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1
14 package org.aspectj.runtime.internal.cflowstack;
15
16 import java.util.Enumeration  ;
17 import java.util.Hashtable ;
18 import java.util.Stack ;
19
20 public class ThreadStackImpl11 implements ThreadStack {
21 private Hashtable stacks = new Hashtable ();
22 private Thread cached_thread;
23 private Stack cached_stack;
24 private int change_count = 0;
25 private static final int COLLECT_AT = 20000;
26 private static final int MIN_COLLECT_AT = 100;
27
28 public synchronized Stack getThreadStack() {
29 if (Thread.currentThread() != cached_thread) {
30 cached_thread = Thread.currentThread();
31 cached_stack = (Stack )stacks.get(cached_thread);
32 if (cached_stack == null) {
33 cached_stack = new Stack ();
34 stacks.put(cached_thread, cached_stack);
35 }
36 change_count++;
37 int size = Math.max(1, stacks.size()); if (change_count > Math.max(MIN_COLLECT_AT, COLLECT_AT/size)) {
40 Stack dead_stacks = new Stack ();
41 for (Enumeration e = stacks.keys(); e.hasMoreElements(); ) {
42 Thread t = (Thread )e.nextElement();
43 if (!t.isAlive()) dead_stacks.push(t);
44 }
45 for (Enumeration e = dead_stacks.elements(); e.hasMoreElements(); ) {
46 Thread t = (Thread )e.nextElement();
47 stacks.remove(t);
48 }
49 change_count = 0;
50 }
51 }
52 return cached_stack;
53 }
54
55 }
56 |
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