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Add xSemaphoreCreateBinary() so vSemaphoreCreate() can be deprecated.

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This commit is contained in:
Richard Barry 2013-11-07 10:53:23 +00:00
parent ca2191c6ee
commit dcf261a3e6
1 changed files with 155 additions and 101 deletions
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58
FreeRTOS/Source/include/semphr.h
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@ -83,6 +83,13 @@ typedef xQueueHandle xSemaphoreHandle;
* semphr. h
* <pre>vSemaphoreCreateBinary( xSemaphoreHandle xSemaphore )</pre>
*
* This old vSemaphoreCreateBinary() macro is now deprecated in favour of the
* xSemaphoreCreateBinary() function. Note that binary semaphores created using
* the vSemaphoreCreateBinary() macro are created in a state such that the
* first call to 'take' the semaphore would pass, whereas binary semaphores
* created using xSemaphoreCreateBinary() are created in a state such that the
* the semaphore must first be 'given' before it can be 'taken'.
*
* <i>Macro</i> that implements a semaphore by using the existing queue mechanism.
* The queue length is 1 as this is a binary semaphore. The data size is 0
* as we don't want to actually store any data - we just want to know if the
@ -99,7 +106,7 @@ typedef xQueueHandle xSemaphoreHandle;
*
* Example usage:
<pre>
xSemaphoreHandle xSemaphore;
xSemaphoreHandle xSemaphore = NULL;
void vATask( void * pvParameters )
{
@ -122,10 +129,57 @@ typedef xQueueHandle xSemaphoreHandle;
( xSemaphore ) = xQueueGenericCreate( ( unsigned portBASE_TYPE ) 1, semSEMAPHORE_QUEUE_ITEM_LENGTH, queueQUEUE_TYPE_BINARY_SEMAPHORE ); \
if( ( xSemaphore ) != NULL ) \
{ \
( void ) xSemaphoreGive( ( xSemaphore ) ); \
( void ) xSemaphoreGive( ( xSemaphore ) ); \
} \
}
/**
* semphr. h
* <pre>xSemaphoreHandle xSemaphoreCreateBinary( void )</pre>
*
* The old vSemaphoreCreateBinary() macro is now deprecated in favour of this
* xSemaphoreCreateBinary() function. Note that binary semaphores created using
* the vSemaphoreCreateBinary() macro are created in a state such that the
* first call to 'take' the semaphore would pass, whereas binary semaphores
* created using xSemaphoreCreateBinary() are created in a state such that the
* the semaphore must first be 'given' before it can be 'taken'.
*
* Function that creates a semaphore by using the existing queue mechanism.
* The queue length is 1 as this is a binary semaphore. The data size is 0
* as nothing is actually stored - all that is important is whether the queue is
* empty or full (the binary semaphore is available or not).
*
* This type of semaphore can be used for pure synchronisation between tasks or
* between an interrupt and a task. The semaphore need not be given back once
* obtained, so one task/interrupt can continuously 'give' the semaphore while
* another continuously 'takes' the semaphore. For this reason this type of
* semaphore does not use a priority inheritance mechanism. For an alternative
* that does use priority inheritance see xSemaphoreCreateMutex().
*
* @return Handle to the created semaphore.
*
* Example usage:
<pre>
xSemaphoreHandle xSemaphore = NULL;
void vATask( void * pvParameters )
{
// Semaphore cannot be used before a call to vSemaphoreCreateBinary ().
// This is a macro so pass the variable in directly.
xSemaphore = xSemaphoreCreateBinary();
if( xSemaphore != NULL )
{
// The semaphore was created successfully.
// The semaphore can now be used.
}
}
</pre>
* \defgroup vSemaphoreCreateBinary vSemaphoreCreateBinary
* \ingroup Semaphores
*/
#define xSemaphoreCreateBinary() xQueueGenericCreate( ( unsigned portBASE_TYPE ) 1, semSEMAPHORE_QUEUE_ITEM_LENGTH, queueQUEUE_TYPE_BINARY_SEMAPHORE )
/**
* semphr. h
* <pre>xSemaphoreTake(