorithms are:
53	* For large (>= 512 bytes) requests, it is a pure best-fit allocator,
54	with ties normally decided via FIFO (i.e. least recently used).
55	* For small (<= 64 bytes by default) requests, it is a caching
56	allocator, that maintains pools of quickly recycled chunks.
57	* In between, and for combinations of large and small requests, it does
58	the best it can trying to meet both goals at once.
59	* For very large requests (>= 128KB by default), it relies on system
60	memory mapping facilities, if supported.
61
62	For a longer but slightly out of date high-level description, see
63	http://gee.cs.oswego.edu/dl/html/malloc.html
64
65	You may already by default be using a C library containing a malloc
66	that is based on some version of this malloc (for example in
67	linux). You might still want to use the one in this file in order to
68	customize settings or to avoid overheads associated with library
69	versions.
70
71	* Contents, described in more detail in "description of public routines" below.
72
73	Standard (ANSI/SVID/...) functions:
74	malloc(size_t n);
75	calloc(size_t n_elements, size_t element_size);
76	free(void p);*
77	realloc(void p, size_t n);*
78	memalign(size_t alignment, size_t n);
79	valloc(size_t n);
80	mallinfo()
81	mallopt(int parameter_number, int parameter_value)
82
83	Additional functions:
84	independent_calloc(size_t n_elements, size_t size, void chunks[]);*
85	independent_comalloc(size_t n_elements, size_t sizes[], void chunks[]);*
86	pvalloc(size_t n);
87	cfree(void p);*
88	malloc_trim(size_t pad);
89	malloc_usable_size(void p);*
90	malloc_stats();
91
92	* Vital statistics:
93
94	Supported pointer representation: 4 or 8 bytes
95	Supported size_t representation: 4 or 8 bytes
96	Note that size_t is allowed to be 4 bytes even if pointers are 8.
97	You can adjust this by defining INTERNAL_SIZE_T
98
99	Alignment: 2 sizeof(size_t) (default)*
100	(i.e., 8 byte alignment with 4byte size_t). This suffices for
101	nearly all current machines and C compilers. However, you can
102	define MALLOC_ALIGNMENT to be wider than this if necessary.
103
104	Minimum overhead per allocated chunk: 4 or 8 bytes
105	Each malloced chunk has a hidden word of overhead holding size
106	and status information.
107
108	Minimum allocated size: 4-byte ptrs: 16 bytes (including 4 overhead)
109	8-byte ptrs: 24/32 bytes (including, 4/8 overhead)
110
111	When a chunk is freed, 12 (for 4byte ptrs) or 20 (for 8 byte
112	ptrs but 4 byte size) or 24 (for 8/8) additional bytes are
113	needed; 4 (8) for a trailing size field and 8 (16) bytes for
114	free list pointers. Thus, the minimum allocatable size is
115	16/24/32 bytes.
116
117	Even a request for zero bytes (i.e., malloc(0)) returns a
118	pointer to something of the minimum allocatable size.
119
120	The maximum overhead wastage (i.e., number of extra bytes
121	allocated than were requested in malloc) is less than or equal
122	to the minimum size, except for requests >= mmap_threshold that
123	are serviced via mmap(), where the worst case wastage is 2 *
124	sizeof(size_t) bytes plus the remainder from a system page (the
125	minimal mmap unit); typically 4096 or 8192 bytes.
126
127	Maximum allocated size: 4-byte size_t: 2^32 minus about two pages
128	8-byte size_t: 2^64 minus about two pages
129
130	It is assumed that (possibly signed) size_t values suffice to
131	represent chunk sizes. `Possibly signed' is due to the fact
132	that `size_t' may be defined on a system as either a signed or
133	an unsigned type. The ISO C standard says that it must be
134	unsigned, but a few systems are known not to adhere to this.
135	Additionally, even when size_t is unsigned, sbrk (which is by
136	default used to obtain memory from system) accepts signed
137	arguments, and may not be able to handle size_t-wide arguments
138	with negative sign bit. Generally, values that would
139	appear as negative after accounting for overhead and alignment
140	are supported only via mmap(), which does not have this
141	limitation.
142
143	Requests for sizes outside the allowed range will perform an optional
144	failure action and then return null. (Requests may also
145	also fail because a system is out of memory.)
146
147	Thread-safety: thread-safe
148
149	Compliance: I believe it is compliant with the 1997 Single Unix Specification
150	Also SVID/XPG, ANSI C, and probably others as well.
151
152	* Synopsis of compile-time options:
153
154	People have reported using previous versions of this malloc on all
155	versions of Unix, sometimes by tweaking some of the defines
156	below. It has been tested most extensively on Solaris and Linux.
157	People also report using it in stand-alone embedded systems.
158
159	The implementation is in straight, hand-tuned ANSI C. It is not
160	at all modular. (Sorry!) It uses a lot of macros. To be at all
161	usable, this code should be compiled using an optimizing compiler
162	(for example gcc -O3) that can simplify expressions and control
163	paths. (FAQ: some macros import variables as arguments rather than
164	declare locals because people reported that some debuggers
165	otherwise get confused.)
166
167	OPTION DEFAULT VALUE
168
169	Compilation Environment options:
170
171	HAVE_MREMAP 0
172
173	Changing default word sizes:
174
175	INTERNAL_SIZE_T size_t
176
177	Configuration and functionality options:
178
179	USE_PUBLIC_MALLOC_WRAPPERS NOT defined
180	USE_MALLOC_LOCK NOT defined
181	MALLOC_DEBUG NOT defined
182	REALLOC_ZERO_BYTES_FREES 1
183	TRIM_FASTBINS 0
184
185	Options for customizing MORECORE:
186
187	MORECORE sbrk
188	MORECORE_FAILURE -1
189	MORECORE_CONTIGUOUS 1
190	MORECORE_CANNOT_TRIM NOT defined
191	MORECORE_CLEARS 1
192	MMAP_AS_MORECORE_SIZE (1024 1024)*
193
194	Tuning options that are also dynamically changeable via mallopt:
195
196	DEFAULT_MXFAST 64 (for 32bit), 128 (for 64bit)
197	DEFAULT_TRIM_THRESHOLD 128 1024*
198	DEFAULT_TOP_PAD 0
199	DEFAULT_MMAP_THRESHOLD 128 1024*
200	DEFAULT_MMAP_MAX 65536
201
202	There are several other #defined constants and macros that you
203	probably don't want to touch unless you are extending or adapting malloc. /*
204
205	/*
206	void is the pointer type that malloc should say it returns*
207	*/
208
209	#ifndef void
210	#define void void
211	#endif /void/
212
213	#include <stddef.h> /* for size_t */
214	#include <stdlib.h> /* for getenv(), abort() */
215	#include <unistd.h> /* for __libc_enable_secure */
216
217	#include <atomic.h>
218	#include <_itoa.h>
219	#include <bits/wordsize.h>
220	#include <sys/sysinfo.h>
221
222	#include <ldsodefs.h>
223
224	#include <unistd.h>
225	#include <stdio.h> /* needed for malloc_stats */
226	#include <errno.h>
227
228	#include <shlib-compat.h>
229
230	/ For uintptr_t. /
231	#include <stdint.h>
232
233	/ For va_arg, va_start, va_end. /
234	#include <stdarg.h>
235
236	/ For MIN, MAX, powerof2. /
237	#include <sys/param.h>
238
239	/ For ALIGN_UP et. al. /
240	#include <libc-internal.h>
241
242	#include <malloc/malloc-internal.h>
243
244	/*
245	Debugging:
246
247	Because freed chunks may be overwritten with bookkeeping fields, this
248	malloc will often die when freed memory is overwritten by user
249	programs. This can be very effective (albeit in an annoying way)
250	in helping track down dangling pointers.
251
252	If you compile with -DMALLOC_DEBUG, a number of assertion checks are
253	enabled that will catch more memory errors. You probably won't be
254	able to make much sense of the actual assertion errors, but they
255	should help you locate incorrectly overwritten memory. The checking
256	is fairly extensive, and will slow down execution
257	noticeably. Calling malloc_stats or mallinfo with MALLOC_DEBUG set
258	will attempt to check every non-mmapped allocated and free chunk in
259	the course of computing the summmaries. (By nature, mmapped regions
260	cannot be checked very much automatically.)
261
262	Setting MALLOC_DEBUG may also be helpful if you are trying to modify
263	this code. The assertions in the check routines spell out in more
264	detail the assumptions and invariants underlying the algorithms.
265
266	Setting MALLOC_DEBUG does NOT provide an automated mechanism for
267	checking that all accesses to malloced memory stay within their
268	bounds. However, there are several add-ons and adaptations of this
269	or other mallocs available that do this.
270	*/
271
272	#ifndef MALLOC_DEBUG
273	#define MALLOC_DEBUG 0
274	#endif
275
276	#ifdef NDEBUG
277	# define assert(expr) ((void) 0)
278	#else
279	# define assert(expr) \
280	((expr) \
281	? ((void) 0) \
282	: __malloc_assert (#expr, __FILE__, __LINE__, __func__))
283
284	extern const char *__progname;
285
286	static void
287	__malloc_assert (const char assertion, const* char file, unsigned* int line,
288	const char *function)
289	{
290	(void) __fxprintf (NULL, "%s%s%s:%u: %s%sAssertion `%s' failed.\n",
291	__progname, __progname[`0`] ? ": " : "",
292	file, line,
293	function ? function : "", function ? ": " : "",
294	assertion);
295	fflush (stderr);
296	abort ();
297	}
298	#endif
299
300
301	/*
302	REALLOC_ZERO_BYTES_FREES should be set if a call to
303	realloc with zero bytes should be the same as a call to free.
304	This is required by the C standard. Otherwise, since this malloc
305	returns a unique pointer for malloc(0), so does realloc(p, 0).
306	*/
307
308	#ifndef REALLOC_ZERO_BYTES_FREES
309	#define REALLOC_ZERO_BYTES_FREES 1
310	#endif
311
312	/*
313	TRIM_FASTBINS controls whether free() of a very small chunk can
314	immediately lead to trimming. Setting to true (1) can reduce memory
315	footprint, but will almost always slow down programs that use a lot
316	of small chunks.
317
318	Define this only if you are willing to give up some speed to more
319	aggressively reduce system-level memory footprint when releasing
320	memory in programs that use many small chunks. You can get
321	essentially the same effect by setting MXFAST to 0, but this can
322	lead to even greater slowdowns in programs using many small chunks.
323	TRIM_FASTBINS is an in-between compile-time option, that disables
324	only those chunks bordering topmost memory from being placed in
325	fastbins.
326	*/
327
328	#ifndef TRIM_FASTBINS
329	#define TRIM_FASTBINS 0
330	#endif
331
332
333	/ Definition for getting more memory from the OS. /
334	#define MORECORE (*__morecore)
335	#define MORECORE_FAILURE 0
336	void * __default_morecore (ptrdiff_t);
337	void (__morecore)(ptrdiff_t) = __default_morecore;
338
339
340	#include <string.h>
341
342	/*
343	MORECORE-related declarations. By default, rely on sbrk
344	*/
345
346
347	/*
348	MORECORE is the name of the routine to call to obtain more memory
349	from the system. See below for general guidance on writing
350	alternative MORECORE functions, as well as a version for WIN32 and a
351	sample version for pre-OSX macos.
352	*/
353
354	#ifndef MORECORE
355	#define MORECORE sbrk
356	#endif
357
358	/*
359	MORECORE_FAILURE is the value returned upon failure of MORECORE
360	as well as mmap. Since it cannot be an otherwise valid memory address,
361	and must reflect values of standard sys calls, you probably ought not
362	try to redefine it.
363	*/
364
365	#ifndef MORECORE_FAILURE
366	#define MORECORE_FAILURE (-1)
367	#endif
368
369	/*
370	If MORECORE_CONTIGUOUS is true, take advantage of fact that
371	consecutive calls to MORECORE with positive arguments always return
372	contiguous increasing addresses. This is true of unix sbrk. Even
373	if not defined, when regions happen to be contiguous, malloc will
374	permit allocations spanning regions obtained from different
375	calls. But defining this when applicable enables some stronger
376	consistency checks and space efficiencies.
377	*/
378
379	#ifndef MORECORE_CONTIGUOUS
380	#define MORECORE_CONTIGUOUS 1
381	#endif
382
383	/*
384	Define MORECORE_CANNOT_TRIM if your version of MORECORE
385	cannot release space back to the system when given negative
386	arguments. This is generally necessary only if you are using
387	a hand-crafted MORECORE function that cannot handle negative arguments.
388	*/
389
390	/ #define MORECORE_CANNOT_TRIM /
391
392	/ MORECORE_CLEARS (default 1)*
393	The degree to which the routine mapped to MORECORE zeroes out
394	memory: never (0), only for newly allocated space (1) or always
395	(2). The distinction between (1) and (2) is necessary because on
396	some systems, if the application first decrements and then
397	increments the break value, the contents of the reallocated space
398	are unspecified.
399	*/
400
401	#ifndef MORECORE_CLEARS
402	# define MORECORE_CLEARS 1
403	#endif
404
405
406	/*
407	MMAP_AS_MORECORE_SIZE is the minimum mmap size argument to use if
408	sbrk fails, and mmap is used as a backup. The value must be a
409	multiple of page size. This backup strategy generally applies only
410	when systems have "holes" in address space, so sbrk cannot perform
411	contiguous expansion, but there is still space available on system.
412	On systems for which this is known to be useful (i.e. most linux
413	kernels), this occurs only when programs allocate huge amounts of
414	memory. Between this, and the fact that mmap regions tend to be
415	limited, the size should be large, to avoid too many mmap calls and
416	thus avoid running out of kernel resources. /*
417
418	#ifndef MMAP_AS_MORECORE_SIZE
419	#define MMAP_AS_MORECORE_SIZE (1024 * 1024)
420	#endif
421
422	/*
423	Define HAVE_MREMAP to make realloc() use mremap() to re-allocate
424	large blocks.
425	*/
426
427	#ifndef HAVE_MREMAP
428	#define HAVE_MREMAP 0
429	#endif
430
431	/ We may need to support __malloc_initialize_hook for backwards*
432	compatibility. /*
433
434	#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_24)
435	# define HAVE_MALLOC_INIT_HOOK 1
436	#else
437	# define HAVE_MALLOC_INIT_HOOK 0
438	#endif
439
440
441	/*
442	This version of malloc supports the standard SVID/XPG mallinfo
443	routine that returns a struct containing usage properties and
444	statistics. It should work on any SVID/XPG compliant system that has
445	a /usr/include/malloc.h defining struct mallinfo. (If you'd like to
446	install such a thing yourself, cut out the preliminary declarations
447	as described above and below and save them in a malloc.h file. But
448	there's no compelling reason to bother to do this.)
449
450	The main declaration needed is the mallinfo struct that is returned
451	(by-copy) by mallinfo(). The SVID/XPG malloinfo struct contains a
452	bunch of fields that are not even meaningful in this version of
453	malloc. These fields are are instead filled by mallinfo() with
454	other numbers that might be of interest.
455	*/
456
457
458	/ ---------- description of public routines ------------ /
459
460	/*
461	malloc(size_t n)
462	Returns a pointer to a newly allocated chunk of at least n bytes, or null
463	if no space is available. Additionally, on failure, errno is
464	set to ENOMEM on ANSI C systems.
465
466	If n is zero, malloc returns a minumum-sized chunk. (The minimum
467	size is 16 bytes on most 32bit systems, and 24 or 32 bytes on 64bit
468	systems.) On most systems, size_t is an unsigned type, so calls
469	with negative arguments are interpreted as requests for huge amounts
470	of space, which will often fail. The maximum supported value of n
471	differs across systems, but is in all cases less than the maximum
472	representable value of a size_t.
473	*/
474	void* __libc_malloc(size_t);
475	libc_hidden_proto (__libc_malloc)
476
477	/*
478	free(void p)*
479	Releases the chunk of memory pointed to by p, that had been previously
480	allocated using malloc or a related routine such as realloc.
481	It has no effect if p is null. It can have arbitrary (i.e., bad!)
482	effects if p has already been freed.
483
484	Unless disabled (using mallopt), freeing very large spaces will
485	when possible, automatically trigger operations that give
486	back unused memory to the system, thus reducing program footprint.
487	*/
488	void __libc_free(void*);
489	libc_hidden_proto (__libc_free)
490
491	/*
492	calloc(size_t n_elements, size_t element_size);
493	Returns a pointer to n_elements element_size bytes, with all locations*
494	set to zero.
495	*/
496	void* __libc_calloc(size_t, size_t);
497
498	/*
499	realloc(void p, size_t n)*
500	Returns a pointer to a chunk of size n that contains the same data
501	as does chunk p up to the minimum of (n, p's size) bytes, or null
502	if no space is available.
503
504	The returned pointer may or may not be the same as p. The algorithm
505	prefers extending p when possible, otherwise it employs the
506	equivalent of a malloc-copy-free sequence.
507
508	If p is null, realloc is equivalent to malloc.
509
510	If space is not available, realloc returns null, errno is set (if on
511	ANSI) and p is NOT freed.
512
513	if n is for fewer bytes than already held by p, the newly unused
514	space is lopped off and freed if possible. Unless the #define
515	REALLOC_ZERO_BYTES_FREES is set, realloc with a size argument of
516	zero (re)allocates a minimum-sized chunk.
517
518	Large chunks that were internally obtained via mmap will always
519	be reallocated using malloc-copy-free sequences unless
520	the system supports MREMAP (currently only linux).
521
522	The old unix realloc convention of allowing the last-free'd chunk
523	to be used as an argument to realloc is not supported.
524	*/
525	void* __libc_realloc(void*, size_t);
526	libc_hidden_proto (__libc_realloc)
527
528	/*
529	memalign(size_t alignment, size_t n);
530	Returns a pointer to a newly allocated chunk of n bytes, aligned
531	in accord with the alignment argument.
532
533	The alignment argument should be a power of two. If the argument is
534	not a power of two, the nearest greater power is used.
535	8-byte alignment is guaranteed by normal malloc calls, so don't
536	bother calling memalign with an argument of 8 or less.
537
538	Overreliance on memalign is a sure way to fragment space.
539	*/
540	void* __libc_memalign(size_t, size_t);
541	libc_hidden_proto (__libc_memalign)
542
543	/*
544	valloc(size_t n);
545	Equivalent to memalign(pagesize, n), where pagesize is the page
546	size of the system. If the pagesize is unknown, 4096 is used.
547	*/
548	void* __libc_valloc(size_t);
549
550
551
552	/*
553	mallopt(int parameter_number, int parameter_value)
554	Sets tunable parameters The format is to provide a
555	(parameter-number, parameter-value) pair. mallopt then sets the
556	corresponding parameter to the argument value if it can (i.e., so
557	long as the value is meaningful), and returns 1 if successful else
558	0. SVID/XPG/ANSI defines four standard param numbers for mallopt,
559	normally defined in malloc.h. Only one of these (M_MXFAST) is used
560	in this malloc. The others (M_NLBLKS, M_GRAIN, M_KEEP) don't apply,
561	so setting them has no effect. But this malloc also supports four
562	other options in mallopt. See below for details. Briefly, supported
563	parameters are as follows (listed defaults are for "typical"
564	configurations).
565
566	Symbol param # default allowed param values
567	M_MXFAST 1 64 0-80 (0 disables fastbins)
568	M_TRIM_THRESHOLD -1 1281024 any (-1U disables trimming)*
569	M_TOP_PAD -2 0 any
570	M_MMAP_THRESHOLD -3 1281024 any (or 0 if no MMAP support)*
571	M_MMAP_MAX -4 65536 any (0 disables use of mmap)
572	*/
573	int __libc_mallopt(int, int);
574	libc_hidden_proto (__libc_mallopt)
575
576
577	/*
578	mallinfo()
579	Returns (by copy) a struct containing various summary statistics:
580
581	arena: current total non-mmapped bytes allocated from system
582	ordblks: the number of free chunks
583	smblks: the number of fastbin blocks (i.e., small chunks that
584	have been freed but not use resused or consolidated)
585	hblks: current number of mmapped regions
586	hblkhd: total bytes held in mmapped regions
587	usmblks: always 0
588	fsmblks: total bytes held in fastbin blocks
589	uordblks: current total allocated space (normal or mmapped)
590	fordblks: total free space
591	keepcost: the maximum number of bytes that could ideally be released
592	back to system via malloc_trim. ("ideally" means that
593	it ignores page restrictions etc.)
594
595	Because these fields are ints, but internal bookkeeping may
596	be kept as longs, the reported values may wrap around zero and
597	thus be inaccurate.
598	*/
599	struct mallinfo __libc_mallinfo(void);
600
601
602	/*
603	pvalloc(size_t n);
604	Equivalent to valloc(minimum-page-that-holds(n)), that is,
605	round up n to nearest pagesize.
606	*/
607	void* __libc_pvalloc(size_t);
608
609	/*
610	malloc_trim(size_t pad);
611
612	If possible, gives memory back to the system (via negative
613	arguments to sbrk) if there is unused memory at the `high' end of
614	the malloc pool. You can call this after freeing large blocks of
615	memory to potentially reduce the system-level memory requirements
616	of a program. However, it cannot guarantee to reduce memory. Under
617	some allocation patterns, some large free blocks of memory will be
618	locked between two used chunks, so they cannot be given back to
619	the system.
620
621	The `pad' argument to malloc_trim represents the amount of free
622	trailing space to leave untrimmed. If this argument is zero,
623	only the minimum amount of memory to maintain internal data
624	structures will be left (one page or less). Non-zero arguments
625	can be supplied to maintain enough trailing space to service
626	future expected allocations without having to re-obtain memory
627	from the system.
628
629	Malloc_trim returns 1 if it actually released any memory, else 0.
630	On systems that do not support "negative sbrks", it will always
631	return 0.
632	*/
633	int __malloc_trim(size_t);
634
635	/*
636	malloc_usable_size(void p);*
637
638	Returns the number of bytes you can actually use in
639	an allocated chunk, which may be more than you requested (although
640	often not) due to alignment and minimum size constraints.
641	You can use this many bytes without worrying about
642	overwriting other allocated objects. This is not a particularly great
643	programming practice. malloc_usable_size can be more useful in
644	debugging and assertions, for example:
645
646	p = malloc(n);
647	assert(malloc_usable_size(p) >= 256);
648
649	*/
650	size_t __malloc_usable_size(void*);
651
652	/*
653	malloc_stats();
654	Prints on stderr the amount of space obtained from the system (both
655	via sbrk and mmap), the maximum amount (which may be more than
656	current if malloc_trim and/or munmap got called), and the current
657	number of bytes allocated via malloc (or realloc, etc) but not yet
658	freed. Note that this is the number of bytes allocated, not the
659	number requested. It will be larger than the number requested
660	because of alignment and bookkeeping overhead. Because it includes
661	alignment wastage as being in use, this figure may be greater than
662	zero even when no user-level chunks are allocated.
663
664	The reported current and maximum system memory can be inaccurate if
665	a program makes other calls to system memory allocation functions
666	(normally sbrk) outside of malloc.
667
668	malloc_stats prints only the most commonly interesting statistics.
669	More information can be obtained by calling mallinfo.
670
671	*/
672	void __malloc_stats(void);
673
674	/*
675	malloc_get_state(void);
676
677	Returns the state of all malloc variables in an opaque data
678	structure.
679	*/
680	void* __malloc_get_state(void);
681
682	/*
683	malloc_set_state(void state);*
684
685	Restore the state of all malloc variables from data obtained with
686	malloc_get_state().
687	*/
688	int __malloc_set_state(void*);
689
690	/*
691	posix_memalign(void memptr, size_t alignment, size_t size);
692
693	POSIX wrapper like memalign(), checking for validity of size.
694	*/
695	int __posix_memalign(void **, size_t, size_t);
696
697	/ mallopt tuning options /
698
699	/*
700	M_MXFAST is the maximum request size used for "fastbins", special bins
701	that hold returned chunks without consolidating their spaces. This
702	enables future requests for chunks of the same size to be handled
703	very quickly, but can increase fragmentation, and thus increase the
704	overall memory footprint of a program.
705
706	This malloc manages fastbins very conservatively yet still
707	efficiently, so fragmentation is rarely a problem for values less
708	than or equal to the default. The maximum supported value of MXFAST
709	is 80. You wouldn't want it any higher than this anyway. Fastbins
710	are designed especially for use with many small structs, objects or
711	strings -- the default handles structs/objects/arrays with sizes up
712	to 8 4byte fields, or small strings representing words, tokens,
713	etc. Using fastbins for larger objects normally worsens
714	fragmentation without improving speed.
715
716	M_MXFAST is set in REQUEST size units. It is internally used in
717	chunksize units, which adds padding and alignment. You can reduce
718	M_MXFAST to 0 to disable all use of fastbins. This causes the malloc
719	algorithm to be a closer approximation of fifo-best-fit in all cases,
720	not just for larger requests, but will generally cause it to be
721	slower.
