/* FreeRTOS V8.0.1 - Copyright (C) 2014 Real Time Engineers Ltd. All rights reserved VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. *************************************************************************** * * * FreeRTOS provides completely free yet professionally developed, * * robust, strictly quality controlled, supported, and cross * * platform software that has become a de facto standard. * * * * Help yourself get started quickly and support the FreeRTOS * * project by purchasing a FreeRTOS tutorial book, reference * * manual, or both from: http://www.FreeRTOS.org/Documentation * * * * Thank you! * * * *************************************************************************** This file is part of the FreeRTOS distribution. FreeRTOS is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License (version 2) as published by the Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception. >>! NOTE: The modification to the GPL is included to allow you to !<< >>! distribute a combined work that includes FreeRTOS without being !<< >>! obliged to provide the source code for proprietary components !<< >>! outside of the FreeRTOS kernel. !<< FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. Full license text is available from the following link: http://www.freertos.org/a00114.html 1 tab == 4 spaces! *************************************************************************** * * * Having a problem? Start by reading the FAQ "My application does * * not run, what could be wrong?" * * * * http://www.FreeRTOS.org/FAQHelp.html * * * *************************************************************************** http://www.FreeRTOS.org - Documentation, books, training, latest versions, license and Real Time Engineers Ltd. contact details. http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products, including FreeRTOS+Trace - an indispensable productivity tool, a DOS compatible FAT file system, and our tiny thread aware UDP/IP stack. http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS licenses offer ticketed support, indemnification and middleware. http://www.SafeRTOS.com - High Integrity Systems also provide a safety engineered and independently SIL3 certified version for use in safety and mission critical applications that require provable dependability. 1 tab == 4 spaces! */ #ifndef CO_ROUTINE_H #define CO_ROUTINE_H #ifndef INC_FREERTOS_H #error "include FreeRTOS.h must appear in source files before include croutine.h" #endif #include "list.h" #ifdef __cplusplus extern "C" { #endif /* Used to hide the implementation of the co-routine control block. The control block structure however has to be included in the header due to the macro implementation of the co-routine functionality. */ typedef void * CoRoutineHandle_t; /* Defines the prototype to which co-routine functions must conform. */ typedef void (*crCOROUTINE_CODE)( CoRoutineHandle_t, UBaseType_t ); typedef struct corCoRoutineControlBlock { crCOROUTINE_CODE pxCoRoutineFunction; ListItem_t xGenericListItem; /*< List item used to place the CRCB in ready and blocked queues. */ ListItem_t xEventListItem; /*< List item used to place the CRCB in event lists. */ UBaseType_t uxPriority; /*< The priority of the co-routine in relation to other co-routines. */ UBaseType_t uxIndex; /*< Used to distinguish between co-routines when multiple co-routines use the same co-routine function. */ uint16_t uxState; /*< Used internally by the co-routine implementation. */ } CRCB_t; /* Co-routine control block. Note must be identical in size down to uxPriority with TCB_t. */ /** * croutine. h *
BaseType_t xCoRoutineCreate( crCOROUTINE_CODE pxCoRoutineCode, UBaseType_t uxPriority, UBaseType_t uxIndex );* * Create a new co-routine and add it to the list of co-routines that are * ready to run. * * @param pxCoRoutineCode Pointer to the co-routine function. Co-routine * functions require special syntax - see the co-routine section of the WEB * documentation for more information. * * @param uxPriority The priority with respect to other co-routines at which * the co-routine will run. * * @param uxIndex Used to distinguish between different co-routines that * execute the same function. See the example below and the co-routine section * of the WEB documentation for further information. * * @return pdPASS if the co-routine was successfully created and added to a ready * list, otherwise an error code defined with ProjDefs.h. * * Example usage:
// Co-routine to be created. void vFlashCoRoutine( CoRoutineHandle_t xHandle, UBaseType_t uxIndex ) { // Variables in co-routines must be declared static if they must maintain value across a blocking call. // This may not be necessary for const variables. static const char cLedToFlash[ 2 ] = { 5, 6 }; static const TickType_t uxFlashRates[ 2 ] = { 200, 400 }; // Must start every co-routine with a call to crSTART(); crSTART( xHandle ); for( ;; ) { // This co-routine just delays for a fixed period, then toggles // an LED. Two co-routines are created using this function, so // the uxIndex parameter is used to tell the co-routine which // LED to flash and how int32_t to delay. This assumes xQueue has // already been created. vParTestToggleLED( cLedToFlash[ uxIndex ] ); crDELAY( xHandle, uxFlashRates[ uxIndex ] ); } // Must end every co-routine with a call to crEND(); crEND(); } // Function that creates two co-routines. void vOtherFunction( void ) { uint8_t ucParameterToPass; TaskHandle_t xHandle; // Create two co-routines at priority 0. The first is given index 0 // so (from the code above) toggles LED 5 every 200 ticks. The second // is given index 1 so toggles LED 6 every 400 ticks. for( uxIndex = 0; uxIndex < 2; uxIndex++ ) { xCoRoutineCreate( vFlashCoRoutine, 0, uxIndex ); } }* \defgroup xCoRoutineCreate xCoRoutineCreate * \ingroup Tasks */ BaseType_t xCoRoutineCreate( crCOROUTINE_CODE pxCoRoutineCode, UBaseType_t uxPriority, UBaseType_t uxIndex ); /** * croutine. h *
void vCoRoutineSchedule( void );* * Run a co-routine. * * vCoRoutineSchedule() executes the highest priority co-routine that is able * to run. The co-routine will execute until it either blocks, yields or is * preempted by a task. Co-routines execute cooperatively so one * co-routine cannot be preempted by another, but can be preempted by a task. * * If an application comprises of both tasks and co-routines then * vCoRoutineSchedule should be called from the idle task (in an idle task * hook). * * Example usage:
// This idle task hook will schedule a co-routine each time it is called. // The rest of the idle task will execute between co-routine calls. void vApplicationIdleHook( void ) { vCoRoutineSchedule(); } // Alternatively, if you do not require any other part of the idle task to // execute, the idle task hook can call vCoRoutineScheduler() within an // infinite loop. void vApplicationIdleHook( void ) { for( ;; ) { vCoRoutineSchedule(); } }* \defgroup vCoRoutineSchedule vCoRoutineSchedule * \ingroup Tasks */ void vCoRoutineSchedule( void ); /** * croutine. h *
crSTART( CoRoutineHandle_t xHandle );* * This macro MUST always be called at the start of a co-routine function. * * Example usage:
// Co-routine to be created. void vACoRoutine( CoRoutineHandle_t xHandle, UBaseType_t uxIndex ) { // Variables in co-routines must be declared static if they must maintain value across a blocking call. static int32_t ulAVariable; // Must start every co-routine with a call to crSTART(); crSTART( xHandle ); for( ;; ) { // Co-routine functionality goes here. } // Must end every co-routine with a call to crEND(); crEND(); }* \defgroup crSTART crSTART * \ingroup Tasks */ #define crSTART( pxCRCB ) switch( ( ( CRCB_t * )( pxCRCB ) )->uxState ) { case 0: /** * croutine. h *
crEND();* * This macro MUST always be called at the end of a co-routine function. * * Example usage:
// Co-routine to be created. void vACoRoutine( CoRoutineHandle_t xHandle, UBaseType_t uxIndex ) { // Variables in co-routines must be declared static if they must maintain value across a blocking call. static int32_t ulAVariable; // Must start every co-routine with a call to crSTART(); crSTART( xHandle ); for( ;; ) { // Co-routine functionality goes here. } // Must end every co-routine with a call to crEND(); crEND(); }* \defgroup crSTART crSTART * \ingroup Tasks */ #define crEND() } /* * These macros are intended for internal use by the co-routine implementation * only. The macros should not be used directly by application writers. */ #define crSET_STATE0( xHandle ) ( ( CRCB_t * )( xHandle ) )->uxState = (__LINE__ * 2); return; case (__LINE__ * 2): #define crSET_STATE1( xHandle ) ( ( CRCB_t * )( xHandle ) )->uxState = ((__LINE__ * 2)+1); return; case ((__LINE__ * 2)+1): /** * croutine. h *
