From 41f5c3f4dc06e82afdb33bb09525de4865edc00f Mon Sep 17 00:00:00 2001 From: richardbarry Date: Thu, 27 Jun 2013 09:21:43 +0000 Subject: [PATCH] Add xQueueOverwrite() and a common demo task to demonstrate its use. Update MSVC Win32 demo to include the xQueueOverwrite() common demo tasks. git-svn-id: https://svn.code.sf.net/p/freertos/code/trunk@1953 1d2547de-c912-0410-9cb9-b8ca96c0e9e2 --- FreeRTOS/Demo/Common/Minimal/QueueOverwrite.c | 197 ++++++++++++++++++ FreeRTOS/Demo/Common/include/QueueOverwrite.h | 83 ++++++++ FreeRTOS/Demo/WIN32-MSVC/WIN32.vcxproj | 1 + .../Demo/WIN32-MSVC/WIN32.vcxproj.filters | 3 + FreeRTOS/Demo/WIN32-MSVC/main.c | 159 ++++++++------ FreeRTOS/Source/include/queue.h | 87 +++++++- FreeRTOS/Source/queue.c | 26 ++- FreeRTOS/Source/tasks.c | 9 +- 8 files changed, 491 insertions(+), 74 deletions(-) create mode 100644 FreeRTOS/Demo/Common/Minimal/QueueOverwrite.c create mode 100644 FreeRTOS/Demo/Common/include/QueueOverwrite.h diff --git a/FreeRTOS/Demo/Common/Minimal/QueueOverwrite.c b/FreeRTOS/Demo/Common/Minimal/QueueOverwrite.c new file mode 100644 index 000000000..e554201bd --- /dev/null +++ b/FreeRTOS/Demo/Common/Minimal/QueueOverwrite.c @@ -0,0 +1,197 @@ +/* + FreeRTOS V7.4.2 - Copyright (C) 2013 Real Time Engineers Ltd. + + FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT + http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. + + *************************************************************************** + * * + * FreeRTOS tutorial books are available in pdf and paperback. * + * Complete, revised, and edited pdf reference manuals are also * + * available. * + * * + * Purchasing FreeRTOS documentation will not only help you, by * + * ensuring you get running as quickly as possible and with an * + * in-depth knowledge of how to use FreeRTOS, it will also help * + * the FreeRTOS project to continue with its mission of providing * + * professional grade, cross platform, de facto standard solutions * + * for microcontrollers - completely free of charge! * + * * + * >>> See http://www.FreeRTOS.org/Documentation for details. <<< * + * * + * Thank you for using FreeRTOS, and thank you for your support! * + * * + *************************************************************************** + + + 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. See the GNU General Public License for more + details. You should have received a copy of the GNU General Public License + and the FreeRTOS license exception along with FreeRTOS; if not it can be + viewed here: http://www.freertos.org/a00114.html and also obtained by + writing to Real Time Engineers Ltd., contact details for whom are available + on the FreeRTOS WEB site. + + 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, and our new + fully thread aware and reentrant UDP/IP stack. + + http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High + Integrity Systems, who sell the code with commercial support, + indemnification and middleware, under the OpenRTOS brand. + + 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. +*/ + +/* + * Basic task to demonstrate the xQueueOverwrite() function. See the comments + * in the function itself. + */ + +/* Scheduler include files. */ +#include "FreeRTOS.h" +#include "task.h" +#include "queue.h" + +/* Demo program include files. */ +#include "QueueOverwrite.h" + +/* A block time of 0 just means "don't block". */ +#define qoDONT_BLOCK 0 + +/* Number of times to overwrite the value in the queue. */ +#define qoLOOPS 5 + +/* The task that uses the queue. */ +static void prvQueueOverwriteTask( void *pvParameters ); + +/* Variable that is incremented on each loop of prvQueueOverwriteTask() provided +prvQueueOverwriteTask() has not found any errors. */ +static unsigned long ulLoopCounter = 0; + +/*-----------------------------------------------------------*/ + +void vStartQueueOverwriteTask( unsigned portBASE_TYPE uxPriority ) +{ + /* Create the test task. */ + xTaskCreate( prvQueueOverwriteTask, ( signed char * ) "QOver", configMINIMAL_STACK_SIZE, NULL, uxPriority, ( xTaskHandle * ) NULL ); +} +/*-----------------------------------------------------------*/ + +static void prvQueueOverwriteTask( void *pvParameters ) +{ +xQueueHandle xQueue; +const unsigned portBASE_TYPE uxQueueLength = 1; +unsigned long ulValue, ulStatus = pdPASS, x; + + /* The parameter is not used. */ + ( void ) pvParameters; + + /* Create the queue. xQueueOverwrite() should only be used on queues that + have a length of 1. */ + xQueue = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( unsigned long ) ); + configASSERT( xQueue ); + + for( ;; ) + { + /* The queue is empty. Writing to the queue then reading from the queue + should return the item written. */ + ulValue = 10; + xQueueOverwrite( xQueue, &ulValue ); + + ulValue = 0; + xQueueReceive( xQueue, &ulValue, qoDONT_BLOCK ); + + if( ulValue != 10 ) + { + ulStatus = pdFAIL; + } + + /* Now try writing to the queue several times. Each time the value + in the queue should get overwritten. */ + for( x = 0; x < qoLOOPS; x++ ) + { + /* Write to the queue. */ + xQueueOverwrite( xQueue, &x ); + + /* Check the value in the queue is that written, even though the + queue was not necessarily empty. */ + xQueuePeek( xQueue, &ulValue, qoDONT_BLOCK ); + if( ulValue != x ) + { + ulStatus = pdFAIL; + } + + /* There should always be one item in the queue. */ + if( uxQueueMessagesWaiting( xQueue ) != uxQueueLength ) + { + ulStatus = pdFAIL; + } + } + + /* Empty the queue again. */ + xQueueReceive( xQueue, &ulValue, qoDONT_BLOCK ); + + if( uxQueueMessagesWaiting( xQueue ) != 0 ) + { + ulStatus = pdFAIL; + } + + if( ulStatus != pdFAIL ) + { + /* Increment a counter to show this task is still running without + error. */ + ulLoopCounter++; + } + } +} +/*-----------------------------------------------------------*/ + +portBASE_TYPE xIsQueueOverwriteTaskStillRunning( void ) +{ +portBASE_TYPE xReturn; + + if( ulLoopCounter > 0 ) + { + xReturn = pdPASS; + } + else + { + /* The task has either stalled of discovered an error. */ + xReturn = pdFAIL; + } + + ulLoopCounter = 0; + + return xReturn; +} + diff --git a/FreeRTOS/Demo/Common/include/QueueOverwrite.h b/FreeRTOS/Demo/Common/include/QueueOverwrite.h new file mode 100644 index 000000000..c4fba5ffb --- /dev/null +++ b/FreeRTOS/Demo/Common/include/QueueOverwrite.h @@ -0,0 +1,83 @@ +/* + FreeRTOS V7.4.2 - Copyright (C) 2013 Real Time Engineers Ltd. + + FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT + http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. + + *************************************************************************** + * * + * FreeRTOS tutorial books are available in pdf and paperback. * + * Complete, revised, and edited pdf reference manuals are also * + * available. * + * * + * Purchasing