LUCENE-5626: Fix bug in SimpleFSLockFactory's obtain() that sometimes throwed IOException (ERROR_ACESS_DENIED) on Windows if the lock file was created concurrently

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1589394 13f79535-47bb-0310-9956-ffa450edef68

lucene/CHANGES.txt

@@ -99,6 +99,11 @@ Bug fixes
 * LUCENE-5600: HttpClientBase did not properly consume a connection if a server
   error occurred. (Christoph Kaser via Shai Erera)
 
+* LUCENE-5626: Fix bug in SimpleFSLockFactory's obtain() that sometimes throwed
+  IOException (ERROR_ACESS_DENIED) on Windows if the lock file was created
+  concurrently. This error is now handled the same way like in NativeFSLockFactory
+  by returning false.  (Uwe Schindler, Robert Muir, Dawid Weiss)
+
 ======================= Lucene 4.8.0 =======================
 
 System Requirements

lucene/core/src/java/org/apache/lucene/store/SimpleFSLockFactory.java

@@ -132,7 +132,17 @@ class SimpleFSLock extends Lock {
       throw new IOException("Found regular file where directory expected: " + 
                             lockDir.getAbsolutePath());
     }
-    return lockFile.createNewFile();
+    
+    try {
+      return lockFile.createNewFile();
+    } catch (IOException ioe) {
+      // On Windows, on concurrent createNewFile, the 2nd process gets "access denied".
+      // In that case, the lock was not aquired successfully, so return false.
+      // We record the failure reason here; the obtain with timeout (usually the
+      // one calling us) will use this as "root cause" if it fails to get the lock.
+      failureReason = ioe;
+      return false;
+    }
   }
 
   @Override