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/*
    FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd.
 
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    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 exception to the GPL is included to allow you to distribute
    a combined work that includes FreeRTOS without being obliged to provide the
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    FreeRTOS is distributed in the hope that it will be useful, but WITHOUT
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    by writing to Richard Barry, contact details for whom are available on the
    FreeRTOS WEB site.
 
    1 tab == 4 spaces!
 
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*/
 
#ifndef INC_FREERTOS_H
        #error "#include FreeRTOS.h" must appear in source files before "#include semphr.h"
#endif
 
#ifndef SEMAPHORE_H
#define SEMAPHORE_H
 
#include "queue.h"
 
typedef xQueueHandle xSemaphoreHandle;
 
#define semBINARY_SEMAPHORE_QUEUE_LENGTH        ( ( unsigned char ) 1 )
#define semSEMAPHORE_QUEUE_ITEM_LENGTH          ( ( unsigned char ) 0 )
#define semGIVE_BLOCK_TIME                                      ( ( portTickType ) 0 )
 
 
/**
 * semphr. h
 * <pre>vSemaphoreCreateBinary( xSemaphoreHandle xSemaphore )</pre>
 *
 * <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
 * queue is empty or full.
 *
 * 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().
 *
 * @param xSemaphore Handle to the created semaphore.  Should be of type xSemaphoreHandle.
 *
 * Example usage:
 <pre>
 xSemaphoreHandle xSemaphore;
 
 void vATask( void * pvParameters )
 {
    // Semaphore cannot be used before a call to vSemaphoreCreateBinary ().
    // This is a macro so pass the variable in directly.
    vSemaphoreCreateBinary( xSemaphore );
 
    if( xSemaphore != NULL )
    {
        // The semaphore was created successfully.
        // The semaphore can now be used.
    }
 }
 </pre>
 * \defgroup vSemaphoreCreateBinary vSemaphoreCreateBinary
 * \ingroup Semaphores
 */
#define vSemaphoreCreateBinary( xSemaphore )            {                                                                                                                                                                                               \
                                                                                                                xSemaphore = xQueueCreate( ( unsigned portBASE_TYPE ) 1, semSEMAPHORE_QUEUE_ITEM_LENGTH );      \
                                                                                                                if( xSemaphore != NULL )                                                                                                                                        \
                                                                                                                {                                                                                                                                                                                       \
                                                                                                                        xSemaphoreGive( xSemaphore );                                                                                                                   \
                                                                                                                }                                                                                                                                                                                       \
                                                                                                        }
 
/**
 * semphr. h
 * <pre>xSemaphoreTake(
 *                   xSemaphoreHandle xSemaphore,
 *                   portTickType xBlockTime
 *               )</pre>
 *
 * <i>Macro</i> to obtain a semaphore.  The semaphore must have previously been
 * created with a call to vSemaphoreCreateBinary(), xSemaphoreCreateMutex() or
 * xSemaphoreCreateCounting().
 *
 * @param xSemaphore A handle to the semaphore being taken - obtained when
 * the semaphore was created.
 *
 * @param xBlockTime The time in ticks to wait for the semaphore to become
 * available.  The macro portTICK_RATE_MS can be used to convert this to a
 * real time.  A block time of zero can be used to poll the semaphore.  A block
 * time of portMAX_DELAY can be used to block indefinitely (provided
 * INCLUDE_vTaskSuspend is set to 1 in FreeRTOSConfig.h).
 *
 * @return pdTRUE if the semaphore was obtained.  pdFALSE
 * if xBlockTime expired without the semaphore becoming available.
 *
 * Example usage:
 <pre>
 xSemaphoreHandle xSemaphore = NULL;
 
 // A task that creates a semaphore.
 void vATask( void * pvParameters )
 {
    // Create the semaphore to guard a shared resource.
    vSemaphoreCreateBinary( xSemaphore );
 }
 
 // A task that uses the semaphore.
 void vAnotherTask( void * pvParameters )
 {
    // ... Do other things.
 
    if( xSemaphore != NULL )
    {
        // See if we can obtain the semaphore.  If the semaphore is not available
        // wait 10 ticks to see if it becomes free.
        if( xSemaphoreTake( xSemaphore, ( portTickType ) 10 ) == pdTRUE )
        {
            // We were able to obtain the semaphore and can now access the
            // shared resource.
 
