+++ /dev/null
-/*\r
- FreeRTOS V8.2.2 - Copyright (C) 2015 Real Time Engineers Ltd.\r
- All rights reserved\r
-\r
- VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.\r
-\r
- This file is part of the FreeRTOS distribution.\r
-\r
- FreeRTOS is free software; you can redistribute it and/or modify it under\r
- the terms of the GNU General Public License (version 2) as published by the\r
- Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.\r
-\r
- ***************************************************************************\r
- >>! NOTE: The modification to the GPL is included to allow you to !<<\r
- >>! distribute a combined work that includes FreeRTOS without being !<<\r
- >>! obliged to provide the source code for proprietary components !<<\r
- >>! outside of the FreeRTOS kernel. !<<\r
- ***************************************************************************\r
-\r
- FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY\r
- WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS\r
- FOR A PARTICULAR PURPOSE. Full license text is available on the following\r
- link: http://www.freertos.org/a00114.html\r
-\r
- ***************************************************************************\r
- * *\r
- * FreeRTOS provides completely free yet professionally developed, *\r
- * robust, strictly quality controlled, supported, and cross *\r
- * platform software that is more than just the market leader, it *\r
- * is the industry's de facto standard. *\r
- * *\r
- * Help yourself get started quickly while simultaneously helping *\r
- * to support the FreeRTOS project by purchasing a FreeRTOS *\r
- * tutorial book, reference manual, or both: *\r
- * http://www.FreeRTOS.org/Documentation *\r
- * *\r
- ***************************************************************************\r
-\r
- http://www.FreeRTOS.org/FAQHelp.html - Having a problem? Start by reading\r
- the FAQ page "My application does not run, what could be wrong?". Have you\r
- defined configASSERT()?\r
-\r
- http://www.FreeRTOS.org/support - In return for receiving this top quality\r
- embedded software for free we request you assist our global community by\r
- participating in the support forum.\r
-\r
- http://www.FreeRTOS.org/training - Investing in training allows your team to\r
- be as productive as possible as early as possible. Now you can receive\r
- FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers\r
- Ltd, and the world's leading authority on the world's leading RTOS.\r
-\r
- http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,\r
- including FreeRTOS+Trace - an indispensable productivity tool, a DOS\r
- compatible FAT file system, and our tiny thread aware UDP/IP stack.\r
-\r
- http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate.\r
- Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.\r
-\r
- http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High\r
- Integrity Systems ltd. to sell under the OpenRTOS brand. Low cost OpenRTOS\r
- licenses offer ticketed support, indemnification and commercial middleware.\r
-\r
- http://www.SafeRTOS.com - High Integrity Systems also provide a safety\r
- engineered and independently SIL3 certified version for use in safety and\r
- mission critical applications that require provable dependability.\r
-\r
- 1 tab == 4 spaces!\r
-*/\r
-\r
-/*\r
- The tasks defined on this page demonstrate the use of recursive mutexes.\r
-\r
- For recursive mutex functionality the created mutex should be created using\r
- xSemaphoreCreateRecursiveMutex(), then be manipulated\r
- using the xSemaphoreTakeRecursive() and xSemaphoreGiveRecursive() API\r
- functions.\r
-\r
- This demo creates three tasks all of which access the same recursive mutex:\r
-\r
- prvRecursiveMutexControllingTask() has the highest priority so executes \r
- first and grabs the mutex. It then performs some recursive accesses - \r
- between each of which it sleeps for a short period to let the lower \r
- priority tasks execute. When it has completed its demo functionality\r
- it gives the mutex back before suspending itself.\r