722	*/
723
724
725	/ M_MXFAST is a standard SVID/XPG tuning option, usually listed in malloc.h /
726	#ifndef M_MXFAST
727	#define M_MXFAST 1
728	#endif
729
730	#ifndef DEFAULT_MXFAST
731	#define DEFAULT_MXFAST (64 * SIZE_SZ / 4)
732	#endif
733
734
735	/*
736	M_TRIM_THRESHOLD is the maximum amount of unused top-most memory
737	to keep before releasing via malloc_trim in free().
738
739	Automatic trimming is mainly useful in long-lived programs.
740	Because trimming via sbrk can be slow on some systems, and can
741	sometimes be wasteful (in cases where programs immediately
742	afterward allocate more large chunks) the value should be high
743	enough so that your overall system performance would improve by
744	releasing this much memory.
745
746	The trim threshold and the mmap control parameters (see below)
747	can be traded off with one another. Trimming and mmapping are
748	two different ways of releasing unused memory back to the
749	system. Between these two, it is often possible to keep
750	system-level demands of a long-lived program down to a bare
751	minimum. For example, in one test suite of sessions measuring
752	the XF86 X server on Linux, using a trim threshold of 128K and a
753	mmap threshold of 192K led to near-minimal long term resource
754	consumption.
755
756	If you are using this malloc in a long-lived program, it should
757	pay to experiment with these values. As a rough guide, you
758	might set to a value close to the average size of a process
759	(program) running on your system. Releasing this much memory
760	would allow such a process to run in memory. Generally, it's
761	worth it to tune for trimming rather tham memory mapping when a
762	program undergoes phases where several large chunks are
763	allocated and released in ways that can reuse each other's
764	storage, perhaps mixed with phases where there are no such
765	chunks at all. And in well-behaved long-lived programs,
766	controlling release of large blocks via trimming versus mapping
767	is usually faster.
768
769	However, in most programs, these parameters serve mainly as
770	protection against the system-level effects of carrying around
771	massive amounts of unneeded memory. Since frequent calls to
772	sbrk, mmap, and munmap otherwise degrade performance, the default
773	parameters are set to relatively high values that serve only as
774	safeguards.
775
776	The trim value It must be greater than page size to have any useful
777	effect. To disable trimming completely, you can set to
778	(unsigned long)(-1)
779
780	Trim settings interact with fastbin (MXFAST) settings: Unless
781	TRIM_FASTBINS is defined, automatic trimming never takes place upon
782	freeing a chunk with size less than or equal to MXFAST. Trimming is
783	instead delayed until subsequent freeing of larger chunks. However,
784	you can still force an attempted trim by calling malloc_trim.
785
786	Also, trimming is not generally possible in cases where
787	the main arena is obtained via mmap.
788
789	Note that the trick some people use of mallocing a huge space and
790	then freeing it at program startup, in an attempt to reserve system
791	memory, doesn't have the intended effect under automatic trimming,
792	since that memory will immediately be returned to the system.
793	*/
794
795	#define M_TRIM_THRESHOLD -1
796
797	#ifndef DEFAULT_TRIM_THRESHOLD
798	#define DEFAULT_TRIM_THRESHOLD (128 * 1024)
799	#endif
800
801	/*
802	M_TOP_PAD is the amount of extra `padding' space to allocate or
803	retain whenever sbrk is called. It is used in two ways internally:
804
805	* When sbrk is called to extend the top of the arena to satisfy
806	a new malloc request, this much padding is added to the sbrk
807	request.
808
809	* When malloc_trim is called automatically from free(),
810	it is used as the `pad' argument.
811
812	In both cases, the actual amount of padding is rounded
813	so that the end of the arena is always a system page boundary.
814
815	The main reason for using padding is to avoid calling sbrk so
816	often. Having even a small pad greatly reduces the likelihood
817	that nearly every malloc request during program start-up (or
818	after trimming) will invoke sbrk, which needlessly wastes
819	time.
820
821	Automatic rounding-up to page-size units is normally sufficient
822	to avoid measurable overhead, so the default is 0. However, in
823	systems where sbrk is relatively slow, it can pay to increase
824	this value, at the expense of carrying around more memory than
825	the program needs.
826	*/
827
828	#define M_TOP_PAD -2
829
830	#ifndef DEFAULT_TOP_PAD
831	#define DEFAULT_TOP_PAD (0)
832	#endif
833
834	/*
835	MMAP_THRESHOLD_MAX and _MIN are the bounds on the dynamically
836	adjusted MMAP_THRESHOLD.
837	*/
838
839	#ifndef DEFAULT_MMAP_THRESHOLD_MIN
840	#define DEFAULT_MMAP_THRESHOLD_MIN (128 * 1024)
841	#endif
842
843	#ifndef DEFAULT_MMAP_THRESHOLD_MAX
844	/ For 32-bit platforms we cannot increase the maximum mmap*
845	threshold much because it is also the minimum value for the
846	maximum heap size and its alignment. Going above 512k (i.e., 1M
847	for new heaps) wastes too much address space. /*
848	# if __WORDSIZE == 32
849	# define DEFAULT_MMAP_THRESHOLD_MAX (512 * 1024)
850	# else
851	# define DEFAULT_MMAP_THRESHOLD_MAX (4 * 1024 * 1024 * sizeof(long))
852	# endif
853	#endif
854
855	/*
856	M_MMAP_THRESHOLD is the request size threshold for using mmap()
857	to service a request. Requests of at least this size that cannot
858	be allocated using already-existing space will be serviced via mmap.
859	(If enough normal freed space already exists it is used instead.)
860
861	Using mmap segregates relatively large chunks of memory so that
862	they can be individually obtained and released from the host
863	system. A request serviced through mmap is never reused by any
864	other request (at least not directly; the system may just so
865	happen to remap successive requests to the same locations).
866
867	Segregating space in this way has the benefits that:
868
869	1. Mmapped space can ALWAYS be individually released back
870	to the system, which helps keep the system level memory
871	demands of a long-lived program low.
872	2. Mapped memory can never become `locked' between
873	other chunks, as can happen with normally allocated chunks, which
874	means that even trimming via malloc_trim would not release them.
875	3. On some systems with "holes" in address spaces, mmap can obtain
876	memory that sbrk cannot.
877
878	However, it has the disadvantages that:
879
880	1. The space cannot be reclaimed, consolidated, and then
881	used to service later requests, as happens with normal chunks.
882	2. It can lead to more wastage because of mmap page alignment
883	requirements
884	3. It causes malloc performance to be more dependent on host
885	system memory management support routines which may vary in
886	implementation quality and may impose arbitrary
887	limitations. Generally, servicing a request via normal
888	malloc steps is faster than going through a system's mmap.
889
890	The advantages of mmap nearly always outweigh disadvantages for
891	"large" chunks, but the value of "large" varies across systems. The
892	default is an empirically derived value that works well in most
893	systems.
894
895
896	Update in 2006:
897	The above was written in 2001. Since then the world has changed a lot.
898	Memory got bigger. Applications got bigger. The virtual address space
899	layout in 32 bit linux changed.
900
901	In the new situation, brk() and mmap space is shared and there are no
902	artificial limits on brk size imposed by the kernel. What is more,
903	applications have started using transient allocations larger than the
904	128Kb as was imagined in 2001.
905
906	The price for mmap is also high now; each time glibc mmaps from the
907	kernel, the kernel is forced to zero out the memory it gives to the
908	application. Zeroing memory is expensive and eats a lot of cache and
909	memory bandwidth. This has nothing to do with the efficiency of the
910	virtual memory system, by doing mmap the kernel just has no choice but
911	to zero.
912
913	In 2001, the kernel had a maximum size for brk() which was about 800
914	megabytes on 32 bit x86, at that point brk() would hit the first
915	mmaped shared libaries and couldn't expand anymore. With current 2.6
916	kernels, the VA space layout is different and brk() and mmap
917	both can span the entire heap at will.
918
919	Rather than using a static threshold for the brk/mmap tradeoff,
920	we are now using a simple dynamic one. The goal is still to avoid
921	fragmentation. The old goals we kept are
922	1) try to get the long lived large allocations to use mmap()
923	2) really large allocations should always use mmap()
924	and we're adding now:
925	3) transient allocations should use brk() to avoid forcing the kernel
926	having to zero memory over and over again
927
928	The implementation works with a sliding threshold, which is by default
929	limited to go between 128Kb and 32Mb (64Mb for 64 bitmachines) and starts
930	out at 128Kb as per the 2001 default.
931
932	This allows us to satisfy requirement 1) under the assumption that long
933	lived allocations are made early in the process' lifespan, before it has
934	started doing dynamic allocations of the same size (which will
935	increase the threshold).
936
937	The upperbound on the threshold satisfies requirement 2)
938
939	The threshold goes up in value when the application frees memory that was
940	allocated with the mmap allocator. The idea is that once the application
941	starts freeing memory of a certain size, it's highly probable that this is
942	a size the application uses for transient allocations. This estimator
943	is there to satisfy the new third requirement.
944
945	*/
946
947	#define M_MMAP_THRESHOLD -3
948
949	#ifndef DEFAULT_MMAP_THRESHOLD
950	#define DEFAULT_MMAP_THRESHOLD DEFAULT_MMAP_THRESHOLD_MIN
951	#endif
952
953	/*
954	M_MMAP_MAX is the maximum number of requests to simultaneously
955	service using mmap. This parameter exists because
956	some systems have a limited number of internal tables for
957	use by mmap, and using more than a few of them may degrade
958	performance.
959
960	The default is set to a value that serves only as a safeguard.
961	Setting to 0 disables use of mmap for servicing large requests.
962	*/
963
964	#define M_MMAP_MAX -4
965
966	#ifndef DEFAULT_MMAP_MAX
967	#define DEFAULT_MMAP_MAX (65536)
968	#endif
969
970	#include <malloc.h>
971
972	#ifndef RETURN_ADDRESS
973	#define RETURN_ADDRESS(X_) (NULL)
974	#endif
975
976	/ On some platforms we can compile internal, not exported functions better.*
977	Let the environment provide a macro and define it to be empty if it
978	is not available. /*
979	#ifndef internal_function
980	# define internal_function
981	#endif
982
983	/ Forward declarations. /
984	struct malloc_chunk;
985	typedef struct malloc_chunk* mchunkptr;
986
987	/ Internal routines. /
988
989	static void* _int_malloc(mstate, size_t);
990	static void _int_free(mstate, mchunkptr, int);
991	static void* _int_realloc(mstate, mchunkptr, INTERNAL_SIZE_T,
992	INTERNAL_SIZE_T);
993	static void* _int_memalign(mstate, size_t, size_t);
994	static void* _mid_memalign(size_t, size_t, void *);
995
996	static void malloc_printerr(int action, const char str, void* *ptr, mstate av);
997
998	static void* internal_function mem2mem_check(void *p, size_t sz);
999	static int internal_function top_check(void);
1000	static void internal_function munmap_chunk(mchunkptr p);
1001	#if HAVE_MREMAP
1002	static mchunkptr internal_function mremap_chunk(mchunkptr p, size_t new_size);
1003	#endif
1004
1005	static void* malloc_check(size_t sz, const void *caller);
1006	static void free_check(void* mem, const void *caller);
1007	static void* realloc_check(void* oldmem, size_t bytes,
1008	const void *caller);
1009	static void* memalign_check(size_t alignment, size_t bytes,
1010	const void *caller);
1011
1012	/ ------------------ MMAP support ------------------ /
1013
1014
1015	#include <fcntl.h>
1016	#include <sys/mman.h>
1017
1018	#if !defined(MAP_ANONYMOUS) && defined(MAP_ANON)
1019	# define MAP_ANONYMOUS MAP_ANON
1020	#endif
1021
1022	#ifndef MAP_NORESERVE
1023	# define MAP_NORESERVE 0
1024	#endif
1025
1026	#define MMAP(addr, size, prot, flags) \
1027	__mmap((addr), (size), (prot), (flags)\|MAP_ANONYMOUS\|MAP_PRIVATE, -1, 0)
1028
1029
1030	/*
1031	----------------------- Chunk representations -----------------------
1032	*/
1033
1034
1035	/*
1036	This struct declaration is misleading (but accurate and necessary).
1037	It declares a "view" into memory allowing access to necessary
1038	fields at known offsets from a given base. See explanation below.
1039	*/
1040
1041	struct malloc_chunk {
1042
1043	INTERNAL_SIZE_T mchunk_prev_size; / Size of previous chunk (if free). /
1044	INTERNAL_SIZE_T mchunk_size; / Size in bytes, including overhead. /
1045
1046	struct malloc_chunk* fd; / double links -- used only if free. /
1047	struct malloc_chunk* bk;
1048
1049	/ Only used for large blocks: pointer to next larger size. /
1050	struct malloc_chunk* fd_nextsize; / double links -- used only if free. /
1051	struct malloc_chunk* bk_nextsize;
1052	};
1053
1054
1055	/*
1056	malloc_chunk details:
1057
1058	(The following includes lightly edited explanations by Colin Plumb.)
1059
1060	Chunks of memory are maintained using a `boundary tag' method as
1061	described in e.g., Knuth or Standish. (See the paper by Paul
1062	Wilson ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps for a
1063	survey of such techniques.) Sizes of free chunks are stored both
1064	in the front of each chunk and at the end. This makes
1065	consolidating fragmented chunks into bigger chunks very fast. The
1066	size fields also hold bits representing whether chunks are free or
1067	in use.
1068
1069	An allocated chunk looks like this:
1070
1071
1072	chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1073	\| Size of previous chunk, if unallocated (P clear) \|
1074	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1075	\| Size of chunk, in bytes \|A\|M\|P\|
1076	mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1077	\| User data starts here... .
1078	. .
1079	. (malloc_usable_size() bytes) .
1080	. \|
1081	nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1082	\| (size of chunk, but used for application data) \|
1083	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1084	\| Size of next chunk, in bytes \|A\|0\|1\|
1085	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1086
1087	Where "chunk" is the front of the chunk for the purpose of most of
1088	the malloc code, but "mem" is the pointer that is returned to the
1089	user. "Nextchunk" is the beginning of the next contiguous chunk.
1090
1091	Chunks always begin on even word boundaries, so the mem portion
1092	(which is returned to the user) is also on an even word boundary, and
1093	thus at least double-word aligned.
1094
1095	Free chunks are stored in circular doubly-linked lists, and look like this:
1096
1097	chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1098	\| Size of previous chunk, if unallocated (P clear) \|
1099	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1100	`head:' \| Size of chunk, in bytes \|A\|0\|P\|
1101	mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1102	\| Forward pointer to next chunk in list \|
1103	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1104	\| Back pointer to previous chunk in list \|
1105	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1106	\| Unused space (may be 0 bytes long) .
1107	. .
1108	. \|
1109	nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1110	`foot:' \| Size of chunk, in bytes \|
1111	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1112	\| Size of next chunk, in bytes \|A\|0\|0\|
1113	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1114
1115	The P (PREV_INUSE) bit, stored in the unused low-order bit of the
1116	chunk size (which is always a multiple of two words), is an in-use
1117	bit for the previous* chunk. If that bit is clear, then the*
1118	word before the current chunk size contains the previous chunk
1119	size, and can be used to find the front of the previous chunk.
1120	The very first chunk allocated always has this bit set,
1121	preventing access to non-existent (or non-owned) memory. If
1122	prev_inuse is set for any given chunk, then you CANNOT determine
1123	the size of the previous chunk, and might even get a memory
1124	addressing fault when trying to do so.
1125
1126	The A (NON_MAIN_ARENA) bit is cleared for chunks on the initial,
1127	main arena, described by the main_arena variable. When additional
1128	threads are spawned, each thread receives its own arena (up to a
1129	configurable limit, after which arenas are reused for multiple
1130	threads), and the chunks in these arenas have the A bit set. To
1131	find the arena for a chunk on such a non-main arena, heap_for_ptr
1132	performs a bit mask operation and indirection through the ar_ptr
1133	member of the per-heap header heap_info (see arena.c).
1134
1135	Note that the `foot' of the current chunk is actually represented
1136	as the prev_size of the NEXT chunk. This makes it easier to
1137	deal with alignments etc but can be very confusing when trying
1138	to extend or adapt this code.
1139
1140	The three exceptions to all this are:
1141
1142	1. The special chunk `top' doesn't bother using the
1143	trailing size field since there is no next contiguous chunk
1144	that would have to index off it. After initialization, `top'
1145	is forced to always exist. If it would become less than
1146	MINSIZE bytes long, it is replenished.
1147
1148	2. Chunks allocated via mmap, which have the second-lowest-order
1149	bit M (IS_MMAPPED) set in their size fields. Because they are
1150	allocated one-by-one, each must contain its own trailing size
1151	field. If the M bit is set, the other bits are ignored
1152	(because mmapped chunks are neither in an arena, nor adjacent
1153	to a freed chunk). The M bit is also used for chunks which
1154	originally came from a dumped heap via malloc_set_state in
1155	hooks.c.
1156
1157	3. Chunks in fastbins are treated as allocated chunks from the
1158	point of view of the chunk allocator. They are consolidated
1159	with their neighbors only in bulk, in malloc_consolidate.
1160	*/
1161
1162	/*
1163	---------- Size and alignment checks and conversions ----------
1164	*/
1165
1166	/ conversion from malloc headers to user pointers, and back /
1167
1168	#define chunk2mem(p) ((void)((char)(p) + 2*SIZE_SZ))
1169	#define mem2chunk(mem) ((mchunkptr)((char)(mem) - 2SIZE_SZ))
1170
1171	/ The smallest possible chunk /
1172	#define MIN_CHUNK_SIZE (offsetof(struct malloc_chunk, fd_nextsize))
1173
1174	/ The smallest size we can malloc is an aligned minimal chunk /
1175
1176	#define MINSIZE \
1177	(unsigned long)(((MIN_CHUNK_SIZE+MALLOC_ALIGN_MASK) & ~MALLOC_ALIGN_MASK))
1178
1179	/ Check if m has acceptable alignment /
1180
1181	#define aligned_OK(m) (((unsigned long)(m) & MALLOC_ALIGN_MASK) == 0)
1182
1183	#define misaligned_chunk(p) \
1184	((uintptr_t)(MALLOC_ALIGNMENT == 2 * SIZE_SZ ? (p) : chunk2mem (p)) \
1185	& MALLOC_ALIGN_MASK)
1186
1187
1188	/*
1189	Check if a request is so large that it would wrap around zero when
1190	padded and aligned. To simplify some other code, the bound is made
1191	low enough so that adding MINSIZE will also not wrap around zero.
1192	*/
1193
1194	#define REQUEST_OUT_OF_RANGE(req) \
1195	((unsigned long) (req) >= \
1196	(unsigned long) (INTERNAL_SIZE_T) (-2 * MINSIZE))
1197
1198	/ pad request bytes into a usable size -- internal version /
1199
1200	#define request2size(req) \
1201	(((req) + SIZE_SZ + MALLOC_ALIGN_MASK < MINSIZE) ? \
1202	MINSIZE : \
1203	((req) + SIZE_SZ + MALLOC_ALIGN_MASK) & ~MALLOC_ALIGN_MASK)
1204
1205	/ Same, except also perform argument check /
1206
1207	#define checked_request2size(req, sz) \
1208	if (REQUEST_OUT_OF_RANGE (req)) { \
1209	__set_errno (ENOMEM); \
1210	return 0; \
1211	} \
1212	(sz) = request2size (req);
1213
1214	/*
1215	--------------- Physical chunk operations ---------------
1216	*/
1217
1218
1219	/ size field is or'ed with PREV_INUSE when previous adjacent chunk in use /
1220	#define PREV_INUSE 0x1
1221
1222	/ extract inuse bit of previous chunk /
1223	#define prev_inuse(p) ((p)->mchunk_size & PREV_INUSE)
1224
1225
1226	/ size field is or'ed with IS_MMAPPED if the chunk was obtained with mmap() /
1227	#define IS_MMAPPED 0x2
1228
1229	/ check for mmap()'ed chunk /
1230	#define chunk_is_mmapped(p) ((p)->mchunk_size & IS_MMAPPED)
1231
1232
1233	/ size field is or'ed with NON_MAIN_ARENA if the chunk was obtained*
1234	from a non-main arena. This is only set immediately before handing
1235	the chunk to the user, if necessary. /*
1236	#define NON_MAIN_ARENA 0x4
1237
1238	/ Check for chunk from main arena. /
1239	#define chunk_main_arena(p) (((p)->mchunk_size & NON_MAIN_ARENA) == 0)
1240
1241	/ Mark a chunk as not being on the main arena. /
1242	#define set_non_main_arena(p) ((p)->mchunk_size \|= NON_MAIN_ARENA)
1243
1244
1245	/*
1246	Bits to mask off when extracting size
1247
1248	Note: IS_MMAPPED is intentionally not masked off from size field in
1249	macros for which mmapped chunks should never be seen. This should
1250	cause helpful core dumps to occur if it is tried by accident by
1251	people extending or adapting this malloc.
1252	*/
1253	#define SIZE_BITS (PREV_INUSE \| IS_MMAPPED \| NON_MAIN_ARENA)
1254
1255	/ Get size, ignoring use bits /
1256	#define chunksize(p) (chunksize_nomask (p) & ~(SIZE_BITS))
1257
1258	/ Like chunksize, but do not mask SIZE_BITS. /
1259	#define chunksize_nomask(p) ((p)->mchunk_size)
1260
1261	/ Ptr to next physical malloc_chunk. /
1262	#define next_chunk(p) ((mchunkptr) (((char *) (p)) + chunksize (p)))
1263
1264	/ Size of the chunk below P. Only valid if prev_inuse (P). /
1265	#define prev_size(p) ((p)->mchunk_prev_size)
1266
1267	/ Set the size of the chunk below P. Only valid if prev_inuse (P). /
1268	#define set_prev_size(p, sz) ((p)->mchunk_prev_size = (sz))
1269
1270	/ Ptr to previous physical malloc_chunk. Only valid if prev_inuse (P). /
1271	#define prev_chunk(p) ((mchunkptr) (((char *) (p)) - prev_size (p)))
1272
1273	/ Treat space at ptr + offset as a chunk /
1274	#define chunk_at_offset(p, s) ((mchunkptr) (((char *) (p)) + (s)))
1275
1276	/ extract p's inuse bit /
1277	#define inuse(p) \
1278	((((mchunkptr) (((char *) (p)) + chunksize (p)))->mchunk_size) & PREV_INUSE)
1279
1280	/ set/clear chunk as being inuse without otherwise disturbing /
1281	#define set_inuse(p) \
1282	((mchunkptr) (((char *) (p)) + chunksize (p)))->mchunk_size \|= PREV_INUSE
1283
1284	#define clear_inuse(p) \
1285	((mchunkptr) (((char *) (p)) + chunksize (p)))->mchunk_size &= ~(PREV_INUSE)
1286
1287
1288	/ check/set/clear inuse bits in known places /
1289	#define inuse_bit_at_offset(p, s) \
1290	(((mchunkptr) (((char *) (p)) + (s)))->mchunk_size & PREV_INUSE)
1291
1292	#define set_inuse_bit_at_offset(p, s) \
1293	(((mchunkptr) (((char *) (p)) + (s)))->mchunk_size \|= PREV_INUSE)
1294
1295	#define clear_inuse_bit_at_offset(p, s) \
1296	(((mchunkptr) (((char *) (p)) + (s)))->mchunk_size &= ~(PREV_INUSE))
1297
1298
1299	/ Set size at head, without disturbing its use bit /
1300	#define set_head_size(p, s) ((p)->mchunk_size = (((p)->mchunk_size & SIZE_BITS) \| (s)))
1301
1302	/ Set size/use field /
1303	#define set_head(p, s) ((p)->mchunk_size = (s))
1304
1305	/ Set size at footer (only when chunk is not in use) /
1306	#define set_foot(p, s) (((mchunkptr) ((char *) (p) + (s)))->mchunk_prev_size = (s))
1307
1308
1309	#pragma GCC poison mchunk_size
1310	#pragma GCC poison mchunk_prev_size
1311
1312	/*
1313	-------------------- Internal data structures --------------------
1314
1315	All internal state is held in an instance of malloc_state defined
1316	below. There are no other static variables, except in two optional
1317	cases:
1318	* If USE_MALLOC_LOCK is defined, the mALLOC_MUTEx declared above.
1319	* If mmap doesn't support MAP_ANONYMOUS, a dummy file descriptor
1320	for mmap.
1321
1322	Beware of lots of tricks that minimize the total bookkeeping space
1323	requirements. The result is a little over 1K bytes (for 4byte
1324	pointers and size_t.)
