[Mulgara-svn] r1481 - trunk/src/jar/resolver-store/java/org/mulgara/store/statement/xa

[ronald at mulgara.org]

Author: ronald
Date: 2009-02-12 09:59:50 -0800 (Thu, 12 Feb 2009)
New Revision: 1481

Modified:
   trunk/src/jar/resolver-store/java/org/mulgara/store/statement/xa/TripleWriteThread.java
Log:
Fix potential starvation issue if the writer thread completely empties
the queue while the client is waiting for space in a full queue.

Modified: trunk/src/jar/resolver-store/java/org/mulgara/store/statement/xa/TripleWriteThread.java
===================================================================
--- trunk/src/jar/resolver-store/java/org/mulgara/store/statement/xa/TripleWriteThread.java	2009-02-12 11:45:10 UTC (rev 1480)
+++ trunk/src/jar/resolver-store/java/org/mulgara/store/statement/xa/TripleWriteThread.java	2009-02-12 17:59:50 UTC (rev 1481)
@@ -93,31 +93,28 @@
       synchronized (this) {
         checkForException();
 
+        // Make sure the Queue doesn't exceed its maximum size.
+        if (queue.size() == QUEUE_MAX_BUFFERS) {
+          if (logger.isInfoEnabled()) {
+            logger.info("Triple write queue full for file: " + file + "  Waiting.");
+          }
+
+          // Wait for the Queue to be less than full.
+          do {
+            try {
+              wait();
+            } catch (InterruptedException ie) {
+              throw new RuntimeException("Exception in " + getName(), ie);
+            }
+          } while (queue.size() == QUEUE_MAX_BUFFERS);
+        }
+
+        // Put the buffer in the queue.
         if (queue.isEmpty()) {
           // Transition from empty to not empty.
           notifyAll();
-        } else {
-          // Make sure the Queue doesn't exceed its maximum size.
-          if (queue.size() == QUEUE_MAX_BUFFERS) {
-            // Queue is full.  Log a message.
-            if (logger.isInfoEnabled()) {
-              logger.info(
-                  "Triple write queue full for file: " + file + "  Waiting."
-              );
-            }
-
-            // Wait for the Queue to be less than full.
-            do {
-              try {
-                wait();
-              } catch (InterruptedException ie) {
-                throw new RuntimeException("Exception in " + getName(), ie);
-              }
-            } while (queue.size() == QUEUE_MAX_BUFFERS);
-          }
         }
 
-        // Put the buffer in the queue.
         queue.addLast(buffer);
       }
       buffer = null;