gcc/libobjc/thr-posix.c

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/* GNU Objective C Runtime Thread Interface for POSIX compliant threads
Copyright (C) 1996, 1997, 2009 Free Software Foundation, Inc.
Contributed by Galen C. Hunt (gchunt@cs.rochester.edu)
Modified for Linux/Pthreads by Kai-Uwe Sattler (kus@iti.cs.uni-magdeburg.de)
Modified for posix compliance by Chris Ball (cball@fmco.com)
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
GCC 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 General Public License for more
details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#include "objc/thr.h"
#include "objc/runtime.h"
#include <pthread.h>
/* Key structure for maintaining thread specific storage */
static pthread_key_t _objc_thread_storage;
static pthread_attr_t _objc_thread_attribs;
/* Backend initialization functions */
/* Initialize the threads subsystem. */
int
__objc_init_thread_system(void)
{
/* Initialize the thread storage key */
if (pthread_key_create(&_objc_thread_storage, NULL) == 0)
{
/*
* The normal default detach state for threads is PTHREAD_CREATE_JOINABLE
* which causes threads to not die when you think they should.
*/
if (pthread_attr_init(&_objc_thread_attribs) == 0)
{
if (pthread_attr_setdetachstate(&_objc_thread_attribs,
PTHREAD_CREATE_DETACHED) == 0)
return 0;
}
}
return -1;
}
/* Close the threads subsystem. */
int
__objc_close_thread_system(void)
{
if (pthread_key_delete(_objc_thread_storage) == 0)
{
if (pthread_attr_destroy(&_objc_thread_attribs) == 0)
return 0;
}
return -1;
}
/* Backend thread functions */
/* Create a new thread of execution. */
objc_thread_t
__objc_thread_detach(void (*func)(void *arg), void *arg)
{
objc_thread_t thread_id;
pthread_t new_thread_handle;
if (!(pthread_create(&new_thread_handle, &_objc_thread_attribs,
(void *)func, arg)))
thread_id = *(objc_thread_t *)&new_thread_handle;
else
thread_id = NULL;
return thread_id;
}
/* Set the current thread's priority.
*
* Be aware that the default schedpolicy often disallows thread priorities.
*/
int
__objc_thread_set_priority(int priority)
{
pthread_t thread_id = pthread_self();
int policy;
struct sched_param params;
int priority_min, priority_max;
if (pthread_getschedparam(thread_id, &policy, &params) == 0)
{
if ((priority_max = sched_get_priority_max(policy)) != 0)
return -1;
if ((priority_min = sched_get_priority_min(policy)) != 0)
return -1;
if (priority > priority_max)
priority = priority_max;
else if (priority < priority_min)
priority = priority_min;
params.sched_priority = priority;
/*
* The solaris 7 and several other man pages incorrectly state that
* this should be a pointer to policy but pthread.h is universally
* at odds with this.
*/
if (pthread_setschedparam(thread_id, policy, &params) == 0)
return 0;
}
return -1;
}
/* Return the current thread's priority. */
int
__objc_thread_get_priority(void)
{
int policy;
struct sched_param params;
if (pthread_getschedparam(pthread_self(), &policy, &params) == 0)
return params.sched_priority;
else
return -1;
}
/* Yield our process time to another thread. */
void
__objc_thread_yield(void)
{
sched_yield();
}
/* Terminate the current thread. */
int
__objc_thread_exit(void)
{
/* exit the thread */
pthread_exit(&__objc_thread_exit_status);
/* Failed if we reached here */
return -1;
}
/* Returns an integer value which uniquely describes a thread. */
objc_thread_t
__objc_thread_id(void)
{
pthread_t self = pthread_self();
return *(objc_thread_t *)&self;
}
/* Sets the thread's local storage pointer. */
int
__objc_thread_set_data(void *value)
{
if (pthread_setspecific(_objc_thread_storage, value) == 0)
return 0;
else
return -1;
}
/* Returns the thread's local storage pointer. */
void *
__objc_thread_get_data(void)
{
return pthread_getspecific(_objc_thread_storage);
}
/* Backend mutex functions */
/* Allocate a mutex. */
int
__objc_mutex_allocate(objc_mutex_t mutex)
{
mutex->backend = objc_malloc(sizeof(pthread_mutex_t));
if (pthread_mutex_init((pthread_mutex_t *)mutex->backend, NULL))
{
objc_free(mutex->backend);
mutex->backend = NULL;
return -1;
}
return 0;
}
/* Deallocate a mutex. */
int
__objc_mutex_deallocate(objc_mutex_t mutex)
{
int count = 1;
/*
* Posix Threads specifically require that the thread be unlocked for
* pthread_mutex_destroy to work.
*/
while (count)
{
if ((count = pthread_mutex_unlock((pthread_mutex_t*)mutex->backend)) < 0)
return -1;
}
if (pthread_mutex_destroy((pthread_mutex_t *)mutex->backend))
return -1;
objc_free(mutex->backend);
mutex->backend = NULL;
return 0;
}
/* Grab a lock on a mutex. */
int
__objc_mutex_lock(objc_mutex_t mutex)
{
if (pthread_mutex_lock((pthread_mutex_t *)mutex->backend) == 0)
return 0;
else
return -1;
}
/* Try to grab a lock on a mutex. */
int
__objc_mutex_trylock(objc_mutex_t mutex)
{
if (pthread_mutex_trylock((pthread_mutex_t *)mutex->backend) == 0)
return 0;
else
return -1;
}
/* Unlock the mutex */
int
__objc_mutex_unlock(objc_mutex_t mutex)
{
if (pthread_mutex_unlock((pthread_mutex_t *)mutex->backend) == 0)
return 0;
else
return -1;
}
/* Backend condition mutex functions */
/* Allocate a condition. */
int
__objc_condition_allocate(objc_condition_t condition)
{
condition->backend = objc_malloc(sizeof(pthread_cond_t));
if (pthread_cond_init((pthread_cond_t *)condition->backend, NULL))
{
objc_free(condition->backend);
condition->backend = NULL;
return -1;
}
return 0;
}
/* Deallocate a condition. */
int
__objc_condition_deallocate(objc_condition_t condition)
{
if (pthread_cond_destroy((pthread_cond_t *)condition->backend))
return -1;
objc_free(condition->backend);
condition->backend = NULL;
return 0;
}
/* Wait on the condition */
int
__objc_condition_wait(objc_condition_t condition, objc_mutex_t mutex)
{
if (pthread_cond_wait((pthread_cond_t *)condition->backend,
(pthread_mutex_t *)mutex->backend) == 0)
return 0;
else
return -1;
}
/* Wake up all threads waiting on this condition. */
int
__objc_condition_broadcast(objc_condition_t condition)
{
if (pthread_cond_broadcast((pthread_cond_t *)condition->backend) == 0)
return 0;
else
return -1;
}
/* Wake up one thread waiting on this condition. */
int
__objc_condition_signal(objc_condition_t condition)
{
if (pthread_cond_signal((pthread_cond_t *)condition->backend) == 0)
return 0;
else
return -1;
}