bzr commit into mysql-6.0-falcon-team branch (cpowers:2906) Bug#39696

[Christopher Powers]

#At file:///home/cpowers/work/dev/dev-11/mysql/

 2906 Christopher Powers	2008-11-08
      Bug#39696, "Assertion in Table.cpp (dup->state == recDeleted) fails during
falcon_chill_thaw"
      
      The record chill operation sometimes generates SRLUpdateRecord entries in the serial
      log that have zero data length. This causes a corruption of the serial log.
      
      The total data length of the chilled records is known only after all of the records
have
      been processed in SRLUpdateRecords::append(). If none of the record versions within
      a given savepoint are eligible to be chilled, the total data length of the serial
log
      record will be zero.
      
      Even when there are zero bytes of data to commit to disk, SRLUpdateRecords::append()
issues
      a serial log flush and forces the creation of a new serial log window. This creates
a one-byte
      offset error in the serial log that ultimately results in a fatal assertion during
gopher
      thread processing.
      
      To prevent this error, SRLUpdateRecords::append() now only flushes serial log
records with a
      non-zero data length.
modified:
  storage/falcon/SRLUpdateRecords.cpp

per-file messages:
  storage/falcon/SRLUpdateRecords.cpp
    Don't flush serial log records having zero data length.
=== modified file 'storage/falcon/SRLUpdateRecords.cpp'
--- a/storage/falcon/SRLUpdateRecords.cpp	2008-11-07 01:09:04 +0000
+++ b/storage/falcon/SRLUpdateRecords.cpp	2008-11-09 01:44:58 +0000
@@ -124,12 +124,11 @@ void SRLUpdateRecords::append(Transactio
 {
 	uint32 chilledRecordsWindow = 0;
 	uint32 chilledBytesWindow   = 0;
-	uint32 windowNumber         = 0;
 	SerialLogTransaction *srlTrans = NULL;
 	int savepointId;
 	
 	// Generate one serial log record per write window. To ensure that
-	// record updates are grouped by savepoint, start a new serial
+	// chilled records are grouped by savepoint, start a new serial
 	// log record for each savepoint. Several serial log records may
 	// be generated for one savepoint.
 	
@@ -165,7 +164,6 @@ void SRLUpdateRecords::append(Transactio
 			if (record->state == recChilled)
 				{
 				transaction->chillPoint = &record->nextInTrans;
-				
 				continue;
 				}
 				
@@ -235,11 +233,11 @@ void SRLUpdateRecords::append(Transactio
 				 byteCount(stream.totalLength) + stream.totalLength >= end)
 				break;
 			
-			// Set the virtual offset of the record in the serial log
-
 			ASSERT(record->recordNumber >= 0);
 			ASSERT(log->writePtr > (UCHAR *)log->writeWindow->buffer);
 			
+			// Set the virtual offset of the record in the serial log
+
 			record->setVirtualOffset(log->writeWindow->currentLength +
log->writeWindow->virtualOffset);
 			uint32 sectionId = table->dataSectionId;
 			log->updateSectionUseVector(sectionId, tableSpaceId, 1);
@@ -259,10 +257,14 @@ void SRLUpdateRecords::append(Transactio
 		
 		int len = (int) (log->writePtr - start);
 		
+		// The length field is 0, update if necessary
+		
 		if (len > 0)
 			putFixedInt(len, lengthPtr);
 		
-		if (record)
+		// Flush record data, if any, and force the creation of a new serial log window
+		
+		if (record && len > 0)
 			log->flush(true, 0, &sync);
 		else
 			sync.unlock();
@@ -273,7 +275,7 @@ void SRLUpdateRecords::append(Transactio
 			log->chilledBytes   += chilledBytesWindow;
 			transaction->chilledRecords += chilledRecordsWindow;
 			transaction->chilledBytes += chilledBytesWindow;
-			windowNumber = (uint32)log->writeWindow->virtualOffset / SRL_WINDOW_SIZE;
+//			uint32 windowNumber = (uint32)log->writeWindow->virtualOffset /
SRL_WINDOW_SIZE;
 			}
 		} // next serial log record and write window
 }