bzr commit into mysql-6.0-falcon-team branch (kevin.lewis:2713) Bug#44911

[Kevin Lewis]

#At file:///C:/Work/bzr/Merge/mysql-6.0-falcon-team/ based on revid:kevin.lewis@stripped

 2713 Kevin Lewis	2009-05-26
      Bug#44911 - Suppose a call to fetchForUpdate is called for a base lockRecord returned from Table::fetch, but before it is evaluated, the lockRecord is superceded by an update record and the transaction is committed.  FetchForUpdate will need to re-fetch the new committed record as if getRelativeState() had returned WasActive.  But getRelativeState() returned CommittedVisible.  That would have caused this FATAL condition that a "Committed non-deleted record has no data buffer".  So a check for (source->state == recLock) needs to be done in order to re-fetch the base record.  A lockRecord can still be linked to a transaction after the commit if it was updated at a higher savepoint.  But they are always superceded with newer records.  Regular lockRecords are unlinked fro transaction during the commit in the call to  Transaction::releaseRecordLocks().

    modified:
      storage/falcon/Table.cpp
=== modified file 'storage/falcon/Table.cpp'
--- a/storage/falcon/Table.cpp	2009-05-26 18:11:13 +0000
+++ b/storage/falcon/Table.cpp	2009-05-26 18:32:05 +0000
@@ -3502,7 +3502,7 @@ Record* Table::fetchForUpdate(Transactio
 		return prior;
 		}
 
-	// The record number is not currently locked.
+	// The record number is not currently locked by us.
 
 	for (;;)
 		{
@@ -3532,6 +3532,9 @@ Record* Table::fetchForUpdate(Transactio
 
 			case CommittedVisible:
 				{
+				if (source->state == recLock)
+					break;  // need to re-fetch the base record
+
 				if (source->state == recDeleted)
 					{
 					source->release(REC_HISTORY);
@@ -3539,18 +3542,6 @@ Record* Table::fetchForUpdate(Transactio
 					return NULL;
 					}
 
-				if (!source->hasRecord())
-					{
-					if (source->isVersion())
-						{
-						RecordVersion *rv = (RecordVersion *) source;
-						FATAL("Committed non-deleted record has no data buffer. state=%d, useCount=%d, virtualOffset=" I64FORMAT "\n", 
-							rv->state, rv->useCount, rv->virtualOffset);
-						}
-					else
-						FATAL("Committed non-deleted record has no data buffer. state=%d, useCount=%d" I64FORMAT "\n", 
-							source->state, source->useCount);
-					}
 
 				// Lock the record
 
@@ -3558,6 +3549,10 @@ Record* Table::fetchForUpdate(Transactio
 					Log::debug("Table::fetchForUpdate: TransactionId=%d, isolationLevel=%d, recordNumber=%d\n", 
 					           transaction->transactionId, transaction->isolationLevel, recordNumber);
 
+				if (!source->hasRecord())
+					FATAL("Committed non-deleted record has no data buffer. state=%d, useCount=%d\n", 
+							source->state, source->useCount);
+
 				RecordVersion *lockRecord = allocRecordVersion(NULL, transaction, source);
 				lockRecord->state = recLock;
 


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