rt-thread/components/pthreads/pthread_cond.c

#include <pthread.h>
#include "pthread_internal.h"

int pthread_condattr_destroy(pthread_condattr_t *attr)
{
	if (!attr) return EINVAL;

	return 0;
}

int pthread_condattr_init(pthread_condattr_t *attr)
{
	if (!attr) return EINVAL;
	*attr = PTHREAD_PROCESS_PRIVATE;

	return 0;
}

int pthread_condattr_getclock(const pthread_condattr_t *attr,
       clockid_t *clock_id)
{
	return 0;
}

int pthread_condattr_setclock(pthread_condattr_t *attr,
       clockid_t clock_id)
{
	return 0;
}

int pthread_condattr_getpshared(const pthread_condattr_t *attr, int *pshared)
{
	if (!attr || !pshared) return EINVAL;

	*pshared = PTHREAD_PROCESS_PRIVATE;
	return 0;
}

int pthread_condattr_setpshared(pthread_condattr_t*attr, int pshared)
{
	if ((pshared != PTHREAD_PROCESS_PRIVATE) && (pshared != PTHREAD_PROCESS_SHARED))
    	return EINVAL;

	if (pshared != PTHREAD_PROCESS_PRIVATE)
    	return ENOSYS;

	return 0;
}

int pthread_cond_init(pthread_cond_t *cond, const pthread_condattr_t *attr)
{
	rt_err_t result;
	char cond_name[RT_NAME_MAX];
	static rt_uint16_t cond_num = 0;

	/* parameter check */
	if (cond == RT_NULL) return EINVAL;
	if ((attr != RT_NULL) && (*attr != PTHREAD_PROCESS_PRIVATE)) return EINVAL;

	rt_snprintf(cond_name, sizeof(cond_name),
			"cond%02d", cond_num++);

	cond->attr = *attr;
	result = rt_sem_init(&cond->sem, cond_name, 0, RT_IPC_FLAG_FIFO);
	if (result != RT_EOK) return EINVAL;

	/* detach the object from system object container */
	rt_object_detach(&(cond->sem.parent.parent));

	return 0;
}

int pthread_cond_destroy(pthread_cond_t *cond)
{
	rt_err_t result;
	if (cond == RT_NULL) return EINVAL;
	if (cond->attr == -1) return 0; /* which is not initialized */

	result = rt_sem_trytake(&(cond->sem));
	if (result != RT_EOK) return EBUSY;

	/* clean condition */
	rt_memset(cond, 0, sizeof(pthread_cond_t));
	cond->attr = -1;

	return 0;
}

int pthread_cond_broadcast(pthread_cond_t *cond)
{
	rt_err_t result;
	if (cond->attr == -1)
		pthread_cond_init(cond, RT_NULL);

	rt_enter_critical();
	while (1)
	{
		/* try to take condition semaphore */
		result = rt_sem_trytake(&(cond->sem));
		if (result == -RT_ETIMEOUT)
		{
			/* it's timeout, release this semaphore */
			rt_sem_release(&(cond->sem));
		}
		else if (result == RT_EOK)
		{
			/* has taken this semaphore, release it */
			rt_sem_release(&(cond->sem));
			break;
		}
		else
		{
			rt_exit_critical();
			return EINVAL;
		}
	}
	rt_exit_critical();

	return 0;
}

int pthread_cond_signal(pthread_cond_t *cond)
{
	rt_err_t result;

	if (cond->attr == -1)
		pthread_cond_init(cond, RT_NULL);

	result = rt_sem_release(&(cond->sem));
	if (result == RT_EOK) return 0;

	return 0;
}

rt_err_t _pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex,
		rt_int32_t timeout)
{
	rt_err_t result;

	if (!cond || !mutex) return -RT_ERROR;
	/* check whether initialized */
	if (cond->attr == -1) pthread_cond_init(cond, RT_NULL);

	/* The mutex was not owned by the current thread at the time of the call. */
	if (mutex->lock.owner != pthread_self()) return -RT_ERROR;
	/* unlock a mutex failed */
	if (pthread_mutex_unlock(mutex) != 0)
		return -RT_ERROR;

	result = rt_sem_take(&(cond->sem), timeout);
	/* lock mutex again */
	pthread_mutex_lock(mutex);
	return result;
}

int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
{
	rt_err_t result;

	result = _pthread_cond_timedwait(cond, mutex, RT_WAITING_FOREVER);
	if (result == RT_EOK) return 0;

	return EINVAL;
}

int pthread_cond_timedwait(pthread_cond_t *cond,
	pthread_mutex_t * mutex,
	const struct timespec *abstime)
{
	int timeout;
	rt_err_t result;

	timeout = clock_time_to_tick(abstime);
	result = _pthread_cond_timedwait(cond, mutex, timeout);
	if (result == RT_EOK) return 0;
	if (result == -RT_ETIMEOUT) return ETIMEDOUT;

	return EINVAL;
}