Removing entries with the MapIterator may also result in a ConcurrentModificationException (COLLECTIONS-330).

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/collections/trunk@785844 13f79535-47bb-0310-9956-ffa450edef68

src/test/org/apache/commons/collections/map/TestLRUMap.java

@@ -26,6 +26,7 @@ import junit.framework.Test;
 import junit.textui.TestRunner;
 
 import org.apache.commons.collections.BulkTest;
+import org.apache.commons.collections.MapIterator;
 import org.apache.commons.collections.OrderedMap;
 import org.apache.commons.collections.ResettableIterator;
 
@@ -455,6 +456,87 @@ public class TestLRUMap extends AbstractTestOrderedMap {
         } catch (IndexOutOfBoundsException ex) {}
     }
     
+    // TODO: COLLECTIONS-330
+    public void todoTestSynchronizedRemoveFromMapIterator() throws InterruptedException {
+
+        final LRUMap map = new LRUMap(10000);
+        
+        final Map exceptions = new HashMap();
+        final ThreadGroup tg = new ThreadGroup(getName()) {
+            public void uncaughtException(Thread t, Throwable e) {
+                exceptions.put(e, t.getName());
+                super.uncaughtException(t, e);
+            }
+        };
+
+        final int[] counter = new int[1];
+        counter[0] = 0;
+        final Thread[] threads = new Thread[50];
+        for (int i = 0; i < threads.length; ++i) {
+            threads[i] = new Thread(tg, "JUnit Thread " + i) {
+
+                public void run() {
+                    int i = 0;
+                    try {
+                        synchronized (this) {
+                            notifyAll();
+                            wait();
+                        }
+                        Thread thread = Thread.currentThread();
+                        while (i < 1000  && !interrupted()) {
+                            synchronized (map) {
+                                map.put(thread.getName() + "[" + ++i + "]", thread);
+                            }
+                        }
+                        synchronized (map) {
+                            for (MapIterator iter = map.mapIterator(); iter.hasNext();) {
+                                if (map.get(iter.getValue()) == this) {
+                                    iter.remove();
+                                }
+                            }
+                        }
+                    } catch (InterruptedException e) {
+                        fail("Unexpected InterruptedException");
+                    }
+                    if (i > 0) {
+                        synchronized (counter) {
+                            counter[0]++;
+                        }
+                    }
+                }
+
+            };
+        }
+
+        for (int i = 0; i < threads.length; ++i) {
+            synchronized (threads[i]) {
+                threads[i].start();
+                threads[i].wait();
+            }
+        }
+
+        for (int i = 0; i < threads.length; ++i) {
+            synchronized (threads[i]) {
+                threads[i].notifyAll();
+            }
+        }
+
+        Thread.sleep(1000);
+
+        for (int i = 0; i < threads.length; ++i) {
+            threads[i].interrupt();
+        }
+        for (int i = 0; i < threads.length; ++i) {
+            synchronized (threads[i]) {
+                threads[i].join();
+            }
+        }
+
+        assertEquals("Exceptions have been thrown: " + exceptions, 0, exceptions.size());
+        assertTrue("Each thread should have put at least 1 element into the map, but only " 
+                + counter[0] + " did succeed", counter[0] >= threads.length);
+    }
+    
     public void testSynchronizedRemoveFromEntrySet() throws InterruptedException {
 
         final Map map = new LRUMap(10000);
@@ -536,7 +618,7 @@ public class TestLRUMap extends AbstractTestOrderedMap {
                 + counter[0] + " did succeed", counter[0] >= threads.length);
     }
     
-    // TODO: COLLECTIONS-3
+    // TODO: COLLECTIONS-330
     public void todoTestSynchronizedRemoveFromKeySet() throws InterruptedException {
 
         final Map map = new LRUMap(10000);