glibc/htl/pt-join.c
2020-02-10 00:06:59 +00:00

77 lines
2.3 KiB
C

/* Wait for thread termination.
Copyright (C) 2000-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <pthread.h>
#include <stddef.h>
#include <pt-internal.h>
/* Make calling thread wait for termination of thread THREAD. Return
the exit status of the thread in *STATUS. */
int
__pthread_join (pthread_t thread, void **status)
{
struct __pthread *pthread;
int err = 0;
/* Lookup the thread structure for THREAD. */
pthread = __pthread_getid (thread);
if (pthread == NULL)
return ESRCH;
__pthread_mutex_lock (&pthread->state_lock);
pthread_cleanup_push ((void (*)(void *)) __pthread_mutex_unlock,
&pthread->state_lock);
/* Rely on pthread_cond_wait being a cancellation point to make
pthread_join one too. */
while (pthread->state == PTHREAD_JOINABLE)
__pthread_cond_wait (&pthread->state_cond, &pthread->state_lock);
pthread_cleanup_pop (0);
switch (pthread->state)
{
case PTHREAD_EXITED:
/* THREAD has already exited. Salvage its exit status. */
if (status != NULL)
*status = pthread->status;
__pthread_mutex_unlock (&pthread->state_lock);
__pthread_dealloc (pthread);
break;
case PTHREAD_TERMINATED:
/* Pretend THREAD wasn't there in the first place. */
__pthread_mutex_unlock (&pthread->state_lock);
err = ESRCH;
break;
default:
/* Thou shalt not join non-joinable threads! */
__pthread_mutex_unlock (&pthread->state_lock);
err = EINVAL;
break;
}
return err;
}
strong_alias (__pthread_join, pthread_join);