df42f1ac5f
the thread kernel into a garbage collector thread which is started when the fisrt thread is created (other than the initial thread). This removes the window of opportunity where a context switch will cause a thread that has locked the malloc spinlock, to enter the thread kernel, find there is a dead thread and try to free memory, therefore trying to lock the malloc spinlock against itself. The garbage collector thread acts just like any other thread, so instead of having a spinlock to control accesses to the dead thread list, it uses a mutex and a condition variable so that it can happily wait to be signalled when a thread exists.
165 lines
5.1 KiB
C
165 lines
5.1 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. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by John Birrell.
|
|
* 4. 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 REGENTS 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.
|
|
*
|
|
*/
|
|
#include <errno.h>
|
|
#include <unistd.h>
|
|
#include <fcntl.h>
|
|
#include <string.h>
|
|
#ifdef _THREAD_SAFE
|
|
#include <pthread.h>
|
|
#include "pthread_private.h"
|
|
|
|
void _exit(int status)
|
|
{
|
|
int flags;
|
|
int i;
|
|
struct itimerval itimer;
|
|
|
|
/* Disable the interval timer: */
|
|
itimer.it_interval.tv_sec = 0;
|
|
itimer.it_interval.tv_usec = 0;
|
|
itimer.it_value.tv_sec = 0;
|
|
itimer.it_value.tv_usec = 0;
|
|
setitimer(ITIMER_VIRTUAL, &itimer, NULL);
|
|
|
|
/* Close the pthread kernel pipe: */
|
|
_thread_sys_close(_thread_kern_pipe[0]);
|
|
_thread_sys_close(_thread_kern_pipe[1]);
|
|
|
|
/*
|
|
* Enter a loop to set all file descriptors to blocking
|
|
* if they were not created as non-blocking:
|
|
*/
|
|
for (i = 0; i < _thread_dtablesize; i++) {
|
|
/* Check if this file descriptor is in use: */
|
|
if (_thread_fd_table[i] != NULL &&
|
|
!(_thread_fd_table[i]->flags & O_NONBLOCK)) {
|
|
/* Get the current flags: */
|
|
flags = _thread_sys_fcntl(i, F_GETFL, NULL);
|
|
/* Clear the nonblocking file descriptor flag: */
|
|
_thread_sys_fcntl(i, F_SETFL, flags & ~O_NONBLOCK);
|
|
}
|
|
}
|
|
|
|
/* Call the _exit syscall: */
|
|
_thread_sys__exit(status);
|
|
}
|
|
|
|
void
|
|
_thread_exit(char *fname, int lineno, char *string)
|
|
{
|
|
char s[256];
|
|
|
|
/* Prepare an error message string: */
|
|
strcpy(s, "Fatal error '");
|
|
strcat(s, string);
|
|
strcat(s, "' at line ? ");
|
|
strcat(s, "in file ");
|
|
strcat(s, fname);
|
|
strcat(s, " (errno = ?");
|
|
strcat(s, ")\n");
|
|
|
|
/* Write the string to the standard error file descriptor: */
|
|
_thread_sys_write(2, s, strlen(s));
|
|
|
|
/* Force this process to exit: */
|
|
_exit(1);
|
|
}
|
|
|
|
void
|
|
pthread_exit(void *status)
|
|
{
|
|
int sig;
|
|
long l;
|
|
pthread_t pthread;
|
|
|
|
/* Check if this thread is already in the process of exiting: */
|
|
if ((_thread_run->flags & PTHREAD_EXITING) != 0) {
|
|
char msg[128];
|
|
snprintf(msg,"Thread %p has called pthread_exit() from a destructor. POSIX 1003.1 1996 s16.2.5.2 does not allow this!",_thread_run);
|
|
PANIC(msg);
|
|
}
|
|
|
|
/* Flag this thread as exiting: */
|
|
_thread_run->flags |= PTHREAD_EXITING;
|
|
|
|
/* Save the return value: */
|
|
_thread_run->ret = status;
|
|
|
|
while (_thread_run->cleanup != NULL) {
|
|
pthread_cleanup_pop(1);
|
|
}
|
|
|
|
if (_thread_run->attr.cleanup_attr != NULL) {
|
|
_thread_run->attr.cleanup_attr(_thread_run->attr.arg_attr);
|
|
}
|
|
/* Check if there is thread specific data: */
|
|
if (_thread_run->specific_data != NULL) {
|
|
/* Run the thread-specific data destructors: */
|
|
_thread_cleanupspecific();
|
|
}
|
|
/* Check if there are any threads joined to this one: */
|
|
while ((pthread = _thread_queue_deq(&(_thread_run->join_queue))) != NULL) {
|
|
/* Wake the joined thread and let it detach this thread: */
|
|
PTHREAD_NEW_STATE(pthread,PS_RUNNING);
|
|
}
|
|
|
|
/*
|
|
* Lock the garbage collector mutex to ensure that the garbage
|
|
* collector is not using the dead thread list.
|
|
*/
|
|
if (pthread_mutex_lock(&_gc_mutex) != 0)
|
|
PANIC("Cannot lock gc mutex");
|
|
|
|
/* Add this thread to the list of dead threads. */
|
|
_thread_run->nxt_dead = _thread_dead;
|
|
_thread_dead = _thread_run;
|
|
|
|
/*
|
|
* Signal the garbage collector thread that there is something
|
|
* to clean up.
|
|
*/
|
|
if (pthread_cond_signal(&_gc_cond) != 0)
|
|
PANIC("Cannot signal gc cond");
|
|
|
|
/* Unlock the garbage collector mutex: */
|
|
if (pthread_mutex_unlock(&_gc_mutex) != 0)
|
|
PANIC("Cannot lock gc mutex");
|
|
|
|
/* This this thread will never be re-scheduled. */
|
|
_thread_kern_sched_state(PS_DEAD, __FILE__, __LINE__);
|
|
|
|
/* This point should not be reached. */
|
|
PANIC("Dead thread has resumed");
|
|
}
|
|
#endif
|