Diff: core/MtxCircBuffer.h

Revision:

97:7d9cc95e2ea7

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/core/MtxCircBuffer.h	Wed Feb 18 14:11:24 2015 +0000
@@ -0,0 +1,107 @@
+/* MtxCircBuf.h */
+/* Copyright (C) 2012 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 MTXCIRCBUFFER_H
+#define MTXCIRCBUFFER_H
+
+#include "fwk.h"
+
+#include "rtos.h"
+
+//Mutex protected circualr buffer
+template<typename T, int size>
+class MtxCircBuffer
+{
+public:
+  MtxCircBuffer() //:
+      //mtx()
+  {
+    write = 0;
+    read = 0;
+  }
+
+  bool isFull()
+  {
+    mtx.lock();
+    bool r = (((write + 1) % size) == read);
+    mtx.unlock();
+    return r;
+  }
+
+  bool isEmpty()
+  {
+    mtx.lock();
+    bool r = (read == write);
+    mtx.unlock();
+    return r;
+  }
+
+  void queue(T k)
+  {
+    // XXX Some modems spew stuff out on multiple interfaces
+    // which can cause the circular buffer to block if
+    // the unread queues are not flushed. Need to make this
+    // non-blocking: just overwrite oldest chars for example.
+    mtx.lock();
+    while (((write + 1) % size) == read) //if (isFull())
+    {
+      /*while((((write + 1) % size) == read))
+      {*/
+        mtx.unlock();
+        Thread::wait(10);
+        mtx.lock();
+      /*}*/
+      //read++;
+      //read %= size;
+    }
+    buf[write++] = k;
+    write %= size;
+    mtx.unlock();
+  }
+
+  uint16_t available()
+  {
+    mtx.lock();
+    uint16_t a = (write >= read) ? (write - read) : (size - read + write);
+    mtx.unlock();
+    return a;
+  }
+
+  bool dequeue(T * c)
+  {
+    mtx.lock();
+    bool empty = (read == write);
+    if (!empty)
+    {
+      *c = buf[read++];
+      read %= size;
+    }
+    mtx.unlock();
+    return (!empty);
+  }
+
+private:
+  volatile uint16_t write;
+  volatile uint16_t read;
+  volatile T buf[size];
+  Mutex mtx;
+};
+
+#endif
+