8253a7d685
calling thread from being rescheduled based on an unspecified wakeup time. Bug/fix pointed out by Alexandre Fenyo <fenyo@email.enst.fr>.
348 lines
8.4 KiB
C
348 lines
8.4 KiB
C
/*
|
|
* Copyright (c) 1995 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 <stdlib.h>
|
|
#include <errno.h>
|
|
#ifdef _THREAD_SAFE
|
|
#include <pthread.h>
|
|
#include "pthread_private.h"
|
|
|
|
int
|
|
pthread_cond_init(pthread_cond_t * cond, const pthread_condattr_t * cond_attr)
|
|
{
|
|
enum pthread_cond_type type;
|
|
pthread_cond_t pcond;
|
|
int rval = 0;
|
|
|
|
if (cond == NULL) {
|
|
errno = EINVAL;
|
|
rval = -1;
|
|
} else {
|
|
/*
|
|
* Check if a pointer to a condition variable attribute
|
|
* structure was passed by the caller:
|
|
*/
|
|
if (cond_attr != NULL && *cond_attr != NULL) {
|
|
/* Default to a fast condition variable: */
|
|
type = (*cond_attr)->c_type;
|
|
} else {
|
|
/* Default to a fast condition variable: */
|
|
type = COND_TYPE_FAST;
|
|
}
|
|
|
|
/* Process according to condition variable type: */
|
|
switch (type) {
|
|
/* Fast condition variable: */
|
|
case COND_TYPE_FAST:
|
|
/* Nothing to do here. */
|
|
break;
|
|
|
|
/* Trap invalid condition variable types: */
|
|
default:
|
|
/* Return an invalid argument error: */
|
|
errno = EINVAL;
|
|
rval = -1;
|
|
break;
|
|
}
|
|
|
|
/* Check for no errors: */
|
|
if (rval == 0) {
|
|
if ((pcond = (pthread_cond_t)
|
|
malloc(sizeof(struct pthread_cond))) == NULL) {
|
|
errno = ENOMEM;
|
|
rval = -1;
|
|
} else {
|
|
/*
|
|
* Initialise the condition variable
|
|
* structure:
|
|
*/
|
|
_thread_queue_init(&pcond->c_queue);
|
|
pcond->c_flags |= COND_FLAGS_INITED;
|
|
pcond->c_type = type;
|
|
*cond = pcond;
|
|
}
|
|
}
|
|
}
|
|
/* Return the completion status: */
|
|
return (rval);
|
|
}
|
|
|
|
int
|
|
pthread_cond_destroy(pthread_cond_t * cond)
|
|
{
|
|
int rval = 0;
|
|
|
|
if (cond == NULL || *cond == NULL) {
|
|
errno = EINVAL;
|
|
rval = -1;
|
|
} else {
|
|
/* Process according to condition variable type: */
|
|
switch ((*cond)->c_type) {
|
|
/* Fast condition variable: */
|
|
case COND_TYPE_FAST:
|
|
/* Nothing to do here. */
|
|
break;
|
|
|
|
/* Trap invalid condition variable types: */
|
|
default:
|
|
/* Return an invalid argument error: */
|
|
errno = EINVAL;
|
|
rval = -1;
|
|
break;
|
|
}
|
|
|
|
/* Check for errors: */
|
|
if (rval == 0) {
|
|
/* Destroy the contents of the condition structure: */
|
|
_thread_queue_init(&(*cond)->c_queue);
|
|
(*cond)->c_flags = 0;
|
|
free(*cond);
|
|
*cond = NULL;
|
|
}
|
|
}
|
|
/* Return the completion status: */
|
|
return (rval);
|
|
}
|
|
|
|
int
|
|
pthread_cond_wait(pthread_cond_t * cond, pthread_mutex_t * mutex)
|
|
{
|
|
int rval = 0;
|
|
int status;
|
|
|
|
if (cond == NULL || *cond == NULL) {
|
|
errno = EINVAL;
|
|
rval = -1;
|
|
} else {
|
|
/* Block signals: */
|
|
_thread_kern_sig_block(&status);
|
|
|
|
/* Process according to condition variable type: */
|
|
switch ((*cond)->c_type) {
|
|
/* Fast condition variable: */
|
|
case COND_TYPE_FAST:
|
|
/*
|
|
* Queue the running thread for the condition
|
|
* variable:
|
|
*/
|
|
_thread_queue_enq(&(*cond)->c_queue, _thread_run);
|
|
|
|
/* Unlock the mutex: */
|
|
pthread_mutex_unlock(mutex);
|
|
|
|
/* Wait forever: */
|
|
_thread_run->wakeup_time.tv_sec = -1;
|
|
|
|
/* Schedule the next thread: */
|
|
_thread_kern_sched_state(PS_COND_WAIT,
|
|
__FILE__, __LINE__);
|
|
|
|
/* Block signals: */
|
|
_thread_kern_sig_block(NULL);
|
|
|
|
/* Lock the mutex: */
|
|
rval = pthread_mutex_lock(mutex);
|
|
break;
|
|
|
|
/* Trap invalid condition variable types: */
|
|
default:
|
|
/* Return an invalid argument error: */
|
|
errno = EINVAL;
|
|
rval = -1;
|
|
break;
|
|
}
|
|
|
|
/* Unblock signals: */
|
|