            // ...
 
            // We have finished accessing the shared resource.  Release the
            // semaphore.
            xSemaphoreGive( xSemaphore );
        }
        else
        {
            // We could not obtain the semaphore and can therefore not access
            // the shared resource safely.
        }
    }
 }
 </pre>
 * \defgroup xSemaphoreTake xSemaphoreTake
 * \ingroup Semaphores
 */
#define xSemaphoreTake( xSemaphore, xBlockTime )                xQueueGenericReceive( ( xQueueHandle ) xSemaphore, NULL, xBlockTime, pdFALSE )
 
/**
 * semphr. h
 * xSemaphoreTakeRecursive(
 *                          xSemaphoreHandle xMutex,
 *                          portTickType xBlockTime
 *                        )
 *
 * <i>Macro</i> to recursively obtain, or 'take', a mutex type semaphore.
 * The mutex must have previously been created using a call to
 * xSemaphoreCreateRecursiveMutex();
 *
 * configUSE_RECURSIVE_MUTEXES must be set to 1 in FreeRTOSConfig.h for this
 * macro to be available.
 *
 * This macro must not be used on mutexes created using xSemaphoreCreateMutex().
 *
 * A mutex used recursively can be 'taken' repeatedly by the owner. The mutex
 * doesn't become available again until the owner has called
 * xSemaphoreGiveRecursive() for each successful 'take' request.  For example,
 * if a task successfully 'takes' the same mutex 5 times then the mutex will
 * not be available to any other task until it has also  'given' the mutex back
 * exactly five times.
 *
 * @param xMutex A handle to the mutex being obtained.  This is the
 * handle returned by xSemaphoreCreateRecursiveMutex();
 *
 * @param xBlockTime The time in ticks to wait for the semaphore to become
 * available.  The macro portTICK_RATE_MS can be used to convert this to a
 * real time.  A block time of zero can be used to poll the semaphore.  If
 * the task already owns the semaphore then xSemaphoreTakeRecursive() will
 * return immediately no matter what the value of xBlockTime.
 *
 * @return pdTRUE if the semaphore was obtained.  pdFALSE if xBlockTime
 * expired without the semaphore becoming available.
 *
 * Example usage:
 <pre>
 xSemaphoreHandle xMutex = NULL;
 
 // A task that creates a mutex.
 void vATask( void * pvParameters )
 {
    // Create the mutex to guard a shared resource.
    xMutex = xSemaphoreCreateRecursiveMutex();
 }
 
 // A task that uses the mutex.
 void vAnotherTask( void * pvParameters )
 {
    // ... Do other things.
 
    if( xMutex != NULL )
    {
        // See if we can obtain the mutex.  If the mutex is not available
        // wait 10 ticks to see if it becomes free.
        if( xSemaphoreTakeRecursive( xSemaphore, ( portTickType ) 10 ) == pdTRUE )
        {
            // We were able to obtain the mutex and can now access the
            // shared resource.
 
            // ...
            // For some reason due to the nature of the code further calls to
                        // xSemaphoreTakeRecursive() are made on the same mutex.  In real
                        // code these would not be just sequential calls as this would make
                        // no sense.  Instead the calls are likely to be buried inside
                        // a more complex call structure.
            xSemaphoreTakeRecursive( xMutex, ( portTickType ) 10 );
            xSemaphoreTakeRecursive( xMutex, ( portTickType ) 10 );
 
            // The mutex has now been 'taken' three times, so will not be
                        // available to another task until it has also been given back
                        // three times.  Again it is unlikely that real code would have
                        // these calls sequentially, but instead buried in a more complex
                        // call structure.  This is just for illustrative purposes.
            xSemaphoreGiveRecursive( xMutex );
                        xSemaphoreGiveRecursive( xMutex );
                        xSemaphoreGiveRecursive( xMutex );
 
                        // Now the mutex can be taken by other tasks.
        }
        else
        {
            // We could not obtain the mutex and can therefore not access
            // the shared resource safely.
        }
    }
 }
 </pre>
 * \defgroup xSemaphoreTakeRecursive xSemaphoreTakeRecursive
 * \ingroup Semaphores
 */
#define xSemaphoreTakeRecursive( xMutex, xBlockTime )   xQueueTakeMutexRecursive( xMutex, xBlockTime )
 