FreeRTOS documentation will not only help you, by * + * ensuring you get running as quickly as possible and with an * + * in-depth knowledge of how to use FreeRTOS, it will also help * + * the FreeRTOS project to continue with its mission of providing * + * professional grade, cross platform, de facto standard solutions * + * for microcontrollers - completely free of charge! * + * * + * >>> See http://www.FreeRTOS.org/Documentation for details. <<< * + * * + * Thank you for using FreeRTOS, and thank you for your support! * + * * + *************************************************************************** + + + 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. See the GNU General Public License for more + details. You should have received a copy of the GNU General Public License + and the FreeRTOS license exception along with FreeRTOS; if not it can be + viewed here: http://www.freertos.org/a00114.html and also obtained by + writing to Real Time Engineers Ltd., contact details for whom are available + on the FreeRTOS WEB site. + + 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, and our new + fully thread aware and reentrant UDP/IP stack. + + http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High + Integrity Systems, who sell the code with commercial support, + indemnification and middleware, under the OpenRTOS brand. + + 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. +*/ + +#ifndef QUEUE_OVERWRITE_H +#define QUEUE_OVERWRITE_H + +void vStartQueueOverwriteTask( unsigned portBASE_TYPE uxPriority ); +portBASE_TYPE xIsQueueOverwriteTaskStillRunning( void ); + +#endif /* QUEUE_OVERWRITE_H */ + + diff --git a/FreeRTOS/Demo/WIN32-MSVC/WIN32.vcxproj b/FreeRTOS/Demo/WIN32-MSVC/WIN32.vcxproj index 5dc922e25..d508250e0 100644 --- a/FreeRTOS/Demo/WIN32-MSVC/WIN32.vcxproj +++ b/FreeRTOS/Demo/WIN32-MSVC/WIN32.vcxproj @@ -143,6 +143,7 @@ + diff --git a/FreeRTOS/Demo/WIN32-MSVC/WIN32.vcxproj.filters b/FreeRTOS/Demo/WIN32-MSVC/WIN32.vcxproj.filters index 9717019cf..910b75716 100644 --- a/FreeRTOS/Demo/WIN32-MSVC/WIN32.vcxproj.filters +++ b/FreeRTOS/Demo/WIN32-MSVC/WIN32.vcxproj.filters @@ -121,6 +121,9 @@ Demo App Source\FreeRTOS+Trace Recorder + + Demo App Source\Common Demo Tasks + diff --git a/FreeRTOS/Demo/WIN32-MSVC/main.c b/FreeRTOS/Demo/WIN32-MSVC/main.c index 1160a05ea..0dc4dcd45 100644 --- a/FreeRTOS/Demo/WIN32-MSVC/main.c +++ b/FreeRTOS/Demo/WIN32-MSVC/main.c @@ -132,6 +132,7 @@ #include "death.h" #include "dynamic.h" #include "QueueSet.h" +#include "QueueOverwrite.h" /* Priorities at which the tasks are created. */ #define mainCHECK_TASK_PRIORITY ( configMAX_PRIORITIES - 1 ) @@ -144,6 +145,7 @@ #define mainINTEGER_TASK_PRIORITY ( tskIDLE_PRIORITY ) #define mainGEN_QUEUE_TASK_PRIORITY ( tskIDLE_PRIORITY ) #define mainFLOP_TASK_PRIORITY ( tskIDLE_PRIORITY ) +#define mainQUEUE_OVERWRITE_PRIORITY ( tskIDLE_PRIORITY ) #define mainTIMER_TEST_PERIOD ( 50 ) @@ -160,6 +162,12 @@ static void prvTestTask( void *pvParameters ); */ static void prvSaveTraceFile( void ); +/* + * Called from the idle task hook function to demonstrate a few utility + * functions that are not demonstrated by any of the standard demo tasks. + */ +static void prvDemonstrateTaskStateAndHandleGetFunctions( void ); + /*-----------------------------------------------------------*/ /* The variable into which error messages are latched. */ @@ -200,6 +208,7 @@ int main( void ) vStartCountingSemaphoreTasks(); vStartDynamicPriorityTasks(); vStartQueueSetTasks(); + vStartQueueOverwriteTask( mainQUEUE_OVERWRITE_PRIORITY ); /* The suicide tasks must be created last as they need to know how many tasks were running prior to their creation. This then allows them to @@ -294,6 +303,10 @@ const portTickType xCycleFrequency = 1000 / portTICK_RATE_MS; { pcStatusMessage = "Error: Queue set\r\n"; } + else if( xIsQueueOverwriteTaskStillRunning() != pdPASS ) + { + pcStatusMessage = "Error: Queue overwrite\r\n"; + } /* This is the only task that uses stdout so its ok to call printf() directly. */ @@ -323,9 +336,7 @@ const unsigned long ulMSToSleep = 5; void vApplicationIdleHook( void ) { const unsigned long ulMSToSleep = 15; -xTaskHandle xIdleTaskHandle, xTimerTaskHandle, xTestTask; -signed char *pcTaskName; -const unsigned char ucConstQueueNumber = 0xaaU, ucConstTaskNumber = 0x55U; +const unsigned char ucConstQueueNumber = 0xaaU; void *pvAllocated; static portBASE_TYPE xTraceRunning = pdTRUE; @@ -341,39 +352,9 @@ extern unsigned portBASE_TYPE uxTaskGetTaskNumber( xTaskHandle xTask ); tasks waiting to be terminated by the idle task. */ Sleep( ulMSToSleep ); - /* Demonstrate the use of the xTimerGetTimerDaemonTaskHandle() and - xTaskGetIdleTaskHandle() functions. Also try using the function that sets - the task number. */ - xIdleTaskHandle = xTaskGetIdleTaskHandle(); - xTimerTaskHandle = xTimerGetTimerDaemonTaskHandle(); - vTaskSetTaskNumber( xIdleTaskHandle, ( unsigned long ) ucConstTaskNumber ); - configASSERT( uxTaskGetTaskNumber( xIdleTaskHandle ) == ucConstTaskNumber ); - - /* This is the idle hook, so the current task handle should equal the - returned idle task handle. */ - if( xTaskGetCurrentTaskHandle() != xIdleTaskHandle ) - { - pcStatusMessage = "Error: Returned idle task handle was incorrect"; - } - - /* Check the timer task handle was returned correctly. */ - pcTaskName = pcTaskGetTaskName( xTimerTaskHandle ); - if( strcmp( pcTaskName, "Tmr Svc" ) != 0 ) - { - pcStatusMessage = "Error: Returned timer task handle was incorrect"; - } - - /* This task is running, make sure its state is returned as running. */ - if( eTaskStateGet( xIdleTaskHandle ) != eRunning ) - { - pcStatusMessage = "Error: Returned idle task state was incorrect"; - } - - /* If this task is running, then the timer task must be blocked. */ - if( eTaskStateGet( xTimerTaskHandle ) != eBlocked ) - { - pcStatusMessage = "Error: Returned timer task state was incorrect"; - } + /* Demonstrate a few utility functions that are not demonstrated by any of + the standard demo tasks. */ + prvDemonstrateTaskStateAndHandleGetFunctions(); /* If xMutexToDelete has not already been deleted, then delete it now. This is done purely to demonstrate the use of, and test, the @@ -393,34 +374,6 @@ extern unsigned portBASE_TYPE uxTaskGetTaskNumber( xTaskHandle xTask ); configASSERT( ucQueueGetQueueType( xMutexToDelete ) == queueQUEUE_TYPE_MUTEX ); vSemaphoreDelete( xMutexToDelete ); xMutexToDelete = NULL; - - /* Other tests that should only be performed once follow. The test task - is not created on each iteration because to do so would cause the death - task to report an error (too many tasks running). */ - - /* Create a test task to use to test other eTaskStateGet() return values. */ - if( xTaskCreate( prvTestTask, "Test", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY, &xTestTask ) == pdPASS ) - { - /* If this task is running, the test task must be in the ready state. */ - if( eTaskStateGet( xTestTask ) != eReady ) - { - pcStatusMessage = "Error: Returned test task state was incorrect 1"; - } - - /* Now suspend the test task and check its state is reported correctly. */ - vTaskSuspend( xTestTask ); - if( eTaskStateGet( xTestTask ) != eSuspended ) - { - pcStatusMessage = "Error: Returned test task state was incorrect 2"; - } - - /* Now delete the task and check its state is reported correctly. */ - vTaskDelete( xTestTask ); - if( eTaskStateGet( xTestTask ) != eDeleted ) - { - pcStatusMessage = "Error: Returned test task state was incorrect 3"; - } - } } /* Exercise heap_4 a bit. The malloc failed hook will trap failed @@ -499,3 +452,81 @@ FILE* pxOutputFile; printf( "\r\nFailed to create trace dump file\r\n" ); } } +/*-----------------------------------------------------------*/ + +static void prvDemonstrateTaskStateAndHandleGetFunctions( void ) +{ +xTaskHandle xIdleTaskHandle, xTimerTaskHandle; +const unsigned char ucConstTaskNumber = 0x55U; +signed char *pcTaskName; +static portBASE_TYPE xPerformedOneShotTests = pdFALSE; +xTaskHandle xTestTask; + + /* Demonstrate the use of the xTimerGetTimerDaemonTaskHandle() and + xTaskGetIdleTaskHandle() functions. Also try using the function that sets + the task number. */ + xIdleTaskHandle = xTaskGetIdleTaskHandle(); + xTimerTaskHandle = xTimerGetTimerDaemonTaskHandle(); + vTaskSetTaskNumber( xIdleTaskHandle, ( unsigned long ) ucConstTaskNumber ); + configASSERT( uxTaskGetTaskNumber( xIdleTaskHandle ) == ucConstTaskNumber ); + + /* This is the idle hook, so the current task handle should equal the + returned idle task handle. */ + if( xTaskGetCurrentTaskHandle() != xIdleTaskHandle ) + { + pcStatusMessage = "Error: Returned idle task handle was incorrect"; + } + + /* Check the timer task handle was returned correctly. */ + pcTaskName = pcTaskGetTaskName( xTimerTaskHandle ); + if( strcmp( pcTaskName, "Tmr Svc" ) != 0 ) + { + pcStatusMessage = "Error: Returned timer task handle was incorrect"; + } + + /* This task is running, make sure it's state is returned as running. */ + if( eTaskStateGet( xIdleTaskHandle ) != eRunning ) + { + pcStatusMessage = "Error: Returned idle task state was incorrect"; + } + + /* If this task is running, then the timer task must be blocked. */ + if( eTaskStateGet( xTimerTaskHandle ) != eBlocked ) + { + pcStatusMessage = "Error: Returned timer task state was incorrect"; + } + + /* Other tests that should only be performed once follow. The test task + is not created on each iteration because to do so would cause the death + task to report an error (too many tasks running). */ + if( xPerformedOneShotTests == pdFALSE ) + { + /* Don't run this part of the test again. */ + xPerformedOneShotTests = pdTRUE; + + /* Create a test task to use to test other eTaskStateGet() return values. */ + if( xTaskCreate( prvTestTask, "Test", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY, &xTestTask ) == pdPASS ) + { + /* If this task is running, the test task must be in the ready state. */ + if( eTaskStateGet( xTestTask ) != eReady ) + { + pcStatusMessage = "Error: Returned test task state was incorrect 1"; + } + + /* Now suspend the test task and check its state is reported correctly. */ + vTaskSuspend( xTestTask ); + if( eTaskStateGet( xTestTask ) != eSuspended ) + { + pcStatusMessage = "Error: Returned test task state was incorrect 2"; + } + + /* Now delete the task and check its state is reported correctly. */ + vTaskDelete( xTestTask ); + if( eTaskStateGet( xTestTask ) != eDeleted ) + { + pcStatusMessage = "Error: Returned test task state was incorrect 3"; + } + } + } +} + diff --git a/FreeRTOS/Source/include/queue.h b/FreeRTOS/Source/include/queue.h index 3de926022..f81a91fae 100644 --- a/FreeRTOS/Source/include/queue.h +++ b/FreeRTOS/Source/include/queue.h @@ -109,8 +109,9 @@ typedef void * xQueueSetHandle; typedef void * xQueueSetMemberHandle; /* For internal use only. */ -#define queueSEND_TO_BACK ( 0 ) -#define queueSEND_TO_FRONT ( 1 ) +#define queueSEND_TO_BACK ( 0 ) +#define queueSEND_TO_FRONT ( 1 ) +#define queueOVERWRITE ( 2 ) /* For internal use only. These definitions *must* match those in queue.c. */ #define queueQUEUE_TYPE_BASE ( 0U ) @@ -426,6 +427,88 @@ typedef void * xQueueSetMemberHandle; */ #define xQueueSend( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_BACK ) +/** + * queue. h + * 
+ portBASE_TYPE xQueueOverwrite(
+							  xQueueHandle xQueue,
+							  const void * pvItemToQueue,
+						 );
+ *
+ * + * Only for use with queues that can hold a single item - so the queue is either + * empty or full. + * + * Post an item on a queue. If the queue is already full then overwrite the + * value held in the queue. The item is queued by copy, not by reference. + * This function must not be called from an interrupt service routine. + * See xQueueOverwriteFromISR () for an alternative which may be used in an ISR. + * + * @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. + * + * @return xQueueOverwrite() is a macro that calls xQueueGenericSend(), and + * therefore has the same return values as xQueueSendToFront(). However, as + * xQueueOverwrite() will write to the queue even when the queue is full pdPASS + * will be returned in all cases (errQUEUE_FULL will never be returned). + * + * Example usage: + 
+
+ void vFunction( void *pvParameters )
+ {
+ xQueueHandle xQueue;
+ unsigned long ulVarToSend, ulValReceived;
+
+	// Create a queue to hold one unsigned long value.  It is strongly
+	// recommended *not* to use xQueueOverwrite() on queues that can
+	// contain more than one value, and doing so will trigger an assertion
+	// if configASSERT() is defined.
+	xQueue = xQueueCreate( 1, sizeof( unsigned long ) );
+
+	// Write the value 10 to the queue using xQueueOverwrite().
+	ulVarToSend = 10;
+	xQueueOverwrite( xQueue, &ulVarToSend );
+
+	// Peeking the queue should now return 10, but leave the value 10 in
+	// the queue.  A block time of zero is used as it is known that the
+	// queue holds a value.
+	ulValReceived = 0;
+	xQueuePeek( xQueue, &ulValReceived, 0 );
+
+	if( ulValReceived != 10 )
+	{
+		// Error!
+	}
+
+	// The queue is still full.  Use xQueueOverwrite() to overwrite the
+	// value held in the queue with 100.
+	ulVarToSend = 100;
+	xQueueOverwrite( xQueue, &ulVarToSend );
+
+	// This time read from the queue, leaving the queue empty once more.
+	// A block time of 0 is used again.
+	xQueueReceive( xQueue, &ulValReceived, 0 );
+
+	// The value read should be the last value written, even though the
+	// queue was already full when the value was written.
+	if( ulValReceived != 100 )
+	{
+		// Error!
+	}
+
+	// ...
