dirkv 2004/07/04 10:31:11
Modified: pool/src/java/org/apache/commons/pool/impl
GenericKeyedObjectPool.java
Log:
Bugzilla Bug 27493: GenericKeyedObjectPool: maxTotal limit enhancement
- apply patch from Todd Carmichael with minor modifications
Revision Changes Path
1.27 +66 -4
jakarta-commons/pool/src/java/org/apache/commons/pool/impl/GenericKeyedObjectPool.java
Index: GenericKeyedObjectPool.java
===================================================================
RCS file:
/home/cvs/jakarta-commons/pool/src/java/org/apache/commons/pool/impl/GenericKeyedObjectPool.java,v
retrieving revision 1.26
retrieving revision 1.27
diff -u -r1.26 -r1.27
--- GenericKeyedObjectPool.java 28 Feb 2004 11:46:33 -0000 1.26
+++ GenericKeyedObjectPool.java 4 Jul 2004 17:31:11 -0000 1.27
@@ -18,7 +18,10 @@
import java.util.HashMap;
import java.util.Iterator;
+import java.util.Map;
import java.util.NoSuchElementException;
+import java.util.Set;
+import java.util.TreeMap;
import org.apache.commons.collections.CursorableLinkedList;
import org.apache.commons.pool.BaseKeyedObjectPool;
@@ -734,9 +737,8 @@
if(null == pair) {
// if there is a totalMaxActive and we are at the limit then
// we have to make room
- // TODO: this could be improved by only removing the oldest object
if ((_maxTotal > 0) && (_totalActive + _totalIdle >= _maxTotal)) {
- clear();
+ clearOldest();
}
// check if we can create one
@@ -808,6 +810,56 @@
notifyAll();
}
+ /**
+ * Method clears oldest 15% of objects in pool. The method sorts the
+ * objects into a TreeMap and then iterates the first 15% for removal
+ */
+ public synchronized void clearOldest() {
+ // build sorted map of idle objects
+ TreeMap map = new TreeMap();
+ for (Iterator keyiter = _poolList.iterator(); keyiter.hasNext();) {
+ Object key = keyiter.next();
+ CursorableLinkedList list = (CursorableLinkedList) _poolMap.get(key);
+ for (Iterator it = list.iterator(); it.hasNext();) {
+ // each item into the map uses the objectimestamppair object
+ // as the key. It then gets sorted based on the timstamp field
+ // each value in the map is the parent list it belongs in.
+ ObjectTimestampPair pair = (ObjectTimestampPair) it.next();
+ map.put(pair, key);
+ }
+ }
+
+ // Now iterate created map and kill the first 15% plus one to account for
zero
+ Set setPairKeys = map.entrySet();
+ int itemsToRemove = ((int) (map.size() * 0.15)) + 1;
+
+ Iterator iter = setPairKeys.iterator();
+ while (iter.hasNext() && itemsToRemove > 0) {
+ Map.Entry entry = (Map.Entry) iter.next();
+ // kind of backwards on naming. In the map, each key is the
objecttimestamppair
+ // because it has the ordering with the timestamp value. Each value
that the
+ // key references is the key of the list it belongs to.
+ Object key = entry.getValue();
+ ObjectTimestampPair pairTimeStamp = (ObjectTimestampPair)
entry.getKey();
+ CursorableLinkedList list = (CursorableLinkedList) _poolMap.get(key);
+ list.remove(pairTimeStamp);
+
+ try {
+ _factory.destroyObject(key, pairTimeStamp.value);
+ } catch (Exception e) {
+ // ignore error, keep destroying the rest
+ }
+ // if that was the last object for that key, drop that pool
+ if (list.isEmpty()) {
+ _poolMap.remove(key);
+ _poolList.remove(key);
+ }
+ _totalIdle--;
+ itemsToRemove--;
+ }
+ notifyAll();
+ }
+
public synchronized void clear(Object key) {
CursorableLinkedList pool = (CursorableLinkedList)(_poolMap.remove(key));
if(null == pool) {
@@ -1105,8 +1157,10 @@
/**
* A simple "struct" encapsulating an object instance and a timestamp.
+ *
+ * Implements Comparable, objects are sorted from old to new.
*/
- class ObjectTimestampPair {
+ class ObjectTimestampPair implements Comparable {
Object value;
long tstamp;
@@ -1122,6 +1176,14 @@
public String toString() {
return value + ";" + tstamp;
+ }
+
+ public int compareTo(Object obj) {
+ return compareTo((ObjectTimestampPair) obj);
+ }
+
+ public int compareTo(ObjectTimestampPair other) {
+ return (int) (this.tstamp - other.tstamp);
}
}
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