 
/*
 * xSemaphoreAltTake() is an alternative version of xSemaphoreTake().
 *
 * The source code that implements the alternative (Alt) API is much
 * simpler      because it executes everything from within a critical section.
 * This is      the approach taken by many other RTOSes, but FreeRTOS.org has the
 * preferred fully featured API too.  The fully featured API has more
 * complex      code that takes longer to execute, but makes much less use of
 * critical sections.  Therefore the alternative API sacrifices interrupt
 * responsiveness to gain execution speed, whereas the fully featured API
 * sacrifices execution speed to ensure better interrupt responsiveness.
 */
#define xSemaphoreAltTake( xSemaphore, xBlockTime )             xQueueAltGenericReceive( ( xQueueHandle ) xSemaphore, NULL, xBlockTime, pdFALSE )
 
/**
 * semphr. h
 * <pre>xSemaphoreGive( xSemaphoreHandle xSemaphore )</pre>
 *
 * <i>Macro</i> to release a semaphore.  The semaphore must have previously been
 * created with a call to vSemaphoreCreateBinary(), xSemaphoreCreateMutex() or
 * xSemaphoreCreateCounting(). and obtained using sSemaphoreTake().
 *
 * This macro must not be used from an ISR.  See xSemaphoreGiveFromISR () for
 * an alternative which can be used from an ISR.
 *
 * This macro must also not be used on semaphores created using
 * xSemaphoreCreateRecursiveMutex().
 *
 * @param xSemaphore A handle to the semaphore being released.  This is the
 * handle returned when the semaphore was created.
 *
 * @return pdTRUE if the semaphore was released.  pdFALSE if an error occurred.
 * Semaphores are implemented using queues.  An error can occur if there is
 * no space on the queue to post a message - indicating that the
 * semaphore was not first obtained correctly.
 *
 * Example usage:
 <pre>
 xSemaphoreHandle xSemaphore = NULL;
 
 void vATask( void * pvParameters )
 {
    // Create the semaphore to guard a shared resource.
    vSemaphoreCreateBinary( xSemaphore );
 
    if( xSemaphore != NULL )
    {
        if( xSemaphoreGive( xSemaphore ) != pdTRUE )
        {
            // We would expect this call to fail because we cannot give
            // a semaphore without first "taking" it!
        }
 
        // Obtain the semaphore - don't block if the semaphore is not
        // immediately available.
        if( xSemaphoreTake( xSemaphore, ( portTickType ) 0 ) )
        {
            // We now have the semaphore and can access the shared resource.
 
            // ...
 
            // We have finished accessing the shared resource so can free the
            // semaphore.
            if( xSemaphoreGive( xSemaphore ) != pdTRUE )
            {
                // We would not expect this call to fail because we must have
                // obtained the semaphore to get here.
            }
        }
    }
 }
 </pre>
 * \defgroup xSemaphoreGive xSemaphoreGive
 * \ingroup Semaphores
 */
#define xSemaphoreGive( xSemaphore )            xQueueGenericSend( ( xQueueHandle ) xSemaphore, NULL, semGIVE_BLOCK_TIME, queueSEND_TO_BACK )
 
/**
 * semphr. h
 * <pre>xSemaphoreGiveRecursive( xSemaphoreHandle xMutex )</pre>
 *
 * <i>Macro</i> to recursively release, or 'give', a mutex type semaphore.
 * The mutex must have previously been created using a call to
 * xSemaphoreCreateRecursiveMutex();
 *
 * configUSE_RECURSIVE_MUTEXES must be set to 1 in FreeRTOSConfig.h for this
 * macro to be available.
 *
 * This macro must not be used on mutexes created using xSemaphoreCreateMutex().
 *
 * A mutex used recursively can be 'taken' repeatedly by the owner. The mutex
 * doesn't become available again until the owner has called
 * xSemaphoreGiveRecursive() for each successful 'take' request.  For example,
 * if a task successfully 'takes' the same mutex 5 times then the mutex will
 * not be available to any other task until it has also  'given' the mutex back
 * exactly five times.
 *
 * @param xMutex A handle to the mutex being released, or 'given'.  This is the
 * handle returned by xSemaphoreCreateMutex();
 *
 * @return pdTRUE if the semaphore was given.
 *
 * Example usage:
 <pre>
 xSemaphoreHandle xMutex = NULL;
 