_thread_kern_sig_unblock(status);
|
|
}
|
|
|
|
/* Return the completion status: */
|
|
return (rval);
|
|
}
|
|
|
|
int
|
|
pthread_cond_timedwait(pthread_cond_t * cond, pthread_mutex_t * mutex,
|
|
const struct timespec * abstime)
|
|
{
|
|
int rval = 0;
|
|
int status;
|
|
|
|
if (cond == NULL || *cond == NULL) {
|
|
errno = EINVAL;
|
|
rval = -1;
|
|
} else {
|
|
/* Block signals: */
|
|
_thread_kern_sig_block(&status);
|
|
|
|
/* Process according to condition variable type: */
|
|
switch ((*cond)->c_type) {
|
|
/* Fast condition variable: */
|
|
case COND_TYPE_FAST:
|
|
/* Set the wakeup time: */
|
|
_thread_run->wakeup_time.tv_sec = abstime->tv_sec;
|
|
_thread_run->wakeup_time.tv_nsec = abstime->tv_nsec;
|
|
|
|
/* Reset the timeout flag: */
|
|
_thread_run->timeout = 0;
|
|
|
|
/*
|
|
* Queue the running thread for the condition
|
|
* variable:
|
|
*/
|
|
_thread_queue_enq(&(*cond)->c_queue, _thread_run);
|
|
|
|
/* Unlock the mutex: */
|
|
if ((rval = pthread_mutex_unlock(mutex)) != 0) {
|
|
/*
|
|
* Cannot unlock the mutex, so remove the
|
|
* running thread from the condition
|
|
* variable queue:
|
|
*/
|
|
_thread_queue_deq(&(*cond)->c_queue);
|
|
} else {
|
|
/* Schedule the next thread: */
|
|
_thread_kern_sched_state(PS_COND_WAIT,
|
|
__FILE__, __LINE__);
|
|
|
|
/* Block signals: */
|
|
_thread_kern_sig_block(NULL);
|
|
|
|
/* Lock the mutex: */
|
|
if ((rval = pthread_mutex_lock(mutex)) != 0) {
|
|
}
|
|
/* Check if the wait timed out: */
|
|
else if (_thread_run->timeout) {
|
|
/* Return a timeout error: */
|
|
errno = EAGAIN;
|
|
rval = -1;
|
|
}
|
|
}
|
|
break;
|
|
|
|
/* Trap invalid condition variable types: */
|
|
default:
|
|
/* Return an invalid argument error: */
|
|
errno = EINVAL;
|
|
rval = -1;
|
|
break;
|
|
}
|
|
|
|
/* Unblock signals: */
|
|
_thread_kern_sig_unblock(status);
|
|
}
|
|
|
|
/* Return the completion status: */
|
|
return (rval);
|
|
}
|
|
|
|
int
|
|
pthread_cond_signal(pthread_cond_t * cond)
|
|
{
|
|
int rval = 0;
|
|
int status;
|
|
pthread_t pthread;
|
|
|
|
if (cond == NULL || *cond == NULL) {
|
|
errno = EINVAL;
|
|
rval = -1;
|
|
} else {
|
|
/* Block signals: */
|
|
_thread_kern_sig_block(&status);
|
|
|
|
/* Process according to condition variable type: */
|
|
switch ((*cond)->c_type) {
|
|
/* Fast condition variable: */
|
|
case COND_TYPE_FAST:
|
|
/* Bring the next thread off the condition queue: */
|
|
if ((pthread = _thread_queue_deq(&(*cond)->c_queue)) != NULL) {
|
|
/* Allow the thread to run: */
|
|
PTHREAD_NEW_STATE(pthread,PS_RUNNING);
|
|
}
|
|
break;
|
|
|
|
/* Trap invalid condition variable types: */
|
|
default:
|
|
/* Return an invalid argument error: */
|
|
errno = EINVAL;
|
|
rval = -1;
|
|
break;
|
|
}
|
|
|
|
/* Unblock signals: */
|
|
_thread_kern_sig_unblock(status);
|
|
}
|
|
|
|
/* Return the completion status: */
|
|
return (rval);
|
|
}
|
|
|
|
int
|
|
pthread_cond_broadcast(pthread_cond_t * cond)
|
|
{
|
|
int rval = 0;
|
|
int status;
|
|
pthread_t pthread;
|
|
|
|
/* Block signals: */
|
|
_thread_kern_sig_block(&status);
|
|
|
|
/* Process according to condition variable type: */
|
|
switch ((*cond)->c_type) {
|
|
/* Fast condition variable: */
|
|
case COND_TYPE_FAST:
|
|
/*
|
|
* Enter a loop to bring all threads off the
|
|
* condition queue:
|
|
*/
|
|
while ((pthread =
|
|
_thread_queue_deq(&(*cond)->c_queue)) != NULL) {
|
|
/* Allow the thread to run: */
|
|
PTHREAD_NEW_STATE(pthread,PS_RUNNING);
|
|
}
|
|
break;
|
|
|
|
/* Trap invalid condition variable types: */
|
|
default:
|
|
/* Return an invalid argument error: */
|
|
errno = EINVAL;
|
|
rval = -1;
|
|
break;
|
|
}
|
|
|
|
/* Unblock signals: */
|
|
_thread_kern_sig_unblock(status);
|
|
|
|
/* Return the completion status: */
|
|
return (rval);
|
|
}
|
|
#endif
|