[Planeshift-cvs] SF.net SVN: planeshift: [1361] trunk/src/common/util/genrefqueue.h

[<kha...@us...>]

Revision: 1361
          http://planeshift.svn.sourceforge.net/planeshift/?rev=1361&view=rev
Author:   khakilord
Date:     2008-04-19 11:10:04 -0700 (Sat, 19 Apr 2008)

Log Message:
-----------
Rethought and reverted approach to full message queue as old implementation had bugs in acking. The network thread now blocks on a full queue, the most elegant solution. Not dealing with acks reduces potential bugs and reduces cpu spinning.

Modified Paths:
--------------
    trunk/src/common/util/genrefqueue.h

Modified: trunk/src/common/util/genrefqueue.h
===================================================================
--- trunk/src/common/util/genrefqueue.h	2008-04-19 14:40:49 UTC (rev 1360)
+++ trunk/src/common/util/genrefqueue.h	2008-04-19 18:10:04 UTC (rev 1361)
@@ -48,8 +48,33 @@
     {
         delete[] qbuffer;
     }
-
-    /** This adds a message to the queue */
+    
+    /** like above, but waits to add the next message, if the queue is full
+     *  be careful with this. It's easy to deadlock! */
+    bool AddWait(queuetype* msg, csTicks timeout = 0)
+    {
+        // is there's a space in the queue left just add it
+        CS::Threading::RecursiveMutexScopedLock lock(mutex);
+        while(true)
+        {
+            bool added = Add(msg);
+            if (added)
+            {
+                return true;
+            }
+            Error1("Queue full! Waiting.\n");
+            
+            // Wait release mutex before waiting so that it is possible to
+            // add new messages.
+            if (!datacondition.Wait(mutex, timeout))
+            {
+                // Timed out waiting for new message
+                return false;
+            }
+        }
+    }
+        
+    /** This adds a message to the queue and waits if it is full */
     bool Add(queuetype* msg)
     {
         unsigned int tqend;
@@ -60,9 +85,9 @@
         {
             tqend = (qend + 1) % qsize;
             // check if queue is full
-            if (tqend == qstart)
+            while (tqend == qstart)
             {
-                return false;
+                datacondition.Wait(mutex);
             }
             // check are we having a refcount race (in which msg would already be destroyed)
 			CS_ASSERT(msg->GetRefCount() > 0);
@@ -103,6 +128,7 @@
         }
 
         ptr->SetPending(false);
+        Interrupt();
 
         return csPtr<queuetype>(ptr);
     }
@@ -112,38 +138,24 @@
     {
         // is there's a message in the queue left just return it
         CS::Threading::RecursiveMutexScopedLock lock(mutex);
-        csRef<queuetype> temp = Get();
-        if (temp)
+        while(true)
         {
-            return csPtr<queuetype> (temp);
-        }
+            csRef<queuetype> temp = Get();
+            if (temp)
+            {
+                return csPtr<queuetype> (temp);
+            }
 
-        // Wait release mutex before waiting so that it is possible to
-        // add new messages.
-        if (!datacondition.Wait(mutex, timeout))
-        {
-            // Timed out waiting for new message
-            return 0;
-        }
-
-        csRef<queuetype> ptr;
-        // if this is a weakref queue we should skip over null entries
-        while(!ptr.IsValid())
-        {
-            // check if queue is empty
-            if (qstart == qend)
+            // Wait release mutex before waiting so that it is possible to
+            // add new messages.
+            if (!datacondition.Wait(mutex, timeout))
+            {
+                // Timed out waiting for new message
                 return 0;
-
-            // removes Message from queue
-            ptr = qbuffer[qstart];
-            qbuffer[qstart] = 0;
-            
-            qstart = (qstart + 1) % qsize;
+            }
         }
-
-        ptr->SetPending(false);
-
-        return csPtr<queuetype>(ptr);
+        CS_ASSERT(false);
+        return 0;
     }
 
     /**


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