 // A task that creates a mutex.
 void vATask( void * pvParameters )
 {
    // Create the mutex to guard a shared resource.
    xMutex = xSemaphoreCreateRecursiveMutex();
 }
 
 // A task that uses the mutex.
 void vAnotherTask( void * pvParameters )
 {
    // ... Do other things.
 
    if( xMutex != NULL )
    {
        // See if we can obtain the mutex.  If the mutex is not available
        // wait 10 ticks to see if it becomes free.
        if( xSemaphoreTakeRecursive( xMutex, ( portTickType ) 10 ) == pdTRUE )
        {
            // We were able to obtain the mutex and can now access the
            // shared resource.
 
            // ...
            // For some reason due to the nature of the code further calls to
                        // xSemaphoreTakeRecursive() are made on the same mutex.  In real
                        // code these would not be just sequential calls as this would make
                        // no sense.  Instead the calls are likely to be buried inside
                        // a more complex call structure.
            xSemaphoreTakeRecursive( xMutex, ( portTickType ) 10 );
            xSemaphoreTakeRecursive( xMutex, ( portTickType ) 10 );
 
            // The mutex has now been 'taken' three times, so will not be
                        // available to another task until it has also been given back
                        // three times.  Again it is unlikely that real code would have
                        // these calls sequentially, it would be more likely that the calls
                        // to xSemaphoreGiveRecursive() would be called as a call stack
                        // unwound.  This is just for demonstrative purposes.
            xSemaphoreGiveRecursive( xMutex );
                        xSemaphoreGiveRecursive( xMutex );
                        xSemaphoreGiveRecursive( xMutex );
 
                        // Now the mutex can be taken by other tasks.
        }
        else
        {
            // We could not obtain the mutex and can therefore not access
            // the shared resource safely.
        }
    }
 }
 </pre>
 * \defgroup xSemaphoreGiveRecursive xSemaphoreGiveRecursive
 * \ingroup Semaphores
 */
#define xSemaphoreGiveRecursive( xMutex )       xQueueGiveMutexRecursive( xMutex )
 
/*
 * xSemaphoreAltGive() is an alternative version of xSemaphoreGive().
 *
 * The source code that implements the alternative (Alt) API is much
 * simpler      because it executes everything from within a critical section.
 * This is      the approach taken by many other RTOSes, but FreeRTOS.org has the
 * preferred fully featured API too.  The fully featured API has more
 * complex      code that takes longer to execute, but makes much less use of
 * critical sections.  Therefore the alternative API sacrifices interrupt
 * responsiveness to gain execution speed, whereas the fully featured API
 * sacrifices execution speed to ensure better interrupt responsiveness.
 */
#define xSemaphoreAltGive( xSemaphore )         xQueueAltGenericSend( ( xQueueHandle ) xSemaphore, NULL, semGIVE_BLOCK_TIME, queueSEND_TO_BACK )
 
/**
 * semphr. h
 * <pre>
 xSemaphoreGiveFromISR(
                          xSemaphoreHandle xSemaphore,
                          signed portBASE_TYPE *pxHigherPriorityTaskWoken
                      )</pre>
 *
 * <i>Macro</i> to  release a semaphore.  The semaphore must have previously been
 * created with a call to vSemaphoreCreateBinary() or xSemaphoreCreateCounting().
 *
 * Mutex type semaphores (those created using a call to xSemaphoreCreateMutex())
 * must not be used with this macro.
 *
 * This macro can be used from an ISR.
 *
 * @param xSemaphore A handle to the semaphore being released.  This is the
 * handle returned when the semaphore was created.
 *
 * @param pxHigherPriorityTaskWoken xSemaphoreGiveFromISR() will set
 * *pxHigherPriorityTaskWoken to pdTRUE if giving the semaphore caused a task
 * to unblock, and the unblocked task has a priority higher than the currently
 * running task.  If xSemaphoreGiveFromISR() sets this value to pdTRUE then
 * a context switch should be requested before the interrupt is exited.
 *
 * @return pdTRUE if the semaphore was successfully given, otherwise errQUEUE_FULL.
 *
 * Example usage:
 <pre>
 \#define LONG_TIME 0xffff
 \#define TICKS_TO_WAIT 10
 xSemaphoreHandle xSemaphore = NULL;
 
 // Repetitive task.
 void vATask( void * pvParameters )
 {
    for( ;; )
    {
        // We want this task to run every 10 ticks of a timer.  The semaphore
        // was created before this task was started.
 
