1/* Thread termination.
2 Copyright (C) 2000-2024 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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 <assert.h>
20#include <errno.h>
21#include <pthread.h>
22#include <stdlib.h>
23
24#include <pt-internal.h>
25#include <pthreadP.h>
26
27#include <atomic.h>
28
29
30/* Terminate the current thread and make STATUS available to any
31 thread that might join it. */
32void
33__pthread_exit (void *status)
34{
35 struct __pthread *self = _pthread_self ();
36 struct __pthread_cancelation_handler **handlers;
37 int oldstate;
38
39 /* Run any cancelation handlers. According to POSIX, the
40 cancellation cleanup handlers should be called with cancellation
41 disabled. */
42 __pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &oldstate);
43
44 for (handlers = __pthread_get_cleanup_stack ();
45 *handlers != NULL;
46 *handlers = (*handlers)->__next)
47 (*handlers)->__handler ((*handlers)->__arg);
48
49 /* Call destructors for the thread_local TLS variables. */
50 call_function_static_weak (__call_tls_dtors);
51
52 __pthread_setcancelstate (oldstate, &oldstate);
53
54 /* Decrease the number of threads. We use an atomic operation to
55 make sure that only the last thread calls `exit'. */
56 if (atomic_fetch_add_relaxed (&__pthread_total, -1) == 1)
57 /* We are the last thread. */
58 exit (status: 0);
59
60 /* Destroy any thread specific data. */
61 __pthread_destroy_specific (thread: self);
62
63 /* Note that after this point the process can be terminated at any
64 point if another thread calls `pthread_exit' and happens to be
65 the last thread. */
66
67 __pthread_mutex_lock (mutex: &self->state_lock);
68
69 if (self->cancel_state == PTHREAD_CANCEL_ENABLE && self->cancel_pending)
70 status = PTHREAD_CANCELED;
71
72 switch (self->state)
73 {
74 default:
75 assert (!"Consistency error: unexpected self->state");
76 abort ();
77 break;
78
79 case PTHREAD_DETACHED:
80 __pthread_mutex_unlock (mutex: &self->state_lock);
81
82 break;
83
84 case PTHREAD_JOINABLE:
85 /* We need to stay around for a while since another thread
86 might want to join us. */
87 self->state = PTHREAD_EXITED;
88
89 /* We need to remember the exit status. A thread joining us
90 might ask for it. */
91 self->status = status;
92
93 /* Broadcast the condition. This will wake up threads that are
94 waiting to join us. */
95 __pthread_cond_broadcast (cond: &self->state_cond);
96 __pthread_mutex_unlock (mutex: &self->state_lock);
97
98 break;
99 }
100
101 /* Destroy any signal state. */
102 __pthread_sigstate_destroy (thread: self);
103
104 /* Self terminating requires TLS, so defer the release of the TCB until
105 the thread structure is reused. */
106
107 /* Release kernel resources, including the kernel thread and the stack,
108 and drop the self reference. */
109 __pthread_thread_terminate (thread: self);
110
111 /* NOTREACHED */
112 abort ();
113}
114
115weak_alias (__pthread_exit, pthread_exit);
116

source code of glibc/htl/pt-exit.c