1325	*/
1326
1327	/*
1328	Bins
1329
1330	An array of bin headers for free chunks. Each bin is doubly
1331	linked. The bins are approximately proportionally (log) spaced.
1332	There are a lot of these bins (128). This may look excessive, but
1333	works very well in practice. Most bins hold sizes that are
1334	unusual as malloc request sizes, but are more usual for fragments
1335	and consolidated sets of chunks, which is what these bins hold, so
1336	they can be found quickly. All procedures maintain the invariant
1337	that no consolidated chunk physically borders another one, so each
1338	chunk in a list is known to be preceeded and followed by either
1339	inuse chunks or the ends of memory.
1340
1341	Chunks in bins are kept in size order, with ties going to the
1342	approximately least recently used chunk. Ordering isn't needed
1343	for the small bins, which all contain the same-sized chunks, but
1344	facilitates best-fit allocation for larger chunks. These lists
1345	are just sequential. Keeping them in order almost never requires
1346	enough traversal to warrant using fancier ordered data
1347	structures.
1348
1349	Chunks of the same size are linked with the most
1350	recently freed at the front, and allocations are taken from the
1351	back. This results in LRU (FIFO) allocation order, which tends
1352	to give each chunk an equal opportunity to be consolidated with
1353	adjacent freed chunks, resulting in larger free chunks and less
1354	fragmentation.
1355
1356	To simplify use in double-linked lists, each bin header acts
1357	as a malloc_chunk. This avoids special-casing for headers.
1358	But to conserve space and improve locality, we allocate
1359	only the fd/bk pointers of bins, and then use repositioning tricks
1360	to treat these as the fields of a malloc_chunk.*
1361	*/
1362
1363	typedef struct malloc_chunk *mbinptr;
1364
1365	/ addressing -- note that bin_at(0) does not exist /
1366	#define bin_at(m, i) \
1367	(mbinptr) (((char ) &((m)->bins[((i) - 1) 2])) \
1368	- offsetof (struct malloc_chunk, fd))
1369
1370	/ analog of ++bin /
1371	#define next_bin(b) ((mbinptr) ((char *) (b) + (sizeof (mchunkptr) << 1)))
1372
1373	/ Reminders about list directionality within bins /
1374	#define first(b) ((b)->fd)
1375	#define last(b) ((b)->bk)
1376
1377	/ Take a chunk off a bin list /
1378	#define unlink(AV, P, BK, FD) { \
1379	FD = P->fd; \
1380	BK = P->bk; \
1381	if (__builtin_expect (FD->bk != P \|\| BK->fd != P, 0)) \
1382	malloc_printerr (check_action, "corrupted double-linked list", P, AV); \
1383	else { \
1384	FD->bk = BK; \
1385	BK->fd = FD; \
1386	if (!in_smallbin_range (chunksize_nomask (P)) \
1387	&& __builtin_expect (P->fd_nextsize != NULL, 0)) { \
1388	if (__builtin_expect (P->fd_nextsize->bk_nextsize != P, 0) \
1389	\|\| __builtin_expect (P->bk_nextsize->fd_nextsize != P, 0)) \
1390	malloc_printerr (check_action, \
1391	"corrupted double-linked list (not small)", \
1392	P, AV); \
1393	if (FD->fd_nextsize == NULL) { \
1394	if (P->fd_nextsize == P) \
1395	FD->fd_nextsize = FD->bk_nextsize = FD; \
1396	else { \
1397	FD->fd_nextsize = P->fd_nextsize; \
1398	FD->bk_nextsize = P->bk_nextsize; \
1399	P->fd_nextsize->bk_nextsize = FD; \
1400	P->bk_nextsize->fd_nextsize = FD; \
1401	} \
1402	} else { \
1403	P->fd_nextsize->bk_nextsize = P->bk_nextsize; \
1404	P->bk_nextsize->fd_nextsize = P->fd_nextsize; \
1405	} \
1406	} \
1407	} \
1408	}
1409
1410	/*
1411	Indexing
1412
1413	Bins for sizes < 512 bytes contain chunks of all the same size, spaced
1414	8 bytes apart. Larger bins are approximately logarithmically spaced:
1415
1416	64 bins of size 8
1417	32 bins of size 64
1418	16 bins of size 512
1419	8 bins of size 4096
1420	4 bins of size 32768
1421	2 bins of size 262144
1422	1 bin of size what's left
1423
1424	There is actually a little bit of slop in the numbers in bin_index
1425	for the sake of speed. This makes no difference elsewhere.
1426
1427	The bins top out around 1MB because we expect to service large
1428	requests via mmap.
1429
1430	Bin 0 does not exist. Bin 1 is the unordered list; if that would be
1431	a valid chunk size the small bins are bumped up one.
1432	*/
1433
1434	#define NBINS 128
1435	#define NSMALLBINS 64
1436	#define SMALLBIN_WIDTH MALLOC_ALIGNMENT
1437	#define SMALLBIN_CORRECTION (MALLOC_ALIGNMENT > 2 * SIZE_SZ)
1438	#define MIN_LARGE_SIZE ((NSMALLBINS - SMALLBIN_CORRECTION) * SMALLBIN_WIDTH)
1439
1440	#define in_smallbin_range(sz) \
1441	((unsigned long) (sz) < (unsigned long) MIN_LARGE_SIZE)
1442
1443	#define smallbin_index(sz) \
1444	((SMALLBIN_WIDTH == 16 ? (((unsigned) (sz)) >> 4) : (((unsigned) (sz)) >> 3))\
1445	+ SMALLBIN_CORRECTION)
1446
1447	#define largebin_index_32(sz) \
1448	(((((unsigned long) (sz)) >> 6) <= 38) ? 56 + (((unsigned long) (sz)) >> 6) :\
1449	((((unsigned long) (sz)) >> 9) <= 20) ? 91 + (((unsigned long) (sz)) >> 9) :\
1450	((((unsigned long) (sz)) >> 12) <= 10) ? 110 + (((unsigned long) (sz)) >> 12) :\
1451	((((unsigned long) (sz)) >> 15) <= 4) ? 119 + (((unsigned long) (sz)) >> 15) :\
1452	((((unsigned long) (sz)) >> 18) <= 2) ? 124 + (((unsigned long) (sz)) >> 18) :\
1453	126)
1454
1455	#define largebin_index_32_big(sz) \
1456	(((((unsigned long) (sz)) >> 6) <= 45) ? 49 + (((unsigned long) (sz)) >> 6) :\
1457	((((unsigned long) (sz)) >> 9) <= 20) ? 91 + (((unsigned long) (sz)) >> 9) :\
1458	((((unsigned long) (sz)) >> 12) <= 10) ? 110 + (((unsigned long) (sz)) >> 12) :\
1459	((((unsigned long) (sz)) >> 15) <= 4) ? 119 + (((unsigned long) (sz)) >> 15) :\
1460	((((unsigned long) (sz)) >> 18) <= 2) ? 124 + (((unsigned long) (sz)) >> 18) :\
1461	126)
1462
1463	// XXX It remains to be seen whether it is good to keep the widths of
1464	// XXX the buckets the same or whether it should be scaled by a factor
1465	// XXX of two as well.
1466	#define largebin_index_64(sz) \
1467	(((((unsigned long) (sz)) >> 6) <= 48) ? 48 + (((unsigned long) (sz)) >> 6) :\
1468	((((unsigned long) (sz)) >> 9) <= 20) ? 91 + (((unsigned long) (sz)) >> 9) :\
1469	((((unsigned long) (sz)) >> 12) <= 10) ? 110 + (((unsigned long) (sz)) >> 12) :\
1470	((((unsigned long) (sz)) >> 15) <= 4) ? 119 + (((unsigned long) (sz)) >> 15) :\
1471	((((unsigned long) (sz)) >> 18) <= 2) ? 124 + (((unsigned long) (sz)) >> 18) :\
1472	126)
1473
1474	#define largebin_index(sz) \
1475	(SIZE_SZ == 8 ? largebin_index_64 (sz) \
1476	: MALLOC_ALIGNMENT == 16 ? largebin_index_32_big (sz) \
1477	: largebin_index_32 (sz))
1478
1479	#define bin_index(sz) \
1480	((in_smallbin_range (sz)) ? smallbin_index (sz) : largebin_index (sz))
1481
1482
1483	/*
1484	Unsorted chunks
1485
1486	All remainders from chunk splits, as well as all returned chunks,
1487	are first placed in the "unsorted" bin. They are then placed
1488	in regular bins after malloc gives them ONE chance to be used before
1489	binning. So, basically, the unsorted_chunks list acts as a queue,
1490	with chunks being placed on it in free (and malloc_consolidate),
1491	and taken off (to be either used or placed in bins) in malloc.
1492
1493	The NON_MAIN_ARENA flag is never set for unsorted chunks, so it
1494	does not have to be taken into account in size comparisons.
1495	*/
1496
1497	/ The otherwise unindexable 1-bin is used to hold unsorted chunks. /
1498	#define unsorted_chunks(M) (bin_at (M, 1))
1499
1500	/*
1501	Top
1502
1503	The top-most available chunk (i.e., the one bordering the end of
1504	available memory) is treated specially. It is never included in
1505	any bin, is used only if no other chunk is available, and is
1506	released back to the system if it is very large (see
1507	M_TRIM_THRESHOLD). Because top initially
1508	points to its own bin with initial zero size, thus forcing
1509	extension on the first malloc request, we avoid having any special
1510	code in malloc to check whether it even exists yet. But we still
1511	need to do so when getting memory from system, so we make
1512	initial_top treat the bin as a legal but unusable chunk during the
1513	interval between initialization and the first call to
1514	sysmalloc. (This is somewhat delicate, since it relies on
1515	the 2 preceding words to be zero during this interval as well.)
1516	*/
1517
1518	/ Conveniently, the unsorted bin can be used as dummy top on first call /
1519	#define initial_top(M) (unsorted_chunks (M))
1520
1521	/*
1522	Binmap
1523
1524	To help compensate for the large number of bins, a one-level index
1525	structure is used for bin-by-bin searching. `binmap' is a
1526	bitvector recording whether bins are definitely empty so they can
1527	be skipped over during during traversals. The bits are NOT always
1528	cleared as soon as bins are empty, but instead only
1529	when they are noticed to be empty during traversal in malloc.
1530	*/
1531
1532	/ Conservatively use 32 bits per map word, even if on 64bit system /
1533	#define BINMAPSHIFT 5
1534	#define BITSPERMAP (1U << BINMAPSHIFT)
1535	#define BINMAPSIZE (NBINS / BITSPERMAP)
1536
1537	#define idx2block(i) ((i) >> BINMAPSHIFT)
1538	#define idx2bit(i) ((1U << ((i) & ((1U << BINMAPSHIFT) - 1))))
1539
1540	#define mark_bin(m, i) ((m)->binmap[idx2block (i)] \|= idx2bit (i))
1541	#define unmark_bin(m, i) ((m)->binmap[idx2block (i)] &= ~(idx2bit (i)))
1542	#define get_binmap(m, i) ((m)->binmap[idx2block (i)] & idx2bit (i))
1543
1544	/*
1545	Fastbins
1546
1547	An array of lists holding recently freed small chunks. Fastbins
1548	are not doubly linked. It is faster to single-link them, and
1549	since chunks are never removed from the middles of these lists,
1550	double linking is not necessary. Also, unlike regular bins, they
1551	are not even processed in FIFO order (they use faster LIFO) since
1552	ordering doesn't much matter in the transient contexts in which
1553	fastbins are normally used.
1554
1555	Chunks in fastbins keep their inuse bit set, so they cannot
1556	be consolidated with other free chunks. malloc_consolidate
1557	releases all chunks in fastbins and consolidates them with
1558	other free chunks.
1559	*/
1560
1561	typedef struct malloc_chunk *mfastbinptr;
1562	#define fastbin(ar_ptr, idx) ((ar_ptr)->fastbinsY[idx])
1563
1564	/ offset 2 to use otherwise unindexable first 2 bins /
1565	#define fastbin_index(sz) \
1566	((((unsigned int) (sz)) >> (SIZE_SZ == 8 ? 4 : 3)) - 2)
1567
1568
1569	/ The maximum fastbin request size we support /
1570	#define MAX_FAST_SIZE (80 * SIZE_SZ / 4)
1571
1572	#define NFASTBINS (fastbin_index (request2size (MAX_FAST_SIZE)) + 1)
1573
1574	/*
1575	FASTBIN_CONSOLIDATION_THRESHOLD is the size of a chunk in free()
1576	that triggers automatic consolidation of possibly-surrounding
1577	fastbin chunks. This is a heuristic, so the exact value should not
1578	matter too much. It is defined at half the default trim threshold as a
1579	compromise heuristic to only attempt consolidation if it is likely
1580	to lead to trimming. However, it is not dynamically tunable, since
1581	consolidation reduces fragmentation surrounding large chunks even
1582	if trimming is not used.
1583	*/
1584
1585	#define FASTBIN_CONSOLIDATION_THRESHOLD (65536UL)
1586
1587	/*
1588	Since the lowest 2 bits in max_fast don't matter in size comparisons,
1589	they are used as flags.
1590	*/
1591
1592	/*
1593	FASTCHUNKS_BIT held in max_fast indicates that there are probably
1594	some fastbin chunks. It is set true on entering a chunk into any
1595	fastbin, and cleared only in malloc_consolidate.
1596
1597	The truth value is inverted so that have_fastchunks will be true
1598	upon startup (since statics are zero-filled), simplifying
1599	initialization checks.
1600	*/
1601
1602	#define FASTCHUNKS_BIT (1U)
1603
1604	#define have_fastchunks(M) (((M)->flags & FASTCHUNKS_BIT) == 0)
1605	#define clear_fastchunks(M) catomic_or (&(M)->flags, FASTCHUNKS_BIT)
1606	#define set_fastchunks(M) catomic_and (&(M)->flags, ~FASTCHUNKS_BIT)
1607
1608	/*
1609	NONCONTIGUOUS_BIT indicates that MORECORE does not return contiguous
1610	regions. Otherwise, contiguity is exploited in merging together,
1611	when possible, results from consecutive MORECORE calls.
1612
1613	The initial value comes from MORECORE_CONTIGUOUS, but is
1614	changed dynamically if mmap is ever used as an sbrk substitute.
1615	*/
1616
1617	#define NONCONTIGUOUS_BIT (2U)
1618
1619	#define contiguous(M) (((M)->flags & NONCONTIGUOUS_BIT) == 0)
1620	#define noncontiguous(M) (((M)->flags & NONCONTIGUOUS_BIT) != 0)
1621	#define set_noncontiguous(M) ((M)->flags \|= NONCONTIGUOUS_BIT)
1622	#define set_contiguous(M) ((M)->flags &= ~NONCONTIGUOUS_BIT)
1623
1624	/ ARENA_CORRUPTION_BIT is set if a memory corruption was detected on the*
1625	arena. Such an arena is no longer used to allocate chunks. Chunks
1626	allocated in that arena before detecting corruption are not freed. /*
1627
1628	#define ARENA_CORRUPTION_BIT (4U)
1629
1630	#define arena_is_corrupt(A) (((A)->flags & ARENA_CORRUPTION_BIT))
1631	#define set_arena_corrupt(A) ((A)->flags \|= ARENA_CORRUPTION_BIT)
1632
1633	/*
1634	Set value of max_fast.
1635	Use impossibly small value if 0.
1636	Precondition: there are no existing fastbin chunks.
1637	Setting the value clears fastchunk bit but preserves noncontiguous bit.
1638	*/
1639
1640	#define set_max_fast(s) \
1641	global_max_fast = (((s) == 0) \
1642	? SMALLBIN_WIDTH : ((s + SIZE_SZ) & ~MALLOC_ALIGN_MASK))
1643	#define get_max_fast() global_max_fast
1644
1645
1646	/*
1647	----------- Internal state representation and initialization -----------
1648	*/
1649
1650	struct malloc_state
1651	{
1652	/ Serialize access. /
1653	__libc_lock_define (, mutex);
1654
1655	/ Flags (formerly in max_fast). /
1656	int flags;
1657
1658	/ Fastbins /
1659	mfastbinptr fastbinsY[NFASTBINS];
1660
1661	/ Base of the topmost chunk -- not otherwise kept in a bin /
1662	mchunkptr top;
1663
1664	/ The remainder from the most recent split of a small request /
1665	mchunkptr last_remainder;
1666
1667	/ Normal bins packed as described above /
1668	mchunkptr bins[NBINS * `2` - `2`];
1669
1670	/ Bitmap of bins /
1671	unsigned int binmap[BINMAPSIZE];
1672
1673	/ Linked list /
1674	struct malloc_state *next;
1675
1676	/ Linked list for free arenas. Access to this field is serialized*
1677	by free_list_lock in arena.c. /*
1678	struct malloc_state *next_free;
1679
1680	/ Number of threads attached to this arena. 0 if the arena is on*
1681	the free list. Access to this field is serialized by
1682	free_list_lock in arena.c. /*
1683	INTERNAL_SIZE_T attached_threads;
1684
1685	/ Memory allocated from the system in this arena. /
1686	INTERNAL_SIZE_T system_mem;
1687	INTERNAL_SIZE_T max_system_mem;
1688	};
1689
1690	struct malloc_par
1691	{
1692	/ Tunable parameters /
1693	unsigned long trim_threshold;
1694	INTERNAL_SIZE_T top_pad;
1695	INTERNAL_SIZE_T mmap_threshold;
1696	INTERNAL_SIZE_T arena_test;
1697	INTERNAL_SIZE_T arena_max;
1698
1699	/ Memory map support /
1700	int n_mmaps;
1701	int n_mmaps_max;
1702	int max_n_mmaps;
1703	/ the mmap_threshold is dynamic, until the user sets*
1704	it manually, at which point we need to disable any
1705	dynamic behavior. /*
1706	int no_dyn_threshold;
1707
1708	/ Statistics /
1709	INTERNAL_SIZE_T mmapped_mem;
1710	INTERNAL_SIZE_T max_mmapped_mem;
1711
1712	/ First address handed out by MORECORE/sbrk. /
1713	char *sbrk_base;
1714	};
1715
1716	/ There are several instances of this struct ("arenas") in this*
1717	malloc. If you are adapting this malloc in a way that does NOT use
1718	a static or mmapped malloc_state, you MUST explicitly zero-fill it
1719	before using. This malloc relies on the property that malloc_state
1720	is initialized to all zeroes (as is true of C statics). /*
1721
1722	static struct malloc_state main_arena =
1723	{
1724	.mutex = _LIBC_LOCK_INITIALIZER,
1725	.next = &main_arena,
1726	.attached_threads = `1`
1727	};
1728
1729	/ These variables are used for undumping support. Chunked are marked*
1730	as using mmap, but we leave them alone if they fall into this
1731	range. NB: The chunk size for these chunks only includes the
1732	initial size field (of SIZE_SZ bytes), there is no trailing size
1733	field (unlike with regular mmapped chunks). /*
1734	static mchunkptr dumped_main_arena_start; / Inclusive. /
1735	static mchunkptr dumped_main_arena_end; / Exclusive. /
1736
1737	/ True if the pointer falls into the dumped arena. Use this after*
1738	chunk_is_mmapped indicates a chunk is mmapped. /*
1739	#define DUMPED_MAIN_ARENA_CHUNK(p) \
1740	((p) >= dumped_main_arena_start && (p) < dumped_main_arena_end)
1741
1742	/ There is only one instance of the malloc parameters. /
1743
1744	static struct malloc_par mp_ =
1745	{
1746	.top_pad = DEFAULT_TOP_PAD,
1747	.n_mmaps_max = DEFAULT_MMAP_MAX,
1748	.mmap_threshold = DEFAULT_MMAP_THRESHOLD,
1749	.trim_threshold = DEFAULT_TRIM_THRESHOLD,
1750	#define NARENAS_FROM_NCORES(n) ((n) * (sizeof (long) == 4 ? 2 : 8))
1751	.arena_test = NARENAS_FROM_NCORES (`1`)
1752	};
1753
1754	/ Maximum size of memory handled in fastbins. /
1755	static INTERNAL_SIZE_T global_max_fast;
1756
1757	/*
1758	Initialize a malloc_state struct.
1759
1760	This is called only from within malloc_consolidate, which needs
1761	be called in the same contexts anyway. It is never called directly
1762	outside of malloc_consolidate because some optimizing compilers try
1763	to inline it at all call points, which turns out not to be an
1764	optimization at all. (Inlining it in malloc_consolidate is fine though.)
1765	*/
1766
1767	static void
1768	malloc_init_state (mstate av)
1769	{
1770	int i;
1771	mbinptr bin;
1772
1773	/ Establish circular links for normal bins /
1774	for (i = `1`; i < NBINS; ++i)
1775	{
1776	bin = bin_at (av, i);
1777	bin->fd = bin->bk = bin;
1778	}
1779
1780	#if MORECORE_CONTIGUOUS
1781	if (av != &main_arena)
1782	#endif
1783	set_noncontiguous (av);
1784	if (av == &main_arena)
1785	set_max_fast (DEFAULT_MXFAST);
1786	av->flags \|= FASTCHUNKS_BIT;
1787
1788	av->top = initial_top (av);
1789	}
1790
1791	/*
1792	Other internal utilities operating on mstates
1793	*/
1794
1795	static void *sysmalloc (INTERNAL_SIZE_T, mstate);
1796	static int systrim (size_t, mstate);
1797	static void malloc_consolidate (mstate);
1798
1799
1800	/ -------------- Early definitions for debugging hooks ---------------- /
1801
1802	/ Define and initialize the hook variables. These weak definitions must*
1803	appear before any use of the variables in a function (arena.c uses one). /*
1804	#ifndef weak_variable
1805	/ In GNU libc we want the hook variables to be weak definitions to*
1806	avoid a problem with Emacs. /*
1807	# define weak_variable weak_function
1808	#endif
1809
1810	/ Forward declarations. /
1811	static void *malloc_hook_ini (size_t sz,
1812	const void *caller) __THROW;
1813	static void realloc_hook_ini (void* *ptr, size_t sz,
1814	const void *caller) __THROW;
1815	static void *memalign_hook_ini (size_t alignment, size_t sz,
1816	const void *caller) __THROW;
1817
1818	#if HAVE_MALLOC_INIT_HOOK
1819	void weak_variable (__malloc_initialize_hook) (void*) = NULL;
1820	compat_symbol (libc, __malloc_initialize_hook,
1821	__malloc_initialize_hook, GLIBC_2_0);
1822	#endif
1823
1824	void weak_variable (__free_hook) (void* *__ptr,
1825	const void *) = NULL;
1826	void weak_variable (__malloc_hook)
1827	(size_t __size, const void *) = malloc_hook_ini;
1828	void weak_variable (__realloc_hook)
1829	(void __ptr, size_t __size, const* void *)
1830	= realloc_hook_ini;
1831	void weak_variable (__memalign_hook)
1832	(size_t __alignment, size_t __size, const void *)
1833	= memalign_hook_ini;
1834	void weak_variable (__after_morecore_hook) (void*) = NULL;
1835
1836
1837	/ ---------------- Error behavior ------------------------------------ /
1838
1839	#ifndef DEFAULT_CHECK_ACTION
1840	# define DEFAULT_CHECK_ACTION 3
1841	#endif
1842
1843	static int check_action = DEFAULT_CHECK_ACTION;
1844
1845
1846	/ ------------------ Testing support ----------------------------------/
1847
1848	static int perturb_byte;
1849
1850	static void
1851	alloc_perturb (char *p, size_t n)
1852	{
1853	if (__glibc_unlikely (perturb_byte))
1854	memset (p, perturb_byte ^ `0xff`, n);
1855	}
1856
1857	static void
1858	free_perturb (char *p, size_t n)
1859	{
1860	if (__glibc_unlikely (perturb_byte))
1861	memset (p, perturb_byte, n);
1862	}
1863
1864
1865
1866	#include <stap-probe.h>
1867
1868	/ ------------------- Support for multiple arenas -------------------- /
1869	#include "arena.c"
1870
1871	/*
1872	Debugging support
1873
1874	These routines make a number of assertions about the states
1875	of data structures that should be true at all times. If any
1876	are not true, it's very likely that a user program has somehow
1877	trashed memory. (It's also possible that there is a coding error
1878	in malloc. In which case, please report it!)
