Diff: USBHostSerial/MtxCircBuffer.h

Revision:

0:a554658735bf

Child:

4:b320d68e98e7

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/USBHostSerial/MtxCircBuffer.h	Wed Mar 06 16:27:14 2013 +0000
@@ -0,0 +1,88 @@
+/* Copyright (c) 2010-2011 mbed.org, MIT License
+*
+* 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 MTXCIRCBUFFER_H
+#define MTXCIRCBUFFER_H
+
+#include "stdint.h"
+#include "rtos.h"
+
+//Mutex protected circular buffer
+template<typename T, int size>
+class MtxCircBuffer {
+public:
+    
+    MtxCircBuffer() {
+        write = 0;
+        read = 0;
+    }
+
+    bool isFull() {
+        mtx.lock();
+        bool r = (((write + 1) % size) == read);
+        mtx.unlock();
+        return r;
+    }
+
+    bool isEmpty() {
+        mtx.lock();
+        bool r = (read == write);
+        mtx.unlock();
+        return r;
+    }
+
+    void queue(T k) {
+        mtx.lock();
+        while (((write + 1) % size) == read) {
+            mtx.unlock();
+            Thread::wait(10);
+            mtx.lock();
+        }
+        buf[write++] = k;
+        write %= size;
+        mtx.unlock();
+    }
+
+    uint16_t available() {
+        mtx.lock();
+        uint16_t a = (write >= read) ? (write - read) : (size - read + write);
+        mtx.unlock();
+        return a;
+    }
+
+    bool dequeue(T * c) {
+        mtx.lock();
+        bool empty = (read == write);
+        if (!empty) {
+            *c = buf[read++];
+            read %= size;
+        }
+        mtx.unlock();
+        return (!empty);
+    }
+
+private:
+    volatile uint16_t write;
+    volatile uint16_t read;
+    volatile T buf[size];
+    Mutex mtx;
+};
+
+#endif
+
+