Move CircularBuffer.h into platform/ given there is no hardware required.

Author: sg-

platform/CircularBuffer.h

@@ -0,0 +1,115 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2015 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 MBED_CIRCULARBUFFER_H
+#define MBED_CIRCULARBUFFER_H
+
+#include "critical.h"
+
+namespace mbed {
+
+/** Templated Circular buffer class
+ *
+ *  @Note Synchronization level: Interrupt safe
+ */
+template<typename T, uint32_t BufferSize, typename CounterType = uint32_t>
+class CircularBuffer {
+public:
+    CircularBuffer() : _head(0), _tail(0), _full(false) {
+    }
+
+    ~CircularBuffer() {
+    }
+
+    /** Push the transaction to the buffer. This overwrites the buffer if it's
+     *  full
+     *
+     * @param data Data to be pushed to the buffer
+     */
+    void push(const T& data) {
+        core_util_critical_section_enter();
+        if (full()) {
+            _tail++;
+            _tail %= BufferSize;
+        }
+        _pool[_head++] = data;
+        _head %= BufferSize;
+        if (_head == _tail) {
+            _full = true;
+        }
+        core_util_critical_section_exit();
+    }
+
+    /** Pop the transaction from the buffer
+     *
+     * @param data Data to be pushed to the buffer
+     * @return True if the buffer is not empty and data contains a transaction, false otherwise
+     */
+    bool pop(T& data) {
+        bool data_popped = false;
+        core_util_critical_section_enter();
+        if (!empty()) {
+            data = _pool[_tail++];
+            _tail %= BufferSize;
+            _full = false;
+            data_popped = true;
+        }
+        core_util_critical_section_exit();
+        return data_popped;
+    }
+
+    /** Check if the buffer is empty
+     *
+     * @return True if the buffer is empty, false if not
+     */
+    bool empty() {
+        core_util_critical_section_enter();
+        bool is_empty = (_head == _tail) && !_full;
+        core_util_critical_section_exit();
+        return is_empty;
+    }
+
+    /** Check if the buffer is full
+     *
+     * @return True if the buffer is full, false if not
+     */
+    bool full() {
+        core_util_critical_section_enter();
+        bool full = _full;
+        core_util_critical_section_exit();
+        return full;
+    }
+
+    /** Reset the buffer
+     *
+     */
+    void reset() {
+        core_util_critical_section_enter();
+        _head = 0;
+        _tail = 0;
+        _full = false;
+        core_util_critical_section_exit();
+    }
+
+private:
+    T _pool[BufferSize];
+    volatile CounterType _head;
+    volatile CounterType _tail;
+    volatile bool _full;
+};
+
+}
+
+#endif