1879	*/
1880
1881	#if !MALLOC_DEBUG
1882
1883	# define check_chunk(A, P)
1884	# define check_free_chunk(A, P)
1885	# define check_inuse_chunk(A, P)
1886	# define check_remalloced_chunk(A, P, N)
1887	# define check_malloced_chunk(A, P, N)
1888	# define check_malloc_state(A)
1889
1890	#else
1891
1892	# define check_chunk(A, P) do_check_chunk (A, P)
1893	# define check_free_chunk(A, P) do_check_free_chunk (A, P)
1894	# define check_inuse_chunk(A, P) do_check_inuse_chunk (A, P)
1895	# define check_remalloced_chunk(A, P, N) do_check_remalloced_chunk (A, P, N)
1896	# define check_malloced_chunk(A, P, N) do_check_malloced_chunk (A, P, N)
1897	# define check_malloc_state(A) do_check_malloc_state (A)
1898
1899	/*
1900	Properties of all chunks
1901	*/
1902
1903	static void
1904	do_check_chunk (mstate av, mchunkptr p)
1905	{
1906	unsigned long sz = chunksize (p);
1907	/ min and max possible addresses assuming contiguous allocation /
1908	char max_address = (char* *) (av->top) + chunksize (av->top);
1909	char *min_address = max_address - av->system_mem;
1910
1911	if (!chunk_is_mmapped (p))
1912	{
1913	/ Has legal address ... /
1914	if (p != av->top)
1915	{
1916	if (contiguous (av))
1917	{
1918	assert (((char *) p) >= min_address);
1919	assert (((char ) p + sz) <= ((char* *) (av->top)));
1920	}
1921	}
1922	else
1923	{
1924	/ top size is always at least MINSIZE /
1925	assert ((unsigned long) (sz) >= MINSIZE);
1926	/ top predecessor always marked inuse /
1927	assert (prev_inuse (p));
1928	}
1929	}
1930	else if (!DUMPED_MAIN_ARENA_CHUNK (p))
1931	{
1932	/ address is outside main heap /
1933	if (contiguous (av) && av->top != initial_top (av))
1934	{
1935	assert (((char ) p) < min_address \|\| ((char* *) p) >= max_address);
1936	}
1937	/ chunk is page-aligned /
1938	assert (((prev_size (p) + sz) & (GLRO (dl_pagesize) - `1`)) == `0`);
1939	/ mem is aligned /
1940	assert (aligned_OK (chunk2mem (p)));
1941	}
1942	}
1943
1944	/*
1945	Properties of free chunks
1946	*/
1947
1948	static void
1949	do_check_free_chunk (mstate av, mchunkptr p)
1950	{
1951	INTERNAL_SIZE_T sz = p->size & ~(PREV_INUSE \| NON_MAIN_ARENA);
1952	mchunkptr next = chunk_at_offset (p, sz);
1953
1954	do_check_chunk (av, p);
1955
1956	/ Chunk must claim to be free ... /
1957	assert (!inuse (p));
1958	assert (!chunk_is_mmapped (p));
1959
1960	/ Unless a special marker, must have OK fields /
1961	if ((unsigned long) (sz) >= MINSIZE)
1962	{
1963	assert ((sz & MALLOC_ALIGN_MASK) == `0`);
1964	assert (aligned_OK (chunk2mem (p)));
1965	/ ... matching footer field /
1966	assert (prev_size (p) == sz);
1967	/ ... and is fully consolidated /
1968	assert (prev_inuse (p));
1969	assert (next == av->top \|\| inuse (next));
1970
1971	/ ... and has minimally sane links /
1972	assert (p->fd->bk == p);
1973	assert (p->bk->fd == p);
1974	}
1975	else / markers are always of size SIZE_SZ /
1976	assert (sz == SIZE_SZ);
1977	}
1978
1979	/*
1980	Properties of inuse chunks
1981	*/
1982
1983	static void
1984	do_check_inuse_chunk (mstate av, mchunkptr p)
1985	{
1986	mchunkptr next;
1987
1988	do_check_chunk (av, p);
1989
1990	if (chunk_is_mmapped (p))
1991	return; / mmapped chunks have no next/prev /
1992
1993	/ Check whether it claims to be in use ... /
1994	assert (inuse (p));
1995
1996	next = next_chunk (p);
1997
1998	/ ... and is surrounded by OK chunks.*
1999	Since more things can be checked with free chunks than inuse ones,
2000	if an inuse chunk borders them and debug is on, it's worth doing them.
2001	*/
2002	if (!prev_inuse (p))
2003	{
2004	/ Note that we cannot even look at prev unless it is not inuse /
2005	mchunkptr prv = prev_chunk (p);
2006	assert (next_chunk (prv) == p);
2007	do_check_free_chunk (av, prv);
2008	}
2009
2010	if (next == av->top)
2011	{
2012	assert (prev_inuse (next));
2013	assert (chunksize (next) >= MINSIZE);
2014	}
2015	else if (!inuse (next))
2016	do_check_free_chunk (av, next);
2017	}
2018
2019	/*
2020	Properties of chunks recycled from fastbins
2021	*/
2022
2023	static void
2024	do_check_remalloced_chunk (mstate av, mchunkptr p, INTERNAL_SIZE_T s)
2025	{
2026	INTERNAL_SIZE_T sz = p->size & ~(PREV_INUSE \| NON_MAIN_ARENA);
2027
2028	if (!chunk_is_mmapped (p))
2029	{
2030	assert (av == arena_for_chunk (p));
2031	if (chunk_main_arena (p))
2032	assert (av == &main_arena);
2033	else
2034	assert (av != &main_arena);
2035	}
2036
2037	do_check_inuse_chunk (av, p);
2038
2039	/ Legal size ... /
2040	assert ((sz & MALLOC_ALIGN_MASK) == `0`);
2041	assert ((unsigned long) (sz) >= MINSIZE);
2042	/ ... and alignment /
2043	assert (aligned_OK (chunk2mem (p)));
2044	/ chunk is less than MINSIZE more than request /
2045	assert ((long) (sz) - (long) (s) >= `0`);
2046	assert ((long) (sz) - (long) (s + MINSIZE) < `0`);
2047	}
2048
2049	/*
2050	Properties of nonrecycled chunks at the point they are malloced
2051	*/
2052
2053	static void
2054	do_check_malloced_chunk (mstate av, mchunkptr p, INTERNAL_SIZE_T s)
2055	{
2056	/ same as recycled case ... /
2057	do_check_remalloced_chunk (av, p, s);
2058
2059	/*
2060	... plus, must obey implementation invariant that prev_inuse is
2061	always true of any allocated chunk; i.e., that each allocated
2062	chunk borders either a previously allocated and still in-use
2063	chunk, or the base of its memory arena. This is ensured
2064	by making all allocations from the `lowest' part of any found
2065	chunk. This does not necessarily hold however for chunks
2066	recycled via fastbins.
2067	*/
2068
2069	assert (prev_inuse (p));
2070	}
2071
2072
2073	/*
2074	Properties of malloc_state.
2075
2076	This may be useful for debugging malloc, as well as detecting user
2077	programmer errors that somehow write into malloc_state.
2078
2079	If you are extending or experimenting with this malloc, you can
2080	probably figure out how to hack this routine to print out or
2081	display chunk addresses, sizes, bins, and other instrumentation.
2082	*/
2083
2084	static void
2085	do_check_malloc_state (mstate av)
2086	{
2087	int i;
2088	mchunkptr p;
2089	mchunkptr q;
2090	mbinptr b;
2091	unsigned int idx;
2092	INTERNAL_SIZE_T size;
2093	unsigned long total = `0`;
2094	int max_fast_bin;
2095
2096	/ internal size_t must be no wider than pointer type /
2097	assert (sizeof (INTERNAL_SIZE_T) <= sizeof (char *));
2098
2099	/ alignment is a power of 2 /
2100	assert ((MALLOC_ALIGNMENT & (MALLOC_ALIGNMENT - `1`)) == `0`);
2101
2102	/ cannot run remaining checks until fully initialized /
2103	if (av->top == `0` \|\| av->top == initial_top (av))
2104	return;
2105
2106	/ pagesize is a power of 2 /
2107	assert (powerof2(GLRO (dl_pagesize)));
2108
2109	/ A contiguous main_arena is consistent with sbrk_base. /
2110	if (av == &main_arena && contiguous (av))
2111	assert ((char *) mp_.sbrk_base + av->system_mem ==
2112	(char *) av->top + chunksize (av->top));
2113
2114	/ properties of fastbins /
2115
2116	/ max_fast is in allowed range /
2117	assert ((get_max_fast () & ~`1`) <= request2size (MAX_FAST_SIZE));
2118
2119	max_fast_bin = fastbin_index (get_max_fast ());
2120
2121	for (i = `0`; i < NFASTBINS; ++i)
2122	{
2123	p = fastbin (av, i);
2124
2125	/ The following test can only be performed for the main arena.*
2126	While mallopt calls malloc_consolidate to get rid of all fast
2127	bins (especially those larger than the new maximum) this does
2128	only happen for the main arena. Trying to do this for any
2129	other arena would mean those arenas have to be locked and
2130	malloc_consolidate be called for them. This is excessive. And
2131	even if this is acceptable to somebody it still cannot solve
2132	the problem completely since if the arena is locked a
2133	concurrent malloc call might create a new arena which then
2134	could use the newly invalid fast bins. /*
2135
2136	/ all bins past max_fast are empty /
2137	if (av == &main_arena && i > max_fast_bin)
2138	assert (p == `0`);
2139
2140	while (p != `0`)
2141	{
2142	/ each chunk claims to be inuse /
2143	do_check_inuse_chunk (av, p);
2144	total += chunksize (p);
2145	/ chunk belongs in this bin /
2146	assert (fastbin_index (chunksize (p)) == i);
2147	p = p->fd;
2148	}
2149	}
2150
2151	if (total != `0`)
2152	assert (have_fastchunks (av));
2153	else if (!have_fastchunks (av))
2154	assert (total == `0`);
2155
2156	/ check normal bins /
2157	for (i = `1`; i < NBINS; ++i)
2158	{
2159	b = bin_at (av, i);
2160
2161	/ binmap is accurate (except for bin 1 == unsorted_chunks) /
2162	if (i >= `2`)
2163	{
2164	unsigned int binbit = get_binmap (av, i);
2165	int empty = last (b) == b;
2166	if (!binbit)
2167	assert (empty);
2168	else if (!empty)
2169	assert (binbit);
2170	}
2171
2172	for (p = last (b); p != b; p = p->bk)
2173	{
2174	/ each chunk claims to be free /
2175	do_check_free_chunk (av, p);
2176	size = chunksize (p);
2177	total += size;
2178	if (i >= `2`)
2179	{
2180	/ chunk belongs in bin /
2181	idx = bin_index (size);
2182	assert (idx == i);
2183	/ lists are sorted /
2184	assert (p->bk == b \|\|
2185	(unsigned long) chunksize (p->bk) >= (unsigned long) chunksize (p));
2186
2187	if (!in_smallbin_range (size))
2188	{
2189	if (p->fd_nextsize != NULL)
2190	{
2191	if (p->fd_nextsize == p)
2192	assert (p->bk_nextsize == p);
2193	else
2194	{
2195	if (p->fd_nextsize == first (b))
2196	assert (chunksize (p) < chunksize (p->fd_nextsize));
2197	else
2198	assert (chunksize (p) > chunksize (p->fd_nextsize));
2199
2200	if (p == first (b))
2201	assert (chunksize (p) > chunksize (p->bk_nextsize));
2202	else
2203	assert (chunksize (p) < chunksize (p->bk_nextsize));
2204	}
2205	}
2206	else
2207	assert (p->bk_nextsize == NULL);
2208	}
2209	}
2210	else if (!in_smallbin_range (size))
2211	assert (p->fd_nextsize == NULL && p->bk_nextsize == NULL);
2212	/ chunk is followed by a legal chain of inuse chunks /
2213	for (q = next_chunk (p);
2214	(q != av->top && inuse (q) &&
2215	(unsigned long) (chunksize (q)) >= MINSIZE);
2216	q = next_chunk (q))
2217	do_check_inuse_chunk (av, q);
2218	}
2219	}
2220
2221	/ top chunk is OK /
2222	check_chunk (av, av->top);
2223	}
2224	#endif
2225
2226
2227	/ ----------------- Support for debugging hooks -------------------- /
2228	#include "hooks.c"
2229
2230
2231	/ ----------- Routines dealing with system allocation -------------- /
2232
2233	/*
2234	sysmalloc handles malloc cases requiring more memory from the system.
2235	On entry, it is assumed that av->top does not have enough
2236	space to service request for nb bytes, thus requiring that av->top
2237	be extended or replaced.
2238	*/
2239
2240	static void *
2241	sysmalloc (INTERNAL_SIZE_T nb, mstate av)
2242	{
2243	mchunkptr old_top; / incoming value of av->top /
2244	INTERNAL_SIZE_T old_size; / its size /
2245	char old_end; /* its end address /
2246
2247	long size; / arg to first MORECORE or mmap call /
2248	char brk; /* return value from MORECORE /
2249
2250	long correction; / arg to 2nd MORECORE call /
2251	char snd_brk; /* 2nd return val /
2252
2253	INTERNAL_SIZE_T front_misalign; / unusable bytes at front of new space /
2254	INTERNAL_SIZE_T end_misalign; / partial page left at end of new space /
2255	char aligned_brk; /* aligned offset into brk /
2256
2257	mchunkptr p; / the allocated/returned chunk /
2258	mchunkptr remainder; / remainder from allocation /
2259	unsigned long remainder_size; / its size /
2260
2261
2262	size_t pagesize = GLRO (dl_pagesize);
2263	bool tried_mmap = false;
2264
2265
2266	/*
2267	If have mmap, and the request size meets the mmap threshold, and
2268	the system supports mmap, and there are few enough currently
2269	allocated mmapped regions, try to directly map this request
2270	rather than expanding top.
2271	*/
2272
2273	if (av == NULL
2274	\|\| ((unsigned long) (nb) >= (unsigned long) (mp_.mmap_threshold)
2275	&& (mp_.n_mmaps < mp_.n_mmaps_max)))
2276	{
2277	char mm; /* return value from mmap call/
2278
2279	try_mmap:
2280	/*
2281	Round up size to nearest page. For mmapped chunks, the overhead
2282	is one SIZE_SZ unit larger than for normal chunks, because there
2283	is no following chunk whose prev_size field could be used.
2284
2285	See the front_misalign handling below, for glibc there is no
2286	need for further alignments unless we have have high alignment.
2287	*/
2288	if (MALLOC_ALIGNMENT == `2` * SIZE_SZ)
2289	size = ALIGN_UP (nb + SIZE_SZ, pagesize);
2290	else
2291	size = ALIGN_UP (nb + SIZE_SZ + MALLOC_ALIGN_MASK, pagesize);
2292	tried_mmap = true;
2293
2294	/ Don't try if size wraps around 0 /
2295	if ((unsigned long) (size) > (unsigned long) (nb))
2296	{
2297	mm = (char *) (MMAP (`0`, size, PROT_READ \| PROT_WRITE, `0`));
2298
2299	if (mm != MAP_FAILED)
2300	{
2301	/*
2302	The offset to the start of the mmapped region is stored
2303	in the prev_size field of the chunk. This allows us to adjust
2304	returned start address to meet alignment requirements here
2305	and in memalign(), and still be able to compute proper
2306	address argument for later munmap in free() and realloc().
2307	*/
2308
2309	if (MALLOC_ALIGNMENT == `2` * SIZE_SZ)
2310	{
2311	/ For glibc, chunk2mem increases the address by 2SIZE_SZ and
2312	MALLOC_ALIGN_MASK is 2SIZE_SZ-1. Each mmap'ed area is page*
2313	aligned and therefore definitely MALLOC_ALIGN_MASK-aligned. /*
2314	assert (((INTERNAL_SIZE_T) chunk2mem (mm) & MALLOC_ALIGN_MASK) == `0`);
2315	front_misalign = `0`;
2316	}
2317	else
2318	front_misalign = (INTERNAL_SIZE_T) chunk2mem (mm) & MALLOC_ALIGN_MASK;
2319	if (front_misalign > `0`)
2320	{
2321	correction = MALLOC_ALIGNMENT - front_misalign;
2322	p = (mchunkptr) (mm + correction);
2323	set_prev_size (p, correction);
2324	set_head (p, (size - correction) \| IS_MMAPPED);
2325	}
2326	else
2327	{
2328	p = (mchunkptr) mm;
2329	set_prev_size (p, `0`);
2330	set_head (p, size \| IS_MMAPPED);
2331	}
2332
2333	/ update statistics /
2334
2335	int new = atomic_exchange_and_add (&mp_.n_mmaps, `1`) + `1`;
2336	atomic_max (&mp_.max_n_mmaps, new);
2337
2338	unsigned long sum;
2339	sum = atomic_exchange_and_add (&mp_.mmapped_mem, size) + size;
2340	atomic_max (&mp_.max_mmapped_mem, sum);
2341
2342	check_chunk (av, p);
2343
2344	return chunk2mem (p);
2345	}
2346	}
2347	}
2348
2349	/ There are no usable arenas and mmap also failed. /
2350	if (av == NULL)
2351	return `0`;
2352
2353	/ Record incoming configuration of top /
2354
2355	old_top = av->top;
2356	old_size = chunksize (old_top);
2357	old_end = (char *) (chunk_at_offset (old_top, old_size));
2358
2359	brk = snd_brk = (char *) (MORECORE_FAILURE);
2360
2361	/*
2362	If not the first time through, we require old_size to be
2363	at least MINSIZE and to have prev_inuse set.
2364	*/
2365
2366	assert ((old_top == initial_top (av) && old_size == `0`) \|\|
2367	((unsigned long) (old_size) >= MINSIZE &&
2368	prev_inuse (old_top) &&
2369	((unsigned long) old_end & (pagesize - `1`)) == `0`));
2370
2371	/ Precondition: not enough current space to satisfy nb request /
2372	assert ((unsigned long) (old_size) < (unsigned long) (nb + MINSIZE));
2373
2374
2375	if (av != &main_arena)
2376	{
2377	heap_info old_heap, heap;
2378	size_t old_heap_size;
2379
2380	/ First try to extend the current heap. /
2381	old_heap = heap_for_ptr (old_top);
2382	old_heap_size = old_heap->size;
2383	if ((long) (MINSIZE + nb - old_size) > `0`
2384	&& grow_heap (old_heap, MINSIZE + nb - old_size) == `0`)
2385	{
2386	av->system_mem += old_heap->size - old_heap_size;
2387	set_head (old_top, (((char ) old_heap + old_heap->size) - (char* *) old_top)
2388	\| PREV_INUSE);
2389	}
2390	else if ((heap = new_heap (nb + (MINSIZE + sizeof (*heap)), mp_.top_pad)))
2391	{
2392	/ Use a newly allocated heap. /
2393	heap->ar_ptr = av;
2394	heap->prev = old_heap;
2395	av->system_mem += heap->size;
2396	/ Set up the new top. /
2397	top (av) = chunk_at_offset (heap, sizeof (*heap));
2398	set_head (top (av), (heap->size - sizeof (*heap)) \| PREV_INUSE);
2399
2400	/ Setup fencepost and free the old top chunk with a multiple of*
2401	MALLOC_ALIGNMENT in size. /*
2402	/ The fencepost takes at least MINSIZE bytes, because it might*
2403	become the top chunk again later. Note that a footer is set
2404	up, too, although the chunk is marked in use. /*
2405	old_size = (old_size - MINSIZE) & ~MALLOC_ALIGN_MASK;
2406	set_head (chunk_at_offset (old_top, old_size + `2` * SIZE_SZ), `0` \| PREV_INUSE);
2407	if (old_size >= MINSIZE)
2408	{
2409	set_head (chunk_at_offset (old_top, old_size), (`2` * SIZE_SZ) \| PREV_INUSE);
2410	set_foot (chunk_at_offset (old_top, old_size), (`2` * SIZE_SZ));
2411	set_head (old_top, old_size \| PREV_INUSE \| NON_MAIN_ARENA);
2412	_int_free (av, old_top, `1`);
2413	}
2414	else
2415	{
2416	set_head (old_top, (old_size + `2` * SIZE_SZ) \| PREV_INUSE);
2417	set_foot (old_top, (old_size + `2` * SIZE_SZ));
2418	}
2419	}
2420	else if (!tried_mmap)
2421	/ We can at least try to use to mmap memory. /
2422	goto try_mmap;
2423	}
2424	else / av == main_arena /
2425
2426
2427	{ / Request enough space for nb + pad + overhead /
2428	size = nb + mp_.top_pad + MINSIZE;
2429
2430	/*
2431	If contiguous, we can subtract out existing space that we hope to
2432	combine with new space. We add it back later only if
2433	we don't actually get contiguous space.
2434	*/
2435
2436	if (contiguous (av))
2437	size -= old_size;
2438
2439	/*
2440	Round to a multiple of page size.
2441	If MORECORE is not contiguous, this ensures that we only call it
2442	with whole-page arguments. And if MORECORE is contiguous and
2443	this is not first time through, this preserves page-alignment of
2444	previous calls. Otherwise, we correct to page-align below.
2445	*/
2446
2447	size = ALIGN_UP (size, pagesize);
2448
2449	/*
2450	Don't try to call MORECORE if argument is so big as to appear
2451	negative. Note that since mmap takes size_t arg, it may succeed
2452	below even if we cannot call MORECORE.
2453	*/
2454
2455	if (size > `0`)
2456	{
2457	brk = (char *) (MORECORE (size));
2458	LIBC_PROBE (memory_sbrk_more, `2`, brk, size);
2459	}
2460
2461	if (brk != (char *) (MORECORE_FAILURE))
2462	{
2463	/ Call the `morecore' hook if necessary. /
2464	void (hook) (void*) = atomic_forced_read (__after_morecore_hook);
2465	if (__builtin_expect (hook != NULL, `0`))
2466	(*hook)();
2467	}
2468	else
2469	{
2470	/*
2471	If have mmap, try using it as a backup when MORECORE fails or
2472	cannot be used. This is worth doing on systems that have "holes" in
2473	address space, so sbrk cannot extend to give contiguous space, but
2474	space is available elsewhere. Note that we ignore mmap max count
2475	and threshold limits, since the space will not be used as a
2476	segregated mmap region.
2477	*/
2478
2479	/ Cannot merge with old top, so add its size back in /
2480	if (contiguous (av))
2481	size = ALIGN_UP (size + old_size, pagesize);
2482
2483	/ If we are relying on mmap as backup, then use larger units /
2484	if ((unsigned long) (size) < (unsigned long) (MMAP_AS_MORECORE_SIZE))
2485	size = MMAP_AS_MORECORE_SIZE;
2486
2487	/ Don't try if size wraps around 0 /
2488	if ((unsigned long) (size) > (unsigned long) (nb))
2489	{
2490	char mbrk = (char* *) (MMAP (`0`, size, PROT_READ \| PROT_WRITE, `0`));
2491
2492	if (mbrk != MAP_FAILED)
2493	{
2494	/ We do not need, and cannot use, another sbrk call to find end /
2495	brk = mbrk;
2496	snd_brk = brk + size;
2497
2498	/*
2499	Record that we no longer have a contiguous sbrk region.
2500	After the first time mmap is used as backup, we do not
2501	ever rely on contiguous space since this could incorrectly
2502	bridge regions.
2503	*/
2504	set_noncontiguous (av);
2505	}
2506	}
2507	}
2508
2509	if (brk != (char *) (MORECORE_FAILURE))
2510	{
2511	if (mp_.sbrk_base == `0`)
2512	mp_.sbrk_base = brk;
2513	av->system_mem += size;
2514
2515	/*
2516	If MORECORE extends previous space, we can likewise extend top size.
2517	*/
2518
2519	if (brk == old_end && snd_brk == (char *) (MORECORE_FAILURE))
2520	set_head (old_top, (size + old_size) \| PREV_INUSE);
2521
2522	else if (contiguous (av) && old_size && brk < old_end)
2523	{
2524	/ Oops! Someone else killed our space.. Can't touch anything. /
2525	malloc_printerr (`3`, "break adjusted to free malloc space", brk,
2526	av);
2527	}
2528
2529	/*
2530	Otherwise, make adjustments:
2531
2532	* If the first time through or noncontiguous, we need to call sbrk
2533	just to find out where the end of memory lies.
2534
2535	* We need to ensure that all returned chunks from malloc will meet
2536	MALLOC_ALIGNMENT
2537
2538	* If there was an intervening foreign sbrk, we need to adjust sbrk
2539	request size to account for fact that we will not be able to
2540	combine new space with existing space in old_top.
2541
2542	* Almost all systems internally allocate whole pages at a time, in
2543	which case we might as well use the whole last page of request.
2544	So we allocate enough more memory to hit a page boundary now,
2545	which in turn causes future contiguous calls to page-align.
