[Mulgara-svn] r375 - trunk/src/jar/resolver/java/org/mulgara/resolver

[andrae at mulgara.org]

Author: andrae
Date: 2007-08-24 01:49:41 -0500 (Fri, 24 Aug 2007)
New Revision: 375

Modified:
   trunk/src/jar/resolver/java/org/mulgara/resolver/MulgaraTransaction.java
   trunk/src/jar/resolver/java/org/mulgara/resolver/MulgaraTransactionManager.java
Log:
Reviewed ronald's fix to the transaction manager;
Extracted a one line function to document the intent better;
Added two lines of cleanup to the transaction abort cascade to allow for the
implicitRollback control flow to now be truncated by an exception.



Modified: trunk/src/jar/resolver/java/org/mulgara/resolver/MulgaraTransaction.java
===================================================================
--- trunk/src/jar/resolver/java/org/mulgara/resolver/MulgaraTransaction.java	2007-08-23 17:23:56 UTC (rev 374)
+++ trunk/src/jar/resolver/java/org/mulgara/resolver/MulgaraTransaction.java	2007-08-24 06:49:41 UTC (rev 375)
@@ -493,18 +493,24 @@
       try {
         errorReport(errorMessage + " - Aborting", cause);
       } finally { try {
+        if (transaction != null) {
+          transaction.rollback();
+        }
+      } finally { try {
         manager.transactionAborted(this);
       } finally { try {
         abortEnlistedResources();
       } finally { try {
         context.clear();
       } finally { try {
+        enlisted.clear();
+      } finally { try {
         transaction = null;
       } finally { try {
         manager = null;
       } finally {
         state = State.FAILED;
-      } } } } } }
+      } } } } } } } }
       return new MulgaraTransactionException(errorMessage + " - Aborting", cause);
     } catch (Throwable th) {
       throw new MulgaraTransactionException(errorMessage + " - Failed to abort cleanly", th);

Modified: trunk/src/jar/resolver/java/org/mulgara/resolver/MulgaraTransactionManager.java
===================================================================
--- trunk/src/jar/resolver/java/org/mulgara/resolver/MulgaraTransactionManager.java	2007-08-23 17:23:56 UTC (rev 374)
+++ trunk/src/jar/resolver/java/org/mulgara/resolver/MulgaraTransactionManager.java	2007-08-24 06:49:41 UTC (rev 375)
@@ -167,7 +167,7 @@
    */
   private MulgaraTransaction obtainWriteLock(DatabaseSession session)
       throws MulgaraTransactionException {
-    while (currentWritingSession != null || writeLockReserved()) {
+    while (writeLockHeld() || writeLockReserved()) {
       try {
         writeLockCondition.await();
       } catch (InterruptedException ei) {
@@ -532,6 +532,9 @@
     mutex.lock();
   }
 
+  /**
+   * Used to reserve the write lock during a commit or rollback.
+   */
   private void reserveWriteLock() throws MulgaraTransactionException {
     if (!mutex.isHeldByCurrentThread()) {
       throw new IllegalStateException("Attempt to set modify without holding mutex");
@@ -552,9 +555,14 @@
   }
 
   private boolean writeLockReserved() {
+    // TRUE iff there is a reserving thread AND it is different thread to the current thread.
     return reservingThread != null && !Thread.currentThread().equals(reservingThread);
   }
 
+  private boolean writeLockHeld() {
+    return currentWritingSession != null;
+  }
+
   private void releaseMutex() {
     if (!mutex.isHeldByCurrentThread()) {
       throw new IllegalStateException("Attempt to release mutex without holding mutex");