Squashed 'tmk_core/' changes from 7967731..b9e0ea0

b9e0ea0 Merge commit '7fa9d8bdea3773d1195b04d98fcf27cf48ddd81d' as 'tool/mbed/mbed-sdk'
7fa9d8b Squashed 'tool/mbed/mbed-sdk/' content from commit 7c21ce5

git-subtree-dir: tmk_core
git-subtree-split: b9e0ea08cb940de20b3610ecdda18e9d8cd7c552

tool/mbed/mbed-sdk/libraries/USBDevice/USBSerial/CircBuffer.h

@@ -0,0 +1,63 @@
+/* Copyright (c) 2010-2011 mbed.org, MIT License
+*
+* Permission is hereby granted, free of charge, to any person obtaining a copy of this software
+* and associated documentation files (the "Software"), to deal in the Software without
+* restriction, including without limitation the rights to use, copy, modify, merge, publish,
+* distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
+* Software is furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included in all copies or
+* substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
+* BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+#ifndef CIRCBUFFER_H
+#define CIRCBUFFER_H
+
+template <class T, int Size>
+class CircBuffer {
+public:
+    CircBuffer():write(0), read(0){}
+    bool isFull() {
+        return ((write + 1) % size == read);
+    };
+
+    bool isEmpty() {
+        return (read == write);
+    };
+
+    void queue(T k) {
+        if (isFull()) {
+            read++;
+            read %= size;
+        }
+        buf[write++] = k;
+        write %= size;
+    }
+
+    uint16_t available() {
+        return (write >= read) ? write - read : size - read + write;
+    };
+
+    bool dequeue(T * c) {
+        bool empty = isEmpty();
+        if (!empty) {
+            *c = buf[read++];
+            read %= size;
+        }
+        return(!empty);
+    };
+
+private:
+    volatile uint16_t write;
+    volatile uint16_t read;
+    static const int size = Size+1;  //a modern optimizer should be able to remove this so it uses no ram.
+    T buf[Size];
+};
+
+#endif