        // Block waiting for the semaphore to become available.
        if( xSemaphoreTake( xSemaphore, LONG_TIME ) == pdTRUE )
        {
            // It is time to execute.
 
            // ...
 
            // We have finished our task.  Return to the top of the loop where
            // we will block on the semaphore until it is time to execute
            // again.  Note when using the semaphore for synchronisation with an
                        // ISR in this manner there is no need to 'give' the semaphore back.
        }
    }
 }
 
 // Timer ISR
 void vTimerISR( void * pvParameters )
 {
 static unsigned char ucLocalTickCount = 0;
 static signed portBASE_TYPE xHigherPriorityTaskWoken;
 
    // A timer tick has occurred.
 
    // ... Do other time functions.
 
    // Is it time for vATask () to run?
        xHigherPriorityTaskWoken = pdFALSE;
    ucLocalTickCount++;
    if( ucLocalTickCount >= TICKS_TO_WAIT )
    {
        // Unblock the task by releasing the semaphore.
        xSemaphoreGiveFromISR( xSemaphore, &xHigherPriorityTaskWoken );
 
        // Reset the count so we release the semaphore again in 10 ticks time.
        ucLocalTickCount = 0;
    }
 
    if( xHigherPriorityTaskWoken != pdFALSE )
    {
        // We can force a context switch here.  Context switching from an
        // ISR uses port specific syntax.  Check the demo task for your port
        // to find the syntax required.
    }
 }
 </pre>
 * \defgroup xSemaphoreGiveFromISR xSemaphoreGiveFromISR
 * \ingroup Semaphores
 */
#define xSemaphoreGiveFromISR( xSemaphore, pxHigherPriorityTaskWoken )                  xQueueGenericSendFromISR( ( xQueueHandle ) xSemaphore, NULL, pxHigherPriorityTaskWoken, queueSEND_TO_BACK )
 
/**
 * semphr. h
 * <pre>xSemaphoreHandle xSemaphoreCreateMutex( void )</pre>
 *
 * <i>Macro</i> that implements a mutex semaphore by using the existing queue
 * mechanism.
 *
 * Mutexes created using this macro can be accessed using the xSemaphoreTake()
 * and xSemaphoreGive() macros.  The xSemaphoreTakeRecursive() and
 * xSemaphoreGiveRecursive() macros should not be used.
 *
 * This type of semaphore uses a priority inheritance mechanism so a task
 * 'taking' a semaphore MUST ALWAYS 'give' the semaphore back once the
 * semaphore it is no longer required.
 *
 * Mutex type semaphores cannot be used from within interrupt service routines.
 *
 * See vSemaphoreCreateBinary() for an alternative implementation that can be
 * used for pure synchronisation (where one task or interrupt always 'gives' the
 * semaphore and another always 'takes' the semaphore) and from within interrupt
 * service routines.
 *
 * @return xSemaphore Handle to the created mutex semaphore.  Should be of type
 *              xSemaphoreHandle.
 *
 * Example usage:
 <pre>
 xSemaphoreHandle xSemaphore;
 
 void vATask( void * pvParameters )
 {
    // Semaphore cannot be used before a call to xSemaphoreCreateMutex().
    // This is a macro so pass the variable in directly.
    xSemaphore = xSemaphoreCreateMutex();
 
    if( xSemaphore != NULL )
    {
        // The semaphore was created successfully.
        // The semaphore can now be used.
    }
 }
 </pre>
 * \defgroup vSemaphoreCreateMutex vSemaphoreCreateMutex
 * \ingroup Semaphores
 */
#define xSemaphoreCreateMutex() xQueueCreateMutex()
 