2546	*/
2547
2548	else
2549	{
2550	front_misalign = `0`;
2551	end_misalign = `0`;
2552	correction = `0`;
2553	aligned_brk = brk;
2554
2555	/ handle contiguous cases /
2556	if (contiguous (av))
2557	{
2558	/ Count foreign sbrk as system_mem. /
2559	if (old_size)
2560	av->system_mem += brk - old_end;
2561
2562	/ Guarantee alignment of first new chunk made from this space /
2563
2564	front_misalign = (INTERNAL_SIZE_T) chunk2mem (brk) & MALLOC_ALIGN_MASK;
2565	if (front_misalign > `0`)
2566	{
2567	/*
2568	Skip over some bytes to arrive at an aligned position.
2569	We don't need to specially mark these wasted front bytes.
2570	They will never be accessed anyway because
2571	prev_inuse of av->top (and any chunk created from its start)
2572	is always true after initialization.
2573	*/
2574
2575	correction = MALLOC_ALIGNMENT - front_misalign;
2576	aligned_brk += correction;
2577	}
2578
2579	/*
2580	If this isn't adjacent to existing space, then we will not
2581	be able to merge with old_top space, so must add to 2nd request.
2582	*/
2583
2584	correction += old_size;
2585
2586	/ Extend the end address to hit a page boundary /
2587	end_misalign = (INTERNAL_SIZE_T) (brk + size + correction);
2588	correction += (ALIGN_UP (end_misalign, pagesize)) - end_misalign;
2589
2590	assert (correction >= `0`);
2591	snd_brk = (char *) (MORECORE (correction));
2592
2593	/*
2594	If can't allocate correction, try to at least find out current
2595	brk. It might be enough to proceed without failing.
2596
2597	Note that if second sbrk did NOT fail, we assume that space
2598	is contiguous with first sbrk. This is a safe assumption unless
2599	program is multithreaded but doesn't use locks and a foreign sbrk
2600	occurred between our first and second calls.
2601	*/
2602
2603	if (snd_brk == (char *) (MORECORE_FAILURE))
2604	{
2605	correction = `0`;
2606	snd_brk = (char *) (MORECORE (`0`));
2607	}
2608	else
2609	{
2610	/ Call the `morecore' hook if necessary. /
2611	void (hook) (void*) = atomic_forced_read (__after_morecore_hook);
2612	if (__builtin_expect (hook != NULL, `0`))
2613	(*hook)();
2614	}
2615	}
2616
2617	/ handle non-contiguous cases /
2618	else
2619	{
2620	if (MALLOC_ALIGNMENT == `2` * SIZE_SZ)
2621	/ MORECORE/mmap must correctly align /
2622	assert (((unsigned long) chunk2mem (brk) & MALLOC_ALIGN_MASK) == `0`);
2623	else
2624	{
2625	front_misalign = (INTERNAL_SIZE_T) chunk2mem (brk) & MALLOC_ALIGN_MASK;
2626	if (front_misalign > `0`)
2627	{
2628	/*
2629	Skip over some bytes to arrive at an aligned position.
2630	We don't need to specially mark these wasted front bytes.
2631	They will never be accessed anyway because
2632	prev_inuse of av->top (and any chunk created from its start)
2633	is always true after initialization.
2634	*/
2635
2636	aligned_brk += MALLOC_ALIGNMENT - front_misalign;
2637	}
2638	}
2639
2640	/ Find out current end of memory /
2641	if (snd_brk == (char *) (MORECORE_FAILURE))
2642	{
2643	snd_brk = (char *) (MORECORE (`0`));
2644	}
2645	}
2646
2647	/ Adjust top based on results of second sbrk /
2648	if (snd_brk != (char *) (MORECORE_FAILURE))
2649	{
2650	av->top = (mchunkptr) aligned_brk;
2651	set_head (av->top, (snd_brk - aligned_brk + correction) \| PREV_INUSE);
2652	av->system_mem += correction;
2653
2654	/*
2655	If not the first time through, we either have a
2656	gap due to foreign sbrk or a non-contiguous region. Insert a
2657	double fencepost at old_top to prevent consolidation with space
2658	we don't own. These fenceposts are artificial chunks that are
2659	marked as inuse and are in any case too small to use. We need
2660	two to make sizes and alignments work out.
2661	*/
2662
2663	if (old_size != `0`)
2664	{
2665	/*
2666	Shrink old_top to insert fenceposts, keeping size a
2667	multiple of MALLOC_ALIGNMENT. We know there is at least
2668	enough space in old_top to do this.
2669	*/
2670	old_size = (old_size - `4` * SIZE_SZ) & ~MALLOC_ALIGN_MASK;
2671	set_head (old_top, old_size \| PREV_INUSE);
2672
2673	/*
2674	Note that the following assignments completely overwrite
2675	old_top when old_size was previously MINSIZE. This is
2676	intentional. We need the fencepost, even if old_top otherwise gets
2677	lost.
2678	*/
2679	set_head (chunk_at_offset (old_top, old_size),
2680	(`2` * SIZE_SZ) \| PREV_INUSE);
2681	set_head (chunk_at_offset (old_top, old_size + `2` * SIZE_SZ),
2682	(`2` * SIZE_SZ) \| PREV_INUSE);
2683
2684	/ If possible, release the rest. /
2685	if (old_size >= MINSIZE)
2686	{
2687	_int_free (av, old_top, `1`);
2688	}
2689	}
2690	}
2691	}
2692	}
2693	} / if (av != &main_arena) /
2694
2695	if ((unsigned long) av->system_mem > (unsigned long) (av->max_system_mem))
2696	av->max_system_mem = av->system_mem;
2697	check_malloc_state (av);
2698
2699	/ finally, do the allocation /
2700	p = av->top;
2701	size = chunksize (p);
2702
2703	/ check that one of the above allocation paths succeeded /
2704	if ((unsigned long) (size) >= (unsigned long) (nb + MINSIZE))
2705	{
2706	remainder_size = size - nb;
2707	remainder = chunk_at_offset (p, nb);
2708	av->top = remainder;
2709	set_head (p, nb \| PREV_INUSE \| (av != &main_arena ? NON_MAIN_ARENA : `0`));
2710	set_head (remainder, remainder_size \| PREV_INUSE);
2711	check_malloced_chunk (av, p, nb);
2712	return chunk2mem (p);
2713	}
2714
2715	/ catch all failure paths /
2716	__set_errno (ENOMEM);
2717	return `0`;
2718	}
2719
2720
2721	/*
2722	systrim is an inverse of sorts to sysmalloc. It gives memory back
2723	to the system (via negative arguments to sbrk) if there is unused
2724	memory at the `high' end of the malloc pool. It is called
2725	automatically by free() when top space exceeds the trim
2726	threshold. It is also called by the public malloc_trim routine. It
2727	returns 1 if it actually released any memory, else 0.
2728	*/
2729
2730	static int
2731	systrim (size_t pad, mstate av)
2732	{
2733	long top_size; / Amount of top-most memory /
2734	long extra; / Amount to release /
2735	long released; / Amount actually released /
2736	char current_brk; /* address returned by pre-check sbrk call /
2737	char new_brk; /* address returned by post-check sbrk call /
2738	size_t pagesize;
2739	long top_area;
2740
2741	pagesize = GLRO (dl_pagesize);
2742	top_size = chunksize (av->top);
2743
2744	top_area = top_size - MINSIZE - `1`;
2745	if (top_area <= pad)
2746	return `0`;
2747
2748	/ Release in pagesize units and round down to the nearest page. /
2749	extra = ALIGN_DOWN(top_area - pad, pagesize);
2750
2751	if (extra == `0`)
2752	return `0`;
2753
2754	/*
2755	Only proceed if end of memory is where we last set it.
2756	This avoids problems if there were foreign sbrk calls.
2757	*/
2758	current_brk = (char *) (MORECORE (`0`));
2759	if (current_brk == (char *) (av->top) + top_size)
2760	{
2761	/*
2762	Attempt to release memory. We ignore MORECORE return value,
2763	and instead call again to find out where new end of memory is.
2764	This avoids problems if first call releases less than we asked,
2765	of if failure somehow altered brk value. (We could still
2766	encounter problems if it altered brk in some very bad way,
2767	but the only thing we can do is adjust anyway, which will cause
2768	some downstream failure.)
2769	*/
2770
2771	MORECORE (-extra);
2772	/ Call the `morecore' hook if necessary. /
2773	void (hook) (void*) = atomic_forced_read (__after_morecore_hook);
2774	if (__builtin_expect (hook != NULL, `0`))
2775	(*hook)();
2776	new_brk = (char *) (MORECORE (`0`));
2777
2778	LIBC_PROBE (memory_sbrk_less, `2`, new_brk, extra);
2779
2780	if (new_brk != (char *) MORECORE_FAILURE)
2781	{
2782	released = (long) (current_brk - new_brk);
2783
2784	if (released != `0`)
2785	{
2786	/ Success. Adjust top. /
2787	av->system_mem -= released;
2788	set_head (av->top, (top_size - released) \| PREV_INUSE);
2789	check_malloc_state (av);
2790	return `1`;
2791	}
2792	}
2793	}
2794	return `0`;
2795	}
2796
2797	static void
2798	internal_function
2799	munmap_chunk (mchunkptr p)
2800	{
2801	INTERNAL_SIZE_T size = chunksize (p);
2802
2803	assert (chunk_is_mmapped (p));
2804
2805	/ Do nothing if the chunk is a faked mmapped chunk in the dumped*
2806	main arena. We never free this memory. /*
2807	if (DUMPED_MAIN_ARENA_CHUNK (p))
2808	return;
2809
2810	uintptr_t block = (uintptr_t) p - prev_size (p);
2811	size_t total_size = prev_size (p) + size;
2812	/ Unfortunately we have to do the compilers job by hand here. Normally*
2813	we would test BLOCK and TOTAL-SIZE separately for compliance with the
2814	page size. But gcc does not recognize the optimization possibility
2815	(in the moment at least) so we combine the two values into one before
2816	the bit test. /*
2817	if (__builtin_expect (((block \| total_size) & (GLRO (dl_pagesize) - `1`)) != `0`, `0`))
2818	{
2819	malloc_printerr (check_action, "munmap_chunk(): invalid pointer",
2820	chunk2mem (p), NULL);
2821	return;
2822	}
2823
2824	atomic_decrement (&mp_.n_mmaps);
2825	atomic_add (&mp_.mmapped_mem, -total_size);
2826
2827	/ If munmap failed the process virtual memory address space is in a*
2828	bad shape. Just leave the block hanging around, the process will
2829	terminate shortly anyway since not much can be done. /*
2830	__munmap ((char *) block, total_size);
2831	}
2832
2833	#if HAVE_MREMAP
2834
2835	static mchunkptr
2836	internal_function
2837	mremap_chunk (mchunkptr p, size_t new_size)
2838	{
2839	size_t pagesize = GLRO (dl_pagesize);
2840	INTERNAL_SIZE_T offset = prev_size (p);
2841	INTERNAL_SIZE_T size = chunksize (p);
2842	char *cp;
2843
2844	assert (chunk_is_mmapped (p));
2845	assert (((size + offset) & (GLRO (dl_pagesize) - `1`)) == `0`);
2846
2847	/ Note the extra SIZE_SZ overhead as in mmap_chunk(). /
2848	new_size = ALIGN_UP (new_size + offset + SIZE_SZ, pagesize);
2849
2850	/ No need to remap if the number of pages does not change. /
2851	if (size + offset == new_size)
2852	return p;
2853
2854	cp = (char ) __mremap ((char* *) p - offset, size + offset, new_size,
2855	MREMAP_MAYMOVE);
2856
2857	if (cp == MAP_FAILED)
2858	return `0`;
2859
2860	p = (mchunkptr) (cp + offset);
2861
2862	assert (aligned_OK (chunk2mem (p)));
2863
2864	assert (prev_size (p) == offset);
2865	set_head (p, (new_size - offset) \| IS_MMAPPED);
2866
2867	INTERNAL_SIZE_T new;
2868	new = atomic_exchange_and_add (&mp_.mmapped_mem, new_size - size - offset)
2869	+ new_size - size - offset;
2870	atomic_max (&mp_.max_mmapped_mem, new);
2871	return p;
2872	}
2873	#endif /* HAVE_MREMAP */
2874
2875	/------------------------ Public wrappers. --------------------------------/
2876
2877	void *
2878	__libc_malloc (size_t bytes)
2879	{
2880	mstate ar_ptr;
2881	void *victim;
2882
2883	void (hook) (size_t, const void *)
2884	= atomic_forced_read (__malloc_hook);
2885	if (__builtin_expect (hook != NULL, `0`))
2886	return (*hook)(bytes, RETURN_ADDRESS (`0`));
2887
2888	arena_get (ar_ptr, bytes);
2889
2890	victim = _int_malloc (ar_ptr, bytes);
2891	/ Retry with another arena only if we were able to find a usable arena*
2892	before. /*
2893	if (!victim && ar_ptr != NULL)
2894	{
2895	LIBC_PROBE (memory_malloc_retry, `1`, bytes);
2896	ar_ptr = arena_get_retry (ar_ptr, bytes);
2897	victim = _int_malloc (ar_ptr, bytes);
2898	}
2899
2900	if (ar_ptr != NULL)
2901	__libc_lock_unlock (ar_ptr->mutex);
2902
2903	assert (!victim \|\| chunk_is_mmapped (mem2chunk (victim)) \|\|
2904	ar_ptr == arena_for_chunk (mem2chunk (victim)));
2905	return victim;
2906	}
2907	libc_hidden_def (__libc_malloc)
2908
2909	void
2910	__libc_free (void *mem)
2911	{
2912	mstate ar_ptr;
2913	mchunkptr p; / chunk corresponding to mem /
2914
2915	void (hook) (void* , const* void *)
2916	= atomic_forced_read (__free_hook);
2917	if (__builtin_expect (hook != NULL, `0`))
2918	{
2919	(*hook)(mem, RETURN_ADDRESS (`0`));
2920	return;
2921	}
2922
2923	if (mem == `0`) / free(0) has no effect /
2924	return;
2925
2926	p = mem2chunk (mem);
2927
2928	if (chunk_is_mmapped (p)) / release mmapped memory. /
2929	{
2930	/ See if the dynamic brk/mmap threshold needs adjusting.*
2931	Dumped fake mmapped chunks do not affect the threshold. /*
2932	if (!mp_.no_dyn_threshold
2933	&& chunksize_nomask (p) > mp_.mmap_threshold
2934	&& chunksize_nomask (p) <= DEFAULT_MMAP_THRESHOLD_MAX
2935	&& !DUMPED_MAIN_ARENA_CHUNK (p))
2936	{
2937	mp_.mmap_threshold = chunksize (p);
2938	mp_.trim_threshold = `2` * mp_.mmap_threshold;
2939	LIBC_PROBE (memory_mallopt_free_dyn_thresholds, `2`,
2940	mp_.mmap_threshold, mp_.trim_threshold);
2941	}
2942	munmap_chunk (p);
2943	return;
2944	}
2945
2946	ar_ptr = arena_for_chunk (p);
2947	_int_free (ar_ptr, p, `0`);
2948	}
2949	libc_hidden_def (__libc_free)
2950
2951	void *
2952	__libc_realloc (void *oldmem, size_t bytes)
2953	{
2954	mstate ar_ptr;
2955	INTERNAL_SIZE_T nb; / padded request size /
2956
2957	void newp; /* chunk to return /
2958
2959	void (hook) (void , size_t, const* void *) =
2960	atomic_forced_read (__realloc_hook);
2961	if (__builtin_expect (hook != NULL, `0`))
2962	return (*hook)(oldmem, bytes, RETURN_ADDRESS (`0`));
2963
2964	#if REALLOC_ZERO_BYTES_FREES
2965	if (bytes == `0` && oldmem != NULL)
2966	{
2967	__libc_free (oldmem); return `0`;
2968	}
2969	#endif
2970
2971	/ realloc of null is supposed to be same as malloc /
2972	if (oldmem == `0`)
2973	return __libc_malloc (bytes);
2974
2975	/ chunk corresponding to oldmem /
2976	const mchunkptr oldp = mem2chunk (oldmem);
2977	/ its size /
2978	const INTERNAL_SIZE_T oldsize = chunksize (oldp);
2979
2980	if (chunk_is_mmapped (oldp))
2981	ar_ptr = NULL;
2982	else
2983	ar_ptr = arena_for_chunk (oldp);
2984
2985	/ Little security check which won't hurt performance: the allocator*
2986	never wrapps around at the end of the address space. Therefore
2987	we can exclude some size values which might appear here by
2988	accident or by "design" from some intruder. We need to bypass
2989	this check for dumped fake mmap chunks from the old main arena
2990	because the new malloc may provide additional alignment. /*
2991	if ((__builtin_expect ((uintptr_t) oldp > (uintptr_t) -oldsize, `0`)
2992	\|\| __builtin_expect (misaligned_chunk (oldp), `0`))
2993	&& !DUMPED_MAIN_ARENA_CHUNK (oldp))
2994	{
2995	malloc_printerr (check_action, "realloc(): invalid pointer", oldmem,
2996	ar_ptr);
2997	return NULL;
2998	}
2999
3000	checked_request2size (bytes, nb);
3001
3002	if (chunk_is_mmapped (oldp))
3003	{
3004	/ If this is a faked mmapped chunk from the dumped main arena,*
3005	always make a copy (and do not free the old chunk). /*
3006	if (DUMPED_MAIN_ARENA_CHUNK (oldp))
3007	{
3008	/ Must alloc, copy, free. /
3009	void *newmem = __libc_malloc (bytes);
3010	if (newmem == `0`)
3011	return NULL;
3012	/ Copy as many bytes as are available from the old chunk*
3013	and fit into the new size. NB: The overhead for faked
3014	mmapped chunks is only SIZE_SZ, not 2 SIZE_SZ as for*
3015	regular mmapped chunks. /*
3016	if (bytes > oldsize - SIZE_SZ)
3017	bytes = oldsize - SIZE_SZ;
3018	memcpy (newmem, oldmem, bytes);
3019	return newmem;
3020	}
3021
3022	void *newmem;
3023
3024	#if HAVE_MREMAP
3025	newp = mremap_chunk (oldp, nb);
3026	if (newp)
3027	return chunk2mem (newp);
3028	#endif
3029	/ Note the extra SIZE_SZ overhead. /
3030	if (oldsize - SIZE_SZ >= nb)
3031	return oldmem; / do nothing /
3032
3033	/ Must alloc, copy, free. /
3034	newmem = __libc_malloc (bytes);
3035	if (newmem == `0`)
3036	return `0`; / propagate failure /
3037
3038	memcpy (newmem, oldmem, oldsize - `2` * SIZE_SZ);
3039	munmap_chunk (oldp);
3040	return newmem;
3041	}
3042
3043	__libc_lock_lock (ar_ptr->mutex);
3044
3045	newp = _int_realloc (ar_ptr, oldp, oldsize, nb);
3046
3047	__libc_lock_unlock (ar_ptr->mutex);
3048	assert (!newp \|\| chunk_is_mmapped (mem2chunk (newp)) \|\|
3049	ar_ptr == arena_for_chunk (mem2chunk (newp)));
3050
3051	if (newp == NULL)
3052	{
3053	/ Try harder to allocate memory in other arenas. /
3054	LIBC_PROBE (memory_realloc_retry, `2`, bytes, oldmem);
3055	newp = __libc_malloc (bytes);
3056	if (newp != NULL)
3057	{
3058	memcpy (newp, oldmem, oldsize - SIZE_SZ);
3059	_int_free (ar_ptr, oldp, `0`);
3060	}
3061	}
3062
3063	return newp;
3064	}
3065	libc_hidden_def (__libc_realloc)
3066
3067	void *
3068	__libc_memalign (size_t alignment, size_t bytes)
3069	{
3070	void *address = RETURN_ADDRESS (`0`);
3071	return _mid_memalign (alignment, bytes, address);
3072	}
3073
3074	static void *
3075	_mid_memalign (size_t alignment, size_t bytes, void *address)
3076	{
3077	mstate ar_ptr;
3078	void *p;
3079
3080	void (hook) (size_t, size_t, const void *) =
3081	atomic_forced_read (__memalign_hook);
3082	if (__builtin_expect (hook != NULL, `0`))
3083	return (*hook)(alignment, bytes, address);
3084
3085	/ If we need less alignment than we give anyway, just relay to malloc. /
3086	if (alignment <= MALLOC_ALIGNMENT)
3087	return __libc_malloc (bytes);
3088
3089	/ Otherwise, ensure that it is at least a minimum chunk size /
3090	if (alignment < MINSIZE)
3091	alignment = MINSIZE;
3092
3093	/ If the alignment is greater than SIZE_MAX / 2 + 1 it cannot be a*
3094	power of 2 and will cause overflow in the check below. /*
3095	if (alignment > SIZE_MAX / `2` + `1`)
3096	{
3097	__set_errno (EINVAL);
3098	return `0`;
3099	}
3100
3101	/ Check for overflow. /
3102	if (bytes > SIZE_MAX - alignment - MINSIZE)
3103	{
3104	__set_errno (ENOMEM);
3105	return `0`;
3106	}
3107
3108
3109	/ Make sure alignment is power of 2. /
3110	if (!powerof2 (alignment))
3111	{
3112	size_t a = MALLOC_ALIGNMENT * `2`;
3113	while (a < alignment)
3114	a <<= `1`;
3115	alignment = a;
3116	}
3117
3118	arena_get (ar_ptr, bytes + alignment + MINSIZE);
3119
3120	p = _int_memalign (ar_ptr, alignment, bytes);
3121	if (!p && ar_ptr != NULL)
3122	{
3123	LIBC_PROBE (memory_memalign_retry, `2`, bytes, alignment);
3124	ar_ptr = arena_get_retry (ar_ptr, bytes);
3125	p = _int_memalign (ar_ptr, alignment, bytes);
3126	}
3127
3128	if (ar_ptr != NULL)
3129	__libc_lock_unlock (ar_ptr->mutex);
3130
3131	assert (!p \|\| chunk_is_mmapped (mem2chunk (p)) \|\|
3132	ar_ptr == arena_for_chunk (mem2chunk (p)));
3133	return p;
3134	}
3135	/ For ISO C11. /
3136	weak_alias (__libc_memalign, aligned_alloc)
3137	libc_hidden_def (__libc_memalign)
3138
3139	void *
3140	__libc_valloc (size_t bytes)
3141	{
3142	if (__malloc_initialized < `0`)
3143	ptmalloc_init ();
3144
3145	void *address = RETURN_ADDRESS (`0`);
3146	size_t pagesize = GLRO (dl_pagesize);
3147	return _mid_memalign (pagesize, bytes, address);
3148	}
3149
3150	void *
3151	__libc_pvalloc (size_t bytes)
3152	{
3153	if (__malloc_initialized < `0`)
3154	ptmalloc_init ();
3155
3156	void *address = RETURN_ADDRESS (`0`);
3157	size_t pagesize = GLRO (dl_pagesize);
3158	size_t rounded_bytes = ALIGN_UP (bytes, pagesize);
3159
3160	/ Check for overflow. /
3161	if (bytes > SIZE_MAX - `2` * pagesize - MINSIZE)
3162	{
3163	__set_errno (ENOMEM);
3164	return `0`;
3165	}
3166
3167	return _mid_memalign (pagesize, rounded_bytes, address);
3168	}
3169
3170	void *
3171	__libc_calloc (size_t n, size_t elem_size)
3172	{
3173	mstate av;
3174	mchunkptr oldtop, p;
3175	INTERNAL_SIZE_T bytes, sz, csz, oldtopsize;
3176	void *mem;
3177	unsigned long clearsize;
3178	unsigned long nclears;
3179	INTERNAL_SIZE_T *d;
3180
3181	/ size_t is unsigned so the behavior on overflow is defined. /
3182	bytes = n * elem_size;
3183	#define HALF_INTERNAL_SIZE_T \
3184	(((INTERNAL_SIZE_T) 1) << (8 * sizeof (INTERNAL_SIZE_T) / 2))
3185	if (__builtin_expect ((n \| elem_size) >= HALF_INTERNAL_SIZE_T, `0`))
3186	{
3187	if (elem_size != `0` && bytes / elem_size != n)
3188	{
3189	__set_errno (ENOMEM);
3190	return `0`;
3191	}
3192	}
3193
3194	void (hook) (size_t, const void *) =
3195	atomic_forced_read (__malloc_hook);
3196	if (__builtin_expect (hook != NULL, `0`))
3197	{
3198	sz = bytes;
3199	mem = (*hook)(sz, RETURN_ADDRESS (`0`));
3200	if (mem == `0`)
3201	return `0`;
3202
3203	return memset (mem, `0`, sz);
3204	}
3205
3206	sz = bytes;
3207
3208	arena_get (av, sz);
3209	if (av)
3210	{
3211	/ Check if we hand out the top chunk, in which case there may be no*
3212	need to clear. /*
3213	#if MORECORE_CLEARS
3214	oldtop = top (av);
3215	oldtopsize = chunksize (top (av));
3216	# if MORECORE_CLEARS < 2
3217	/ Only newly allocated memory is guaranteed to be cleared. /
3218	if (av == &main_arena &&
3219	oldtopsize < mp_.sbrk_base + av->max_system_mem - (char *) oldtop)
3220	oldtopsize = (mp_.sbrk_base + av->max_system_mem - (char *) oldtop);
3221	# endif
3222	if (av != &main_arena)
3223	{
3224	heap_info *heap = heap_for_ptr (oldtop);
3225	if (oldtopsize < (char ) heap + heap->mprotect_size - (char* *) oldtop)
3226	oldtopsize = (char ) heap + heap->mprotect_size - (char* *) oldtop;
3227	}
3228	#endif
3229	}
3230	else
3231	{
3232	/ No usable arenas. /
3233	oldtop = `0`;
3234	oldtopsize = `0`;
3235	}
3236	mem = _int_malloc (av, sz);
3237
3238
3239	assert (!mem \|\| chunk_is_mmapped (mem2chunk (mem)) \|\|
3240	av == arena_for_chunk (mem2chunk (mem)));
3241
3242	if (mem == `0` && av != NULL)
3243	{
3244	LIBC_PROBE (memory_calloc_retry, `1`, sz);
3245	av = arena_get_retry (av, sz);
3246	mem = _int_malloc (av, sz);
3247	}
3248
3249	if (av != NULL)
3250	__libc_lock_unlock (av->mutex);
3251
3252	/ Allocation failed even after a retry. /
3253	if (mem == `0`)
3254	return `0`;
3255
3256	p = mem2chunk (mem);
3257
3258	/ Two optional cases in which clearing not necessary /
3259	if (chunk_is_mmapped (p))
3260	{
3261	if (__builtin_expect (perturb_byte, `0`))
3262	return memset (mem, `0`, sz);
3263
3264	return mem;
3265	}
3266
3267	csz = chunksize (p);
3268
3269	#if MORECORE_CLEARS
3270	if (perturb_byte == `0` && (p == oldtop && csz > oldtopsize))
3271	{
3272	/ clear only the bytes from non-freshly-sbrked memory /
3273	csz = oldtopsize;
3274	}
3275	#endif
3276
3277	/ Unroll clear of <= 36 bytes (72 if 8byte sizes). We know that*
3278	contents have an odd number of INTERNAL_SIZE_T-sized words;
3279	minimally 3. /*
3280	d = (INTERNAL_SIZE_T *) mem;
3281	clearsize = csz - SIZE_SZ;
3282	nclears = clearsize / sizeof (INTERNAL_SIZE_T);
3283	assert (nclears >= `3`);
3284
3285	if (nclears > `9`)
3286	return memset (d, `0`, clearsize);
3287
3288	else
3289	{
3290	*(d + `0`) = `0`;
3291	*(d + `1`) = `0`;
3292	*(d + `2`) = `0`;
3293	if (nclears > `4`)
3294	{
3295	*(d + `3`) = `0`;
3296	*(d + `4`) = `0`;
3297	if (nclears > `6`)
3298	{
3299	*(d + `5`) = `0`;
3300	*(d + `6`) = `0`;
3301	if (nclears > `8`)
3302	{
3303	*(d + `7`) = `0`;
3304	*(d + `8`) = `0`;
3305	}
3306	}
3307	}
3308	}
3309
3310	return mem;
3311	}
3312
3313	/*
3314	------------------------------ malloc ------------------------------
3315	*/
3316
3317	static void *
3318	_int_malloc (mstate av, size_t bytes)
3319	{
3320	INTERNAL_SIZE_T nb; / normalized request size /
3321	unsigned int idx; / associated bin index /
3322	mbinptr bin; / associated bin /
3323
3324	mchunkptr victim; / inspected/selected chunk /
3325	INTERNAL_SIZE_T size; / its size /
3326	int victim_index; / its bin index /
3327
3328	mchunkptr remainder; / remainder from a split /
3329	unsigned long remainder_size; / its size /
3330
3331	unsigned int block; / bit map traverser /
3332	unsigned int bit; / bit map traverser /
3333	unsigned int map; / current word of binmap /
3334
3335	mchunkptr fwd; / misc temp for linking /
3336	mchunkptr bck; / misc temp for linking /
3337
3338	const char *errstr = NULL;
3339
3340	/*
3341	Convert request size to internal form by adding SIZE_SZ bytes
3342	overhead plus possibly more to obtain necessary alignment and/or
3343	to obtain a size of at least MINSIZE, the smallest allocatable
3344	size. Also, checked_request2size traps (returning 0) request sizes
3345	that are so large that they wrap around zero when padded and
3346	aligned.
