[3/4] jena git commit: Expand internal log error message. Fix some comments.

[an...@apache.org]

Expand internal log error message. Fix some comments.

Project: http://git-wip-us.apache.org/repos/asf/jena/repo
Commit: http://git-wip-us.apache.org/repos/asf/jena/commit/3e865e18
Tree: http://git-wip-us.apache.org/repos/asf/jena/tree/3e865e18
Diff: http://git-wip-us.apache.org/repos/asf/jena/diff/3e865e18

Branch: refs/heads/master
Commit: 3e865e1883b2d4cea700086ba59889636ba1b6b9
Parents: 6dac178
Author: Andy Seaborne <an...@apache.org>
Authored: Thu Aug 2 08:56:03 2018 +0100
Committer: Andy Seaborne <an...@apache.org>
Committed: Thu Aug 2 08:56:03 2018 +0100

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 .../tdb/transaction/TransactionManager.java     | 26 +++++++++++---------
 1 file changed, 15 insertions(+), 11 deletions(-)
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http://git-wip-us.apache.org/repos/asf/jena/blob/3e865e18/jena-tdb/src/main/java/org/apache/jena/tdb/transaction/TransactionManager.java
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diff --git a/jena-tdb/src/main/java/org/apache/jena/tdb/transaction/TransactionManager.java b/jena-tdb/src/main/java/org/apache/jena/tdb/transaction/TransactionManager.java
index 3a3e5e9..2e3c5ba 100644
--- a/jena-tdb/src/main/java/org/apache/jena/tdb/transaction/TransactionManager.java
+++ b/jena-tdb/src/main/java/org/apache/jena/tdb/transaction/TransactionManager.java
@@ -38,6 +38,7 @@ import java.util.concurrent.locks.ReadWriteLock ;
 import java.util.concurrent.locks.ReentrantReadWriteLock ;
 
 import org.apache.jena.atlas.lib.Pair ;
+import org.apache.jena.atlas.logging.FmtLog;
 import org.apache.jena.atlas.logging.Log ;
 import org.apache.jena.query.ReadWrite ;
 import org.apache.jena.query.TxnType;
@@ -131,10 +132,9 @@ public class TransactionManager
     /*package*/ AtomicLong abortedWriters = new AtomicLong(0) ;
     
     // This is the DatasetGraphTDB for the first read-transaction created for
-    // a particular view.  The read DatasetGraphTDB can be used by all the readers
-    // seeing the same view.
-    // A write transaction clears this when it commits; the first reader of a 
-    // particular state creates the view datasetgraph and sets the  lastreader.
+    // a particular view. This read DatasetGraphTDB can be used by all the readers
+    // seeing the same view. A write transaction clears this when it commits; the first
+    // reader of the next state creates a new view DatasetGraph.
     private AtomicReference<DatasetGraphTDB> currentReaderView = new AtomicReference<>(null) ;
     
     // Ensure single writer. A writer calling begin(WRITE) blocks.  
@@ -282,7 +282,7 @@ public class TransactionManager
         // Not implemented
     }
     
-    // Policy for writing where a transaction takes an  MRSW at the start.
+    // Policy for writing where a transaction takes an MRSW at the start.
     // Semaphore for writer entry unnecessary.
     class TSM_MRSW_Writer extends TSM_Base
     {
@@ -316,6 +316,7 @@ public class TransactionManager
 //        committerThread.start() ;
     }
 
+    synchronized
     public void closedown() {
         processDelayedReplayQueue(null) ;
         journal.close() ;
@@ -400,9 +401,9 @@ public class TransactionManager
         if ( txn.getVersion() != version.get() )
             return null;
 
-        // Put ourselves in the serialization timeline of the dataset - that, is grab a writer
+        // Put ourselves in the serialization timeline of the dataset - that is, grab a writer
         // lock as a step toward promotion. We can then test properly because no other writer
-        // can start; readers can between acquireWriterLock and the synchronized in promote2$
+        // can start; readers can between acquireWriterLock and the synchronized in promoteSync$
         // but they don't matter.
         // Potentially blocking - must be outside 'synchronized' so that any active writer
         // can commit/abort.  Otherwise, we have deadlock.
@@ -514,7 +515,7 @@ public class TransactionManager
         return dsgTxn ;
     }
 
-    /* Signal a transaction has commited.  The journal has a commit record
+    /* Signal a transaction has committed.  The journal has a commit record
      * and a sync to disk. The code here manages the inter-transaction stage
      * of deciding how to play the changes back to the base data
      * together with general recording of transaction details and status. 
@@ -849,9 +850,12 @@ public class TransactionManager
     }
     
     private void checkReplaySafe() {
-        if ( ! checking ) return ;
-        if ( activeReaders.get() != 0 || activeWriters.get() != 0 )
-            log.error("There are now active transactions") ;
+        if ( ! checking ) 
+            return ;
+        long r = activeReaders.get();
+        long w = activeWriters.get();
+        if ( r != 0 || w != 0 )
+            FmtLog.error(log, "checkReplaySafe: There are currently active transactions. R=%d, W=%d", r, w) ;
     }
     
     private void noteTxnStart(Transaction transaction) {