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- /* *******************************************************************
- * Copyright (c) 2004 IBM Corporation
- *
- * All rights reserved.
- * This program and the accompanying materials are made available
- * under the terms of the Eclipse Public License v1.0
- * which accompanies this distribution and is available at
- * http://www.eclipse.org/legal/epl-v10.html
- *
- * Contributors:
- * Andy Clement initial implementation
- * Copied from bits of original CFlowStack
- * ******************************************************************/
- package org.aspectj.runtime.internal.cflowstack;
-
- import java.util.Enumeration;
- import java.util.Hashtable;
- import java.util.Stack;
-
- public class ThreadStackImpl11 implements ThreadStack {
- private Hashtable stacks = new Hashtable();
- private Thread cached_thread;
- private Stack cached_stack;
- private int change_count = 0;
- private static final int COLLECT_AT = 20000;
- private static final int MIN_COLLECT_AT = 100;
-
- public synchronized Stack getThreadStack() {
- if (Thread.currentThread() != cached_thread) {
- cached_thread = Thread.currentThread();
- cached_stack = (Stack)stacks.get(cached_thread);
- if (cached_stack == null) {
- cached_stack = new Stack();
- stacks.put(cached_thread, cached_stack);
- }
- change_count++;
- // Collect more often if there are many threads, but not *too* often
- int size = Math.max(1, stacks.size()); // should be >1 b/c always live threads, but...
- if (change_count > Math.max(MIN_COLLECT_AT, COLLECT_AT/size)) {
- Stack dead_stacks = new Stack();
- for (Enumeration e = stacks.keys(); e.hasMoreElements(); ) {
- Thread t = (Thread)e.nextElement();
- if (!t.isAlive()) dead_stacks.push(t);
- }
- for (Enumeration e = dead_stacks.elements(); e.hasMoreElements(); ) {
- Thread t = (Thread)e.nextElement();
- stacks.remove(t);
- }
- change_count = 0;
- }
- }
- return cached_stack;
- }
-
- public void removeThreadStack() {
- // TODO
- }
-
- }
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