1 files changed, 86 insertions, 0 deletions
diff --git a/docs/examples/coordination/Mutex.java b/docs/examples/coordination/Mutex.java
new file mode 100644
index 000000000..2472137c6
--- /dev/null
+++ b/docs/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();
+    }
+}