crDELAY( CoRoutineHandle_t xHandle, TickType_t xTicksToDelay );* * Delay a co-routine for a fixed period of time. * * crDELAY can only be called from the co-routine function itself - not * from within a function called by the co-routine function. This is because * co-routines do not maintain their own stack. * * @param xHandle The handle of the co-routine to delay. This is the xHandle * parameter of the co-routine function. * * @param xTickToDelay The number of ticks that the co-routine should delay * for. The actual amount of time this equates to is defined by * configTICK_RATE_HZ (set in FreeRTOSConfig.h). The constant portTICK_PERIOD_MS * can be used to convert ticks to milliseconds. * * Example usage:
// Co-routine to be created. void vACoRoutine( CoRoutineHandle_t xHandle, UBaseType_t uxIndex ) { // Variables in co-routines must be declared static if they must maintain value across a blocking call. // This may not be necessary for const variables. // We are to delay for 200ms. static const xTickType xDelayTime = 200 / portTICK_PERIOD_MS; // Must start every co-routine with a call to crSTART(); crSTART( xHandle ); for( ;; ) { // Delay for 200ms. crDELAY( xHandle, xDelayTime ); // Do something here. } // Must end every co-routine with a call to crEND(); crEND(); }* \defgroup crDELAY crDELAY * \ingroup Tasks */ #define crDELAY( xHandle, xTicksToDelay ) \ if( ( xTicksToDelay ) > 0 ) \ { \ vCoRoutineAddToDelayedList( ( xTicksToDelay ), NULL ); \ } \ crSET_STATE0( ( xHandle ) ); /** *
crQUEUE_SEND( CoRoutineHandle_t xHandle, QueueHandle_t pxQueue, void *pvItemToQueue, TickType_t xTicksToWait, BaseType_t *pxResult )* * The macro's crQUEUE_SEND() and crQUEUE_RECEIVE() are the co-routine * equivalent to the xQueueSend() and xQueueReceive() functions used by tasks. * * crQUEUE_SEND and crQUEUE_RECEIVE can only be used from a co-routine whereas * xQueueSend() and xQueueReceive() can only be used from tasks. * * crQUEUE_SEND can only be called from the co-routine function itself - not * from within a function called by the co-routine function. This is because * co-routines do not maintain their own stack. * * See the co-routine section of the WEB documentation for information on * passing data between tasks and co-routines and between ISR's and * co-routines. * * @param xHandle The handle of the calling co-routine. This is the xHandle * parameter of the co-routine function. * * @param pxQueue The handle of the queue on which the data will be posted. * The handle is obtained as the return value when the queue is created using * the xQueueCreate() API function. * * @param pvItemToQueue A pointer to the data being posted onto the queue. * The number of bytes of each queued item is specified when the queue is * created. This number of bytes is copied from pvItemToQueue into the queue * itself. * * @param xTickToDelay The number of ticks that the co-routine should block * to wait for space to become available on the queue, should space not be * available immediately. The actual amount of time this equates to is defined * by configTICK_RATE_HZ (set in FreeRTOSConfig.h). The constant * portTICK_PERIOD_MS can be used to convert ticks to milliseconds (see example * below). * * @param pxResult The variable pointed to by pxResult will be set to pdPASS if * data was successfully posted onto the queue, otherwise it will be set to an * error defined within ProjDefs.h. * * Example usage:
// Co-routine function that blocks for a fixed period then posts a number onto // a queue. static void prvCoRoutineFlashTask( CoRoutineHandle_t xHandle, UBaseType_t uxIndex ) { // Variables in co-routines must be declared static if they must maintain value across a blocking call. static BaseType_t xNumberToPost = 0; static BaseType_t xResult; // Co-routines must begin with a call to crSTART(). crSTART( xHandle ); for( ;; ) { // This assumes the queue has already been created. crQUEUE_SEND( xHandle, xCoRoutineQueue, &xNumberToPost, NO_DELAY, &xResult ); if( xResult != pdPASS ) { // The message was not posted! } // Increment the number to be posted onto the queue. xNumberToPost++; // Delay for 100 ticks. crDELAY( xHandle, 100 ); } // Co-routines must end with a call to crEND(). crEND(); }* \defgroup crQUEUE_SEND crQUEUE_SEND * \ingroup Tasks */ #define crQUEUE_SEND( xHandle, pxQueue, pvItemToQueue, xTicksToWait, pxResult ) \ { \ *( pxResult ) = xQueueCRSend( ( pxQueue) , ( pvItemToQueue) , ( xTicksToWait ) ); \ if( *( pxResult ) == errQUEUE_BLOCKED ) \ { \ crSET_STATE0( ( xHandle ) ); \ *pxResult = xQueueCRSend( ( pxQueue ), ( pvItemToQueue ), 0 ); \ } \ if( *pxResult == errQUEUE_YIELD ) \ { \ crSET_STATE1( ( xHandle ) ); \ *pxResult = pdPASS; \ } \ } /** * croutine. h *
