bzr commit into mysql-6.0-falcon-team branch (klewis:2938) Bug#41194

[Kevin Lewis]

#At file:///C:/Work/bzr/Merge/mysql-6.0-falcon-team/

 2938 Kevin Lewis	2008-12-16
      Bug#41194 - Move point of durability up higher in the commit
      so that by the time other waiting threads are signalled that
      this transaction is committed, it will already be durable.  
modified:
  storage/falcon/Transaction.cpp

per-file messages:
  storage/falcon/Transaction.cpp
    Bug#41194 - Move point of durability up higher in the commit
    so that by the time other waiting threads are signalled that
    this transaction is committed, it will already be durable.
=== modified file 'storage/falcon/Transaction.cpp'
--- a/storage/falcon/Transaction.cpp	2008-12-16 20:40:38 +0000
+++ b/storage/falcon/Transaction.cpp	2008-12-16 22:48:55 +0000
@@ -266,6 +266,11 @@ void Transaction::commit()
 
 	database->flushInversion(this);
 
+	// Write the commit message to the serial log for durability.
+	// If a crash happens after this, the recover will commit.
+
+	database->commit(this);
+
 	// Transfer transaction from active list to committed list, set committed state
 
 	Sync syncActiveTransactions(&transactionManager->activeTransactions.syncObject, "Transaction::commit(2)");
@@ -294,8 +299,6 @@ void Transaction::commit()
 	
 	syncIsActive.unlock(); // signal waiting transactions
 
-	database->commit(this);
-
 	delete [] xid;
 	xid = NULL;
 	xidLength = 0;
@@ -1413,12 +1416,30 @@ void Transaction::getInfo(InfoTable* inf
 		}
 }
 
+// Called by the gopher thread to complete this transaction
+
 void Transaction::fullyCommitted(void)
 {
 	ASSERT(inList);
 
 	if (useCount < 2)
-		Log::debug("Transaction::fullyCommitted: funny use count\n");
+		Log::debug("Transaction::fullyCommitted: Unusual use count=%d\n", useCount);
+
+	// The commit record is flushed to the serial log before the transaction
+	// is fully committed and waiting threads are signalled.  This gopher may
+	// have picked up that record too soon, so wait for that transaction.
+
+	while (isActive())
+		{
+		try
+			{
+			Sync sync(&syncIsActive, "Transaction::fullyCommitted");
+			sync.lock(Shared, 1000);
+			}
+		catch  (...)
+			{
+			}
+		}
 
 	writeComplete();
 	releaseCommittedTransaction();