diff options
Diffstat (limited to 'src/FreeRTOS/Source/include/croutine.h')
| -rw-r--r-- | src/FreeRTOS/Source/include/croutine.h | 758 |
1 files changed, 758 insertions, 0 deletions
diff --git a/src/FreeRTOS/Source/include/croutine.h b/src/FreeRTOS/Source/include/croutine.h new file mode 100644 index 0000000..e9fbadc --- /dev/null +++ b/src/FreeRTOS/Source/include/croutine.h @@ -0,0 +1,758 @@ +/*
+ 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
+ *<pre>
+ BaseType_t xCoRoutineCreate(
+ crCOROUTINE_CODE pxCoRoutineCode,
+ UBaseType_t uxPriority,
+ UBaseType_t uxIndex
+ );</pre>
+ *
+ * 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:
+ <pre>
+ // 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 );
+ }
+ }
+ </pre>
+ * \defgroup xCoRoutineCreate xCoRoutineCreate
+ * \ingroup Tasks
+ */
+BaseType_t xCoRoutineCreate( crCOROUTINE_CODE pxCoRoutineCode, UBaseType_t uxPriority, UBaseType_t uxIndex );
+
+
+/**
+ * croutine. h
+ *<pre>
+ void vCoRoutineSchedule( void );</pre>
+ *
+ * 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:
+ <pre>
+ // 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();
+ }
+ }
+ </pre>
+ * \defgroup vCoRoutineSchedule vCoRoutineSchedule
+ * \ingroup Tasks
+ */
+void vCoRoutineSchedule( void );
+
+/**
+ * croutine. h
+ * <pre>
+ crSTART( CoRoutineHandle_t xHandle );</pre>
+ *
+ * This macro MUST always be called at the start of a co-routine function.
+ *
+ * Example usage:
+ <pre>
+ // 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();
+ }</pre>
+ * \defgroup crSTART crSTART
+ * \ingroup Tasks
+ */
+#define crSTART( pxCRCB ) switch( ( ( CRCB_t * )( pxCRCB ) )->uxState ) { case 0:
+
+/**
+ * croutine. h
+ * <pre>
+ crEND();</pre>
+ *
+ * This macro MUST always be called at the end of a co-routine function.
+ *
+ * Example usage:
+ <pre>
+ // 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();
+ }</pre>
+ * \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
+ *<pre>
+ crDELAY( CoRoutineHandle_t xHandle, TickType_t xTicksToDelay );</pre>
+ *
+ * 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:
+ <pre>
+ // 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();
+ }</pre>
+ * \defgroup crDELAY crDELAY
+ * \ingroup Tasks
+ */
+#define crDELAY( xHandle, xTicksToDelay ) \
+ if( ( xTicksToDelay ) > 0 ) \
+ { \
+ vCoRoutineAddToDelayedList( ( xTicksToDelay ), NULL ); \
+ } \
+ crSET_STATE0( ( xHandle ) );
+
+/**
+ * <pre>
+ crQUEUE_SEND(
+ CoRoutineHandle_t xHandle,
+ QueueHandle_t pxQueue,
+ void *pvItemToQueue,
+ TickType_t xTicksToWait,
+ BaseType_t *pxResult
+ )</pre>
+ *
+ * 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:
+ <pre>
+ // 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();
+ }</pre>
+ * \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
+ * <pre>
+ crQUEUE_RECEIVE(
+ CoRoutineHandle_t xHandle,
+ QueueHandle_t pxQueue,
+ void *pvBuffer,
+ TickType_t xTicksToWait,
+ BaseType_t *pxResult
+ )</pre>
+ *
+ * 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:
+ <pre>
+ // 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();
+ }</pre>
+ * \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
+ * <pre>
+ crQUEUE_SEND_FROM_ISR(
+ QueueHandle_t pxQueue,
+ void *pvItemToQueue,
+ BaseType_t xCoRoutinePreviouslyWoken
+ )</pre>
+ *
+ * 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:
+ <pre>
+ // 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 );
+ }
+ }</pre>
+ * \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
+ * <pre>
+ crQUEUE_SEND_FROM_ISR(
+ QueueHandle_t pxQueue,
+ void *pvBuffer,
+ BaseType_t * pxCoRoutineWoken
+ )</pre>
+ *
+ * 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:
+ <pre>
+ // 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 );
+ }
+ }
+ }</pre>
+ * \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 */
|