Diff: USBHost_custom/USBHostSerial/MtxCircBuffer.h

Revision:

166:3a9487d57a5c

diff -r e614a9f1c9e2 -r 3a9487d57a5c USBHost_custom/USBHostSerial/MtxCircBuffer.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/USBHost_custom/USBHostSerial/MtxCircBuffer.h	Thu Jun 29 11:00:41 2017 +0000
@@ -0,0 +1,75 @@
+/* mbed USBHost Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef MTXCIRCBUFFER_H
+#define MTXCIRCBUFFER_H
+
+#include "stdint.h"
+
+//Mutex protected circular buffer
+template<typename T, int size>
+class MtxCircBuffer {
+public:
+
+    MtxCircBuffer() {
+        write = 0;
+        read = 0;
+    }
+
+    bool isFull() {
+        return (((write + 1) % size) == read);
+    }
+
+    bool isEmpty() {
+        return (read == write);
+    }
+
+    void flush() {
+        write = 0;
+        read = 0;
+    }
+
+    bool queue(T k) {
+        if (isFull()) {
+            return false;
+        }
+        buf[write] = k;
+        write = (write + 1) % size;
+        return true;
+    }
+
+    uint32_t available() {
+        uint32_t a = (write >= read) ? (write - read) : (size - read + write);
+        return a;
+    }
+
+    bool dequeue(T * c) {
+        if (isEmpty()) {
+            return false;
+        }
+        *c = buf[read];
+        read = (read + 1) % size;
+        return true;
+    }
+
+private:
+    volatile uint32_t write;
+    volatile uint32_t read;
+    volatile T buf[size];
+};
+
+#endif
+