 
/**
 * semphr. h
 * <pre>xSemaphoreHandle xSemaphoreCreateRecursiveMutex( void )</pre>
 *
 * <i>Macro</i> that implements a recursive mutex by using the existing queue
 * mechanism.
 *
 * Mutexes created using this macro can be accessed using the
 * xSemaphoreTakeRecursive() and xSemaphoreGiveRecursive() macros.  The
 * xSemaphoreTake() and xSemaphoreGive() macros should not be used.
 *
 * A mutex used recursively can be 'taken' repeatedly by the owner. The mutex
 * doesn't become available again until the owner has called
 * xSemaphoreGiveRecursive() for each successful 'take' request.  For example,
 * if a task successfully 'takes' the same mutex 5 times then the mutex will
 * not be available to any other task until it has also  'given' the mutex back
 * exactly five times.
 *
 * This type of semaphore uses a priority inheritance mechanism so a task
 * 'taking' a semaphore MUST ALWAYS 'give' the semaphore back once the
 * semaphore it is no longer required.
 *
 * Mutex type semaphores cannot be used from within interrupt service routines.
 *
 * See vSemaphoreCreateBinary() for an alternative implementation that can be
 * used for pure synchronisation (where one task or interrupt always 'gives' the
 * semaphore and another always 'takes' the semaphore) and from within interrupt
 * service routines.
 *
 * @return xSemaphore Handle to the created mutex semaphore.  Should be of type
 *              xSemaphoreHandle.
 *
 * Example usage:
 <pre>
 xSemaphoreHandle xSemaphore;
 
 void vATask( void * pvParameters )
 {
    // Semaphore cannot be used before a call to xSemaphoreCreateMutex().
    // This is a macro so pass the variable in directly.
    xSemaphore = xSemaphoreCreateRecursiveMutex();
 
    if( xSemaphore != NULL )
    {
        // The semaphore was created successfully.
        // The semaphore can now be used.
    }
 }
 </pre>
 * \defgroup vSemaphoreCreateMutex vSemaphoreCreateMutex
 * \ingroup Semaphores
 */
#define xSemaphoreCreateRecursiveMutex() xQueueCreateMutex()
 
/**
 * semphr. h
 * <pre>xSemaphoreHandle xSemaphoreCreateCounting( unsigned portBASE_TYPE uxMaxCount, unsigned portBASE_TYPE uxInitialCount )</pre>
 *
 * <i>Macro</i> that creates a counting semaphore by using the existing
 * queue mechanism.
 *
 * Counting semaphores are typically used for two things:
 *
 * 1) Counting events.
 *
 *    In this usage scenario an event handler will 'give' a semaphore each time
 *    an event occurs (incrementing the semaphore count value), and a handler
 *    task will 'take' a semaphore each time it processes an event
 *    (decrementing the semaphore count value).  The count value is therefore
 *    the difference between the number of events that have occurred and the
 *    number that have been processed.  In this case it is desirable for the
 *    initial count value to be zero.
 *
 * 2) Resource management.
 *
 *    In this usage scenario the count value indicates the number of resources
 *    available.  To obtain control of a resource a task must first obtain a
 *    semaphore - decrementing the semaphore count value.  When the count value
 *    reaches zero there are no free resources.  When a task finishes with the
 *    resource it 'gives' the semaphore back - incrementing the semaphore count
 *    value.  In this case it is desirable for the initial count value to be
 *    equal to the maximum count value, indicating that all resources are free.
 *
 * @param uxMaxCount The maximum count value that can be reached.  When the
 *        semaphore reaches this value it can no longer be 'given'.
 *
 * @param uxInitialCount The count value assigned to the semaphore when it is
 *        created.
 *
 * @return Handle to the created semaphore.  Null if the semaphore could not be
 *         created.
 *
 * Example usage:
 <pre>
 xSemaphoreHandle xSemaphore;
 
 void vATask( void * pvParameters )
 {
 xSemaphoreHandle xSemaphore = NULL;
 
    // Semaphore cannot be used before a call to xSemaphoreCreateCounting().
    // The max value to which the semaphore can count should be 10, and the
    // initial value assigned to the count should be 0.
    xSemaphore = xSemaphoreCreateCounting( 10, 0 );
 
    if( xSemaphore != NULL )
    {
        // The semaphore was created successfully.
        // The semaphore can now be used.
    }
 }
 </pre>
 * \defgroup xSemaphoreCreateCounting xSemaphoreCreateCounting
 * \ingroup Semaphores
 */
#define xSemaphoreCreateCounting( uxMaxCount, uxInitialCount ) xQueueCreateCountingSemaphore( uxMaxCount, uxInitialCount )
 
 
#endif /* SEMAPHORE_H */
 
 
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