LUCENE-4277: fix IndexWriter deadlock during rollback

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1368157 13f79535-47bb-0310-9956-ffa450edef68

lucene/CHANGES.txt

@@ -140,6 +140,10 @@ Bug Fixes
   IndexWriter to only delete files matching this pattern from an index
   directory, to reduce risk when the wrong index path is accidentally
   passed to IndexWriter (Robert Muir, Mike McCandless)
+  
+* LUCENE-4277: Fix IndexWriter deadlock during rollback if flushable DWPT
+  instance are already checked out and queued up but not yet flushed. 
+  (Simon Willnauer)
 
 Changes in Runtime Behavior
 

lucene/core/src/java/org/apache/lucene/index/DocumentsWriter.java

@@ -202,11 +202,9 @@ final class DocumentsWriter {
    *  discarding any docs added since last flush. */
   synchronized void abort() {
     boolean success = false;
-    synchronized (this) {
-      deleteQueue.clear();
-    }
 
     try {
+      deleteQueue.clear();
       if (infoStream.isEnabled("DW")) {
         infoStream.message("DW", "abort");
       }
@@ -230,6 +228,7 @@ final class DocumentsWriter {
           perThread.unlock();
         }
       }
+      flushControl.abortPendingFlushes();
       flushControl.waitForFlush();
       success = true;
     } finally {

lucene/core/src/java/org/apache/lucene/index/DocumentsWriterFlushControl.java

@@ -567,19 +567,34 @@ final class DocumentsWriterFlushControl  {
   }
 
   synchronized void abortFullFlushes() {
+   try {
+     abortPendingFlushes();
+   } finally {
+     fullFlush = false;
+   }
+  }
+  
+  synchronized void abortPendingFlushes() {
     try {
       for (DocumentsWriterPerThread dwpt : flushQueue) {
-        doAfterFlush(dwpt);
-        dwpt.abort();
+        try {
+          dwpt.abort();
+          doAfterFlush(dwpt);
+        } catch (Throwable ex) {
+          // ignore - keep on aborting the flush queue
+        }
       }
       for (BlockedFlush blockedFlush : blockedFlushes) {
-        flushingWriters
-            .put(blockedFlush.dwpt, Long.valueOf(blockedFlush.bytes));
-        doAfterFlush(blockedFlush.dwpt);
-        blockedFlush.dwpt.abort();
+        try {
+          flushingWriters
+              .put(blockedFlush.dwpt, Long.valueOf(blockedFlush.bytes));
+          blockedFlush.dwpt.abort();
+          doAfterFlush(blockedFlush.dwpt);
+        } catch (Throwable ex) {
+          // ignore - keep on aborting the blocked queue
+        }
       }
     } finally {
-      fullFlush = false;
       flushQueue.clear();
       blockedFlushes.clear();
       updateStallState();