virtualmech / USBHostVM

V18.

Dependencies:   FATFileSystem mbed-rtos

Fork of USBHost by mbed official

USBHostSerial/MtxCircBuffer.h@8:93da8ea2708b, 2013-03-14 (annotated)

Committer:
samux
Date:
Thu Mar 14 11:49:53 2013 +0000
Revision:
8:93da8ea2708b
Parent:
4:b320d68e98e7
Child:
24:868cbfe611a7
update doc + license

Who changed what in which revision?

UserRevisionLine numberNew contents of line
samux 8:93da8ea2708b 1 /* mbed USBHost Library
samux 8:93da8ea2708b 2 * Copyright (c) 2006-2013 ARM Limited
samux 8:93da8ea2708b 3 *
samux 8:93da8ea2708b 4 * Licensed under the Apache License, Version 2.0 (the "License");
samux 8:93da8ea2708b 5 * you may not use this file except in compliance with the License.
samux 8:93da8ea2708b 6 * You may obtain a copy of the License at
samux 8:93da8ea2708b 7 *
samux 8:93da8ea2708b 8 * http://www.apache.org/licenses/LICENSE-2.0
samux 8:93da8ea2708b 9 *
samux 8:93da8ea2708b 10 * Unless required by applicable law or agreed to in writing, software
samux 8:93da8ea2708b 11 * distributed under the License is distributed on an "AS IS" BASIS,
samux 8:93da8ea2708b 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
samux 8:93da8ea2708b 13 * See the License for the specific language governing permissions and
samux 8:93da8ea2708b 14 * limitations under the License.
samux 8:93da8ea2708b 15 */
mbed_official 0:a554658735bf 16
mbed_official 0:a554658735bf 17 #ifndef MTXCIRCBUFFER_H
mbed_official 0:a554658735bf 18 #define MTXCIRCBUFFER_H
mbed_official 0:a554658735bf 19
mbed_official 0:a554658735bf 20 #include "stdint.h"
mbed_official 0:a554658735bf 21 #include "rtos.h"
mbed_official 0:a554658735bf 22
mbed_official 0:a554658735bf 23 //Mutex protected circular buffer
mbed_official 0:a554658735bf 24 template<typename T, int size>
mbed_official 0:a554658735bf 25 class MtxCircBuffer {
mbed_official 0:a554658735bf 26 public:
mbed_official 0:a554658735bf 27
mbed_official 0:a554658735bf 28 MtxCircBuffer() {
mbed_official 0:a554658735bf 29 write = 0;
mbed_official 0:a554658735bf 30 read = 0;
mbed_official 0:a554658735bf 31 }
mbed_official 0:a554658735bf 32
mbed_official 0:a554658735bf 33 bool isFull() {
mbed_official 0:a554658735bf 34 mtx.lock();
mbed_official 0:a554658735bf 35 bool r = (((write + 1) % size) == read);
mbed_official 0:a554658735bf 36 mtx.unlock();
mbed_official 0:a554658735bf 37 return r;
mbed_official 0:a554658735bf 38 }
mbed_official 0:a554658735bf 39
mbed_official 0:a554658735bf 40 bool isEmpty() {
mbed_official 0:a554658735bf 41 mtx.lock();
mbed_official 0:a554658735bf 42 bool r = (read == write);
mbed_official 0:a554658735bf 43 mtx.unlock();
mbed_official 0:a554658735bf 44 return r;
mbed_official 0:a554658735bf 45 }
samux 4:b320d68e98e7 46
samux 4:b320d68e98e7 47 void flush() {
samux 4:b320d68e98e7 48 write = 0;
samux 4:b320d68e98e7 49 read = 0;
samux 4:b320d68e98e7 50 }
mbed_official 0:a554658735bf 51
mbed_official 0:a554658735bf 52 void queue(T k) {
mbed_official 0:a554658735bf 53 mtx.lock();
mbed_official 0:a554658735bf 54 while (((write + 1) % size) == read) {
mbed_official 0:a554658735bf 55 mtx.unlock();
mbed_official 0:a554658735bf 56 Thread::wait(10);
mbed_official 0:a554658735bf 57 mtx.lock();
mbed_official 0:a554658735bf 58 }
mbed_official 0:a554658735bf 59 buf[write++] = k;
mbed_official 0:a554658735bf 60 write %= size;
mbed_official 0:a554658735bf 61 mtx.unlock();
mbed_official 0:a554658735bf 62 }
mbed_official 0:a554658735bf 63
mbed_official 0:a554658735bf 64 uint16_t available() {
mbed_official 0:a554658735bf 65 mtx.lock();
mbed_official 0:a554658735bf 66 uint16_t a = (write >= read) ? (write - read) : (size - read + write);
mbed_official 0:a554658735bf 67 mtx.unlock();
mbed_official 0:a554658735bf 68 return a;
mbed_official 0:a554658735bf 69 }
mbed_official 0:a554658735bf 70
mbed_official 0:a554658735bf 71 bool dequeue(T * c) {
mbed_official 0:a554658735bf 72 mtx.lock();
mbed_official 0:a554658735bf 73 bool empty = (read == write);
mbed_official 0:a554658735bf 74 if (!empty) {
mbed_official 0:a554658735bf 75 *c = buf[read++];
mbed_official 0:a554658735bf 76 read %= size;
mbed_official 0:a554658735bf 77 }
mbed_official 0:a554658735bf 78 mtx.unlock();
mbed_official 0:a554658735bf 79 return (!empty);
mbed_official 0:a554658735bf 80 }
mbed_official 0:a554658735bf 81
mbed_official 0:a554658735bf 82 private:
mbed_official 0:a554658735bf 83 volatile uint16_t write;
mbed_official 0:a554658735bf 84 volatile uint16_t read;
mbed_official 0:a554658735bf 85 volatile T buf[size];
mbed_official 0:a554658735bf 86 Mutex mtx;
mbed_official 0:a554658735bf 87 };
mbed_official 0:a554658735bf 88
mbed_official 0:a554658735bf 89 #endif