*/\r
\r
/*\r
- * Creates two sets of two tasks. The tasks within a set share a variable, access \r
+ * Creates two sets of two tasks. The tasks within a set share a variable, access\r
* to which is guarded by a semaphore.\r
- * \r
- * Each task starts by attempting to obtain the semaphore. On obtaining a \r
- * semaphore a task checks to ensure that the guarded variable has an expected \r
- * value. It then clears the variable to zero before counting it back up to the \r
- * expected value in increments of 1. After each increment the variable is checked \r
- * to ensure it contains the value to which it was just set. When the starting \r
- * value is again reached the task releases the semaphore giving the other task in \r
- * the set a chance to do exactly the same thing. The starting value is high \r
+ *\r
+ * Each task starts by attempting to obtain the semaphore. On obtaining a\r
+ * semaphore a task checks to ensure that the guarded variable has an expected\r
+ * value. It then clears the variable to zero before counting it back up to the\r
+ * expected value in increments of 1. After each increment the variable is checked\r
+ * to ensure it contains the value to which it was just set. When the starting\r
+ * value is again reached the task releases the semaphore giving the other task in\r
+ * the set a chance to do exactly the same thing. The starting value is high\r
* enough to ensure that a tick is likely to occur during the incrementing loop.\r
*\r
- * An error is flagged if at any time during the process a shared variable is \r
- * found to have a value other than that expected. Such an occurrence would \r
- * suggest an error in the mutual exclusion mechanism by which access to the \r
+ * An error is flagged if at any time during the process a shared variable is\r
+ * found to have a value other than that expected. Such an occurrence would\r
+ * suggest an error in the mutual exclusion mechanism by which access to the\r
* variable is restricted.\r
*\r
- * The first set of two tasks poll their semaphore. The second set use blocking \r
+ * The first set of two tasks poll their semaphore. The second set use blocking\r
* calls.\r
*\r
*/\r
if( pxFirstSemaphoreParameters != NULL )\r
{\r
/* Create the semaphore used by the first two tasks. */\r
- pxFirstSemaphoreParameters->xSemaphore = xSemaphoreCreateBinary();\r
- xSemaphoreGive( pxFirstSemaphoreParameters->xSemaphore );\r
+ pxFirstSemaphoreParameters->xSemaphore = xSemaphoreCreateBinary(); \r
\r
if( pxFirstSemaphoreParameters->xSemaphore != NULL )\r
{\r
+ xSemaphoreGive( pxFirstSemaphoreParameters->xSemaphore );\r
+ \r
/* Create the variable which is to be shared by the first two tasks. */\r
pxFirstSemaphoreParameters->pulSharedVariable = ( uint32_t * ) pvPortMalloc( sizeof( uint32_t ) );\r
\r
/* Spawn the first two tasks. As they poll they operate at the idle priority. */\r
xTaskCreate( prvSemaphoreTest, "PolSEM1", semtstSTACK_SIZE, ( void * ) pxFirstSemaphoreParameters, tskIDLE_PRIORITY, ( TaskHandle_t * ) NULL );\r
xTaskCreate( prvSemaphoreTest, "PolSEM2", semtstSTACK_SIZE, ( void * ) pxFirstSemaphoreParameters, tskIDLE_PRIORITY, ( TaskHandle_t * ) NULL );\r
+\r
+ /* vQueueAddToRegistry() adds the semaphore to the registry, if one\r
+ is in use. The registry is provided as a means for kernel aware\r
+ debuggers to locate semaphores and has no purpose if a kernel aware\r
