Fix flapping RecoveryManagerTest

patch by benedict; reviewed by jbellis for CASSANDRA-7084

Author: Sylvain Lebresne

CHANGES.txt

@@ -48,6 +48,7 @@
  * Improve compaction visibility (CASSANDRA-7242)
  * Fix 2ndary index queries with DESC clustering order (CASSANDRA-6950)
  * Invalid key cache entries on DROP (CASSANDRA-6525)
+ * Fix flapping RecoveryManagerTest (CASSANDRA-7084)
 Merged from 1.2:
  * Add Cloudstack snitch (CASSANDRA-7147)
  * Update system.peers correctly when relocating tokens (CASSANDRA-7126)

src/java/org/apache/cassandra/db/commitlog/CommitLogAllocator.java

@@ -29,14 +29,14 @@
 import java.util.concurrent.atomic.AtomicLong;
 
 import com.google.common.collect.Iterables;
+import com.google.common.util.concurrent.Uninterruptibles;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import org.apache.cassandra.config.DatabaseDescriptor;
 import org.apache.cassandra.config.Schema;
 import org.apache.cassandra.db.ColumnFamilyStore;
 import org.apache.cassandra.db.Keyspace;
-import org.apache.cassandra.io.FSError;
 import org.apache.cassandra.io.util.FileUtils;
 import org.apache.cassandra.net.MessagingService;
 import org.apache.cassandra.service.StorageService;
@@ -343,9 +343,11 @@ public void resetUnsafe()
     {
         logger.debug("Closing and clearing existing commit log segments...");
 
-        while (!queue.isEmpty())
+        while (StorageService.tasks.getActiveCount() > 0 || !queue.isEmpty())
             Thread.yield();
 
+        Uninterruptibles.sleepUninterruptibly(10, TimeUnit.MILLISECONDS);
+
         for (CommitLogSegment segment : Iterables.concat(activeSegments, availableSegments))
             segment.close();
 

test/unit/org/apache/cassandra/db/RecoveryManagerTest.java

@@ -23,9 +23,11 @@
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 
+import org.apache.cassandra.OrderedJUnit4ClassRunner;
 import org.apache.cassandra.Util;
 import org.junit.Assert;
 import org.junit.Test;
+import org.junit.runner.RunWith;
 
 import org.apache.cassandra.SchemaLoader;
 import org.apache.cassandra.db.commitlog.CommitLog;
@@ -35,6 +37,7 @@
 import static org.apache.cassandra.Util.column;
 import static org.apache.cassandra.db.KeyspaceTest.assertColumns;
 
+@RunWith(OrderedJUnit4ClassRunner.class)
 public class RecoveryManagerTest extends SchemaLoader
 {
     @Test