CircBufferHostSerial.h

00001 /* mbed USBHost Library
00002  * Copyright (c) 2006-2013 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 
00017 #ifndef CIRCBUFFERHOSTSERIAL_H
00018 #define CIRCBUFFERHOSTSERIAL_H
00019 
00020 #include "stdint.h"
00021 
00022 template<typename T, int size>
00023 class CircBufferHostSerial {
00024 public:
00025 
00026     CircBufferHostSerial() {
00027         write = 0;
00028         read = 0;
00029     }
00030 
00031     bool isFull() {
00032         return (((write + 1) % size) == read);
00033     }
00034 
00035     bool isEmpty() {
00036         return (read == write);
00037     }
00038 
00039     void flush() {
00040         write = 0;
00041         read = 0;
00042     }
00043 
00044     bool queue(T k) {
00045         if (isFull()) {
00046             return false;
00047         }
00048         buf[write] = k;
00049         write = (write + 1) % size;
00050         return true;
00051     }
00052 
00053     uint32_t available() {
00054         uint32_t a = (write >= read) ? (write - read) : (size - read + write);
00055         return a;
00056     }
00057 
00058     bool dequeue(T * c) {
00059         if (isEmpty()) {
00060             return false;
00061         }
00062         *c = buf[read];
00063         read = (read + 1) % size;
00064         return true;
00065     }
00066 
00067 private:
00068     volatile uint32_t write;
00069     volatile uint32_t read;
00070     volatile T buf[size];
00071 };
00072 
00073 #endif
00074