nuttx/sched/pthread/pthread_condwait.c
chao an 4c8d244fae sched/getpid: replace syscall getpid/tid/ppid() to kernel version
NuttX kernel should not use the syscall functions, especially after
enabling CONFIG_SCHED_INSTRUMENTATION_SYSCALL, all system functions
will be traced to backend, which will impact system performance.

Signed-off-by: chao an <anchao@xiaomi.com>
2023-02-02 10:33:01 +08:00

158 lines
4.0 KiB
C

/****************************************************************************
* sched/pthread/pthread_condwait.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <unistd.h>
#include <pthread.h>
#include <sched.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/cancelpt.h>
#include "pthread/pthread.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: int pthread_cond_wait
*
* Description:
* A thread can wait for a condition variable to be signalled or broadcast.
*
* Input Parameters:
* None
*
* Returned Value:
* None
*
* Assumptions:
*
****************************************************************************/
int pthread_cond_wait(FAR pthread_cond_t *cond, FAR pthread_mutex_t *mutex)
{
int status;
int ret;
sinfo("cond=%p mutex=%p\n", cond, mutex);
/* pthread_cond_wait() is a cancellation point */
enter_cancellation_point();
/* Make sure that non-NULL references were provided. */
if (cond == NULL || mutex == NULL)
{
ret = EINVAL;
}
/* Make sure that the caller holds the mutex */
else if (mutex->pid != nxsched_gettid())
{
ret = EPERM;
}
else
{
#ifndef CONFIG_PTHREAD_MUTEX_UNSAFE
uint8_t mflags;
#endif
#ifdef CONFIG_PTHREAD_MUTEX_TYPES
uint8_t type;
int16_t nlocks;
#endif
/* Give up the mutex */
sinfo("Give up mutex / take cond\n");
sched_lock();
mutex->pid = INVALID_PROCESS_ID;
#ifndef CONFIG_PTHREAD_MUTEX_UNSAFE
mflags = mutex->flags;
#endif
#ifdef CONFIG_PTHREAD_MUTEX_TYPES
type = mutex->type;
nlocks = mutex->nlocks;
#endif
ret = pthread_mutex_give(mutex);
/* Take the semaphore. This may be awakened only be a signal (EINTR)
* or if the thread is canceled (ECANCELED)
*/
status = pthread_sem_take(&cond->sem, NULL);
if (ret == OK)
{
/* Report the first failure that occurs */
ret = status;
}
sched_unlock();
/* Reacquire the mutex.
*
* When cancellation points are enabled, we need to hold the mutex
* when the pthread is canceled and cleanup handlers, if any, are
* entered.
*/
sinfo("Reacquire mutex...\n");
status = pthread_mutex_take(mutex, NULL);
if (ret == OK)
{
/* Report the first failure that occurs */
ret = status;
}
/* Did we get the mutex? */
if (status == OK)
{
/* Yes.. Then initialize it properly */
mutex->pid = nxsched_gettid();
#ifndef CONFIG_PTHREAD_MUTEX_UNSAFE
mutex->flags = mflags;
#endif
#ifdef CONFIG_PTHREAD_MUTEX_TYPES
mutex->type = type;
mutex->nlocks = nlocks;
#endif
}
}
leave_cancellation_point();
sinfo("Returning %d\n", ret);
return ret;
}