-\r
- prvRecursiveMutexBlockingTask() attempts to access the mutex by performing\r
- a blocking 'take'. The blocking task has a lower priority than the \r
- controlling task so by the time it executes the mutex has already been\r
- taken by the controlling task, causing the blocking task to block. It \r
- does not unblock until the controlling task has given the mutex back, \r
- and it does not actually run until the controlling task has suspended \r
- itself (due to the relative priorities). When it eventually does obtain\r
- the mutex all it does is give the mutex back prior to also suspending \r
- itself. At this point both the controlling task and the blocking task are \r
- suspended.\r
-\r
- prvRecursiveMutexPollingTask() runs at the idle priority. It spins round\r
- a tight loop attempting to obtain the mutex with a non-blocking call. As\r
- the lowest priority task it will not successfully obtain the mutex until\r
- both the controlling and blocking tasks are suspended. Once it eventually \r
- does obtain the mutex it first unsuspends both the controlling task and\r
- blocking task prior to giving the mutex back - resulting in the polling\r
- task temporarily inheriting the controlling tasks priority.\r
-*/\r
-\r
-/* Scheduler include files. */\r
-#include "FreeRTOS.h"\r
-#include "task.h"\r
-#include "semphr.h"\r
-\r
-/* Demo app include files. */\r
-#include "recmutex.h"\r
-\r
-/* Priorities assigned to the three tasks. */\r
-#define recmuCONTROLLING_TASK_PRIORITY ( tskIDLE_PRIORITY + 2 )\r
-#define recmuBLOCKING_TASK_PRIORITY ( tskIDLE_PRIORITY + 1 )\r
-#define recmuPOLLING_TASK_PRIORITY ( tskIDLE_PRIORITY + 0 )\r
-\r
-/* In this version the tick period is very long, so the short delay cannot be\r
-for too many ticks, or the check task will execute and find that the recmutex\r
-tasks have not completed their functionality and then signal an error. The\r
-delay does however have to be long enough to allow the lower priority tasks\r
-a chance of executing - this is basically achieved by reducing the number\r
-of times the loop that takes/gives the recursive mutex executes. */\r
-#define recmuMAX_COUNT ( 2 )\r
-#define recmuSHORT_DELAY ( 20 )\r
-#define recmuNO_DELAY ( ( TickType_t ) 0 )\r
-#define recmuFIVE_TICK_DELAY ( ( TickType_t ) 5 )\r
-\r
-/* The three tasks as described at the top of this file. */\r
-static void prvRecursiveMutexControllingTask( void *pvParameters );\r
-static void prvRecursiveMutexBlockingTask( void *pvParameters );\r
-static void prvRecursiveMutexPollingTask( void *pvParameters );\r
-\r
-/* The mutex used by the demo. */\r
-static SemaphoreHandle_t xMutex;\r
-\r
-/* Variables used to detect and latch errors. */\r
-static volatile portBASE_TYPE xErrorOccurred = pdFALSE, xControllingIsSuspended = pdFALSE, xBlockingIsSuspended = pdFALSE;\r
-static volatile unsigned portBASE_TYPE uxControllingCycles = 0, uxBlockingCycles = 0, uxPollingCycles = 0;\r
-\r
-/* Handles of the two higher priority tasks, required so they can be resumed \r
-(unsuspended). */\r
-static TaskHandle_t xControllingTaskHandle, xBlockingTaskHandle, xPollingTaskHandle;\r
-\r
-/*-----------------------------------------------------------*/\r
-\r
-void vStartRecursiveMutexTasks( void )\r
-{\r
- /* Just creates the mutex and the three tasks. */\r
-\r
- xMutex = xSemaphoreCreateRecursiveMutex();\r
-\r
- /* vQueueAddToRegistry() adds the mutex to the registry, if one is\r
- in use. The registry is provided as a means for kernel aware \r
- debuggers to locate mutex and has no purpose if a kernel aware debugger\r
- is not being used. The call to vQueueAddToRegistry() will be removed\r
- by the pre-processor if configQUEUE_REGISTRY_SIZE is not defined or is \r
- defined to be less than 1. */\r
- vQueueAddToRegistry( ( QueueHandle_t ) xMutex, "Recursive_Mutex" );\r
-\r
-\r
- if( xMutex != NULL )\r
- {\r
- xTaskCreate( prvRecursiveMutexControllingTask, "Rec1Ctrl", configMINIMAL_STACK_SIZE, NULL, recmuCONTROLLING_TASK_PRIORITY, &xControllingTaskHandle );\r
