====== OSA : OS_Queue_IsEmpty ======
<color blue>**bool OS_Queue_IsEmpty (queue)**</color>\\ 
<color blue>**bool OS_Queue_IsEmpty_I (queue)**</color>\\ 
=== ===

Check if queue of messages is empty.

##[[en:osa:ref:appendix:configuration#System constants|OS_ENABLE_QUEUE]]## constant must be defined in ##[[en:osa:ref:appendix:configuration|OSAcfg.h]]##.
<note>
For PIC16, message queues can be allocated only in **bank0** or **bank1**
</note>


=== Call allowed: ===
Everywhere


=== Parameters: ===
{| class = "fpl"
|-
|//''queue''//
|Queue of messages descriptor. Variable of ##[[en:osa:ref:description:data_types#OST_QUEUE|OST_QUEUE]]## type.
|}


=== Returns: ===
{| class = "fpl"
|-
|//''false''//
| there are some messages in the queue
|-
|//''true''//
| queue is free, no messages
|}


=== Example: ===
<code cpp>
OST_QUEUE queue;

void Task (void)
{
    for (;;) {
        /*...*/
        if (OS_Queue_IsEmpty (queue)) {
            /* The queue is empty */
        } else {
            /* The queue has messages */
        };
        /*...*/
    }
}
</code>


=== Old style name ===

=== See also ===
  * [[en:osa:ref:allservices:OS_Queue_Create|OS_Queue_Create]]

  * [[en:osa:ref:allservices:OS_Queue_Send|OS_Queue_Send]]
  * [[en:osa:ref:allservices:OS_Queue_Send_TO|OS_Queue_Send_TO]]
  * [[en:osa:ref:allservices:OS_Queue_Send_Now|OS_Queue_Send_Now]]


  * [[en:osa:ref:allservices:OS_Queue_Check|OS_Queue_Check]]
  * [[en:osa:ref:allservices:OS_Queue_IsFull|OS_Queue_IsFull]]

  * [[en:osa:ref:allservices:OS_Queue_Wait|OS_Queue_Wait]]
  * [[en:osa:ref:allservices:OS_Queue_Wait_TO|OS_Queue_Wait_TO]]

----
  * [[en:osa:ref:services:alphabetical|Alphabetical]]
  * [[en:osa:ref:services:brieflist|All services]]
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