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Posted to dev@commons.apache.org by ma...@apache.org on 2002/05/09 05:20:59 UTC
cvs commit: jakarta-commons/collections/src/test/org/apache/commons/collections TestLRUMap.java TestSequencedHashMap.java
mas 02/05/08 20:20:59
Modified: collections/src/java/org/apache/commons/collections
SequencedHashMap.java
collections/src/test/org/apache/commons/collections
TestLRUMap.java TestSequencedHashMap.java
Log:
Fixed to have SequencedHashMap throw a ConcurrentModificationException
from its iterators if the map is modified through something other than
the iterator.
Revision Changes Path
1.9 +47 -6 jakarta-commons/collections/src/java/org/apache/commons/collections/SequencedHashMap.java
Index: SequencedHashMap.java
===================================================================
RCS file: /home/cvs/jakarta-commons/collections/src/java/org/apache/commons/collections/SequencedHashMap.java,v
retrieving revision 1.8
retrieving revision 1.9
diff -u -r1.8 -r1.9
--- SequencedHashMap.java 22 Feb 2002 04:58:17 -0000 1.8
+++ SequencedHashMap.java 9 May 2002 03:20:59 -0000 1.9
@@ -1,7 +1,7 @@
/*
- * $Header: /home/cvs/jakarta-commons/collections/src/java/org/apache/commons/collections/SequencedHashMap.java,v 1.8 2002/02/22 04:58:17 mas Exp $
- * $Revision: 1.8 $
- * $Date: 2002/02/22 04:58:17 $
+ * $Header: /home/cvs/jakarta-commons/collections/src/java/org/apache/commons/collections/SequencedHashMap.java,v 1.9 2002/05/09 03:20:59 mas Exp $
+ * $Revision: 1.9 $
+ * $Date: 2002/05/09 03:20:59 $
*
* ====================================================================
*
@@ -77,6 +77,7 @@
import java.util.Map;
import java.util.Set;
import java.util.NoSuchElementException;
+import java.util.ConcurrentModificationException;
/**
* A map of objects whose mapping entries are sequenced based on the order in
@@ -192,6 +193,14 @@
private HashMap entries;
/**
+ * Holds the number of modifications that have occurred to the map,
+ * excluding modifications made through a collection view's iterator
+ * (e.g. entrySet().iterator().remove()). This is used to create a
+ * fail-fast behavior with the iterators.
+ **/
+ private transient long modCount = 0;
+
+ /**
* Construct a new sequenced hash map with default initial size and load
* factor.
**/
@@ -434,6 +443,7 @@
// per Map.put(Object,Object)
public Object put(Object key, Object value) {
+ modCount++;
Object oldValue = null;
@@ -468,6 +478,15 @@
// per Map.remove(Object)
public Object remove(Object key) {
+ modCount++;
+ return removeImpl(key);
+ }
+
+ /**
+ * Removed an entry without changing the map's modification count. This
+ * method should only be called from a collection view's iterator
+ **/
+ private Object removeImpl(Object key) {
Entry e = (Entry)entries.remove(key);
if(e == null) return null;
removeEntry(e);
@@ -494,6 +513,8 @@
// per Map.clear()
public void clear() {
+ modCount++;
+
// remove all from the underlying map
entries.clear();
@@ -633,10 +654,17 @@
private int returnType;
/**
- * Holds the "current" position in the iterator. when pos.next is the
+ * Holds the "current" position in the iterator. When pos.next is the
* sentinel, we've reached the end of the list.
**/
private Entry pos = sentinel;
+
+ /**
+ * Holds the expected modification count. If the actual modification
+ * count of the map differs from this value, then a concurrent
+ * modification has occurred.
+ **/
+ private transient long expectedModCount = modCount;
/**
* Construct an iterator over the sequenced elements in the order in which
@@ -676,8 +704,14 @@
*
* @exception NoSuchElementException if there are no more elements in the
* iterator.
+ *
+ * @exception ConcurrentModificationException if a modification occurs in
+ * the underlying map.
**/
public Object next() {
+ if(modCount != expectedModCount) {
+ throw new ConcurrentModificationException();
+ }
if(pos.next == sentinel) {
throw new NoSuchElementException();
}
@@ -707,14 +741,21 @@
* @exception IllegalStateException if there isn't a "last element" to be
* removed. That is, if {@link #next()} has never been called, or if
* {@link #remove()} was already called on the element.
+ *
+ * @exception ConcurrentModificationException if a modification occurs in
+ * the underlying map.
