Queue.h

00001 /* Copyright (c) 2012 mbed.org */
00002 #ifndef QUEUE_H
00003 #define QUEUE_H 
00004 
00005 #include <stdint.h>
00006 #include <string.h>
00007 
00008 #include "cmsis_os.h"
00009 #include "error.h"
00010 
00011 namespace rtos {
00012 
00013 /*! The Queue class allow to control, send, receive, or wait for messages.
00014  A message can be a integer or pointer value  to a certain type T that is send
00015  to a thread or interrupt service routine.
00016   \tparam  T         data type of a single message element.
00017   \tparam  queue_sz  maximum number of messages in queue.
00018 */
00019 template<typename T, uint32_t queue_sz>
00020 class Queue  {
00021 public:
00022     /*! Create and initialise a message Queue. */
00023     Queue () {
00024     #ifdef CMSIS_OS_RTX
00025         memset(_queue_q, 0, sizeof(_queue_q));
00026         _queue_def.pool = _queue_q;
00027         _queue_def.queue_sz = queue_sz;
00028     #endif
00029         _queue_id = osMessageCreate(&_queue_def, NULL);
00030         if (_queue_id == NULL) {
00031             error("Error initialising the queue object\n");
00032         }
00033     }
00034     
00035     /*! Put a message in a Queue.
00036       \param   data      message pointer.
00037       \param   millisec  timeout value or 0 in case of no time-out. (default: 0)
00038       \return  status code that indicates the execution status of the function. 
00039     */
00040     osStatus put (T* data, uint32_t millisec=0) {
00041         return osMessagePut(_queue_id, (uint32_t)data, millisec);
00042     }
00043     
00044     /*! Get a message or Wait for a message from a Queue.
00045       \param   millisec  timeout value or 0 in case of no time-out. (default: osWaitForever).
00046       \return  event information that includes the message and the status code.
00047     */
00048     osEvent get(uint32_t millisec=osWaitForever) {
00049         return osMessageGet(_queue_id, millisec);
00050     }
00051 
00052 private:
00053     osMessageQId    _queue_id;
00054     osMessageQDef_t _queue_def;
00055 #ifdef CMSIS_OS_RTX
00056     uint32_t        _queue_q[4+(queue_sz)];
00057 #endif
00058 };
00059 
00060 }
00061 #endif