freebsd-skq/lib/libthr/thread/thr_exit.c
davidxu 9dbfb036ab - Copy signal mask out before THR_UNLOCK(), because THR_UNLOCK() may call
_thr_suspend_check() which messes sigmask saved in thread structure.
- Don't suspend a thread has force_exit set.
- In pthread_exit(), if there is a suspension flag set, wake up waiting-
  thread after setting PS_DEAD, this causes waiting-thread to break loop
  in suspend_common().
2008-03-18 02:06:51 +00:00

148 lines
4.5 KiB
C

/*
* Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include "thr_private.h"
void _pthread_exit(void *status);
__weak_reference(_pthread_exit, pthread_exit);
void
_thread_exit(const char *fname, int lineno, const char *msg)
{
/* Write an error message to the standard error file descriptor: */
_thread_printf(2,
"Fatal error '%s' at line %d in file %s (errno = %d)\n",
msg, lineno, fname, errno);
abort();
}
/*
* Only called when a thread is cancelled. It may be more useful
* to call it from pthread_exit() if other ways of asynchronous or
* abnormal thread termination can be found.
*/
void
_thr_exit_cleanup(void)
{
struct pthread *curthread = _get_curthread();
/*
* POSIX states that cancellation/termination of a thread should
* not release any visible resources (such as mutexes) and that
* it is the applications responsibility. Resources that are
* internal to the threads library, including file and fd locks,
* are not visible to the application and need to be released.
*/
/* Unlock all private mutexes: */
_mutex_unlock_private(curthread);
/*
* This still isn't quite correct because we don't account
* for held spinlocks (see libc/stdlib/malloc.c).
*/
}
void
_pthread_exit(void *status)
{
struct pthread *curthread = _get_curthread();
/* Check if this thread is already in the process of exiting: */
if (curthread->cancelling) {
char msg[128];
snprintf(msg, sizeof(msg), "Thread %p has called "
"pthread_exit() from a destructor. POSIX 1003.1 "
"1996 s16.2.5.2 does not allow this!", curthread);
PANIC(msg);
}
/* Flag this thread as exiting. */
curthread->cancelling = 1;
_thr_exit_cleanup();
/* Save the return value: */
curthread->ret = status;
while (curthread->cleanup != NULL) {
_pthread_cleanup_pop(1);
}
/* Check if there is thread specific data: */
if (curthread->specific != NULL) {
/* Run the thread-specific data destructors: */
_thread_cleanupspecific();
}
if (!_thr_isthreaded())
exit(0);
THREAD_LIST_LOCK(curthread);
_thread_active_threads--;
if (_thread_active_threads == 0) {
THREAD_LIST_UNLOCK(curthread);
exit(0);
/* Never reach! */
}
THR_LOCK(curthread);
curthread->state = PS_DEAD;
if (curthread->flags & THR_FLAGS_NEED_SUSPEND) {
curthread->cycle++;
_thr_umtx_wake(&curthread->cycle, INT_MAX);
}
THR_UNLOCK(curthread);
/*
* Thread was created with initial refcount 1, we drop the
* reference count to allow it to be garbage collected.
*/
curthread->refcount--;
if (curthread->tlflags & TLFLAGS_DETACHED)
THR_GCLIST_ADD(curthread);
THREAD_LIST_UNLOCK(curthread);
if (!curthread->force_exit && SHOULD_REPORT_EVENT(curthread, TD_DEATH))
_thr_report_death(curthread);
/*
* Kernel will do wakeup at the address, so joiner thread
* will be resumed if it is sleeping at the address.
*/
thr_exit(&curthread->tid);
PANIC("thr_exit() returned");
/* Never reach! */
}