**/
public void remove() {
if((returnType & REMOVED_MASK) != 0) {
throw new IllegalStateException("remove() must follow next()");
}
+ if(modCount != expectedModCount) {
+ throw new ConcurrentModificationException();
+ }
- // remove the entry
- SequencedHashMap.this.remove(pos.getKey());
+ // remove the entry by calling the removeImpl method which does not
+ // update the mod count. This allows the iterator to remain valid.
+ SequencedHashMap.this.removeImpl(pos.getKey());
// set the removed flag
returnType = returnType | REMOVED_MASK;
1.20 +4 -11 jakarta-commons/collections/src/test/org/apache/commons/collections/TestLRUMap.java
Index: TestLRUMap.java
===================================================================
RCS file: /home/cvs/jakarta-commons/collections/src/test/org/apache/commons/collections/TestLRUMap.java,v
retrieving revision 1.19
retrieving revision 1.20
diff -u -r1.19 -r1.20
--- TestLRUMap.java 8 May 2002 17:34:17 -0000 1.19
+++ TestLRUMap.java 9 May 2002 03:20:59 -0000 1.20
@@ -1,7 +1,7 @@
/*
- * $Header: /home/cvs/jakarta-commons/collections/src/test/org/apache/commons/collections/TestLRUMap.java,v 1.19 2002/05/08 17:34:17 morgand Exp $
- * $Revision: 1.19 $
- * $Date: 2002/05/08 17:34:17 $
+ * $Header: /home/cvs/jakarta-commons/collections/src/test/org/apache/commons/collections/TestLRUMap.java,v 1.20 2002/05/09 03:20:59 mas Exp $
+ * $Revision: 1.20 $
+ * $Date: 2002/05/09 03:20:59 $
*
* ====================================================================
*
@@ -73,7 +73,7 @@
*
* @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
* @author <a href="mailto:morgand@apache.org">Morgan Delagrange</a>
- * @version $Id: TestLRUMap.java,v 1.19 2002/05/08 17:34:17 morgand Exp $
+ * @version $Id: TestLRUMap.java,v 1.20 2002/05/09 03:20:59 mas Exp $
*/
public class TestLRUMap extends TestSequencedHashMap
{
@@ -93,13 +93,6 @@
public Map makeEmptyMap() {
LRUMap map = new LRUMap();
return map;
- }
-
- // had to override from TestSequencedHashMap, because the test performs a get
- // inside a loop. Since get() alter the Map in this class, an infinite loop
- // is produced
- public void testSequenceMap() {
- fail("trying to work out an infinite loop bug");
}
public void testRemoveLRU() {
1.11 +11 -9 jakarta-commons/collections/src/test/org/apache/commons/collections/TestSequencedHashMap.java
Index: TestSequencedHashMap.java
===================================================================
RCS file: /home/cvs/jakarta-commons/collections/src/test/org/apache/commons/collections/TestSequencedHashMap.java,v
retrieving revision 1.10
retrieving revision 1.11
diff -u -r1.10 -r1.11
--- TestSequencedHashMap.java 26 Feb 2002 00:08:07 -0000 1.10
+++ TestSequencedHashMap.java 9 May 2002 03:20:59 -0000 1.11
@@ -137,18 +137,20 @@
SequencedHashMap clone = (SequencedHashMap) labRat.clone();
assertEquals("Size of clone does not match original",
labRat.size(), clone.size());
- Iterator origKeys = labRat.keySet().iterator();
- Iterator copiedKeys = clone.keySet().iterator();
- while (origKeys.hasNext()) {
- Object origKey = origKeys.next();
- Object copiedKey = copiedKeys.next();
- assertEquals("Cloned key does not match orginal",
- origKey, copiedKey);
+ Iterator origEntries = labRat.entrySet().iterator();
+ Iterator copiedEntries = clone.entrySet().iterator();
+ while (origEntries.hasNext()) {
+ Map.Entry origEntry = (Map.Entry)origEntries.next();
+ Map.Entry copiedEntry = (Map.Entry)copiedEntries.next();
+ assertEquals("Cloned key does not match original",
+ origEntry.getKey(), copiedEntry.getKey());
assertEquals("Cloned value does not match original",
- labRat.get(origKey), clone.get(copiedKey));
+ origEntry.getValue(), copiedEntry.getValue());
+ assertEquals("Cloned entry does not match orginal",
+ origEntry, copiedEntry);
}
assertTrue("iterator() returned different number of elements than keys()",
- !copiedKeys.hasNext());
+ !copiedEntries.hasNext());
// Test sequence()
List seq = labRat.sequence();
--
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