crQUEUE_RECEIVE_FROM_ISR macro

// A co-routine that posts a character to a queue then blocks for a fixed // period. The character is incremented each time. static void vSendingCoRoutine( CoRoutineHandle_t xHandle, UBaseType_t uxIndex ) { // cChar holds its value while this co-routine is blocked and must therefore // be declared static. static char cCharToTx = 'a'; BaseType_t xResult; // All co-routines must start with a call to crSTART(). crSTART( xHandle ); for( ;; ) { // Send the next character to the queue. crQUEUE_SEND( xHandle, xCoRoutineQueue, &cCharToTx, NO_DELAY, &xResult ); if( xResult == pdPASS ) { // The character was successfully posted to the queue. } else { // Could not post the character to the queue. } // Enable the UART Tx interrupt to cause an interrupt in this // hypothetical UART. The interrupt will obtain the character // from the queue and send it. ENABLE_RX_INTERRUPT(); // Increment to the next character then block for a fixed period. // cCharToTx will maintain its value across the delay as it is // declared static. cCharToTx++; if( cCharToTx > 'x' ) { cCharToTx = 'a'; } crDELAY( 100 ); } // All co-routines must end with a call to crEND(). crEND(); } // An ISR that uses a queue to receive characters to send on a UART. void vUART_ISR( void ) { char cCharToTx; BaseType_t xCRWokenByPost = pdFALSE; while( UART_TX_REG_EMPTY() ) { // Are there any characters in the queue waiting to be sent? // xCRWokenByPost will automatically be set to pdTRUE if a co-routine // is woken by the post - ensuring that only a single co-routine is // woken no matter how many times we go around this loop. if( crQUEUE_RECEIVE_FROM_ISR( pxQueue, &cCharToTx, &xCRWokenByPost ) ) { SEND_CHARACTER( cCharToTx ); } } }