crQUEUE_RECEIVE( CoRoutineHandle_t xHandle, QueueHandle_t pxQueue, void *pvBuffer, TickType_t xTicksToWait, BaseType_t *pxResult )* * The macro's crQUEUE_SEND() and crQUEUE_RECEIVE() are the co-routine * equivalent to the xQueueSend() and xQueueReceive() functions used by tasks. * * crQUEUE_SEND and crQUEUE_RECEIVE can only be used from a co-routine whereas * xQueueSend() and xQueueReceive() can only be used from tasks. * * crQUEUE_RECEIVE can only be called from the co-routine function itself - not * from within a function called by the co-routine function. This is because * co-routines do not maintain their own stack. * * See the co-routine section of the WEB documentation for information on * passing data between tasks and co-routines and between ISR's and * co-routines. * * @param xHandle The handle of the calling co-routine. This is the xHandle * parameter of the co-routine function. * * @param pxQueue The handle of the queue from which the data will be received. * The handle is obtained as the return value when the queue is created using * the xQueueCreate() API function. * * @param pvBuffer The buffer into which the received item is to be copied. * The number of bytes of each queued item is specified when the queue is * created. This number of bytes is copied into pvBuffer. * * @param xTickToDelay The number of ticks that the co-routine should block * to wait for data to become available from the queue, should data not be * available immediately. The actual amount of time this equates to is defined * by configTICK_RATE_HZ (set in FreeRTOSConfig.h). The constant * portTICK_PERIOD_MS can be used to convert ticks to milliseconds (see the * crQUEUE_SEND example). * * @param pxResult The variable pointed to by pxResult will be set to pdPASS if * data was successfully retrieved from the queue, otherwise it will be set to * an error code as defined within ProjDefs.h. * * Example usage:
// A co-routine receives the number of an LED to flash from a queue. It // blocks on the queue until the number is received. static void prvCoRoutineFlashWorkTask( CoRoutineHandle_t xHandle, UBaseType_t uxIndex ) { // Variables in co-routines must be declared static if they must maintain value across a blocking call. static BaseType_t xResult; static UBaseType_t uxLEDToFlash; // All co-routines must start with a call to crSTART(). crSTART( xHandle ); for( ;; ) { // Wait for data to become available on the queue. crQUEUE_RECEIVE( xHandle, xCoRoutineQueue, &uxLEDToFlash, portMAX_DELAY, &xResult ); if( xResult == pdPASS ) { // We received the LED to flash - flash it! vParTestToggleLED( uxLEDToFlash ); } } crEND(); }* \defgroup crQUEUE_RECEIVE crQUEUE_RECEIVE * \ingroup Tasks */ #define crQUEUE_RECEIVE( xHandle, pxQueue, pvBuffer, xTicksToWait, pxResult ) \ { \ *( pxResult ) = xQueueCRReceive( ( pxQueue) , ( pvBuffer ), ( xTicksToWait ) ); \ if( *( pxResult ) == errQUEUE_BLOCKED ) \ { \ crSET_STATE0( ( xHandle ) ); \ *( pxResult ) = xQueueCRReceive( ( pxQueue) , ( pvBuffer ), 0 ); \ } \ if( *( pxResult ) == errQUEUE_YIELD ) \ { \ crSET_STATE1( ( xHandle ) ); \ *( pxResult ) = pdPASS; \ } \ } /** * croutine. h *
crQUEUE_SEND_FROM_ISR( QueueHandle_t pxQueue, void *pvItemToQueue, BaseType_t xCoRoutinePreviouslyWoken )* * The macro's crQUEUE_SEND_FROM_ISR() and crQUEUE_RECEIVE_FROM_ISR() are the * co-routine equivalent to the xQueueSendFromISR() and xQueueReceiveFromISR() * functions used by tasks. * * crQUEUE_SEND_FROM_ISR() and crQUEUE_RECEIVE_FROM_ISR() can only be used to * pass data between a co-routine and and ISR, whereas xQueueSendFromISR() and * xQueueReceiveFromISR() can only be used to pass data between a task and and * ISR. * * crQUEUE_SEND_FROM_ISR can only be called from an ISR to send data to a queue * that is being used from within a co-routine. * * See the co-routine section of the WEB documentation for information on * passing data between tasks and co-routines and between ISR's and * co-routines. * * @param xQueue The handle to the queue on which the item is to be posted. * * @param pvItemToQueue A pointer to the item that is to be placed on the * queue. The size of the items the queue will hold was defined when the * queue was created, so this many bytes will be copied from pvItemToQueue * into the queue storage area. * * @param xCoRoutinePreviouslyWoken This is included so an ISR can post onto * the same queue multiple times from a single interrupt. The first call * should always pass in pdFALSE. Subsequent calls should pass in * the value returned from the previous call. * * @return pdTRUE if a co-routine was woken by posting onto the queue. This is * used by the ISR to determine if a context switch may be required following * the ISR. * * Example usage:
