xSemaphoreTake macro

semphr. h @code{c} xSemaphoreTake( SemaphoreHandle_t xSemaphore, TickType_t xBlockTime ); @endcode Macro to obtain a semaphore. The semaphore must have previously been created with a call to xSemaphoreCreateBinary(), xSemaphoreCreateMutex() or xSemaphoreCreateCounting(). Example usage: @code{c} SemaphoreHandle_t xSemaphore = NULL; // A task that creates a semaphore. void vATask( void * pvParameters ) { // Create the semaphore to guard a shared resource. xSemaphore = xSemaphoreCreateBinary(); } // A task that uses the semaphore. void vAnotherTask( void * pvParameters ) { // ... Do other things. if( xSemaphore != NULL ) { // See if we can obtain the semaphore. If the semaphore is not available // wait 10 ticks to see if it becomes free. if( xSemaphoreTake( xSemaphore, ( TickType_t ) 10 ) == pdTRUE ) { // We were able to obtain the semaphore and can now access the // shared resource. // ... // We have finished accessing the shared resource. Release the // semaphore. xSemaphoreGive( xSemaphore ); } else { // We could not obtain the semaphore and can therefore not access // the shared resource safely. } } } @endcode