3347	*/
3348
3349	checked_request2size (bytes, nb);
3350
3351	/ There are no usable arenas. Fall back to sysmalloc to get a chunk from*
3352	mmap. /*
3353	if (__glibc_unlikely (av == NULL))
3354	{
3355	void *p = sysmalloc (nb, av);
3356	if (p != NULL)
3357	alloc_perturb (p, bytes);
3358	return p;
3359	}
3360
3361	/*
3362	If the size qualifies as a fastbin, first check corresponding bin.
3363	This code is safe to execute even if av is not yet initialized, so we
3364	can try it without checking, which saves some time on this fast path.
3365	*/
3366
3367	if ((unsigned long) (nb) <= (unsigned long) (get_max_fast ()))
3368	{
3369	idx = fastbin_index (nb);
3370	mfastbinptr *fb = &fastbin (av, idx);
3371	mchunkptr pp = *fb;
3372	do
3373	{
3374	victim = pp;
3375	if (victim == NULL)
3376	break;
3377	}
3378	while ((pp = catomic_compare_and_exchange_val_acq (fb, victim->fd, victim))
3379	!= victim);
3380	if (victim != `0`)
3381	{
3382	if (__builtin_expect (fastbin_index (chunksize (victim)) != idx, `0`))
3383	{
3384	errstr = "malloc(): memory corruption (fast)";
3385	errout:
3386	malloc_printerr (check_action, errstr, chunk2mem (victim), av);
3387	return NULL;
3388	}
3389	check_remalloced_chunk (av, victim, nb);
3390	void *p = chunk2mem (victim);
3391	alloc_perturb (p, bytes);
3392	return p;
3393	}
3394	}
3395
3396	/*
3397	If a small request, check regular bin. Since these "smallbins"
3398	hold one size each, no searching within bins is necessary.
3399	(For a large request, we need to wait until unsorted chunks are
3400	processed to find best fit. But for small ones, fits are exact
3401	anyway, so we can check now, which is faster.)
3402	*/
3403
3404	if (in_smallbin_range (nb))
3405	{
3406	idx = smallbin_index (nb);
3407	bin = bin_at (av, idx);
3408
3409	if ((victim = last (bin)) != bin)
3410	{
3411	if (victim == `0`) / initialization check /
3412	malloc_consolidate (av);
3413	else
3414	{
3415	bck = victim->bk;
3416	if (__glibc_unlikely (bck->fd != victim))
3417	{
3418	errstr = "malloc(): smallbin double linked list corrupted";
3419	goto errout;
3420	}
3421	set_inuse_bit_at_offset (victim, nb);
3422	bin->bk = bck;
3423	bck->fd = bin;
3424
3425	if (av != &main_arena)
3426	set_non_main_arena (victim);
3427	check_malloced_chunk (av, victim, nb);
3428	void *p = chunk2mem (victim);
3429	alloc_perturb (p, bytes);
3430	return p;
3431	}
3432	}
3433	}
3434
3435	/*
3436	If this is a large request, consolidate fastbins before continuing.
3437	While it might look excessive to kill all fastbins before
3438	even seeing if there is space available, this avoids
3439	fragmentation problems normally associated with fastbins.
3440	Also, in practice, programs tend to have runs of either small or
3441	large requests, but less often mixtures, so consolidation is not
3442	invoked all that often in most programs. And the programs that
3443	it is called frequently in otherwise tend to fragment.
3444	*/
3445
3446	else
3447	{
3448	idx = largebin_index (nb);
3449	if (have_fastchunks (av))
3450	malloc_consolidate (av);
3451	}
3452
3453	/*
3454	Process recently freed or remaindered chunks, taking one only if
3455	it is exact fit, or, if this a small request, the chunk is remainder from
3456	the most recent non-exact fit. Place other traversed chunks in
3457	bins. Note that this step is the only place in any routine where
3458	chunks are placed in bins.
3459
3460	The outer loop here is needed because we might not realize until
3461	near the end of malloc that we should have consolidated, so must
3462	do so and retry. This happens at most once, and only when we would
3463	otherwise need to expand memory to service a "small" request.
3464	*/
3465
3466	for (;; )
3467	{
3468	int iters = `0`;
3469	while ((victim = unsorted_chunks (av)->bk) != unsorted_chunks (av))
3470	{
3471	bck = victim->bk;
3472	if (__builtin_expect (chunksize_nomask (victim) <= `2` * SIZE_SZ, `0`)
3473	\|\| __builtin_expect (chunksize_nomask (victim)
3474	> av->system_mem, `0`))
3475	malloc_printerr (check_action, "malloc(): memory corruption",
3476	chunk2mem (victim), av);
3477	size = chunksize (victim);
3478
3479	/*
3480	If a small request, try to use last remainder if it is the
3481	only chunk in unsorted bin. This helps promote locality for
3482	runs of consecutive small requests. This is the only
3483	exception to best-fit, and applies only when there is
3484	no exact fit for a small chunk.
3485	*/
3486
3487	if (in_smallbin_range (nb) &&
3488	bck == unsorted_chunks (av) &&
3489	victim == av->last_remainder &&
3490	(unsigned long) (size) > (unsigned long) (nb + MINSIZE))
3491	{
3492	/ split and reattach remainder /
3493	remainder_size = size - nb;
3494	remainder = chunk_at_offset (victim, nb);
3495	unsorted_chunks (av)->bk = unsorted_chunks (av)->fd = remainder;
3496	av->last_remainder = remainder;
3497	remainder->bk = remainder->fd = unsorted_chunks (av);
3498	if (!in_smallbin_range (remainder_size))
3499	{
3500	remainder->fd_nextsize = NULL;
3501	remainder->bk_nextsize = NULL;
3502	}
3503
3504	set_head (victim, nb \| PREV_INUSE \|
3505	(av != &main_arena ? NON_MAIN_ARENA : `0`));
3506	set_head (remainder, remainder_size \| PREV_INUSE);
3507	set_foot (remainder, remainder_size);
3508
3509	check_malloced_chunk (av, victim, nb);
3510	void *p = chunk2mem (victim);
3511	alloc_perturb (p, bytes);
3512	return p;
3513	}
3514
3515	/ remove from unsorted list /
3516	unsorted_chunks (av)->bk = bck;
3517	bck->fd = unsorted_chunks (av);
3518
3519	/ Take now instead of binning if exact fit /
3520
3521	if (size == nb)
3522	{
3523	set_inuse_bit_at_offset (victim, size);
3524	if (av != &main_arena)
3525	set_non_main_arena (victim);
3526	check_malloced_chunk (av, victim, nb);
3527	void *p = chunk2mem (victim);
3528	alloc_perturb (p, bytes);
3529	return p;
3530	}
3531
3532	/ place chunk in bin /
3533
3534	if (in_smallbin_range (size))
3535	{
3536	victim_index = smallbin_index (size);
3537	bck = bin_at (av, victim_index);
3538	fwd = bck->fd;
3539	}
3540	else
3541	{
3542	victim_index = largebin_index (size);
3543	bck = bin_at (av, victim_index);
3544	fwd = bck->fd;
3545
3546	/ maintain large bins in sorted order /
3547	if (fwd != bck)
3548	{
3549	/ Or with inuse bit to speed comparisons /
3550	size \|= PREV_INUSE;
3551	/ if smaller than smallest, bypass loop below /
3552	assert (chunk_main_arena (bck->bk));
3553	if ((unsigned long) (size)
3554	< (unsigned long) chunksize_nomask (bck->bk))
3555	{
3556	fwd = bck;
3557	bck = bck->bk;
3558
3559	victim->fd_nextsize = fwd->fd;
3560	victim->bk_nextsize = fwd->fd->bk_nextsize;
3561	fwd->fd->bk_nextsize = victim->bk_nextsize->fd_nextsize = victim;
3562	}
3563	else
3564	{
3565	assert (chunk_main_arena (fwd));
3566	while ((unsigned long) size < chunksize_nomask (fwd))
3567	{
3568	fwd = fwd->fd_nextsize;
3569	assert (chunk_main_arena (fwd));
3570	}
3571
3572	if ((unsigned long) size
3573	== (unsigned long) chunksize_nomask (fwd))
3574	/ Always insert in the second position. /
3575	fwd = fwd->fd;
3576	else
3577	{
3578	victim->fd_nextsize = fwd;
3579	victim->bk_nextsize = fwd->bk_nextsize;
3580	fwd->bk_nextsize = victim;
3581	victim->bk_nextsize->fd_nextsize = victim;
3582	}
3583	bck = fwd->bk;
3584	}
3585	}
3586	else
3587	victim->fd_nextsize = victim->bk_nextsize = victim;
3588	}
3589
3590	mark_bin (av, victim_index);
3591	victim->bk = bck;
3592	victim->fd = fwd;
3593	fwd->bk = victim;
3594	bck->fd = victim;
3595
3596	#define MAX_ITERS 10000
3597	if (++iters >= MAX_ITERS)
3598	break;
3599	}
3600
3601	/*
3602	If a large request, scan through the chunks of current bin in
3603	sorted order to find smallest that fits. Use the skip list for this.
3604	*/
3605
3606	if (!in_smallbin_range (nb))
3607	{
3608	bin = bin_at (av, idx);
3609
3610	/ skip scan if empty or largest chunk is too small /
3611	if ((victim = first (bin)) != bin
3612	&& (unsigned long) chunksize_nomask (victim)
3613	>= (unsigned long) (nb))
3614	{
3615	victim = victim->bk_nextsize;
3616	while (((unsigned long) (size = chunksize (victim)) <
3617	(unsigned long) (nb)))
3618	victim = victim->bk_nextsize;
3619
3620	/ Avoid removing the first entry for a size so that the skip*
3621	list does not have to be rerouted. /*
3622	if (victim != last (bin)
3623	&& chunksize_nomask (victim)
3624	== chunksize_nomask (victim->fd))
3625	victim = victim->fd;
3626
3627	remainder_size = size - nb;
3628	unlink (av, victim, bck, fwd);
3629
3630	/ Exhaust /
3631	if (remainder_size < MINSIZE)
3632	{
3633	set_inuse_bit_at_offset (victim, size);
3634	if (av != &main_arena)
3635	set_non_main_arena (victim);
3636	}
3637	/ Split /
3638	else
3639	{
3640	remainder = chunk_at_offset (victim, nb);
3641	/ We cannot assume the unsorted list is empty and therefore*
3642	have to perform a complete insert here. /*
3643	bck = unsorted_chunks (av);
3644	fwd = bck->fd;
3645	if (__glibc_unlikely (fwd->bk != bck))
3646	{
3647	errstr = "malloc(): corrupted unsorted chunks";
3648	goto errout;
3649	}
3650	remainder->bk = bck;
3651	remainder->fd = fwd;
3652	bck->fd = remainder;
3653	fwd->bk = remainder;
3654	if (!in_smallbin_range (remainder_size))
3655	{
3656	remainder->fd_nextsize = NULL;
3657	remainder->bk_nextsize = NULL;
3658	}
3659	set_head (victim, nb \| PREV_INUSE \|
3660	(av != &main_arena ? NON_MAIN_ARENA : `0`));
3661	set_head (remainder, remainder_size \| PREV_INUSE);
3662	set_foot (remainder, remainder_size);
3663	}
3664	check_malloced_chunk (av, victim, nb);
3665	void *p = chunk2mem (victim);
3666	alloc_perturb (p, bytes);
3667	return p;
3668	}
3669	}
3670
3671	/*
3672	Search for a chunk by scanning bins, starting with next largest
3673	bin. This search is strictly by best-fit; i.e., the smallest
3674	(with ties going to approximately the least recently used) chunk
3675	that fits is selected.
3676
3677	The bitmap avoids needing to check that most blocks are nonempty.
3678	The particular case of skipping all bins during warm-up phases
3679	when no chunks have been returned yet is faster than it might look.
3680	*/
3681
3682	++idx;
3683	bin = bin_at (av, idx);
3684	block = idx2block (idx);
3685	map = av->binmap[block];
3686	bit = idx2bit (idx);
3687
3688	for (;; )
3689	{
3690	/ Skip rest of block if there are no more set bits in this block. /
3691	if (bit > map \|\| bit == `0`)
3692	{
3693	do
3694	{
3695	if (++block >= BINMAPSIZE) / out of bins /
3696	goto use_top;
3697	}
3698	while ((map = av->binmap[block]) == `0`);
3699
3700	bin = bin_at (av, (block << BINMAPSHIFT));
3701	bit = `1`;
3702	}
3703
3704	/ Advance to bin with set bit. There must be one. /
3705	while ((bit & map) == `0`)
3706	{
3707	bin = next_bin (bin);
3708	bit <<= `1`;
3709	assert (bit != `0`);
3710	}
3711
3712	/ Inspect the bin. It is likely to be non-empty /
3713	victim = last (bin);
3714
3715	/ If a false alarm (empty bin), clear the bit. /
3716	if (victim == bin)
3717	{
3718	av->binmap[block] = map &= ~bit; / Write through /
3719	bin = next_bin (bin);
3720	bit <<= `1`;
3721	}
3722
3723	else
3724	{
3725	size = chunksize (victim);
3726
3727	/ We know the first chunk in this bin is big enough to use. /
3728	assert ((unsigned long) (size) >= (unsigned long) (nb));
3729
3730	remainder_size = size - nb;
3731
3732	/ unlink /
3733	unlink (av, victim, bck, fwd);
3734
3735	/ Exhaust /
3736	if (remainder_size < MINSIZE)
3737	{
3738	set_inuse_bit_at_offset (victim, size);
3739	if (av != &main_arena)
3740	set_non_main_arena (victim);
3741	}
3742
3743	/ Split /
3744	else
3745	{
3746	remainder = chunk_at_offset (victim, nb);
3747
3748	/ We cannot assume the unsorted list is empty and therefore*
3749	have to perform a complete insert here. /*
3750	bck = unsorted_chunks (av);
3751	fwd = bck->fd;
3752	if (__glibc_unlikely (fwd->bk != bck))
3753	{
3754	errstr = "malloc(): corrupted unsorted chunks 2";
3755	goto errout;
3756	}
3757	remainder->bk = bck;
3758	remainder->fd = fwd;
3759	bck->fd = remainder;
3760	fwd->bk = remainder;
3761
3762	/ advertise as last remainder /
3763	if (in_smallbin_range (nb))
3764	av->last_remainder = remainder;
3765	if (!in_smallbin_range (remainder_size))
3766	{
3767	remainder->fd_nextsize = NULL;
3768	remainder->bk_nextsize = NULL;
3769	}
3770	set_head (victim, nb \| PREV_INUSE \|
3771	(av != &main_arena ? NON_MAIN_ARENA : `0`));
3772	set_head (remainder, remainder_size \| PREV_INUSE);
3773	set_foot (remainder, remainder_size);
3774	}
3775	check_malloced_chunk (av, victim, nb);
3776	void *p = chunk2mem (victim);
3777	alloc_perturb (p, bytes);
3778	return p;
3779	}
3780	}
3781
3782	use_top:
3783	/*
3784	If large enough, split off the chunk bordering the end of memory
3785	(held in av->top). Note that this is in accord with the best-fit
3786	search rule. In effect, av->top is treated as larger (and thus
3787	less well fitting) than any other available chunk since it can
3788	be extended to be as large as necessary (up to system
3789	limitations).
3790
3791	We require that av->top always exists (i.e., has size >=
3792	MINSIZE) after initialization, so if it would otherwise be
3793	exhausted by current request, it is replenished. (The main
3794	reason for ensuring it exists is that we may need MINSIZE space
3795	to put in fenceposts in sysmalloc.)
3796	*/
3797
3798	victim = av->top;
3799	size = chunksize (victim);
3800
3801	if ((unsigned long) (size) >= (unsigned long) (nb + MINSIZE))
3802	{
3803	remainder_size = size - nb;
3804	remainder = chunk_at_offset (victim, nb);
3805	av->top = remainder;
3806	set_head (victim, nb \| PREV_INUSE \|
3807	(av != &main_arena ? NON_MAIN_ARENA : `0`));
3808	set_head (remainder, remainder_size \| PREV_INUSE);
3809
3810	check_malloced_chunk (av, victim, nb);
3811	void *p = chunk2mem (victim);
3812	alloc_perturb (p, bytes);
3813	return p;
3814	}
3815
3816	/ When we are using atomic ops to free fast chunks we can get*
3817	here for all block sizes. /*
3818	else if (have_fastchunks (av))
3819	{
3820	malloc_consolidate (av);
3821	/ restore original bin index /
3822	if (in_smallbin_range (nb))
3823	idx = smallbin_index (nb);
3824	else
3825	idx = largebin_index (nb);
3826	}
3827
3828	/*
3829	Otherwise, relay to handle system-dependent cases
3830	*/
3831	else
3832	{
3833	void *p = sysmalloc (nb, av);
3834	if (p != NULL)
3835	alloc_perturb (p, bytes);
3836	return p;
3837	}
3838	}
3839	}
3840
3841	/*
3842	------------------------------ free ------------------------------
3843	*/
3844
3845	static void
3846	_int_free (mstate av, mchunkptr p, int have_lock)
3847	{
3848	INTERNAL_SIZE_T size; / its size /
3849	mfastbinptr fb; /* associated fastbin /
3850	mchunkptr nextchunk; / next contiguous chunk /
3851	INTERNAL_SIZE_T nextsize; / its size /
3852	int nextinuse; / true if nextchunk is used /
3853	INTERNAL_SIZE_T prevsize; / size of previous contiguous chunk /
3854	mchunkptr bck; / misc temp for linking /
3855	mchunkptr fwd; / misc temp for linking /
3856
3857	const char *errstr = NULL;
3858	int locked = `0`;
3859
3860	size = chunksize (p);
3861
3862	/ Little security check which won't hurt performance: the*
3863	allocator never wrapps around at the end of the address space.
3864	Therefore we can exclude some size values which might appear
3865	here by accident or by "design" from some intruder. /*
3866	if (__builtin_expect ((uintptr_t) p > (uintptr_t) -size, `0`)
3867	\|\| __builtin_expect (misaligned_chunk (p), `0`))
3868	{
3869	errstr = "free(): invalid pointer";
3870	errout:
3871	if (!have_lock && locked)
3872	__libc_lock_unlock (av->mutex);
3873	malloc_printerr (check_action, errstr, chunk2mem (p), av);
3874	return;
3875	}
3876	/ We know that each chunk is at least MINSIZE bytes in size or a*
3877	multiple of MALLOC_ALIGNMENT. /*
3878	if (__glibc_unlikely (size < MINSIZE \|\| !aligned_OK (size)))
3879	{
3880	errstr = "free(): invalid size";
3881	goto errout;
3882	}
3883
3884	check_inuse_chunk(av, p);
3885
3886	/*
3887	If eligible, place chunk on a fastbin so it can be found
3888	and used quickly in malloc.
