svn commit: r1751662 - in /jackrabbit/oak/trunk/oak-core/src: main/java/org/apache/jackrabbit/oak/plugins/document/CommitQueue.java test/java/org/apache/jackrabbit/oak/plugins/document/CommitQueueTest.java

[mr...@apache.org]

Author: mreutegg
Date: Wed Jul  6 11:50:40 2016
New Revision: 1751662

URL: http://svn.apache.org/viewvc?rev=1751662&view=rev
Log:
OAK-4540: Cache update blocks new commits

Modified:
    jackrabbit/oak/trunk/oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/document/CommitQueue.java
    jackrabbit/oak/trunk/oak-core/src/test/java/org/apache/jackrabbit/oak/plugins/document/CommitQueueTest.java

Modified: jackrabbit/oak/trunk/oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/document/CommitQueue.java
URL: http://svn.apache.org/viewvc/jackrabbit/oak/trunk/oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/document/CommitQueue.java?rev=1751662&r1=1751661&r2=1751662&view=diff
==============================================================================
--- jackrabbit/oak/trunk/oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/document/CommitQueue.java (original)
+++ jackrabbit/oak/trunk/oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/document/CommitQueue.java Wed Jul  6 11:50:40 2016
@@ -233,11 +233,11 @@ final class CommitQueue {
             LOG.debug("not head: {}, waiting...", rev);
             commitEntry.await();
         }
+        c.headOfQueue(rev);
         synchronized (this) {
             commits.remove(rev);
             try {
                 LOG.debug("removed {}, head is now {}", rev, commits.isEmpty() ? null : commits.firstKey());
-                c.headOfQueue(rev);
             } finally {
                 // notify next if there is any
                 notifyHead();

Modified: jackrabbit/oak/trunk/oak-core/src/test/java/org/apache/jackrabbit/oak/plugins/document/CommitQueueTest.java
URL: http://svn.apache.org/viewvc/jackrabbit/oak/trunk/oak-core/src/test/java/org/apache/jackrabbit/oak/plugins/document/CommitQueueTest.java?rev=1751662&r1=1751661&r2=1751662&view=diff
==============================================================================
--- jackrabbit/oak/trunk/oak-core/src/test/java/org/apache/jackrabbit/oak/plugins/document/CommitQueueTest.java (original)
+++ jackrabbit/oak/trunk/oak-core/src/test/java/org/apache/jackrabbit/oak/plugins/document/CommitQueueTest.java Wed Jul  6 11:50:40 2016
@@ -23,6 +23,7 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Random;
 import java.util.Set;
+import java.util.concurrent.Semaphore;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicReference;
 
@@ -45,6 +46,7 @@ import static com.google.common.collect.
 import static java.util.Collections.synchronizedList;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.fail;
 
 /**
  * Tests for {@link CommitQueue}.
@@ -346,6 +348,46 @@ public class CommitQueueTest {
         }
     }
 
+    // OAK-4540
+    @Test
+    public void headOfQueueMustNotBlockNewRevision() throws Exception {
+        RevisionContext context = new DummyRevisionContext();
+        final CommitQueue queue = new CommitQueue(context);
+        final Revision r1 = queue.createRevision();
+        final Semaphore s1 = new Semaphore(0);
+        final CommitQueue.Callback c = new CommitQueue.Callback() {
+            @Override
+            public void headOfQueue(@Nonnull Revision revision) {
+                s1.acquireUninterruptibly();
+            }
+        };
+        Thread t1 = new Thread(new Runnable() {
+            @Override
+            public void run() {
+                queue.done(r1, c);
+            }
+        });
+        t1.start();
+        Thread t2 = new Thread(new Runnable() {
+            @Override
+            public void run() {
+                queue.createRevision();
+            }
+        });
+        t2.start();
+        t2.join(3000);
+        try {
+            if (t2.isAlive()) {
+                fail("CommitQueue.Callback.headOfQueue() must not " +
+                        "block CommitQueue.createRevision()");
+            }
+        } finally {
+            s1.release();
+            t1.join();
+            t2.join();
+        }
+    }
+
     private void assertNoExceptions() throws Exception {
         if (!exceptions.isEmpty()) {
             throw exceptions.get(0);