Lee Kai Xuan / mbed-os

mbed-os

Fork of mbed-os by erkin yucel

features/unsupported/USBHost/USBHostSerial/MtxCircBuffer.h@0:f269e3021894, 2016-10-23 (annotated)

Committer:
elessair
Date:
Sun Oct 23 15:10:02 2016 +0000
Revision:
0:f269e3021894
Initial commit

Who changed what in which revision?

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elessair 0:f269e3021894 1 /* mbed USBHost Library
elessair 0:f269e3021894 2 * Copyright (c) 2006-2013 ARM Limited
elessair 0:f269e3021894 3 *
elessair 0:f269e3021894 4 * Licensed under the Apache License, Version 2.0 (the "License");
elessair 0:f269e3021894 5 * you may not use this file except in compliance with the License.
elessair 0:f269e3021894 6 * You may obtain a copy of the License at
elessair 0:f269e3021894 7 *
elessair 0:f269e3021894 8 * http://www.apache.org/licenses/LICENSE-2.0
elessair 0:f269e3021894 9 *
elessair 0:f269e3021894 10 * Unless required by applicable law or agreed to in writing, software
elessair 0:f269e3021894 11 * distributed under the License is distributed on an "AS IS" BASIS,
elessair 0:f269e3021894 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
elessair 0:f269e3021894 13 * See the License for the specific language governing permissions and
elessair 0:f269e3021894 14 * limitations under the License.
elessair 0:f269e3021894 15 */
elessair 0:f269e3021894 16
elessair 0:f269e3021894 17 #ifndef MTXCIRCBUFFER_H
elessair 0:f269e3021894 18 #define MTXCIRCBUFFER_H
elessair 0:f269e3021894 19
elessair 0:f269e3021894 20 #include "stdint.h"
elessair 0:f269e3021894 21 #include "rtos.h"
elessair 0:f269e3021894 22
elessair 0:f269e3021894 23 //Mutex protected circular buffer
elessair 0:f269e3021894 24 template<typename T, int size>
elessair 0:f269e3021894 25 class MtxCircBuffer {
elessair 0:f269e3021894 26 public:
elessair 0:f269e3021894 27
elessair 0:f269e3021894 28 MtxCircBuffer() {
elessair 0:f269e3021894 29 write = 0;
elessair 0:f269e3021894 30 read = 0;
elessair 0:f269e3021894 31 }
elessair 0:f269e3021894 32
elessair 0:f269e3021894 33 bool isFull() {
elessair 0:f269e3021894 34 mtx.lock();
elessair 0:f269e3021894 35 bool r = (((write + 1) % size) == read);
elessair 0:f269e3021894 36 mtx.unlock();
elessair 0:f269e3021894 37 return r;
elessair 0:f269e3021894 38 }
elessair 0:f269e3021894 39
elessair 0:f269e3021894 40 bool isEmpty() {
elessair 0:f269e3021894 41 mtx.lock();
elessair 0:f269e3021894 42 bool r = (read == write);
elessair 0:f269e3021894 43 mtx.unlock();
elessair 0:f269e3021894 44 return r;
elessair 0:f269e3021894 45 }
elessair 0:f269e3021894 46
elessair 0:f269e3021894 47 void flush() {
elessair 0:f269e3021894 48 write = 0;
elessair 0:f269e3021894 49 read = 0;
elessair 0:f269e3021894 50 }
elessair 0:f269e3021894 51
elessair 0:f269e3021894 52 void queue(T k) {
elessair 0:f269e3021894 53 mtx.lock();
elessair 0:f269e3021894 54 while (((write + 1) % size) == read) {
elessair 0:f269e3021894 55 mtx.unlock();
elessair 0:f269e3021894 56 Thread::wait(10);
elessair 0:f269e3021894 57 mtx.lock();
elessair 0:f269e3021894 58 }
elessair 0:f269e3021894 59 buf[write++] = k;
elessair 0:f269e3021894 60 write %= size;
elessair 0:f269e3021894 61 mtx.unlock();
elessair 0:f269e3021894 62 }
elessair 0:f269e3021894 63
elessair 0:f269e3021894 64 uint16_t available() {
elessair 0:f269e3021894 65 mtx.lock();
elessair 0:f269e3021894 66 uint16_t a = (write >= read) ? (write - read) : (size - read + write);
elessair 0:f269e3021894 67 mtx.unlock();
elessair 0:f269e3021894 68 return a;
elessair 0:f269e3021894 69 }
elessair 0:f269e3021894 70
elessair 0:f269e3021894 71 bool dequeue(T * c) {
elessair 0:f269e3021894 72 mtx.lock();
elessair 0:f269e3021894 73 bool empty = (read == write);
elessair 0:f269e3021894 74 if (!empty) {
elessair 0:f269e3021894 75 *c = buf[read++];
elessair 0:f269e3021894 76 read %= size;
elessair 0:f269e3021894 77 }
elessair 0:f269e3021894 78 mtx.unlock();
elessair 0:f269e3021894 79 return (!empty);
elessair 0:f269e3021894 80 }
elessair 0:f269e3021894 81
elessair 0:f269e3021894 82 private:
elessair 0:f269e3021894 83 volatile uint16_t write;
elessair 0:f269e3021894 84 volatile uint16_t read;
elessair 0:f269e3021894 85 volatile T buf[size];
elessair 0:f269e3021894 86 Mutex mtx;
elessair 0:f269e3021894 87 };
elessair 0:f269e3021894 88
elessair 0:f269e3021894 89 #endif