- xTaskCreate( prvRecursiveMutexBlockingTask, "Rec2Blck", configMINIMAL_STACK_SIZE, NULL, recmuBLOCKING_TASK_PRIORITY, &xBlockingTaskHandle );\r
- xTaskCreate( prvRecursiveMutexPollingTask, "Rec3Poll", configMINIMAL_STACK_SIZE, NULL, recmuPOLLING_TASK_PRIORITY, &xPollingTaskHandle );\r
- }\r
-}\r
-/*-----------------------------------------------------------*/\r
-\r
-static void prvRecursiveMutexControllingTask( void *pvParameters )\r
-{\r
-unsigned portBASE_TYPE ux;\r
-\r
- /* Just to remove compiler warning. */\r
- ( void ) pvParameters;\r
-\r
- for( ;; )\r
- {\r
- /* Should not be able to 'give' the mutex, as we have not yet 'taken'\r
- it. The first time through, the mutex will not have been used yet,\r
- subsequent times through, at this point the mutex will be held by the\r
- polling task. */\r
- if( xSemaphoreGiveRecursive( xMutex ) == pdPASS )\r
- {\r
- xErrorOccurred = pdTRUE;\r
- }\r
-\r
- for( ux = 0; ux < recmuMAX_COUNT; ux++ )\r
- {\r
- /* We should now be able to take the mutex as many times as\r
- we like.\r
- \r
- The first time through the mutex will be immediately available, on\r
- subsequent times through the mutex will be held by the polling task\r
- at this point and this Take will cause the polling task to inherit\r
- the priority of this task. In this case the block time must be\r
- long enough to ensure the polling task will execute again before the\r
- block time expires. If the block time does expire then the error\r
- flag will be set here. */\r
- if( xSemaphoreTakeRecursive( xMutex, recmuFIVE_TICK_DELAY ) != pdPASS )\r
- {\r
- xErrorOccurred = pdTRUE;\r
- }\r
-\r
- /* Ensure the other task attempting to access the mutex (and the\r
- other demo tasks) are able to execute to ensure they either block\r
- (where a block time is specified) or return an error (where no \r
- block time is specified) as the mutex is held by this task. */\r
- vTaskDelay( recmuSHORT_DELAY );\r
- }\r
-\r
- /* For each time we took the mutex, give it back. */\r
- for( ux = 0; ux < recmuMAX_COUNT; ux++ )\r
- {\r
- /* Ensure the other task attempting to access the mutex (and the\r
- other demo tasks) are able to execute. */\r
- vTaskDelay( recmuSHORT_DELAY );\r
-\r
- /* We should now be able to give the mutex as many times as we\r
- took it. When the mutex is available again the Blocking task\r
- should be unblocked but not run because it has a lower priority\r
- than this task. The polling task should also not run at this point\r
- as it too has a lower priority than this task. */\r
- if( xSemaphoreGiveRecursive( xMutex ) != pdPASS )\r
- {\r
- xErrorOccurred = pdTRUE;\r
- }\r
-\r
- #if configUSE_PREEMPTION == 0\r
- taskYIELD();\r
- #endif\r
- }\r
-\r
- /* Having given it back the same number of times as it was taken, we\r
- should no longer be the mutex owner, so the next give should fail. */\r
- if( xSemaphoreGiveRecursive( xMutex ) == pdPASS )\r
- {\r
- xErrorOccurred = pdTRUE;\r
- }\r
-\r
- /* Keep count of the number of cycles this task has performed so a \r
- stall can be detected. */\r
- uxControllingCycles++;\r
-\r
- /* Suspend ourselves so the blocking task can execute. */\r
- xControllingIsSuspended = pdTRUE;\r
- vTaskSuspend( NULL );\r
- xControllingIsSuspended = pdFALSE;\r
- }\r
-}\r
-/*-----------------------------------------------------------*/\r
-\r
-static void prvRecursiveMutexBlockingTask( void *pvParameters )\r
-{\r
- /* Just to remove compiler warning. */\r
- ( void ) pvParameters;\r
-\r
- for( ;; )\r
- {\r
- /* This task will run while the controlling task is blocked, and the\r
- controlling task will block only once it has the mutex - therefore\r
- this call should block until the controlling task has given up the \r
- mutex, and not actually execute past this call until the controlling \r
- task is suspended. */\r
- if( xSemaphoreTakeRecursive( xMutex, portMAX_DELAY ) == pdPASS )\r
- {\r
- if( xControllingIsSuspended != pdTRUE )\r
- {\r
- /* Did not expect to execute until the controlling task was\r
- suspended. */\r
- xErrorOccurred = pdTRUE;\r
- }\r
- else\r
- {\r
- /* Give the mutex back before suspending ourselves to allow\r
