1/* Copyright (C) 2003-2021 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>, 2003.
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 License as
7 published by the Free Software Foundation; either version 2.1 of the
8 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; see the file COPYING.LIB. If
17 not, see <https://www.gnu.org/licenses/>. */
18
19#include <pthread.h>
20#include <setjmp.h>
21#include <signal.h>
22#include <sys/types.h>
23
24
25/* Nonzero if the system calls are not available. */
26extern int __no_posix_timers attribute_hidden;
27
28/* Callback to start helper thread. */
29extern void __start_helper_thread (void) attribute_hidden;
30
31/* Control variable for helper thread creation. */
32extern pthread_once_t __helper_once attribute_hidden;
33
34/* TID of the helper thread. */
35extern pid_t __helper_tid attribute_hidden;
36
37/* List of active SIGEV_THREAD timers. */
38extern struct timer *__active_timer_sigev_thread attribute_hidden;
39/* Lock for the __active_timer_sigev_thread. */
40extern pthread_mutex_t __active_timer_sigev_thread_lock attribute_hidden;
41
42
43/* Type of timers in the kernel. */
44typedef int kernel_timer_t;
45
46/* Internal representation of SIGEV_THREAD timer. */
47struct timer
48{
49 kernel_timer_t ktimerid;
50
51 void (*thrfunc) (sigval_t);
52 sigval_t sival;
53 pthread_attr_t attr;
54
55 /* Next element in list of active SIGEV_THREAD timers. */
56 struct timer *next;
57};
58
59
60/* For !SIGEV_THREAD, the resulting 'timer_t' is the returned kernel timer
61 identifer (kernel_timer_t), while for SIGEV_THREAD it uses the fact malloc
62 returns at least _Alignof (max_align_t) pointers plus that valid
63 kernel_timer_t are always positive to set the MSB bit of the returned
64 'timer_t' to indicate the timer handles a SIGEV_THREAD. */
65
66static inline timer_t
67kernel_timer_to_timerid (kernel_timer_t ktimerid)
68{
69 return (timer_t) ((intptr_t) ktimerid);
70}
71
72static inline timer_t
73timer_to_timerid (struct timer *ptr)
74{
75 return (timer_t) (INTPTR_MIN | (uintptr_t) ptr >> 1);
76}
77
78static inline bool
79timer_is_sigev_thread (timer_t timerid)
80{
81 return (intptr_t) timerid < 0;
82}
83
84static inline struct timer *
85timerid_to_timer (timer_t timerid)
86{
87 return (struct timer *)((uintptr_t) timerid << 1);
88}
89
90static inline kernel_timer_t
91timerid_to_kernel_timer (timer_t timerid)
92{
93 if (timer_is_sigev_thread (timerid))
94 return timerid_to_timer (timerid)->ktimerid;
95 else
96 return (kernel_timer_t) ((uintptr_t) timerid);
97}
98