int pthread_cond_timedwait()

in FreeRTOS-Plus-POSIX/source/FreeRTOS_POSIX_pthread_cond.c [215:286]
46 lines of code
6 McCabe index (conditional complexity)

int pthread_cond_timedwait( pthread_cond_t * cond,
                            pthread_mutex_t * mutex,
                            const struct timespec * abstime )
{
    unsigned iLocalWaitingThreads;
    int iStatus = 0;
    pthread_cond_internal_t * pxCond = ( pthread_cond_internal_t * ) ( cond );
    TickType_t xDelay = portMAX_DELAY;

    /* If the cond is uninitialized, perform initialization. */
    prvInitializeStaticCond( pxCond );

    /* Convert abstime to a delay in TickType_t if provided. */
    if( abstime != NULL )
    {
        struct timespec xCurrentTime = { 0 };

        /* Get current time */
        if( clock_gettime( CLOCK_REALTIME, &xCurrentTime ) != 0 )
        {
            iStatus = EINVAL;
        }
        else
        {
            iStatus = UTILS_AbsoluteTimespecToDeltaTicks( abstime, &xCurrentTime, &xDelay );
        }
    }

    /* Increase the counter of threads blocking on condition variable, then
     * unlock mutex. */
    if( iStatus == 0 )
    {
        /* Atomically increments thread waiting by 1, and
         * stores number of threads waiting before increment. */
        iLocalWaitingThreads = Atomic_Increment_u32( ( uint32_t * ) &pxCond->iWaitingThreads );

        iStatus = pthread_mutex_unlock( mutex );
    }

    /* Wait on the condition variable. */
    if( iStatus == 0 )
    {
        if( xSemaphoreTake( ( SemaphoreHandle_t ) &pxCond->xCondWaitSemaphore,
                            xDelay ) == pdPASS )
        {
            /* When successful, relock mutex. */
            iStatus = pthread_mutex_lock( mutex );
        }
        else
        {
            /* Timeout. Relock mutex and decrement number of waiting threads. */
            iStatus = ETIMEDOUT;
            ( void ) pthread_mutex_lock( mutex );

            /* Atomically decrements thread waiting by 1.
             * If iLocalWaitingThreads is updated by other thread(s) in between,
             * this implementation guarantees to decrement by 1 based on the
             * value currently in pxCond->iWaitingThreads. */
            prvTestAndDecrement( pxCond, iLocalWaitingThreads + 1 );
        }
    }
    else
    {
        /* Atomically decrements thread waiting by 1.
         * If iLocalWaitingThreads is updated by other thread(s) in between,
         * this implementation guarantees to decrement by 1 based on the
         * value currently in pxCond->iWaitingThreads. */
        prvTestAndDecrement( pxCond, iLocalWaitingThreads + 1 );
    }

    return iStatus;
}