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<div class="title">xQueueReceive</div> </div>
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<p>queue. h </p><pre>
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BaseType_t xQueueReceive(
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QueueHandle_t xQueue,
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void *pvBuffer,
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TickType_t xTicksToWait
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);</pre><p>Receive an item from a queue. The item is received by copy so a buffer of adequate size must be provided. The number of bytes copied into the buffer was defined when the queue was created.</p>
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<p>Successfully received items are removed from the queue.</p>
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<p>This function must not be used in an interrupt service routine. See xQueueReceiveFromISR for an alternative that can.</p>
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<dl class="params"><dt>Parameters</dt><dd>
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<table class="params">
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<tr><td class="paramname">xQueue</td><td>The handle to the queue from which the item is to be received.</td></tr>
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<tr><td class="paramname">pvBuffer</td><td>Pointer to the buffer into which the received item will be copied.</td></tr>
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<tr><td class="paramname">xTicksToWait</td><td>The maximum amount of time the task should block waiting for an item to receive should the queue be empty at the time of the call. <a class="el" href="queue_8h.html#ae8364d988c6f9b63c771cc2b3dfe5df9">xQueueReceive()</a> will return immediately if xTicksToWait is zero and the queue is empty. The time is defined in tick periods so the constant portTICK_PERIOD_MS should be used to convert to real time if this is required.</td></tr>
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</table>
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</dd>
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</dl>
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<dl class="section return"><dt>Returns</dt><dd>pdTRUE if an item was successfully received from the queue, otherwise pdFALSE.</dd></dl>
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<p>Example usage: </p><pre>
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struct AMessage
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{
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char ucMessageID;
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char ucData[ 20 ];
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} xMessage;</pre><pre>QueueHandle_t xQueue;</pre><pre>// Task to create a queue and post a value.
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void vATask( void *pvParameters )
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{
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struct AMessage *pxMessage;</pre><pre> // Create a queue capable of containing 10 pointers to AMessage structures.
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// These should be passed by pointer as they contain a lot of data.
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xQueue = xQueueCreate( 10, sizeof( struct AMessage * ) );
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if( xQueue == 0 )
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{
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// Failed to create the queue.
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}</pre><pre> // ...</pre><pre> // Send a pointer to a struct AMessage object. Don't block if the
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// queue is already full.
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pxMessage = & xMessage;
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xQueueSend( xQueue, ( void * ) &pxMessage, ( TickType_t ) 0 );</pre><pre> // ... Rest of task code.
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}</pre><pre>// Task to receive from the queue.
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void vADifferentTask( void *pvParameters )
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{
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struct AMessage *pxRxedMessage;</pre><pre> if( xQueue != 0 )
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{
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// Receive a message on the created queue. Block for 10 ticks if a
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// message is not immediately available.
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if( xQueueReceive( xQueue, &( pxRxedMessage ), ( TickType_t ) 10 ) )
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{
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// pcRxedMessage now points to the struct AMessage variable posted
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// by vATask.
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}
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}</pre><pre> // ... Rest of task code.
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}
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