+}
+
+ * \defgroup xQueueOverwrite xQueueOverwrite + * \ingroup QueueManagement + */ +#define xQueueOverwrite( xQueue, pvItemToQueue ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), 0, queueOVERWRITE ) + /** * queue. h diff --git a/FreeRTOS/Source/queue.c b/FreeRTOS/Source/queue.c index 2698099f5..cd1c8545e 100644 --- a/FreeRTOS/Source/queue.c +++ b/FreeRTOS/Source/queue.c @@ -570,6 +570,7 @@ xQUEUE *pxQueue; pxQueue = ( xQUEUE * ) xQueue; configASSERT( pxQueue ); configASSERT( !( ( pvItemToQueue == NULL ) && ( pxQueue->uxItemSize != ( unsigned portBASE_TYPE ) 0U ) ) ); + configASSERT( !( ( xCopyPosition == queueOVERWRITE ) && ( pxQueue->uxLength != 1 ) ) ); /* This function relaxes the coding standard somewhat to allow return statements within the function itself. This is done in the interest @@ -578,9 +579,11 @@ xQUEUE *pxQueue; { taskENTER_CRITICAL(); { - /* Is there room on the queue now? To be running we must be - the highest priority task wanting to access the queue. */ - if( pxQueue->uxMessagesWaiting < pxQueue->uxLength ) + /* Is there room on the queue now? The running task must be + the highest priority task wanting to access the queue. If + the head item in the queue is to be overwritten then it does + not matter if the queue is full. */ + if( ( pxQueue->uxMessagesWaiting < pxQueue->uxLength ) || ( xCopyPosition == queueOVERWRITE ) ) { traceQUEUE_SEND( pxQueue ); prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition ); @@ -1046,7 +1049,8 @@ xQUEUE *pxQueue; the highest priority task wanting to access the queue. */ if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 ) { - /* Remember our read position in case we are just peeking. */ + /* Remember the read position in case the queue is only being + peeked. */ pcOriginalReadPosition = pxQueue->u.pcReadFrom; prvCopyDataFromQueue( pxQueue, pvBuffer ); @@ -1320,7 +1324,7 @@ static void prvCopyDataToQueue( xQUEUE *pxQueue, const void *pvItemToQueue, port pxQueue->pxMutexHolder = NULL; } } - #endif + #endif /* configUSE_MUTEXES */ } else if( xPosition == queueSEND_TO_BACK ) { @@ -1339,6 +1343,18 @@ static void prvCopyDataToQueue( xQUEUE *pxQueue, const void *pvItemToQueue, port { pxQueue->u.pcReadFrom = ( pxQueue->pcTail - pxQueue->uxItemSize ); } + + if( xPosition == queueOVERWRITE ) + { + if( pxQueue->uxMessagesWaiting > 0 ) + { + /* An item is not being added but overwritten, so subtract + one from the recorded number of items in the queue so when + one is added again below the number of recorded items remains + correct. */ + --( pxQueue->uxMessagesWaiting ); + } + } } ++( pxQueue->uxMessagesWaiting ); diff --git a/FreeRTOS/Source/tasks.c b/FreeRTOS/Source/tasks.c index b8dd771ca..6bdf13c4f 100644 --- a/FreeRTOS/Source/tasks.c +++ b/FreeRTOS/Source/tasks.c @@ -115,7 +115,7 @@ typedef struct tskTaskControlBlock xMPU_SETTINGS xMPUSettings; /*< The MPU settings are defined as part of the port layer. THIS MUST BE THE SECOND MEMBER OF THE TCB STRUCT. */ #endif - xListItem xGenericListItem; /*< The list that the state list item of a task is reference from denotes the state of that task (Ready, Blocked, Suspended ). */ + xListItem xGenericListItem; /*< The list that the state list item of a task is reference from denotes the state of that task (Ready, Blocked, Suspended ). */ xListItem xEventListItem; /*< Used to reference a task from an event list. */ unsigned portBASE_TYPE uxPriority; /*< The priority of the task. 0 is the lowest priority. */ portSTACK_TYPE *pxStack; /*< Points to the start of the stack. */ @@ -149,8 +149,11 @@ typedef struct tskTaskControlBlock #if ( configUSE_NEWLIB_REENTRANT == 1 ) /* Allocate a Newlib reent structure that is specific to this task. Note Newlib support has been included by popular demand, but is not - used by the FreeRTOS maintainers themselves, and therefore receives - less rigorous testing than the rest of the FreeRTOS code. */ + used by the FreeRTOS maintainers themselves. FreeRTOS is not + responsible for resulting newlib operation. User must be familiar with + newlib and must provide system-wide implementations of the necessary + stubs. Be warned that (at the time of writing) the current newlib design + implements a system-wide malloc() that must be provided with locks. */ struct _reent xNewLib_reent; #endif -- 2.39.2