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1
22 package org.jboss.aspects.versioned;
23
24 import EDU.oswego.cs.dl.util.concurrent.ReadWriteLock;
25 import EDU.oswego.cs.dl.util.concurrent.WriterPreferenceReadWriteLock;
26 import org.jboss.aop.InstanceAdvised;
27 import org.jboss.aop.util.PayloadKey;
28 import org.jboss.logging.Logger;
29 import org.jboss.util.id.GUID;
30
31
36 public abstract class StateManager implements java.io.Externalizable 
37 {
38 public static final String STATE_MANAGER = "STATE_MANAGER";
39 protected static Logger log = Logger.getLogger(StateManager.class);
40
41
42 public static StateManager getStateManager(InstanceAdvised obj)
43 {
44 return (StateManager)obj._getInstanceAdvisor().getMetaData().getMetaData(STATE_MANAGER, STATE_MANAGER);
45 }
46
47 public static void setStateManager(InstanceAdvised obj, StateManager manager)
48 {
49 obj._getInstanceAdvisor().getMetaData().addMetaData(STATE_MANAGER, STATE_MANAGER, manager, PayloadKey.TRANSIENT);
50 }
51
52 protected GUID guid;
53 protected long timeout;
54 transient protected ReadWriteLock lock = new WriterPreferenceReadWriteLock();
55
56 public StateManager() {}
57
58 public StateManager(GUID guid, long timeout)
59 {
60 this.guid = guid;
61 this.timeout = timeout;
62 }
63
64 public ReadWriteLock getLock() { return lock; }
65 public GUID getGUID() { return guid; }
66
67 public void acquireWriteLock()
68 {
69 try
70 {
71 if (!lock.writeLock().attempt(timeout))
72 {
73 throw new LockAttemptFailure("failed to acquire write lock: " + guid);
74 }
75 log.trace("writelock acquired for: " + guid);
76 }
77 catch (InterruptedException ignored)
78 {
79 throw new LockAttemptFailure("failed to acquire write lock: " + guid);
80 }
81 }
82
83 public void acquireReadLock()
84 {
85 try
86 {
87 if (!lock.readLock().attempt(timeout))
88 {
89 throw new LockAttemptFailure("failed to acquire read lock: " + guid);
90 }
91 log.trace("readlock acquired for: " + guid);
92 }
93 catch (InterruptedException ignored)
94 {
95 throw new LockAttemptFailure("failed to acquire read lock: " + guid);
96 }
97 }
98
99 public void releaseReadLock()
100 {
101 lock.readLock().release();
102 log.trace("readlock released for: " + guid);
103 }
104 public void releaseWriteLock()
105 {
106 lock.writeLock().release();
107 log.trace("writelock released for: " + guid);
108 }
109
110 public void writeExternal(java.io.ObjectOutput out)
111 throws java.io.IOException
112 {
113 out.writeObject(guid);
114 out.writeLong(timeout);
115 }
116
117 public void readExternal(java.io.ObjectInput in)
118 throws java.io.IOException , ClassNotFoundException
119 {
120 this.guid = (GUID)in.readObject();
121 this.timeout = in.readLong();
122 this.lock = new WriterPreferenceReadWriteLock();
123 }
124
125
126 }
127 |
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