3889	*/
3890
3891	if ((unsigned long)(size) <= (unsigned long)(get_max_fast ())
3892
3893	#if TRIM_FASTBINS
3894	/*
3895	If TRIM_FASTBINS set, don't place chunks
3896	bordering top into fastbins
3897	*/
3898	&& (chunk_at_offset(p, size) != av->top)
3899	#endif
3900	) {
3901
3902	if (__builtin_expect (chunksize_nomask (chunk_at_offset (p, size))
3903	<= `2` * SIZE_SZ, `0`)
3904	\|\| __builtin_expect (chunksize (chunk_at_offset (p, size))
3905	>= av->system_mem, `0`))
3906	{
3907	/ We might not have a lock at this point and concurrent modifications*
3908	of system_mem might have let to a false positive. Redo the test
3909	after getting the lock. /*
3910	if (have_lock
3911	\|\| ({ assert (locked == `0`);
3912	__libc_lock_lock (av->mutex);
3913	locked = `1`;
3914	chunksize_nomask (chunk_at_offset (p, size)) <= `2` * SIZE_SZ
3915	\|\| chunksize (chunk_at_offset (p, size)) >= av->system_mem;
3916	}))
3917	{
3918	errstr = "free(): invalid next size (fast)";
3919	goto errout;
3920	}
3921	if (! have_lock)
3922	{
3923	__libc_lock_unlock (av->mutex);
3924	locked = `0`;
3925	}
3926	}
3927
3928	free_perturb (chunk2mem(p), size - `2` * SIZE_SZ);
3929
3930	set_fastchunks(av);
3931	unsigned int idx = fastbin_index(size);
3932	fb = &fastbin (av, idx);
3933
3934	/ Atomically link P to its fastbin: P->FD = FB; FB = P; /
3935	mchunkptr old = *fb, old2;
3936	unsigned int old_idx = ~`0u`;
3937	do
3938	{
3939	/ Check that the top of the bin is not the record we are going to add*
3940	(i.e., double free). /*
3941	if (__builtin_expect (old == p, `0`))
3942	{
3943	errstr = "double free or corruption (fasttop)";
3944	goto errout;
3945	}
3946	/ Check that size of fastbin chunk at the top is the same as*
3947	size of the chunk that we are adding. We can dereference OLD
3948	only if we have the lock, otherwise it might have already been
3949	deallocated. See use of OLD_IDX below for the actual check. /*
3950	if (have_lock && old != NULL)
3951	old_idx = fastbin_index(chunksize(old));
3952	p->fd = old2 = old;
3953	}
3954	while ((old = catomic_compare_and_exchange_val_rel (fb, p, old2)) != old2);
3955
3956	if (have_lock && old != NULL && __builtin_expect (old_idx != idx, `0`))
3957	{
3958	errstr = "invalid fastbin entry (free)";
3959	goto errout;
3960	}
3961	}
3962
3963	/*
3964	Consolidate other non-mmapped chunks as they arrive.
3965	*/
3966
3967	else if (!chunk_is_mmapped(p)) {
3968	if (! have_lock) {
3969	__libc_lock_lock (av->mutex);
3970	locked = `1`;
3971	}
3972
3973	nextchunk = chunk_at_offset(p, size);
3974
3975	/ Lightweight tests: check whether the block is already the*
3976	top block. /*
3977	if (__glibc_unlikely (p == av->top))
3978	{
3979	errstr = "double free or corruption (top)";
3980	goto errout;
3981	}
3982	/ Or whether the next chunk is beyond the boundaries of the arena. /
3983	if (__builtin_expect (contiguous (av)
3984	&& (char *) nextchunk
3985	>= ((char *) av->top + chunksize(av->top)), `0`))
3986	{
3987	errstr = "double free or corruption (out)";
3988	goto errout;
3989	}
3990	/ Or whether the block is actually not marked used. /
3991	if (__glibc_unlikely (!prev_inuse(nextchunk)))
3992	{
3993	errstr = "double free or corruption (!prev)";
3994	goto errout;
3995	}
3996
3997	nextsize = chunksize(nextchunk);
3998	if (__builtin_expect (chunksize_nomask (nextchunk) <= `2` * SIZE_SZ, `0`)
3999	\|\| __builtin_expect (nextsize >= av->system_mem, `0`))
4000	{
4001	errstr = "free(): invalid next size (normal)";
4002	goto errout;
4003	}
4004
4005	free_perturb (chunk2mem(p), size - `2` * SIZE_SZ);
4006
4007	/ consolidate backward /
4008	if (!prev_inuse(p)) {
4009	prevsize = prev_size (p);
4010	size += prevsize;
4011	p = chunk_at_offset(p, -((long) prevsize));
4012	unlink(av, p, bck, fwd);
4013	}
4014
4015	if (nextchunk != av->top) {
4016	/ get and clear inuse bit /
4017	nextinuse = inuse_bit_at_offset(nextchunk, nextsize);
4018
4019	/ consolidate forward /
4020	if (!nextinuse) {
4021	unlink(av, nextchunk, bck, fwd);
4022	size += nextsize;
4023	} else
4024	clear_inuse_bit_at_offset(nextchunk, `0`);
4025
4026	/*
4027	Place the chunk in unsorted chunk list. Chunks are
4028	not placed into regular bins until after they have
4029	been given one chance to be used in malloc.
4030	*/
4031
4032	bck = unsorted_chunks(av);
4033	fwd = bck->fd;
4034	if (__glibc_unlikely (fwd->bk != bck))
4035	{
4036	errstr = "free(): corrupted unsorted chunks";
4037	goto errout;
4038	}
4039	p->fd = fwd;
4040	p->bk = bck;
4041	if (!in_smallbin_range(size))
4042	{
4043	p->fd_nextsize = NULL;
4044	p->bk_nextsize = NULL;
4045	}
4046	bck->fd = p;
4047	fwd->bk = p;
4048
4049	set_head(p, size \| PREV_INUSE);
4050	set_foot(p, size);
4051
4052	check_free_chunk(av, p);
4053	}
4054
4055	/*
4056	If the chunk borders the current high end of memory,
4057	consolidate into top
4058	*/
4059
4060	else {
4061	size += nextsize;
4062	set_head(p, size \| PREV_INUSE);
4063	av->top = p;
4064	check_chunk(av, p);
4065	}
4066
4067	/*
4068	If freeing a large space, consolidate possibly-surrounding
4069	chunks. Then, if the total unused topmost memory exceeds trim
4070	threshold, ask malloc_trim to reduce top.
4071
4072	Unless max_fast is 0, we don't know if there are fastbins
4073	bordering top, so we cannot tell for sure whether threshold
4074	has been reached unless fastbins are consolidated. But we
4075	don't want to consolidate on each free. As a compromise,
4076	consolidation is performed if FASTBIN_CONSOLIDATION_THRESHOLD
4077	is reached.
4078	*/
4079
4080	if ((unsigned long)(size) >= FASTBIN_CONSOLIDATION_THRESHOLD) {
4081	if (have_fastchunks(av))
4082	malloc_consolidate(av);
4083
4084	if (av == &main_arena) {
4085	#ifndef MORECORE_CANNOT_TRIM
4086	if ((unsigned long)(chunksize(av->top)) >=
4087	(unsigned long)(mp_.trim_threshold))
4088	systrim(mp_.top_pad, av);
4089	#endif
4090	} else {
4091	/ Always try heap_trim(), even if the top chunk is not*
4092	large, because the corresponding heap might go away. /*
4093	heap_info *heap = heap_for_ptr(top(av));
4094
4095	assert(heap->ar_ptr == av);
4096	heap_trim(heap, mp_.top_pad);
4097	}
4098	}
4099
4100	if (! have_lock) {
4101	assert (locked);
4102	__libc_lock_unlock (av->mutex);
4103	}
4104	}
4105	/*
4106	If the chunk was allocated via mmap, release via munmap().
4107	*/
4108
4109	else {
4110	munmap_chunk (p);
4111	}
4112	}
4113
4114	/*
4115	------------------------- malloc_consolidate -------------------------
4116
4117	malloc_consolidate is a specialized version of free() that tears
4118	down chunks held in fastbins. Free itself cannot be used for this
4119	purpose since, among other things, it might place chunks back onto
4120	fastbins. So, instead, we need to use a minor variant of the same
4121	code.
4122
4123	Also, because this routine needs to be called the first time through
4124	malloc anyway, it turns out to be the perfect place to trigger
4125	initialization code.
4126	*/
4127
4128	static void malloc_consolidate(mstate av)
4129	{
4130	mfastbinptr* fb; / current fastbin being consolidated /
4131	mfastbinptr* maxfb; / last fastbin (for loop control) /
4132	mchunkptr p; / current chunk being consolidated /
4133	mchunkptr nextp; / next chunk to consolidate /
4134	mchunkptr unsorted_bin; / bin header /
4135	mchunkptr first_unsorted; / chunk to link to /
4136
4137	/ These have same use as in free() /
4138	mchunkptr nextchunk;
4139	INTERNAL_SIZE_T size;
4140	INTERNAL_SIZE_T nextsize;
4141	INTERNAL_SIZE_T prevsize;
4142	int nextinuse;
4143	mchunkptr bck;
4144	mchunkptr fwd;
4145
4146	/*
4147	If max_fast is 0, we know that av hasn't
4148	yet been initialized, in which case do so below
4149	*/
4150
4151	if (get_max_fast () != `0`) {
4152	clear_fastchunks(av);
4153
4154	unsorted_bin = unsorted_chunks(av);
4155
4156	/*
4157	Remove each chunk from fast bin and consolidate it, placing it
4158	then in unsorted bin. Among other reasons for doing this,
4159	placing in unsorted bin avoids needing to calculate actual bins
4160	until malloc is sure that chunks aren't immediately going to be
4161	reused anyway.
4162	*/
4163
4164	maxfb = &fastbin (av, NFASTBINS - `1`);
4165	fb = &fastbin (av, `0`);
4166	do {
4167	p = atomic_exchange_acq (fb, NULL);
4168	if (p != `0`) {
4169	do {
4170	check_inuse_chunk(av, p);
4171	nextp = p->fd;
4172
4173	/ Slightly streamlined version of consolidation code in free() /
4174	size = chunksize (p);
4175	nextchunk = chunk_at_offset(p, size);
4176	nextsize = chunksize(nextchunk);
4177
4178	if (!prev_inuse(p)) {
4179	prevsize = prev_size (p);
4180	size += prevsize;
4181	p = chunk_at_offset(p, -((long) prevsize));
4182	unlink(av, p, bck, fwd);
4183	}
4184
4185	if (nextchunk != av->top) {
4186	nextinuse = inuse_bit_at_offset(nextchunk, nextsize);
4187
4188	if (!nextinuse) {
4189	size += nextsize;
4190	unlink(av, nextchunk, bck, fwd);
4191	} else
4192	clear_inuse_bit_at_offset(nextchunk, `0`);
4193
4194	first_unsorted = unsorted_bin->fd;
4195	unsorted_bin->fd = p;
4196	first_unsorted->bk = p;
4197
4198	if (!in_smallbin_range (size)) {
4199	p->fd_nextsize = NULL;
4200	p->bk_nextsize = NULL;
4201	}
4202
4203	set_head(p, size \| PREV_INUSE);
4204	p->bk = unsorted_bin;
4205	p->fd = first_unsorted;
4206	set_foot(p, size);
4207	}
4208
4209	else {
4210	size += nextsize;
4211	set_head(p, size \| PREV_INUSE);
4212	av->top = p;
4213	}
4214
4215	} while ( (p = nextp) != `0`);
4216
4217	}
4218	} while (fb++ != maxfb);
4219	}
4220	else {
4221	malloc_init_state(av);
4222	check_malloc_state(av);
4223	}
4224	}
4225
4226	/*
4227	------------------------------ realloc ------------------------------
4228	*/
4229
4230	void*
4231	_int_realloc(mstate av, mchunkptr oldp, INTERNAL_SIZE_T oldsize,
4232	INTERNAL_SIZE_T nb)
4233	{
4234	mchunkptr newp; / chunk to return /
4235	INTERNAL_SIZE_T newsize; / its size /
4236	void* newmem; / corresponding user mem /
4237
4238	mchunkptr next; / next contiguous chunk after oldp /
4239
4240	mchunkptr remainder; / extra space at end of newp /
4241	unsigned long remainder_size; / its size /
4242
4243	mchunkptr bck; / misc temp for linking /
4244	mchunkptr fwd; / misc temp for linking /
4245
4246	unsigned long copysize; / bytes to copy /
4247	unsigned int ncopies; / INTERNAL_SIZE_T words to copy /
4248	INTERNAL_SIZE_T* s; / copy source /
4249	INTERNAL_SIZE_T* d; / copy destination /
4250
4251	const char *errstr = NULL;
4252
4253	/ oldmem size /
4254	if (__builtin_expect (chunksize_nomask (oldp) <= `2` * SIZE_SZ, `0`)
4255	\|\| __builtin_expect (oldsize >= av->system_mem, `0`))
4256	{
4257	errstr = "realloc(): invalid old size";
4258	errout:
4259	malloc_printerr (check_action, errstr, chunk2mem (oldp), av);
4260	return NULL;
4261	}
4262
4263	check_inuse_chunk (av, oldp);
4264
4265	/ All callers already filter out mmap'ed chunks. /
4266	assert (!chunk_is_mmapped (oldp));
4267
4268	next = chunk_at_offset (oldp, oldsize);
4269	INTERNAL_SIZE_T nextsize = chunksize (next);
4270	if (__builtin_expect (chunksize_nomask (next) <= `2` * SIZE_SZ, `0`)
4271	\|\| __builtin_expect (nextsize >= av->system_mem, `0`))
4272	{
4273	errstr = "realloc(): invalid next size";
4274	goto errout;
4275	}
4276
4277	if ((unsigned long) (oldsize) >= (unsigned long) (nb))
4278	{
4279	/ already big enough; split below /
4280	newp = oldp;
4281	newsize = oldsize;
4282	}
4283
4284	else
4285	{
4286	/ Try to expand forward into top /
4287	if (next == av->top &&
4288	(unsigned long) (newsize = oldsize + nextsize) >=
4289	(unsigned long) (nb + MINSIZE))
4290	{
4291	set_head_size (oldp, nb \| (av != &main_arena ? NON_MAIN_ARENA : `0`));
4292	av->top = chunk_at_offset (oldp, nb);
4293	set_head (av->top, (newsize - nb) \| PREV_INUSE);
4294	check_inuse_chunk (av, oldp);
4295	return chunk2mem (oldp);
4296	}
4297
4298	/ Try to expand forward into next chunk; split off remainder below /
4299	else if (next != av->top &&
4300	!inuse (next) &&
4301	(unsigned long) (newsize = oldsize + nextsize) >=
4302	(unsigned long) (nb))
4303	{
4304	newp = oldp;
4305	unlink (av, next, bck, fwd);
4306	}
4307
4308	/ allocate, copy, free /
4309	else
4310	{
4311	newmem = _int_malloc (av, nb - MALLOC_ALIGN_MASK);
4312	if (newmem == `0`)
4313	return `0`; / propagate failure /
4314
4315	newp = mem2chunk (newmem);
4316	newsize = chunksize (newp);
4317
4318	/*
4319	Avoid copy if newp is next chunk after oldp.
4320	*/
4321	if (newp == next)
4322	{
4323	newsize += oldsize;
4324	newp = oldp;
4325	}
4326	else
4327	{
4328	/*
4329	Unroll copy of <= 36 bytes (72 if 8byte sizes)
4330	We know that contents have an odd number of
4331	INTERNAL_SIZE_T-sized words; minimally 3.
4332	*/
4333
4334	copysize = oldsize - SIZE_SZ;
4335	s = (INTERNAL_SIZE_T *) (chunk2mem (oldp));
4336	d = (INTERNAL_SIZE_T *) (newmem);
4337	ncopies = copysize / sizeof (INTERNAL_SIZE_T);
4338	assert (ncopies >= `3`);
4339
4340	if (ncopies > `9`)
4341	memcpy (d, s, copysize);
4342
4343	else
4344	{
4345	(d + `0`) = (s + `0`);
4346	(d + `1`) = (s + `1`);
4347	(d + `2`) = (s + `2`);
4348	if (ncopies > `4`)
4349	{
4350	(d + `3`) = (s + `3`);
4351	(d + `4`) = (s + `4`);
4352	if (ncopies > `6`)
4353	{
4354	(d + `5`) = (s + `5`);
4355	(d + `6`) = (s + `6`);
4356	if (ncopies > `8`)
4357	{
4358	(d + `7`) = (s + `7`);
4359	(d + `8`) = (s + `8`);
4360	}
4361	}
4362	}
4363	}
4364
4365	_int_free (av, oldp, `1`);
4366	check_inuse_chunk (av, newp);
4367	return chunk2mem (newp);
4368	}
4369	}
4370	}
4371
4372	/ If possible, free extra space in old or extended chunk /
4373
4374	assert ((unsigned long) (newsize) >= (unsigned long) (nb));
4375
4376	remainder_size = newsize - nb;
4377
4378	if (remainder_size < MINSIZE) / not enough extra to split off /
4379	{
4380	set_head_size (newp, newsize \| (av != &main_arena ? NON_MAIN_ARENA : `0`));
4381	set_inuse_bit_at_offset (newp, newsize);
4382	}
4383	else / split remainder /
4384	{
4385	remainder = chunk_at_offset (newp, nb);
4386	set_head_size (newp, nb \| (av != &main_arena ? NON_MAIN_ARENA : `0`));
4387	set_head (remainder, remainder_size \| PREV_INUSE \|
4388	(av != &main_arena ? NON_MAIN_ARENA : `0`));
4389	/ Mark remainder as inuse so free() won't complain /
4390	set_inuse_bit_at_offset (remainder, remainder_size);
4391	_int_free (av, remainder, `1`);
4392	}
4393
4394	check_inuse_chunk (av, newp);
4395	return chunk2mem (newp);
4396	}
4397
4398	/*
4399	------------------------------ memalign ------------------------------
4400	*/
4401
4402	static void *
4403	_int_memalign (mstate av, size_t alignment, size_t bytes)
4404	{
4405	INTERNAL_SIZE_T nb; / padded request size /
4406	char m; /* memory returned by malloc call /
4407	mchunkptr p; / corresponding chunk /
4408	char brk; /* alignment point within p /
4409	mchunkptr newp; / chunk to return /
4410	INTERNAL_SIZE_T newsize; / its size /
4411	INTERNAL_SIZE_T leadsize; / leading space before alignment point /
4412	mchunkptr remainder; / spare room at end to split off /
4413	unsigned long remainder_size; / its size /
4414	INTERNAL_SIZE_T size;
4415
4416
4417
4418	checked_request2size (bytes, nb);
4419
4420	/*
4421	Strategy: find a spot within that chunk that meets the alignment
4422	request, and then possibly free the leading and trailing space.
4423	*/
4424
4425
4426	/ Call malloc with worst case padding to hit alignment. /
4427
4428	m = (char *) (_int_malloc (av, nb + alignment + MINSIZE));
4429
4430	if (m == `0`)
4431	return `0`; / propagate failure /
4432
4433	p = mem2chunk (m);
4434
4435	if ((((unsigned long) (m)) % alignment) != `0`) / misaligned /
4436
4437	{ /*
4438	Find an aligned spot inside chunk. Since we need to give back
4439	leading space in a chunk of at least MINSIZE, if the first
4440	calculation places us at a spot with less than MINSIZE leader,
4441	we can move to the next aligned spot -- we've allocated enough
4442	total room so that this is always possible.
4443	*/
4444	brk = (char ) mem2chunk (((unsigned* long) (m + alignment - `1`)) &
4445	- ((signed long) alignment));
4446	if ((unsigned long) (brk - (char *) (p)) < MINSIZE)
4447	brk += alignment;
4448
4449	newp = (mchunkptr) brk;
4450	leadsize = brk - (char *) (p);
4451	newsize = chunksize (p) - leadsize;
4452
4453	/ For mmapped chunks, just adjust offset /
4454	if (chunk_is_mmapped (p))
4455	{
4456	set_prev_size (newp, prev_size (p) + leadsize);
4457	set_head (newp, newsize \| IS_MMAPPED);
4458	return chunk2mem (newp);
4459	}
4460
4461	/ Otherwise, give back leader, use the rest /
4462	set_head (newp, newsize \| PREV_INUSE \|
4463	(av != &main_arena ? NON_MAIN_ARENA : `0`));
4464	set_inuse_bit_at_offset (newp, newsize);
4465	set_head_size (p, leadsize \| (av != &main_arena ? NON_MAIN_ARENA : `0`));
4466	_int_free (av, p, `1`);
4467	p = newp;
4468
4469	assert (newsize >= nb &&
4470	(((unsigned long) (chunk2mem (p))) % alignment) == `0`);
4471	}
4472
4473	/ Also give back spare room at the end /
4474	if (!chunk_is_mmapped (p))
4475	{
4476	size = chunksize (p);
4477	if ((unsigned long) (size) > (unsigned long) (nb + MINSIZE))
4478	{
4479	remainder_size = size - nb;
4480	remainder = chunk_at_offset (p, nb);
4481	set_head (remainder, remainder_size \| PREV_INUSE \|
4482	(av != &main_arena ? NON_MAIN_ARENA : `0`));
4483	set_head_size (p, nb);
4484	_int_free (av, remainder, `1`);
4485	}
4486	}
4487
4488	check_inuse_chunk (av, p);
4489	return chunk2mem (p);
4490	}
4491
4492
4493	/*
4494	------------------------------ malloc_trim ------------------------------
4495	*/
4496
4497	static int
4498	mtrim (mstate av, size_t pad)
4499	{
4500	/ Don't touch corrupt arenas. /
4501	if (arena_is_corrupt (av))
4502	return `0`;
4503
4504	/ Ensure initialization/consolidation /
4505	malloc_consolidate (av);
4506
4507	const size_t ps = GLRO (dl_pagesize);
4508	int psindex = bin_index (ps);
4509	const size_t psm1 = ps - `1`;
4510
4511	int result = `0`;
4512	for (int i = `1`; i < NBINS; ++i)
4513	if (i == `1` \|\| i >= psindex)
4514	{
4515	mbinptr bin = bin_at (av, i);
4516
4517	for (mchunkptr p = last (bin); p != bin; p = p->bk)
4518	{
4519	INTERNAL_SIZE_T size = chunksize (p);
4520
4521	if (size > psm1 + sizeof (struct malloc_chunk))
4522	{
4523	/ See whether the chunk contains at least one unused page. /
4524	char paligned_mem = (char* *) (((uintptr_t) p
4525	+ sizeof (struct malloc_chunk)
4526	+ psm1) & ~psm1);
4527
4528	assert ((char ) chunk2mem (p) + `4` SIZE_SZ <= paligned_mem);
4529	assert ((char *) p + size > paligned_mem);
4530
4531	/ This is the size we could potentially free. /
4532	size -= paligned_mem - (char *) p;
4533
4534	if (size > psm1)
4535	{
4536	#if MALLOC_DEBUG
4537	/ When debugging we simulate destroying the memory*
4538	content. /*
4539	memset (paligned_mem, `0x89`, size & ~psm1);
4540	#endif
4541	__madvise (paligned_mem, size & ~psm1, MADV_DONTNEED);
4542
4543	result = `1`;
4544	}
4545	}
4546	}
4547	}
4548
4549	#ifndef MORECORE_CANNOT_TRIM
4550	return result \| (av == &main_arena ? systrim (pad, av) : `0`);
4551
4552	#else
4553	return result;
4554	#endif
4555	}
4556
4557
4558	int
4559	__malloc_trim (size_t s)
4560	{
4561	int result = `0`;
4562
4563	if (__malloc_initialized < `0`)
4564	ptmalloc_init ();
4565
4566	mstate ar_ptr = &main_arena;
4567	do
4568	{
4569	__libc_lock_lock (ar_ptr->mutex);
4570	result \|= mtrim (ar_ptr, s);
4571	__libc_lock_unlock (ar_ptr->mutex);
4572
4573	ar_ptr = ar_ptr->next;
4574	}
4575	while (ar_ptr != &main_arena);
4576
4577	return result;
4578	}
4579
4580
4581	/*
4582	------------------------- malloc_usable_size -------------------------
4583	*/
4584
4585	static size_t
4586	musable (void *mem)
4587	{
4588	mchunkptr p;
4589	if (mem != `0`)
4590	{
4591	p = mem2chunk (mem);
4592
4593	if (__builtin_expect (using_malloc_checking == `1`, `0`))
4594	return malloc_check_get_size (p);
4595
4596	if (chunk_is_mmapped (p))
4597	{
4598	if (DUMPED_MAIN_ARENA_CHUNK (p))
4599	return chunksize (p) - SIZE_SZ;
4600	else
4601	return chunksize (p) - `2` * SIZE_SZ;
4602	}
4603	else if (inuse (p))
4604	return chunksize (p) - SIZE_SZ;
4605	}
4606	return `0`;
4607	}
4608
4609
4610	size_t
4611	__malloc_usable_size (void *m)
4612	{
4613	size_t result;
4614
4615	result = musable (m);
4616	return result;
