bk commit into 6.0 tree (cpowers:1.2639) BUG#36269

[cpowers]

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ChangeSet@stripped, 2008-04-22 18:33:52-05:00, cpowers@stripped +1 -0
  Bug#36269: Thread stalls during DBT2 run
  - Stack trace shows 179 threads blocked on a forced scavenge.
  - Removed syncSysDDL shared lock and corrected scavenge cycle bug.

  storage/falcon/Database.cpp@stripped, 2008-04-22 18:33:50-05:00, cpowers@stripped +10
-11
    Database::retireRecords
    - Removed shared lock on syncSysDDL
    - Save scavenge cycle *before* getting exclusive scavenger lock
    - Increment scavengeCycle at the end of scavenging, not before

diff -Nrup a/storage/falcon/Database.cpp b/storage/falcon/Database.cpp
--- a/storage/falcon/Database.cpp	2008-04-11 21:22:42 -05:00
+++ b/storage/falcon/Database.cpp	2008-04-22 18:33:50 -05:00
@@ -1750,24 +1750,19 @@ void Database::scavenge()
 
 void Database::retireRecords(bool forced)
 {
-	// Commit pending system transactions before proceeding
+	int cycle = scavengeCycle;
 	
-	if (!forced && systemConnection->transaction)
-		commitSystemTransaction();
-
-	Sync syncDDL(&syncSysDDL, "Database::retireRecords");
-	syncDDL.lock(Shared);
-
 	Sync syncScavenger(&syncScavenge, "Database::retireRecords");
 	syncScavenger.lock(Exclusive);
 
-	int cycle = scavengeCycle;
-	
 	if (forced && scavengeCycle > cycle)
 		return;
 	
-	++scavengeCycle;
+	// Commit pending system transactions before proceeding
 	
+	if (!forced && systemConnection->transaction)
+		commitSystemTransaction();
+
 	if (forced)
 		Log::log("Forced record scavenge cycle\n");
 	
@@ -1840,7 +1835,9 @@ void Database::retireRecords(bool forced
 		{
 		recordScavenge.scavengeGeneration = UNDEFINED;
 		cleanupRecords (&recordScavenge);
-		
+
+		++scavengeCycle;
+				
 		return;
 		}
 	else
@@ -1849,6 +1846,8 @@ void Database::retireRecords(bool forced
 		cleanupRecords (&recordScavenge);
 		}
 
+	++scavengeCycle;
+	
 	lastRecordMemory = recordDataPool->activeMemory;
 	INTERLOCKED_INCREMENT (currentGeneration);
 }