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1
19
20 package soot.dava.toolkits.base.DavaMonitor;
21
22 import java.util.HashMap  ;
23 import java.util.LinkedList ;
24
25 public class DavaMonitor
26 {
27 private static DavaMonitor instance = new DavaMonitor();
28
29 private HashMap ref, lockTable;
30 private LinkedList q;
31
32 private DavaMonitor()
33 {
34 ref = new HashMap ( 1, 0.7f);
35 lockTable = new HashMap ( 1, 0.7f);
36 q = new LinkedList ();
37 }
38
39 public static DavaMonitor v() { return instance; }
40
41 public synchronized void enter( Object o) throws NullPointerException
42 {
43 Thread currentThread = Thread.currentThread();
44
45 if (o == null)
46 throw new NullPointerException ();
47
48 Lock lock = (Lock) ref.get( o);
49
50 if (lock == null) {
51 lock = new Lock();
52 ref.put( o, lock);
53 }
54
55 if (lock.level == 0) {
56 lock.level = 1;
57 lock.owner = currentThread;
58 return;
59 }
60
61 if (lock.owner == currentThread) {
62 lock.level++;
63 return;
64 }
65
66 lockTable.put( currentThread, lock);
67 lock.enQ( currentThread);
68
69 while ((lock.level > 0) || (lock.nextThread() != currentThread)) {
70 try {
71 wait();
72 }
73 catch (InterruptedException e) {
74 e.printStackTrace();
75 System.exit(0);
76 }
77
78 currentThread = Thread.currentThread();
79 lock = (Lock) lockTable.get( currentThread);
80 }
81
82 lock.deQ( currentThread);
83
84 lock.level = 1;
85 lock.owner = currentThread;
86 }
87
88 public synchronized void exit( Object o) throws NullPointerException , IllegalMonitorStateException
89 {
90 if (o == null)
91 throw new NullPointerException ();
92
93 Lock lock = (Lock) ref.get( o);
94
95 if ((lock == null) || (lock.level == 0) || (lock.owner != Thread.currentThread()))
96 throw new IllegalMonitorStateException ();
97
98 lock.level--;
99
100 if (lock.level == 0)
101 notifyAll();
102 }
103 }
104 |
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