non blocking queue

Fork of mbed-rtos by mbed official

Revision:
6:350b53afb889
Child:
8:88a1a9c26ae3
diff -r 9654a71f5a90 -r 350b53afb889 rtos/Mail.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rtos/Mail.h	Fri Nov 23 09:57:31 2012 +0000
@@ -0,0 +1,89 @@
+/* Copyright (c) 2012 mbed.org */
+#ifndef MAIL_H
+#define MAIL_H 
+
+#include <stdint.h>
+#include <string.h>
+
+#include "cmsis_os.h"
+
+namespace rtos {
+
+/*! The Mail class allow to control, send, receive, or wait for mail.
+ A mail is a memory block 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.
+*/
+template<typename T, uint32_t queue_sz>
+class Mail {
+public:
+    /*! Create and Initialise Mail queue. */
+    Mail() {
+    #ifdef CMSIS_OS_RTX
+        memset(_mail_q, 0, sizeof(_mail_q));
+        _mail_p[0] = _mail_q;
+        
+        memset(_mail_m, 0, sizeof(_mail_m));
+        _mail_p[1] = _mail_m;
+        
+        _mail_def.pool = _mail_p;
+        _mail_def.queue_sz = queue_sz;
+        _mail_def.item_sz = sizeof(T);
+    #endif
+        _mail_id = osMailCreate(&_mail_def, NULL);
+    }
+    
+    /*! Allocate a memory block of type T
+      \param   millisec  timeout value or 0 in case of no time-out. (default: 0).
+      \return  pointer to memory block that can be filled with mail or NULL in case error.
+    */
+    T* alloc(uint32_t millisec=0) {
+        return (T*)osMailAlloc(_mail_id, millisec);
+    }
+    
+    /*! Allocate a memory block of type T and set memory block to zero. 
+      \param   millisec  timeout value or 0 in case of no time-out.  (default: 0).
+      \return  pointer to memory block that can be filled with mail or NULL in case error.
+    */
+    T* calloc(uint32_t millisec=0) {
+        return (T*)osMailCAlloc(_mail_id, millisec);
+    }
+    
+    /*! Put a mail in the queue.
+      \param   mptr  memory block previously allocated with Mail::alloc or Mail::calloc.
+      \return  status code that indicates the execution status of the function. 
+    */
+    osStatus put(T *mptr) {
+        return osMailPut(_mail_id, (void*)mptr);
+    }
+    
+    /*! Get a mail from a queue.
+      \param   millisec  timeout value or 0 in case of no time-out. (default: osWaitForever).
+      \return  event that contains mail information or error code.
+    */
+    osEvent get(uint32_t millisec=osWaitForever) {
+        return osMailGet(_mail_id, millisec);
+    }
+    
+    /*! Free a memory block from a mail.
+      \param   mptr  pointer to the memory block that was obtained with Mail::get. 
+      \return  status code that indicates the execution status of the function.
+    */
+    osStatus free(T *mptr) {
+        return osMailFree(_mail_id, (void*)mptr);
+    }
+
+private:
+    osMailQId    _mail_id;
+    osMailQDef_t _mail_def;
+#ifdef CMSIS_OS_RTX
+    uint32_t     _mail_q[4+(queue_sz)];
+    uint32_t     _mail_m[3+((sizeof(T)+3)/4)*(queue_sz)];
+    void        *_mail_p[2];
+#endif
+};
+
+}
+
+#endif
+