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1
7 package org.jboss.cache.interceptors;
8
9 import org.jboss.cache.CacheException;
10 import org.jboss.cache.CacheSPI;
11 import org.jboss.cache.GlobalTransaction;
12 import org.jboss.cache.InvocationContext;
13 import org.jboss.cache.NodeSPI;
14 import org.jboss.cache.TransactionEntry;
15 import org.jboss.cache.lock.NodeLock;
16 import org.jboss.cache.marshall.MethodCall;
17 import org.jboss.cache.marshall.MethodDeclarations;
18 import org.jboss.cache.optimistic.TransactionWorkspace;
19 import org.jboss.cache.optimistic.WorkspaceNode;
20
21 import java.lang.reflect.Method  ;
22 import java.util.Collection ;
23 import java.util.Iterator ;
24
25
31 public class OptimisticLockingInterceptor extends OptimisticInterceptor
32 {
33 private long lockAcquisitionTimeout;
34
35 public void setCache(CacheSPI cache)
36 {
37 super.setCache(cache);
38 lockAcquisitionTimeout = cache.getConfiguration().getLockAcquisitionTimeout();
39 }
40
41 public Object invoke(MethodCall m) throws Throwable
42 {
43 if (MethodDeclarations.isBuddyGroupOrganisationMethod(m.getMethodId())) return super.invoke(m);
45
46 InvocationContext ctx = cache.getInvocationContext();
47 Object retval = null;
48 Method meth = m.getMethod();
49
50 if (m.getMethodId() == MethodDeclarations.lockMethodLocal_id)
52 {
53 log.warn("OptimisticLockingInterceptor intercepted a call to CacheImpl._lock(). " +
54 "This should NEVER be called if optimistic locking is used!! " +
55 "Not allowing this call to proceed further down the chain.");
56 return retval;
57 }
58
59 if (ctx.getTransaction() != null)
60 {
61 GlobalTransaction gtx = ctx.getGlobalTransaction();
62
63 if (gtx == null)
64 {
65 throw new Exception ("failed to get global transaction");
66 }
67
69 switch (m.getMethodId())
72 {
73 case MethodDeclarations.optimisticPrepareMethod_id:
74 try
76 {
77 if (log.isDebugEnabled()) log.debug("Calling lockNodes() with gtx " + ctx.getGlobalTransaction());
78 lockNodes(gtx);
79 }
80 catch (Throwable e)
81 {
82 log.debug("Caught exception attempting to lock nodes ", e);
83 try
85 {
86 unlock(gtx);
87 }
88 catch (Throwable t)
89 {
90 log.fatal("Failed to unlock on prepare ", t);
92 }
93 throw e;
94
95 }
96 retval = super.invoke(m);
98 break;
99 case MethodDeclarations.commitMethod_id:
100 case MethodDeclarations.rollbackMethod_id:
101 try
104 {
105 retval = super.invoke(m);
106 unlock(gtx);
107 }
108 catch (Throwable t)
109 {
110 log.debug("exception encountered on " + meth + " running unlock ", t);
111 try
112 {
113 unlock(gtx);
114 }
115 catch (Throwable ct)
116 {
117 log.fatal("Failed to unlock on " + meth, t);
118 }
119 throw t;
120 }
121 break;
122 default:
123 retval = super.invoke(m);
125 break;
126 }
127
128 }
129 else
130 {
131 throw new CacheException("not in a transaction");
132 }
133
134 return retval;
135 }
136
137
138 private Object lockNodes(GlobalTransaction gtx) throws Exception
139 {
140 TransactionWorkspace workspace = getTransactionWorkspace(gtx);
141 log.debug("locking nodes");
142
143 Collection nodes = workspace.getNodes().values();
145
146 for (Iterator it = nodes.iterator(); it.hasNext();)
147 {
148 WorkspaceNode workspaceNode = (WorkspaceNode) it.next();
149 NodeSPI node = workspaceNode.getNode();
150
151 boolean acquired = node.getLock().acquire(gtx, lockAcquisitionTimeout, NodeLock.LockType.WRITE);
152 if (acquired)
153 {
154 if (log.isTraceEnabled()) log.trace("acquired lock on node " + node.getFqn());
155 cache.getTransactionTable().addLock(gtx, node.getLock());
156 }
157 else
158 {
159 throw new CacheException("unable to acquire lock on node " + node.getFqn());
160 }
161
162 }
163 return null;
164
165 }
166
167
168 private void unlock(GlobalTransaction gtx)
169 {
170 TransactionEntry entry = txTable.get(gtx);
171 entry.releaseAllLocksFIFO(gtx);
172 }
173
174 }
175 |
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