Diff: CANQueue.cpp

Revision:

0:7cf23260330d

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/CANQueue.cpp	Sun Jul 15 15:15:20 2012 +0000
@@ -0,0 +1,99 @@
+/// @file CANQueue.h 
+/// The CAN Queue mechanism permits the creation and management of 
+/// messages through a CAN queue.
+///
+/// @todo disable on the relevant interrupts, rather than all when protecting
+///       the critical section.
+///
+/// @note Copyright &copr; 2011 by Smartware Computing, all rights reserved.
+///     Individuals may use this application for evaluation or non-commercial
+///     purposes. Within this restriction, changes may be made to this application
+///     as long as this copyright notice is retained. The user shall make
+///     clear that their work is a derived work, and not the original.
+///     Users of this application and sources accept this application "as is" and
+///     shall hold harmless Smartware Computing, for any undesired results while
+///     using this application - whether real or imagined.
+///
+/// @author David Smart, Smartware Computing
+///
+
+// These are needed by this file
+#include "CANQueue.h"
+//#include "CANUtilities.h"
+
+
+CANQueue::CANQueue(int Size)
+{
+    queue = new CANmsg[Size];
+    queueSize = Size;
+    queueCount = 0;
+    queueMaxCount = 0;
+    enqueuePosition = 0;
+    dequeuePosition = 0;
+}
+
+
+CANQueue::~CANQueue()
+{
+    delete[] queue;
+}
+
+
+bool CANQueue::Enqueue(CANmsg msg)
+{
+#if 1
+    return Enqueue(&msg);
+#else
+    queue[enqueuePosition++] = msg;
+    enqueuePosition = enqueuePosition % queueSize;
+    queueCount++;
+    if (queueCount > queueMaxCount) // track the max
+        queueMaxCount = queueCount;
+    if (queueCount > queueSize)     // just overwrote the oldest
+    {
+        dequeuePosition++;
+        dequeuePosition = dequeuePosition % queueSize;
+        queueCount = queueSize;
+        return false;
+    }
+    return true;
+#endif
+}
+
+
+bool CANQueue::Enqueue(CANmsg *msg)
+{
+    bool retval = true;
+    
+    __disable_irq();
+    queue[enqueuePosition++] = *msg;
+    enqueuePosition = enqueuePosition % queueSize;
+    queueCount++;
+    if (queueCount > queueMaxCount) // track the max
+        queueMaxCount = queueCount;
+    if (queueCount > queueSize)    // just overwrote the oldest
+    {
+        dequeuePosition++;
+        dequeuePosition = dequeuePosition % queueSize;
+        queueCount = queueSize;
+        retval = false;
+    }
+    __enable_irq();
+    return retval;
+}
+
+
+
+bool CANQueue::Dequeue(CANmsg *msg)
+{
+    if (queueCount)
+    {
+        __disable_irq();
+        *msg = queue[dequeuePosition++];
+        dequeuePosition = dequeuePosition % queueSize;
+        queueCount--;
+        __enable_irq();
+        return true;
+    }
+    return false;
+}