4617	}
4618
4619	/*
4620	------------------------------ mallinfo ------------------------------
4621	Accumulate malloc statistics for arena AV into M.
4622	*/
4623
4624	static void
4625	int_mallinfo (mstate av, struct mallinfo *m)
4626	{
4627	size_t i;
4628	mbinptr b;
4629	mchunkptr p;
4630	INTERNAL_SIZE_T avail;
4631	INTERNAL_SIZE_T fastavail;
4632	int nblocks;
4633	int nfastblocks;
4634
4635	/ Ensure initialization /
4636	if (av->top == `0`)
4637	malloc_consolidate (av);
4638
4639	check_malloc_state (av);
4640
4641	/ Account for top /
4642	avail = chunksize (av->top);
4643	nblocks = `1`; / top always exists /
4644
4645	/ traverse fastbins /
4646	nfastblocks = `0`;
4647	fastavail = `0`;
4648
4649	for (i = `0`; i < NFASTBINS; ++i)
4650	{
4651	for (p = fastbin (av, i); p != `0`; p = p->fd)
4652	{
4653	++nfastblocks;
4654	fastavail += chunksize (p);
4655	}
4656	}
4657
4658	avail += fastavail;
4659
4660	/ traverse regular bins /
4661	for (i = `1`; i < NBINS; ++i)
4662	{
4663	b = bin_at (av, i);
4664	for (p = last (b); p != b; p = p->bk)
4665	{
4666	++nblocks;
4667	avail += chunksize (p);
4668	}
4669	}
4670
4671	m->smblks += nfastblocks;
4672	m->ordblks += nblocks;
4673	m->fordblks += avail;
4674	m->uordblks += av->system_mem - avail;
4675	m->arena += av->system_mem;
4676	m->fsmblks += fastavail;
4677	if (av == &main_arena)
4678	{
4679	m->hblks = mp_.n_mmaps;
4680	m->hblkhd = mp_.mmapped_mem;
4681	m->usmblks = `0`;
4682	m->keepcost = chunksize (av->top);
4683	}
4684	}
4685
4686
4687	struct mallinfo
4688	__libc_mallinfo (void)
4689	{
4690	struct mallinfo m;
4691	mstate ar_ptr;
4692
4693	if (__malloc_initialized < `0`)
4694	ptmalloc_init ();
4695
4696	memset (&m, `0`, sizeof (m));
4697	ar_ptr = &main_arena;
4698	do
4699	{
4700	__libc_lock_lock (ar_ptr->mutex);
4701	int_mallinfo (ar_ptr, &m);
4702	__libc_lock_unlock (ar_ptr->mutex);
4703
4704	ar_ptr = ar_ptr->next;
4705	}
4706	while (ar_ptr != &main_arena);
4707
4708	return m;
4709	}
4710
4711	/*
4712	------------------------------ malloc_stats ------------------------------
4713	*/
4714
4715	void
4716	__malloc_stats (void)
4717	{
4718	int i;
4719	mstate ar_ptr;
4720	unsigned int in_use_b = mp_.mmapped_mem, system_b = in_use_b;
4721
4722	if (__malloc_initialized < `0`)
4723	ptmalloc_init ();
4724	_IO_flockfile (stderr);
4725	int old_flags2 = ((_IO_FILE *) stderr)->_flags2;
4726	((_IO_FILE *) stderr)->_flags2 \|= _IO_FLAGS2_NOTCANCEL;
4727	for (i = `0`, ar_ptr = &main_arena;; i++)
4728	{
4729	struct mallinfo mi;
4730
4731	memset (&mi, `0`, sizeof (mi));
4732	__libc_lock_lock (ar_ptr->mutex);
4733	int_mallinfo (ar_ptr, &mi);
4734	fprintf (stderr, "Arena %d:\n", i);
4735	fprintf (stderr, "system bytes = %10u\n", (unsigned int) mi.arena);
4736	fprintf (stderr, "in use bytes = %10u\n", (unsigned int) mi.uordblks);
4737	#if MALLOC_DEBUG > 1
4738	if (i > `0`)
4739	dump_heap (heap_for_ptr (top (ar_ptr)));
4740	#endif
4741	system_b += mi.arena;
4742	in_use_b += mi.uordblks;
4743	__libc_lock_unlock (ar_ptr->mutex);
4744	ar_ptr = ar_ptr->next;
4745	if (ar_ptr == &main_arena)
4746	break;
4747	}
4748	fprintf (stderr, "Total (incl. mmap):\n");
4749	fprintf (stderr, "system bytes = %10u\n", system_b);
4750	fprintf (stderr, "in use bytes = %10u\n", in_use_b);
4751	fprintf (stderr, "max mmap regions = %10u\n", (unsigned int) mp_.max_n_mmaps);
4752	fprintf (stderr, "max mmap bytes = %10lu\n",
4753	(unsigned long) mp_.max_mmapped_mem);
4754	((_IO_FILE *) stderr)->_flags2 \|= old_flags2;
4755	_IO_funlockfile (stderr);
4756	}
4757
4758
4759	/*
4760	------------------------------ mallopt ------------------------------
4761	*/
4762	static inline int
4763	__always_inline
4764	do_set_trim_threshold (size_t value)
4765	{
4766	LIBC_PROBE (memory_mallopt_trim_threshold, `3`, value, mp_.trim_threshold,
4767	mp_.no_dyn_threshold);
4768	mp_.trim_threshold = value;
4769	mp_.no_dyn_threshold = `1`;
4770	return `1`;
4771	}
4772
4773	static inline int
4774	__always_inline
4775	do_set_top_pad (size_t value)
4776	{
4777	LIBC_PROBE (memory_mallopt_top_pad, `3`, value, mp_.top_pad,
4778	mp_.no_dyn_threshold);
4779	mp_.top_pad = value;
4780	mp_.no_dyn_threshold = `1`;
4781	return `1`;
4782	}
4783
4784	static inline int
4785	__always_inline
4786	do_set_mmap_threshold (size_t value)
4787	{
4788	/ Forbid setting the threshold too high. /
4789	if (value <= HEAP_MAX_SIZE / `2`)
4790	{
4791	LIBC_PROBE (memory_mallopt_mmap_threshold, `3`, value, mp_.mmap_threshold,
4792	mp_.no_dyn_threshold);
4793	mp_.mmap_threshold = value;
4794	mp_.no_dyn_threshold = `1`;
4795	return `1`;
4796	}
4797	return `0`;
4798	}
4799
4800	static inline int
4801	__always_inline
4802	do_set_mmaps_max (int32_t value)
4803	{
4804	LIBC_PROBE (memory_mallopt_mmap_max, `3`, value, mp_.n_mmaps_max,
4805	mp_.no_dyn_threshold);
4806	mp_.n_mmaps_max = value;
4807	mp_.no_dyn_threshold = `1`;
4808	return `1`;
4809	}
4810
4811	static inline int
4812	__always_inline
4813	do_set_mallopt_check (int32_t value)
4814	{
4815	LIBC_PROBE (memory_mallopt_check_action, `2`, value, check_action);
4816	check_action = value;
4817	return `1`;
4818	}
4819
4820	static inline int
4821	__always_inline
4822	do_set_perturb_byte (int32_t value)
4823	{
4824	LIBC_PROBE (memory_mallopt_perturb, `2`, value, perturb_byte);
4825	perturb_byte = value;
4826	return `1`;
4827	}
4828
4829	static inline int
4830	__always_inline
4831	do_set_arena_test (size_t value)
4832	{
4833	LIBC_PROBE (memory_mallopt_arena_test, `2`, value, mp_.arena_test);
4834	mp_.arena_test = value;
4835	return `1`;
4836	}
4837
4838	static inline int
4839	__always_inline
4840	do_set_arena_max (size_t value)
4841	{
4842	LIBC_PROBE (memory_mallopt_arena_max, `2`, value, mp_.arena_max);
4843	mp_.arena_max = value;
4844	return `1`;
4845	}
4846
4847
4848	int
4849	__libc_mallopt (int param_number, int value)
4850	{
4851	mstate av = &main_arena;
4852	int res = `1`;
4853
4854	if (__malloc_initialized < `0`)
4855	ptmalloc_init ();
4856	__libc_lock_lock (av->mutex);
4857	/ Ensure initialization/consolidation /
4858	malloc_consolidate (av);
4859
4860	LIBC_PROBE (memory_mallopt, `2`, param_number, value);
4861
4862	switch (param_number)
4863	{
4864	case M_MXFAST:
4865	if (value >= `0` && value <= MAX_FAST_SIZE)
4866	{
4867	LIBC_PROBE (memory_mallopt_mxfast, `2`, value, get_max_fast ());
4868	set_max_fast (value);
4869	}
4870	else
4871	res = `0`;
4872	break;
4873
4874	case M_TRIM_THRESHOLD:
4875	do_set_trim_threshold (value);
4876	break;
4877
4878	case M_TOP_PAD:
4879	do_set_top_pad (value);
4880	break;
4881
4882	case M_MMAP_THRESHOLD:
4883	res = do_set_mmap_threshold (value);
4884	break;
4885
4886	case M_MMAP_MAX:
4887	do_set_mmaps_max (value);
4888	break;
4889
4890	case M_CHECK_ACTION:
4891	do_set_mallopt_check (value);
4892	break;
4893
4894	case M_PERTURB:
4895	do_set_perturb_byte (value);
4896	break;
4897
4898	case M_ARENA_TEST:
4899	if (value > `0`)
4900	do_set_arena_test (value);
4901	break;
4902
4903	case M_ARENA_MAX:
4904	if (value > `0`)
4905	do_set_arena_test (value);
4906	break;
4907	}
4908	__libc_lock_unlock (av->mutex);
4909	return res;
4910	}
4911	libc_hidden_def (__libc_mallopt)
4912
4913
4914	/*
4915	-------------------- Alternative MORECORE functions --------------------
4916	*/
4917
4918
4919	/*
4920	General Requirements for MORECORE.
4921
4922	The MORECORE function must have the following properties:
4923
4924	If MORECORE_CONTIGUOUS is false:
4925
4926	* MORECORE must allocate in multiples of pagesize. It will
4927	only be called with arguments that are multiples of pagesize.
4928
4929	* MORECORE(0) must return an address that is at least
4930	MALLOC_ALIGNMENT aligned. (Page-aligning always suffices.)
4931
4932	else (i.e. If MORECORE_CONTIGUOUS is true):
4933
4934	* Consecutive calls to MORECORE with positive arguments
4935	return increasing addresses, indicating that space has been
4936	contiguously extended.
4937
4938	* MORECORE need not allocate in multiples of pagesize.
4939	Calls to MORECORE need not have args of multiples of pagesize.
4940
4941	* MORECORE need not page-align.
4942
4943	In either case:
4944
4945	* MORECORE may allocate more memory than requested. (Or even less,
4946	but this will generally result in a malloc failure.)
4947
4948	* MORECORE must not allocate memory when given argument zero, but
4949	instead return one past the end address of memory from previous
4950	nonzero call. This malloc does NOT call MORECORE(0)
4951	until at least one call with positive arguments is made, so
4952	the initial value returned is not important.
4953
4954	* Even though consecutive calls to MORECORE need not return contiguous
4955	addresses, it must be OK for malloc'ed chunks to span multiple
4956	regions in those cases where they do happen to be contiguous.
4957
4958	* MORECORE need not handle negative arguments -- it may instead
4959	just return MORECORE_FAILURE when given negative arguments.
4960	Negative arguments are always multiples of pagesize. MORECORE
4961	must not misinterpret negative args as large positive unsigned
4962	args. You can suppress all such calls from even occurring by defining
4963	MORECORE_CANNOT_TRIM,
4964
4965	There is some variation across systems about the type of the
4966	argument to sbrk/MORECORE. If size_t is unsigned, then it cannot
4967	actually be size_t, because sbrk supports negative args, so it is
4968	normally the signed type of the same width as size_t (sometimes
4969	declared as "intptr_t", and sometimes "ptrdiff_t"). It doesn't much
4970	matter though. Internally, we use "long" as arguments, which should
4971	work across all reasonable possibilities.
4972
4973	Additionally, if MORECORE ever returns failure for a positive
4974	request, then mmap is used as a noncontiguous system allocator. This
4975	is a useful backup strategy for systems with holes in address spaces
4976	-- in this case sbrk cannot contiguously expand the heap, but mmap
4977	may be able to map noncontiguous space.
4978
4979	If you'd like mmap to ALWAYS be used, you can define MORECORE to be
4980	a function that always returns MORECORE_FAILURE.
4981
4982	If you are using this malloc with something other than sbrk (or its
4983	emulation) to supply memory regions, you probably want to set
4984	MORECORE_CONTIGUOUS as false. As an example, here is a custom
4985	allocator kindly contributed for pre-OSX macOS. It uses virtually
4986	but not necessarily physically contiguous non-paged memory (locked
4987	in, present and won't get swapped out). You can use it by
4988	uncommenting this section, adding some #includes, and setting up the
4989	appropriate defines above:
4990
4991	*#define MORECORE osMoreCore
4992	*#define MORECORE_CONTIGUOUS 0
4993
4994	There is also a shutdown routine that should somehow be called for
4995	cleanup upon program exit.
4996
4997	*#define MAX_POOL_ENTRIES 100
4998	#define MINIMUM_MORECORE_SIZE (64 1024)
4999	static int next_os_pool;
5000	void our_os_pools[MAX_POOL_ENTRIES];*
5001
5002	void osMoreCore(int size)*
5003	{
5004	void ptr = 0;*
5005	static void sbrk_top = 0;*
5006
5007	if (size > 0)
5008	{
5009	if (size < MINIMUM_MORECORE_SIZE)
5010	size = MINIMUM_MORECORE_SIZE;
5011	if (CurrentExecutionLevel() == kTaskLevel)
5012	ptr = PoolAllocateResident(size + RM_PAGE_SIZE, 0);
5013	if (ptr == 0)
5014	{
5015	return (void ) MORECORE_FAILURE;*
5016	}
5017	// save ptrs so they can be freed during cleanup
5018	our_os_pools[next_os_pool] = ptr;
5019	next_os_pool++;
5020	ptr = (void ) ((((unsigned long) ptr) + RM_PAGE_MASK) & ~RM_PAGE_MASK);*
5021	sbrk_top = (char ) ptr + size;*
5022	return ptr;
5023	}
5024	else if (size < 0)
5025	{
5026	// we don't currently support shrink behavior
5027	return (void ) MORECORE_FAILURE;*
5028	}
5029	else
5030	{
5031	return sbrk_top;
5032	}
5033	}
5034
5035	// cleanup any allocated memory pools
5036	// called as last thing before shutting down driver
5037
5038	void osCleanupMem(void)
5039	{
5040	void ptr;
5041
5042	for (ptr = our_os_pools; ptr < &our_os_pools[MAX_POOL_ENTRIES]; ptr++)
5043	if (ptr)*
5044	{
5045	PoolDeallocate(ptr);*
5046	* ptr = 0;
5047	}
5048	}
5049
5050	*/
5051
5052
5053	/ Helper code. /
5054
5055	extern char **__libc_argv attribute_hidden;
5056
5057	static void
5058	malloc_printerr (int action, const char str, void* *ptr, mstate ar_ptr)
5059	{
5060	/ Avoid using this arena in future. We do not attempt to synchronize this*
5061	with anything else because we minimally want to ensure that __libc_message
5062	gets its resources safely without stumbling on the current corruption. /*
5063	if (ar_ptr)
5064	set_arena_corrupt (ar_ptr);
5065
5066	if ((action & `5`) == `5`)
5067	__libc_message (action & `2`, "%s\n", str);
5068	else if (action & `1`)
5069	{
5070	char buf[`2` * sizeof (uintptr_t) + `1`];
5071
5072	buf[sizeof (buf) - `1`] = `'\0'`;
5073	char cp = _itoa_word ((uintptr_t) ptr, &buf[sizeof* (buf) - `1`], `16`, `0`);
5074	while (cp > buf)
5075	*--cp = `'0'`;
5076
5077	__libc_message (action & `2`, "* Error in `%s': %s: 0x%s *\n",
5078	__libc_argv[`0`] ? : "<unknown>", str, cp);
5079	}
5080	else if (action & `2`)
5081	abort ();
5082	}
5083
5084	/ We need a wrapper function for one of the additions of POSIX. /
5085	int
5086	__posix_memalign (void **memptr, size_t alignment, size_t size)
5087	{
5088	void *mem;
5089
5090	/ Test whether the SIZE argument is valid. It must be a power of*
5091	two multiple of sizeof (void ). /
5092	if (alignment % sizeof (void *) != `0`
5093	\|\| !powerof2 (alignment / sizeof (void *))
5094	\|\| alignment == `0`)
5095	return EINVAL;
5096
5097
5098	void *address = RETURN_ADDRESS (`0`);
5099	mem = _mid_memalign (alignment, size, address);
5100
5101	if (mem != NULL)
5102	{
5103	*memptr = mem;
5104	return `0`;
5105	}
5106
5107	return ENOMEM;
5108	}
5109	weak_alias (__posix_memalign, posix_memalign)
5110
5111
5112	int
5113	__malloc_info (int options, FILE *fp)
5114	{
5115	/ For now, at least. /
5116	if (options != `0`)
5117	return EINVAL;
5118
5119	int n = `0`;
5120	size_t total_nblocks = `0`;
5121	size_t total_nfastblocks = `0`;
5122	size_t total_avail = `0`;
5123	size_t total_fastavail = `0`;
5124	size_t total_system = `0`;
5125	size_t total_max_system = `0`;
5126	size_t total_aspace = `0`;
5127	size_t total_aspace_mprotect = `0`;
5128
5129
5130
5131	if (__malloc_initialized < `0`)
5132	ptmalloc_init ();
5133
5134	fputs ("<malloc version=\"1\">\n", fp);
5135
5136	/ Iterate over all arenas currently in use. /
5137	mstate ar_ptr = &main_arena;
5138	do
5139	{
5140	fprintf (fp, "<heap nr=\"%d\">\n<sizes>\n", n++);
5141
5142	size_t nblocks = `0`;
5143	size_t nfastblocks = `0`;
5144	size_t avail = `0`;
5145	size_t fastavail = `0`;
5146	struct
5147	{
5148	size_t from;
5149	size_t to;
5150	size_t total;
5151	size_t count;
5152	} sizes[NFASTBINS + NBINS - `1`];
5153	#define nsizes (sizeof (sizes) / sizeof (sizes[0]))
5154
5155	__libc_lock_lock (ar_ptr->mutex);
5156
5157	for (size_t i = `0`; i < NFASTBINS; ++i)
5158	{
5159	mchunkptr p = fastbin (ar_ptr, i);
5160	if (p != NULL)
5161	{
5162	size_t nthissize = `0`;
5163	size_t thissize = chunksize (p);
5164
5165	while (p != NULL)
5166	{
5167	++nthissize;
5168	p = p->fd;
5169	}
5170
5171	fastavail += nthissize * thissize;
5172	nfastblocks += nthissize;
5173	sizes[i].from = thissize - (MALLOC_ALIGNMENT - `1`);
5174	sizes[i].to = thissize;
5175	sizes[i].count = nthissize;
5176	}
5177	else
5178	sizes[i].from = sizes[i].to = sizes[i].count = `0`;
5179
5180	sizes[i].total = sizes[i].count * sizes[i].to;
5181	}
5182
5183
5184	mbinptr bin;
5185	struct malloc_chunk *r;
5186
5187	for (size_t i = `1`; i < NBINS; ++i)
5188	{
5189	bin = bin_at (ar_ptr, i);
5190	r = bin->fd;
5191	sizes[NFASTBINS - `1` + i].from = ~((size_t) `0`);
5192	sizes[NFASTBINS - `1` + i].to = sizes[NFASTBINS - `1` + i].total
5193	= sizes[NFASTBINS - `1` + i].count = `0`;
5194
5195	if (r != NULL)
5196	while (r != bin)
5197	{
5198	size_t r_size = chunksize_nomask (r);
5199	++sizes[NFASTBINS - `1` + i].count;
5200	sizes[NFASTBINS - `1` + i].total += r_size;
5201	sizes[NFASTBINS - `1` + i].from
5202	= MIN (sizes[NFASTBINS - `1` + i].from, r_size);
5203	sizes[NFASTBINS - `1` + i].to = MAX (sizes[NFASTBINS - `1` + i].to,
5204	r_size);
5205
5206	r = r->fd;
5207	}
5208
5209	if (sizes[NFASTBINS - `1` + i].count == `0`)
5210	sizes[NFASTBINS - `1` + i].from = `0`;
5211	nblocks += sizes[NFASTBINS - `1` + i].count;
5212	avail += sizes[NFASTBINS - `1` + i].total;
5213	}
5214
5215	__libc_lock_unlock (ar_ptr->mutex);
5216
5217	total_nfastblocks += nfastblocks;
5218	total_fastavail += fastavail;
5219
5220	total_nblocks += nblocks;
5221	total_avail += avail;
5222
5223	for (size_t i = `0`; i < nsizes; ++i)
5224	if (sizes[i].count != `0` && i != NFASTBINS)
5225	fprintf (fp, " \
5226	<size from=\"%zu\" to=\"%zu\" total=\"%zu\" count=\"%zu\"/>\n",
5227	sizes[i].from, sizes[i].to, sizes[i].total, sizes[i].count);
5228
5229	if (sizes[NFASTBINS].count != `0`)
5230	fprintf (fp, "\
5231	<unsorted from=\"%zu\" to=\"%zu\" total=\"%zu\" count=\"%zu\"/>\n",
5232	sizes[NFASTBINS].from, sizes[NFASTBINS].to,
5233	sizes[NFASTBINS].total, sizes[NFASTBINS].count);
5234
5235	total_system += ar_ptr->system_mem;
5236	total_max_system += ar_ptr->max_system_mem;
5237
5238	fprintf (fp,
5239	"</sizes>\n<total type=\"fast\" count=\"%zu\" size=\"%zu\"/>\n"
5240	"<total type=\"rest\" count=\"%zu\" size=\"%zu\"/>\n"
5241	"<system type=\"current\" size=\"%zu\"/>\n"
5242	"<system type=\"max\" size=\"%zu\"/>\n",
5243	nfastblocks, fastavail, nblocks, avail,
5244	ar_ptr->system_mem, ar_ptr->max_system_mem);
5245
5246	if (ar_ptr != &main_arena)
5247	{
5248	heap_info *heap = heap_for_ptr (top (ar_ptr));
5249	fprintf (fp,
5250	"<aspace type=\"total\" size=\"%zu\"/>\n"
5251	"<aspace type=\"mprotect\" size=\"%zu\"/>\n",
5252	heap->size, heap->mprotect_size);
5253	total_aspace += heap->size;
5254	total_aspace_mprotect += heap->mprotect_size;
5255	}
5256	else
5257	{
5258	fprintf (fp,
5259	"<aspace type=\"total\" size=\"%zu\"/>\n"
5260	"<aspace type=\"mprotect\" size=\"%zu\"/>\n",
5261	ar_ptr->system_mem, ar_ptr->system_mem);
5262	total_aspace += ar_ptr->system_mem;
5263	total_aspace_mprotect += ar_ptr->system_mem;
5264	}
5265
5266	fputs ("</heap>\n", fp);
5267	ar_ptr = ar_ptr->next;
5268	}
5269	while (ar_ptr != &main_arena);
5270
5271	fprintf (fp,
5272	"<total type=\"fast\" count=\"%zu\" size=\"%zu\"/>\n"
5273	"<total type=\"rest\" count=\"%zu\" size=\"%zu\"/>\n"
5274	"<total type=\"mmap\" count=\"%d\" size=\"%zu\"/>\n"
5275	"<system type=\"current\" size=\"%zu\"/>\n"
5276	"<system type=\"max\" size=\"%zu\"/>\n"
5277	"<aspace type=\"total\" size=\"%zu\"/>\n"
5278	"<aspace type=\"mprotect\" size=\"%zu\"/>\n"
5279	"</malloc>\n",
5280	total_nfastblocks, total_fastavail, total_nblocks, total_avail,
5281	mp_.n_mmaps, mp_.mmapped_mem,
5282	total_system, total_max_system,
5283	total_aspace, total_aspace_mprotect);
5284
5285	return `0`;
5286	}
5287	weak_alias (__malloc_info, malloc_info)
5288
5289
5290	strong_alias (__libc_calloc, __calloc) weak_alias (__libc_calloc, calloc)
5291	strong_alias (__libc_free, __cfree) weak_alias (__libc_free, cfree)
5292	strong_alias (__libc_free, __free) strong_alias (__libc_free, free)
5293	strong_alias (__libc_malloc, __malloc) strong_alias (__libc_malloc, malloc)
5294	strong_alias (__libc_memalign, __memalign)
5295	weak_alias (__libc_memalign, memalign)
5296	strong_alias (__libc_realloc, __realloc) strong_alias (__libc_realloc, realloc)
5297	strong_alias (__libc_valloc, __valloc) weak_alias (__libc_valloc, valloc)
5298	strong_alias (__libc_pvalloc, __pvalloc) weak_alias (__libc_pvalloc, pvalloc)
5299	strong_alias (__libc_mallinfo, __mallinfo)
5300	weak_alias (__libc_mallinfo, mallinfo)
5301	strong_alias (__libc_mallopt, __mallopt) weak_alias (__libc_mallopt, mallopt)
5302
5303	weak_alias (__malloc_stats, malloc_stats)
5304	weak_alias (__malloc_usable_size, malloc_usable_size)
5305	weak_alias (__malloc_trim, malloc_trim)
5306
5307
5308	/ ------------------------------------------------------------*
5309	History:
5310
5311	[see ftp://g.oswego.edu/pub/misc/malloc.c for the history of dlmalloc]
5312
5313	*/
5314	/*
5315	* Local variables:
5316	* c-basic-offset: 2
5317	* End:
5318	*/
5319

Browse the source code of glibc/malloc/malloc.c