1/* Deallocation thread-specific data structures related to pthread_key_create.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <pthreadP.h>
20
21/* Deallocate POSIX thread-local-storage. */
22void
23__nptl_deallocate_tsd (void)
24{
25 struct pthread *self = THREAD_SELF;
26
27 /* Maybe no data was ever allocated. This happens often so we have
28 a flag for this. */
29 if (THREAD_GETMEM (self, specific_used))
30 {
31 size_t round;
32 size_t cnt;
33
34 round = 0;
35 do
36 {
37 size_t idx;
38
39 /* So far no new nonzero data entry. */
40 THREAD_SETMEM (self, specific_used, false);
41
42 for (cnt = idx = 0; cnt < PTHREAD_KEY_1STLEVEL_SIZE; ++cnt)
43 {
44 struct pthread_key_data *level2;
45
46 level2 = THREAD_GETMEM_NC (self, specific, cnt);
47
48 if (level2 != NULL)
49 {
50 size_t inner;
51
52 for (inner = 0; inner < PTHREAD_KEY_2NDLEVEL_SIZE;
53 ++inner, ++idx)
54 {
55 void *data = level2[inner].data;
56
57 if (data != NULL)
58 {
59 /* Always clear the data. */
60 level2[inner].data = NULL;
61
62 /* Make sure the data corresponds to a valid
63 key. This test fails if the key was
64 deallocated and also if it was
65 re-allocated. It is the user's
66 responsibility to free the memory in this
67 case. */
68 if (level2[inner].seq
69 == __pthread_keys[idx].seq
70 /* It is not necessary to register a destructor
71 function. */
72 && __pthread_keys[idx].destr != NULL)
73 /* Call the user-provided destructor. */
74 __pthread_keys[idx].destr (data);
75 }
76 }
77 }
78 else
79 idx += PTHREAD_KEY_1STLEVEL_SIZE;
80 }
81
82 if (THREAD_GETMEM (self, specific_used) == 0)
83 /* No data has been modified. */
84 goto just_free;
85 }
86 /* We only repeat the process a fixed number of times. */
87 while (__builtin_expect (++round < PTHREAD_DESTRUCTOR_ITERATIONS, 0));
88
89 /* Just clear the memory of the first block for reuse. */
90 memset (&THREAD_SELF->specific_1stblock, '\0',
91 sizeof (self->specific_1stblock));
92
93 just_free:
94 /* Free the memory for the other blocks. */
95 for (cnt = 1; cnt < PTHREAD_KEY_1STLEVEL_SIZE; ++cnt)
96 {
97 struct pthread_key_data *level2;
98
99 level2 = THREAD_GETMEM_NC (self, specific, cnt);
100 if (level2 != NULL)
101 {
102 /* The first block is allocated as part of the thread
103 descriptor. */
104 free (level2);
105 THREAD_SETMEM_NC (self, specific, cnt, NULL);
106 }
107 }
108
109 THREAD_SETMEM (self, specific_used, false);
110 }
111}
112libc_hidden_def (__nptl_deallocate_tsd)
113