+ debugger is not being used. The call to vQueueAddToRegistry() will\r
+ be removed by the pre-processor if configQUEUE_REGISTRY_SIZE is not\r
+ defined or is defined to be less than 1. */\r
+ vQueueAddToRegistry( ( QueueHandle_t ) pxFirstSemaphoreParameters->xSemaphore, "Counting_Sem_1" );\r
}\r
}\r
\r
- /* Do exactly the same to create the second set of tasks, only this time \r
+ /* Do exactly the same to create the second set of tasks, only this time\r
provide a block time for the semaphore calls. */\r
pxSecondSemaphoreParameters = ( xSemaphoreParameters * ) pvPortMalloc( sizeof( xSemaphoreParameters ) );\r
if( pxSecondSemaphoreParameters != NULL )\r
{\r
- pxSecondSemaphoreParameters->xSemaphore = xSemaphoreCreateBinary();\r
- xSemaphoreGive( pxSecondSemaphoreParameters->xSemaphore );\r
+ pxSecondSemaphoreParameters->xSemaphore = xSemaphoreCreateBinary(); \r
\r
if( pxSecondSemaphoreParameters->xSemaphore != NULL )\r
{\r
+ xSemaphoreGive( pxSecondSemaphoreParameters->xSemaphore );\r
+ \r
pxSecondSemaphoreParameters->pulSharedVariable = ( uint32_t * ) pvPortMalloc( sizeof( uint32_t ) );\r
*( pxSecondSemaphoreParameters->pulSharedVariable ) = semtstBLOCKING_EXPECTED_VALUE;\r
pxSecondSemaphoreParameters->xBlockTime = xBlockTime / portTICK_PERIOD_MS;\r
\r
xTaskCreate( prvSemaphoreTest, "BlkSEM1", semtstSTACK_SIZE, ( void * ) pxSecondSemaphoreParameters, uxPriority, ( TaskHandle_t * ) NULL );\r
xTaskCreate( prvSemaphoreTest, "BlkSEM2", semtstSTACK_SIZE, ( void * ) pxSecondSemaphoreParameters, uxPriority, ( TaskHandle_t * ) NULL );\r
+\r
+ /* vQueueAddToRegistry() adds the semaphore to the registry, if one\r
+ is in use. The registry is provided as a means for kernel aware\r
+ debuggers to locate semaphores and has no purpose if a kernel aware\r
+ debugger is not being used. The call to vQueueAddToRegistry() will\r
+ be removed by the pre-processor if configQUEUE_REGISTRY_SIZE is not\r
+ defined or is defined to be less than 1. */\r
+ vQueueAddToRegistry( ( QueueHandle_t ) pxSecondSemaphoreParameters->xSemaphore, "Counting_Sem_2" );\r
}\r
}\r
-\r
- /* vQueueAddToRegistry() adds the semaphore to the registry, if one is\r
- in use. The registry is provided as a means for kernel aware \r
- debuggers to locate semaphores 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 ) pxFirstSemaphoreParameters->xSemaphore, "Counting_Sem_1" );\r
- vQueueAddToRegistry( ( QueueHandle_t ) pxSecondSemaphoreParameters->xSemaphore, "Counting_Sem_2" );\r
}\r
/*-----------------------------------------------------------*/\r
\r
uint32_t ulCounter;\r
short sError = pdFALSE, sCheckVariableToUse;\r
\r
- /* See which check variable to use. sNextCheckVariable is not semaphore \r
+ /* See which check variable to use. sNextCheckVariable is not semaphore\r
protected! */\r
portENTER_CRITICAL();\r
sCheckVariableToUse = sNextCheckVariable;\r
sNextCheckVariable++;\r
portEXIT_CRITICAL();\r
\r
- /* A structure is passed in as the parameter. This contains the shared \r
+ /* A structure is passed in as the parameter. This contains the shared\r
variable being guarded. */\r
pxParameters = ( xSemaphoreParameters * ) pvParameters;\r
pulSharedVariable = pxParameters->pulSharedVariable;\r
{\r
sError = pdTRUE;\r
}\r
- \r
+\r
/* Clear the variable, then count it back up to the expected value\r
before releasing the semaphore. Would expect a context switch or\r
two during this time. */\r
projects / freertos / blobdiff