/* * FreeRTOS Kernel V10.4.4 * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved. * * SPDX-License-Identifier: MIT * * Permission is hereby granted, free of charge, to any person obtaining a copy of * this software and associated documentation files (the "Software"), to deal in * the Software without restriction, including without limitation the rights to * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of * the Software, and to permit persons to whom the Software is furnished to do so, * subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all * copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. * * https://www.FreeRTOS.org * https://github.com/FreeRTOS * */ #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" /* *INDENT-OFF* */ #ifdef __cplusplus extern "C" { #endif /* *INDENT-ON* */ /* 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 vCoRoutineSchedule() 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 ); /* *INDENT-OFF* */ #ifdef __cplusplus } #endif /* *INDENT-ON* */ #endif /* CO_ROUTINE_H */