File content as of revision 4:b320d68e98e7:

/* 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 flush() {
        write = 0;
        read = 0;
    }

    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