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Diffstat (limited to 'docs/modules/ROOT/examples/coordination/Mutex.java')
-rw-r--r-- | docs/modules/ROOT/examples/coordination/Mutex.java | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/docs/modules/ROOT/examples/coordination/Mutex.java b/docs/modules/ROOT/examples/coordination/Mutex.java new file mode 100644 index 000000000..2472137c6 --- /dev/null +++ b/docs/modules/ROOT/examples/coordination/Mutex.java @@ -0,0 +1,86 @@ +/* -*- Mode: Java; -*- + +Copyright (c) Xerox Corporation 1998-2002. All rights reserved. + +Use and copying of this software and preparation of derivative works based +upon this software are permitted. Any distribution of this software or +derivative works must comply with all applicable United States export control +laws. + +This software is made available AS IS, and Xerox Corporation makes no warranty +about the software, its performance or its conformity to any specification. + +|<--- this code is formatted to fit into 80 columns --->| +|<--- this code is formatted to fit into 80 columns --->| +|<--- this code is formatted to fit into 80 columns --->| + +*/ + +package coordination; + +import java.lang.String; + + +class Mutex implements Exclusion { + String[] methodNames; + MethodState[] methodStates; + + String prettyName; + + Mutex (String[] _methodNames) { + methodNames = _methodNames; + methodStates = new MethodState[methodNames.length]; + for (int i = 0; i < methodNames.length; i++) { + methodStates[i] = new MethodState(); + } + } + + private boolean isMethodIn (String _methodName) { + for (int i = 0; i < methodNames.length; i++) { + if (_methodName.equals(methodNames[i])) + return(true); + } + return(false); + } + + private MethodState getMethodState (String _methodName) { + for (int i = 0; i < methodNames.length; i++) { + if (_methodName.equals(methodNames[i])) + return(methodStates[i]); + } + return(null); + } + + public boolean testExclusion (String _methodName) { + Thread ct = Thread.currentThread(); + // + // Loop through each of the other methods in this exclusion set, to be sure + // that no other thread is running them. Note that we have to be careful + // about selfex. + // + for (int i = 0; i < methodNames.length; i++) { + if (!_methodName.equals(methodNames[i])) { + if (methodStates[i].hasOtherThreadThan(ct)) + return(false); + } + } + return (true); + } + + public void enterExclusion (String _methodName) { + MethodState methodState = getMethodState(_methodName); + methodState.enterInThread(Thread.currentThread()); + } + + public void exitExclusion (String _methodName) { + MethodState methodState = getMethodState(_methodName); + methodState.exitInThread(Thread.currentThread()); + } + + public void printNames() { + System.out.print("Mutex names: "); + for (int i = 0; i < methodNames.length; i++) + System.out.print(methodNames[i] + " "); + System.out.println(); + } +} |