- the polling task to obtain the mutex. */\r
- if( xSemaphoreGiveRecursive( xMutex ) != pdPASS )\r
- {\r
- xErrorOccurred = pdTRUE;\r
- }\r
-\r
- xBlockingIsSuspended = pdTRUE;\r
- vTaskSuspend( NULL );\r
- xBlockingIsSuspended = pdFALSE;\r
- }\r
- }\r
- else\r
- {\r
- /* We should not leave the xSemaphoreTakeRecursive() function\r
- until the mutex was obtained. */\r
- xErrorOccurred = pdTRUE;\r
- }\r
-\r
- /* The controlling and blocking tasks should be in lock step. */\r
- if( uxControllingCycles != ( uxBlockingCycles + 1 ) )\r
- {\r
- xErrorOccurred = pdTRUE;\r
- }\r
-\r
- /* Keep count of the number of cycles this task has performed so a \r
- stall can be detected. */\r
- uxBlockingCycles++;\r
- }\r
-}\r
-/*-----------------------------------------------------------*/\r
-\r
-static void prvRecursiveMutexPollingTask( void *pvParameters )\r
-{\r
- /* Just to remove compiler warning. */\r
- ( void ) pvParameters;\r
-\r
- for( ;; )\r
- {\r
- /* Keep attempting to obtain the mutex. We should only obtain it when\r
- the blocking task has suspended itself, which in turn should only\r
- happen when the controlling task is also suspended. */\r
- if( xSemaphoreTakeRecursive( xMutex, recmuNO_DELAY ) == pdPASS )\r
- {\r
- /* Is the blocking task suspended? */\r
- if( ( xBlockingIsSuspended != pdTRUE ) || ( xControllingIsSuspended != pdTRUE ) )\r
- {\r
- xErrorOccurred = pdTRUE;\r
- }\r
- else\r
- {\r
- /* Keep count of the number of cycles this task has performed \r
- so a stall can be detected. */\r
- uxPollingCycles++;\r
-\r
- /* We can resume the other tasks here even though they have a\r
- higher priority than the polling task. When they execute they\r
- will attempt to obtain the mutex but fail because the polling\r
- task is still the mutex holder. The polling task (this task)\r
- will then inherit the higher priority. The Blocking task will\r
- block indefinitely when it attempts to obtain the mutex, the\r
- Controlling task will only block for a fixed period and an\r
- error will be latched if the polling task has not returned the\r
- mutex by the time this fixed period has expired. */ \r
- vTaskResume( xBlockingTaskHandle );\r
- #if configUSE_PREEMPTION == 0\r
- taskYIELD();\r
- #endif\r
-\r
- vTaskResume( xControllingTaskHandle );\r
- #if configUSE_PREEMPTION == 0\r
- taskYIELD();\r
- #endif\r
-\r
- /* The other two tasks should now have executed and no longer\r
- be suspended. */\r
- if( ( xBlockingIsSuspended == pdTRUE ) || ( xControllingIsSuspended == pdTRUE ) )\r
- {\r
- xErrorOccurred = pdTRUE;\r
- } \r
- \r
- /* Release the mutex, disinheriting the higher priority again. */\r
- if( xSemaphoreGiveRecursive( xMutex ) != pdPASS )\r
- {\r
- xErrorOccurred = pdTRUE;\r
- }\r
-\r
- #if configUSE_PREEMPTION == 0\r
- taskYIELD();\r
- #endif\r
- }\r
- }\r
-\r
- #if configUSE_PREEMPTION == 0\r
- {\r
- taskYIELD();\r
- }\r
- #endif\r
- }\r
-}\r
-/*-----------------------------------------------------------*/\r
-\r
-/* This is called to check that all the created tasks are still running. */\r
-portBASE_TYPE xAreRecursiveMutexTasksStillRunning( void )\r
-{\r
-portBASE_TYPE xReturn;\r
-static unsigned portBASE_TYPE uxLastControllingCycles = 0, uxLastBlockingCycles = 0, uxLastPollingCycles = 0;\r
-\r
- /* Is the controlling task still cycling? */\r
- if( uxLastControllingCycles == uxControllingCycles )\r
- {\r
- xErrorOccurred = pdTRUE;\r
- }\r
- else\r
- {\r
- uxLastControllingCycles = uxControllingCycles;\r
- }\r
-\r
- /* Is the blocking task still cycling? */\r
- if( uxLastBlockingCycles == uxBlockingCycles )\r
- {\r
- xErrorOccurred = pdTRUE;\r
- }\r
- else\r
- {\r
- uxLastBlockingCycles = uxBlockingCycles;\r
- }\r
-\r
- /* Is the polling task still cycling? */\r
- if( uxLastPollingCycles == uxPollingCycles )\r
- {\r
- xErrorOccurred = pdTRUE;\r
- }\r
- else\r
- {\r
- uxLastPollingCycles = uxPollingCycles;\r
- }\r
-\r
- if( xErrorOccurred == pdTRUE )\r
- {\r
- xReturn = pdFAIL;\r
- }\r
- else\r
- {\r
- xReturn = pdTRUE;\r
- }\r
-\r
- return xReturn;\r
-}\r
-\r
-\r
-\r
-\r
projects / freertos / blobdiff