Queue

Table of Contents

• Features Supported
• Features NOT Supported
• Important Usage Guidelines
• Example Usage
• API

Features Supported

• APIs to create and destroy Queues
• APIs to Put element in Queue
• APIs to Get element from Queue
• APIs to Check if Queue is Empty

Features NOT Supported

NA

Important Usage Guidelines

• For creating the Queue application needs to provide the QueueP_Object and it should not be modified by the applicaion.
• A field of type QueueP_Elem should be placed at the head of client structs passed as Queue Elements to function QueueP_put.
• It is recommended not to place the QueueP Object and QueueP Element objects in stack as they will be accessed by the driver till they are released.

Example Usage

Include the below file to access the APIs,

#include <kernel/dpl/QueueP.h>

Example usage define Queue Object and Elements

/* Define a client structure for the queue elements.
   The object of type QueueP_Elem should be placed at the head of the structure. */
typedef struct Test_Queue_Elem_s
{
    QueueP_Elem lnk;
    uint32_t    index;
} Test_Queue_Elem;
 
Test_Queue_Elem  elem1, elem2;
QueueP_Object    qObj;

Example to Create and use the Queue

    QueueP_Handle   handle;
    Test_Queue_Elem *pElem;
    /* Create the Queue. */
    handle = QueueP_create(&qObj);
 
    /* Put elements in a Queue. */
    QueueP_put(handle, (QueueP_Elem *)&elem1);
    QueueP_put(handle, (QueueP_Elem *)&elem2);
 
    /* Get elements from the queue. */
    pElem = (Test_Queue_Elem *)QueueP_get(handle);
    pElem = (Test_Queue_Elem *)QueueP_get(handle);
    /* Typically pElem would be processed by application. 
     * In sample typecast to void to kill warning 
     * regarding variable set but not used 
     */
    (void) pElem;
 
    QueueP_delete(handle);

API

APIs for Queue