Fix to resolve OutOfMemoryError has now caused another issue. Try adding a *pause* to see if additional times allows the file delete to complete. If not provide a facility to show that the delete failed.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/io/trunk@1005707 13f79535-47bb-0310-9956-ffa450edef68

Author: Niall Pemberton

src/main/java/org/apache/commons/io/FileCleaningTracker.java

@@ -19,9 +19,11 @@
 import java.io.File;
 import java.lang.ref.PhantomReference;
 import java.lang.ref.ReferenceQueue;
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
+import java.util.List;
 
 /**
  * Keeps track of files awaiting deletion, and deletes them when an associated
@@ -50,6 +52,10 @@ public class FileCleaningTracker {
      * Collection of <code>Tracker</code> instances in existence.
      */
     final Collection<Tracker> trackers = Collections.synchronizedSet(new HashSet<Tracker>()); // synchronized
+    /**
+     * Collection of File paths that failed to delete.
+     */
+    final List<String> deleteFailures = Collections.synchronizedList(new ArrayList<String>());
     /**
      * Whether to terminate the thread when the tracking is complete.
      */
@@ -150,6 +156,16 @@ public int getTrackCount() {
         return trackers.size();
     }
 
+    /**
+     * Return the file paths that failed to delete.
+     *
+     * @return the file paths that failed to delete
+     * @since Commons IO 2.0
+     */
+    public List<String> getDeleteFailures() {
+        return deleteFailures;
+    }
+
     /**
      * Call this method to cause the file cleaner thread to terminate when
      * there are no more objects being tracked for deletion.
@@ -205,7 +221,9 @@ public void run() {
                     // Wait for a tracker to remove.
                     Tracker tracker = (Tracker) q.remove(); // cannot return null
                     trackers.remove(tracker);
-                    tracker.delete();
+                    if (!tracker.delete()) {
+                        deleteFailures.add(tracker.getPath());
+                    }
                     tracker.clear();
                 } catch (InterruptedException e) {
                     continue;
@@ -243,6 +261,15 @@ private static final class Tracker extends PhantomReference<Object> {
             this.deleteStrategy = (deleteStrategy == null ? FileDeleteStrategy.NORMAL : deleteStrategy);
         }
 
+        /**
+         * Return the path.
+         *
+         * @return the path
+         */
+        public String getPath() {
+            return path;
+        }
+
         /**
          * Deletes the file associated with this tracker instance.
          *

src/test/java/org/apache/commons/io/FileCleaningTrackerTestCase.java

@@ -70,6 +70,7 @@ protected void tearDown() throws Exception {
         {
             theInstance.q = new ReferenceQueue<Object>();
             theInstance.trackers.clear();
+            theInstance.deleteFailures.clear();
             theInstance.exitWhenFinished = false;
             theInstance.reaper = null;
         }
@@ -94,9 +95,10 @@ public void testFileCleanerFile() throws Exception {
         r = null;
 
         waitUntilTrackCount();
+        pauseForDeleteToComplete(new File(path));
 
         assertEquals(0, theInstance.getTrackCount());
-        assertEquals(false, new File(path).exists());
+        assertEquals(showFailures(), false, new File(path).exists());
     }
 
     public void testFileCleanerDirectory() throws Exception {
@@ -150,10 +152,11 @@ public void testFileCleanerDirectory_ForceStrategy() throws Exception {
         obj = null;
 
         waitUntilTrackCount();
+        pauseForDeleteToComplete(testFile.getParentFile());
 
         assertEquals(0, theInstance.getTrackCount());
-        assertEquals(false, testFile.exists());
-        assertEquals(false, testFile.getParentFile().exists());
+        assertEquals(showFailures(), false, testFile.exists());
+        assertEquals(showFailures(), false, testFile.getParentFile().exists());
     }
 
     public void testFileCleanerNull() throws Exception {
@@ -237,9 +240,10 @@ public void testFileCleanerExitWhenFinished1() throws Exception {
         r = null;
 
         waitUntilTrackCount();
+        pauseForDeleteToComplete(new File(path));
 
         assertEquals("10-Track Count", 0, theInstance.getTrackCount());
-        assertEquals("11-testFile exists", false, new File(path).exists());
+        assertEquals("11-testFile exists " + showFailures(), false, new File(path).exists());
         assertEquals("12-exitWhenFinished", true, theInstance.exitWhenFinished);
         assertEquals("13-reaper.isAlive", false, theInstance.reaper.isAlive());
     }
@@ -262,9 +266,10 @@ public void testFileCleanerExitWhenFinished2() throws Exception {
         r = null;
 
         waitUntilTrackCount();
+        pauseForDeleteToComplete(new File(path));
 
         assertEquals(0, theInstance.getTrackCount());
-        assertEquals(false, new File(path).exists());
+        assertEquals(showFailures(), false, new File(path).exists());
         assertEquals(false, theInstance.exitWhenFinished);
         assertEquals(true, theInstance.reaper.isAlive());
 
@@ -278,6 +283,16 @@ public void testFileCleanerExitWhenFinished2() throws Exception {
     }
 
     //-----------------------------------------------------------------------
+    private void pauseForDeleteToComplete(File file) throws Exception {
+        int count = 0;
+        while(file.exists() && count++ < 20) {
+            Thread.sleep(500L);
+        }
+    }
+    private String showFailures() throws Exception {
+        return "Failed to delete " + theInstance.deleteFailures.size() + " files";
+    }
+
     private void waitUntilTrackCount() throws Exception {
         int count = 0;
         while(theInstance.getTrackCount() != 0 && count++ < 5) {