// A co-routine that blocks on a queue waiting for characters to be received. static void vReceivingCoRoutine( CoRoutineHandle_t xHandle, UBaseType_t uxIndex ) { char cRxedChar; BaseType_t xResult; // All co-routines must start with a call to crSTART(). crSTART( xHandle ); for( ;; ) { // Wait for data to become available on the queue. This assumes the // queue xCommsRxQueue has already been created! crQUEUE_RECEIVE( xHandle, xCommsRxQueue, &uxLEDToFlash, portMAX_DELAY, &xResult ); // Was a character received? if( xResult == pdPASS ) { // Process the character here. } } // All co-routines must end with a call to crEND(). crEND(); } // An ISR that uses a queue to send characters received on a serial port to // a co-routine. void vUART_ISR( void ) { char cRxedChar; BaseType_t xCRWokenByPost = pdFALSE; // We loop around reading characters until there are none left in the UART. while( UART_RX_REG_NOT_EMPTY() ) { // Obtain the character from the UART. cRxedChar = UART_RX_REG; // Post the character onto a queue. xCRWokenByPost will be pdFALSE // the first time around the loop. If the post causes a co-routine // to be woken (unblocked) then xCRWokenByPost will be set to pdTRUE. // In this manner we can ensure that if more than one co-routine is // blocked on the queue only one is woken by this ISR no matter how // many characters are posted to the queue. xCRWokenByPost = crQUEUE_SEND_FROM_ISR( xCommsRxQueue, &cRxedChar, xCRWokenByPost ); } }* \defgroup crQUEUE_SEND_FROM_ISR crQUEUE_SEND_FROM_ISR * \ingroup Tasks */ #define crQUEUE_SEND_FROM_ISR( pxQueue, pvItemToQueue, xCoRoutinePreviouslyWoken ) xQueueCRSendFromISR( ( pxQueue ), ( pvItemToQueue ), ( xCoRoutinePreviouslyWoken ) ) /** * croutine. h *
crQUEUE_SEND_FROM_ISR( QueueHandle_t pxQueue, void *pvBuffer, BaseType_t * pxCoRoutineWoken )* * The macro's crQUEUE_SEND_FROM_ISR() and crQUEUE_RECEIVE_FROM_ISR() are the * co-routine equivalent to the xQueueSendFromISR() and xQueueReceiveFromISR() * functions used by tasks. * * crQUEUE_SEND_FROM_ISR() and crQUEUE_RECEIVE_FROM_ISR() can only be used to * pass data between a co-routine and and ISR, whereas xQueueSendFromISR() and * xQueueReceiveFromISR() can only be used to pass data between a task and and * ISR. * * crQUEUE_RECEIVE_FROM_ISR can only be called from an ISR to receive data * from a queue that is being used from within a co-routine (a co-routine * posted to the queue). * * See the co-routine section of the WEB documentation for information on * passing data between tasks and co-routines and between ISR's and * co-routines. * * @param xQueue The handle to the queue on which the item is to be posted. * * @param pvBuffer A pointer to a buffer into which the received item will be * placed. The size of the items the queue will hold was defined when the * queue was created, so this many bytes will be copied from the queue into * pvBuffer. * * @param pxCoRoutineWoken A co-routine may be blocked waiting for space to become * available on the queue. If crQUEUE_RECEIVE_FROM_ISR causes such a * co-routine to unblock *pxCoRoutineWoken will get set to pdTRUE, otherwise * *pxCoRoutineWoken will remain unchanged. * * @return pdTRUE an item was successfully received from the queue, otherwise * pdFALSE. * * Example usage:
// 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 ); } } }* \defgroup crQUEUE_RECEIVE_FROM_ISR crQUEUE_RECEIVE_FROM_ISR * \ingroup Tasks */ #define crQUEUE_RECEIVE_FROM_ISR( pxQueue, pvBuffer, pxCoRoutineWoken ) xQueueCRReceiveFromISR( ( pxQueue ), ( pvBuffer ), ( pxCoRoutineWoken ) ) /* * This function is intended for internal use by the co-routine macros only. * The macro nature of the co-routine implementation requires that the * prototype appears here. The function should not be used by application * writers. * * Removes the current co-routine from its ready list and places it in the * appropriate delayed list. */ void vCoRoutineAddToDelayedList( TickType_t xTicksToDelay, List_t *pxEventList ); /* * This function is intended for internal use by the queue implementation only. * The function should not be used by application writers. * * Removes the highest priority co-routine from the event list and places it in * the pending ready list. */ BaseType_t xCoRoutineRemoveFromEventList( const List_t *pxEventList ); #ifdef __cplusplus } #endif #endif /* CO_ROUTINE_H */