dm8148 开发之---互斥量、条件量、枷锁、互斥枷锁

int OSA_semCreate(OSA_SemHndl *hndl, Uint32 maxCount, Uint32 initVal)
{
pthread_mutexattr_t mutex_attr;
pthread_condattr_t cond_attr;
int status=OSA_SOK;

status |= pthread_mutexattr_init(&mutex_attr);
status |= pthread_condattr_init(&cond_attr);

status |= pthread_mutex_init(&hndl->lock, &mutex_attr);
status |= pthread_cond_init(&hndl->cond, &cond_attr);

hndl->count = initVal;
hndl->maxCount = maxCount;

if(hndl->maxCount==0)
hndl->maxCount=1;

if(hndl->count>hndl->maxCount)
hndl->count = hndl->maxCount;

if(status!=OSA_SOK)
OSA_ERROR("OSA_semCreate() = %d \r\n", status);

pthread_condattr_destroy(&cond_attr);
pthread_mutexattr_destroy(&mutex_attr);

return status;
}

int OSA_semWait(OSA_SemHndl *hndl, Uint32 timeout)
{
int status = OSA_EFAIL;

pthread_mutex_lock(&hndl->lock);

while(1) {
if(hndl->count > 0) {
hndl->count--;
status = OSA_SOK;
break;
} else {
if(timeout==OSA_TIMEOUT_NONE)
break;

pthread_cond_wait(&hndl->cond, &hndl->lock);
}
}

pthread_mutex_unlock(&hndl->lock);

return status;
}

int OSA_semSignal(OSA_SemHndl *hndl)
{
int status = OSA_SOK;

pthread_mutex_lock(&hndl->lock);

if(hndl->count<hndl->maxCount) {
hndl->count++;
status |= pthread_cond_signal(&hndl->cond);
}

pthread_mutex_unlock(&hndl->lock);

return status;
}

int OSA_semDelete(OSA_SemHndl *hndl)
{
pthread_cond_destroy(&hndl->cond);
pthread_mutex_destroy(&hndl->lock);

return OSA_SOK;
}

void OSA_waitMsecs(Uint32 msecs)
{
#if 1
struct timespec delayTime, elaspedTime;

delayTime.tv_sec = msecs/1000;
delayTime.tv_nsec = (msecs%1000)*1000000;

nanosleep(&delayTime, &elaspedTime);
#else
usleep(msecs*1000);
#endif
}

http://www.cnblogs.com/mywolrd/archive/2009/02/05/1930707.html#ConVarOverview

http://blog.csdn.net/npuweiwei/article/details/8661829