org.aspectj.runtime.internal.cflowstack.ThreadCounterImpl11 Maven / Gradle / Ivy
/* *******************************************************************
* Copyright (c) 2004 IBM Corporation
*
* All rights reserved.
* This program and the accompanying materials are made available
* under the terms of the Common Public License v1.0
* which accompanies this distribution and is available at
* http://www.eclipse.org/legal/cpl-v10.html
*
* Contributors:
* Andy Clement initial implementation
* Copied from bits of original CFlowStack
* ******************************************************************/
package org.aspectj.runtime.internal.cflowstack;
import java.util.Iterator;
import java.util.List;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.Hashtable;
public class ThreadCounterImpl11 implements ThreadCounter {
private Hashtable counters = new Hashtable();
private Thread cached_thread;
private Counter cached_counter;
private int change_count = 0;
private static final int COLLECT_AT = 20000;
private static final int MIN_COLLECT_AT = 100;
static class Counter {
protected int value = 0;
}
private synchronized Counter getThreadCounter() {
if (Thread.currentThread() != cached_thread) {
cached_thread = Thread.currentThread();
cached_counter = (Counter)counters.get(cached_thread);
if (cached_counter == null) {
cached_counter = new Counter();
counters.put(cached_thread, cached_counter);
}
change_count++;
// Collect more often if there are many threads, but not *too* often
int size = Math.max(1, counters.size()); // should be >1 b/c always live threads, but...
if (change_count > Math.max(MIN_COLLECT_AT, COLLECT_AT/size)) {
List dead_stacks = new ArrayList();
for (Enumeration e = counters.keys(); e.hasMoreElements(); ) {
Thread t = (Thread)e.nextElement();
if (!t.isAlive()) dead_stacks.add(t);
}
for (Iterator e = dead_stacks.iterator(); e.hasNext(); ) {
Thread t = (Thread)e.next();
counters.remove(t);
}
change_count = 0;
}
}
return cached_counter;
}
public void inc() {
getThreadCounter().value++;
}
public void dec() {
getThreadCounter().value--;
}
public boolean isNotZero() {
return getThreadCounter().value!=0;
}
}