Rtos API example

Revision:
0:9fca2b23d0ba
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os/rtos/Queue.h	Sat Feb 23 12:13:36 2019 +0000
@@ -0,0 +1,146 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2012 ARM Limited
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#ifndef QUEUE_H
+#define QUEUE_H
+
+#include <stdint.h>
+#include <string.h>
+
+#include "cmsis_os2.h"
+#include "mbed_rtos_storage.h"
+#include "platform/mbed_error.h"
+#include "platform/NonCopyable.h"
+#include "mbed_rtos1_types.h"
+
+namespace rtos {
+/** \addtogroup rtos */
+/** @{*/
+/**
+ * \defgroup rtos_EventFlags EventFlags class
+ * @{
+ */
+ 
+/** The Queue class allow to control, send, receive, or wait for messages.
+ A message can be a integer or pointer value  to a certain type T that is send
+ to a thread or interrupt service routine.
+  @tparam  T         data type of a single message element.
+  @tparam  queue_sz  maximum number of messages in queue.
+
+ @note
+ Memory considerations: The queue control structures will be created on current thread's stack, both for the mbed OS
+ and underlying RTOS objects (static or dynamic RTOS memory pools are not being used).
+*/
+template<typename T, uint32_t queue_sz>
+class Queue : private mbed::NonCopyable<Queue<T, queue_sz> > {
+public:
+    /** Create and initialize a message Queue. */
+    Queue() {
+        memset(&_obj_mem, 0, sizeof(_obj_mem));
+        osMessageQueueAttr_t attr = { 0 };
+        attr.mq_mem = _queue_mem;
+        attr.mq_size = sizeof(_queue_mem);
+        attr.cb_mem = &_obj_mem;
+        attr.cb_size = sizeof(_obj_mem);
+        _id = osMessageQueueNew(queue_sz, sizeof(T*), &attr);
+        MBED_ASSERT(_id);
+    }
+
+    ~Queue() {
+        osMessageQueueDelete(_id);
+    }
+
+    /** Check if the queue is empty
+     *
+     * @return True if the queue is empty, false if not
+     */
+    bool empty() const {
+        return osMessageQueueGetCount(_id) == 0;
+    }
+
+    /** Check if the queue is full
+     *
+     * @return True if the queue is full, false if not
+     */
+    bool full() const {
+        return osMessageQueueGetSpace(_id) == 0;
+    }
+
+    /** Put a message in a Queue.
+      @param   data      message pointer.
+      @param   millisec  timeout value or 0 in case of no time-out. (default: 0)
+      @param   prio      priority value or 0 in case of default. (default: 0)
+      @return  status code that indicates the execution status of the function:
+               @a osOK the message has been put into the queue.
+               @a osErrorTimeout the message could not be put into the queue in the given time.
+               @a osErrorResource not enough space in the queue.
+               @a osErrorParameter internal error or non-zero timeout specified in an ISR.
+    */
+    osStatus put(T* data, uint32_t millisec=0, uint8_t prio=0) {
+        return osMessageQueuePut(_id, &data, prio, millisec);
+    }
+
+    /** Get a message or Wait for a message from a Queue. Messages are retrieved in a descending priority order or
+        first in first out when the priorities are the same.
+      @param   millisec  timeout value or 0 in case of no time-out. (default: osWaitForever).
+      @return  event information that includes the message in event.value and the status code in event.status:
+               @a osEventMessage message received.
+               @a osOK no message is available in the queue and no timeout was specified.
+               @a osEventTimeout no message has arrived during the given timeout period.
+               @a osErrorParameter a parameter is invalid or outside of a permitted range.
+    */
+    osEvent get(uint32_t millisec=osWaitForever) {
+        osEvent event;
+        T *data = NULL;
+        osStatus_t res = osMessageQueueGet(_id, &data, NULL, millisec);
+
+        switch (res) {
+            case osOK:
+                event.status = (osStatus)osEventMessage;
+                event.value.p = data;
+                break;
+            case osErrorResource:
+                event.status = osOK;
+                break;
+            case osErrorTimeout:
+                event.status = (osStatus)osEventTimeout;
+                break;
+            case osErrorParameter:
+            default:
+                event.status = osErrorParameter;
+                break;
+        }
+        event.def.message_id = _id;
+
+        return event;
+    }
+
+private:
+    osMessageQueueId_t            _id;
+    char                          _queue_mem[queue_sz * (sizeof(T*) + sizeof(mbed_rtos_storage_message_t))];
+    mbed_rtos_storage_msg_queue_t _obj_mem;
+};
+/** @}*/
+/** @}*/
+
+}
+#endif
+