org.eclipse.linuxtools.tmf.core/src/org/eclipse/linuxtools/tmf/core/signal/TmfSignalManager.java

   1 /*******************************************************************************
   2  * Copyright (c) 2009, 2010 Ericsson
   3  *
   4  * All rights reserved. This program and the accompanying materials are
   5  * made available under the terms of the Eclipse Public License v1.0 which
   6  * accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *   Francois Chouinard - Initial API and implementation
  11  *******************************************************************************/
  12
  13 package org.eclipse.linuxtools.tmf.core.signal;
  14
  15 import java.lang.reflect.InvocationTargetException;
  16 import java.lang.reflect.Method;
  17 import java.util.ArrayList;
  18 import java.util.HashMap;
  19 import java.util.List;
  20 import java.util.Map;
  21
  22 import org.eclipse.linuxtools.internal.tmf.core.Activator;
  23 import org.eclipse.linuxtools.internal.tmf.core.Tracer;
  24
  25 /**
  26  * This class manages the set of signal listeners and the signals they are
  27  * interested in. When a signal is broadcasted, the appropriate listeners
  28  * signal handlers are invoked.
  29  *
  30  * @version 1.0
  31  * @author Francois Chouinard
  32 + */
  33 public class TmfSignalManager {
  34
  35         // The set of event listeners and their corresponding handler methods.
  36         // Note: listeners could be restricted to ITmfComponents but there is no
  37         // harm in letting anyone use this since it is not tied to anything but
  38         // the signal data type.
  39         static private Map<Object, Method[]> fListeners = new HashMap<Object, Method[]>();
  40     static private Map<Object, Method[]> fVIPListeners = new HashMap<Object, Method[]>();
  41
  42         // If requested, add universal signal tracer
  43         // TODO: Temporary solution: should be enabled/disabled dynamically
  44         private static boolean fTraceIsActive = false;
  45         private static TmfSignalTracer fSignalTracer;
  46         static {
  47                 if (fTraceIsActive) {
  48                         fSignalTracer = TmfSignalTracer.getInstance();
  49                         register(fSignalTracer);
  50                 }
  51         }
  52
  53         public static synchronized void register(Object listener) {
  54                 Method[] methods = getSignalHandlerMethods(listener);
  55                 if (methods.length > 0)
  56                         fListeners.put(listener, methods);
  57         }
  58
  59     public static synchronized void registerVIP(Object listener) {
  60         Method[] methods = getSignalHandlerMethods(listener);
  61         if (methods.length > 0)
  62             fVIPListeners.put(listener, methods);
  63     }
  64
  65         public static synchronized void deregister(Object listener) {
  66                 fVIPListeners.remove(listener);
  67         fListeners.remove(listener);
  68         }
  69
  70         /**
  71          * Returns the list of signal handlers in the listener. Signal handler name
  72          * is irrelevant; only the annotation (@TmfSignalHandler) is important.
  73          *
  74          * @param listener
  75          * @return
  76          */
  77         static private Method[] getSignalHandlerMethods(Object listener) {
  78                 List<Method> handlers = new ArrayList<Method>();
  79                 Method[] methods = listener.getClass().getMethods();
  80                 for (Method method : methods) {
  81                         if (method.isAnnotationPresent(TmfSignalHandler.class)) {
  82                                 handlers.add(method);
  83                         }
  84                 }
  85                 return handlers.toArray(new Method[handlers.size()]);
  86         }
  87
  88         /**
  89          * Invokes the handling methods that listens to signals of a given type.
  90          *
  91          * The list of handlers is built on-the-fly to allow for the dynamic
  92          * creation/deletion of signal handlers. Since the number of signal
  93          * handlers shouldn't be too high, this is not a big performance issue
  94          * to pay for the flexibility.
  95          *
  96          * For synchronization purposes, the signal is bracketed by two synch signals.
  97          *
  98          * @param signal the signal to dispatch
  99          */
 100         static int fSignalId = 0;
 101         static public synchronized void dispatchSignal(TmfSignal signal) {
 102                 int signalId = fSignalId++;
 103                 sendSignal(new TmfStartSynchSignal(signalId));
 104                 signal.setReference(signalId);
 105                 sendSignal(signal);
 106                 sendSignal(new TmfEndSynchSignal(signalId));
 107         }
 108
 109     static private void sendSignal(TmfSignal signal) {
 110         sendSignal(fVIPListeners, signal);
 111         sendSignal(fListeners, signal);
 112     }
 113
 114     static private void sendSignal(Map<Object, Method[]> listeners, TmfSignal signal) {
 115
 116         if (Tracer.isSignalTraced()) Tracer.traceSignal(signal, "(start)"); //$NON-NLS-1$
 117
 118         // Build the list of listener methods that are registered for this signal
 119         Class<?> signalClass = signal.getClass();
 120         Map<Object, List<Method>> targets = new HashMap<Object, List<Method>>();
 121         targets.clear();
 122         for (Map.Entry<Object, Method[]> entry : listeners.entrySet()) {
 123             List<Method> matchingMethods = new ArrayList<Method>();
 124             for (Method method : entry.getValue()) {
 125                 if (method.getParameterTypes()[0].isAssignableFrom(signalClass)) {
 126                     matchingMethods.add(method);
 127                 }
 128             }
 129             if (!matchingMethods.isEmpty()) {
 130                 targets.put(entry.getKey(), matchingMethods);
 131             }
 132         }
 133
 134         // Call the signal handlers
 135         for (Map.Entry<Object, List<Method>> entry : targets.entrySet()) {
 136             for (Method method : entry.getValue()) {
 137                 try {
 138                     method.invoke(entry.getKey(), new Object[] { signal });
 139                     if (Tracer.isSignalTraced()) {
 140                         Object key = entry.getKey();
 141                         String hash = String.format("%1$08X", entry.getKey().hashCode()); //$NON-NLS-1$
 142                         String target = "[" + hash + "] " + key.getClass().getSimpleName() + ":" + method.getName();   //$NON-NLS-1$//$NON-NLS-2$//$NON-NLS-3$
 143                         Tracer.traceSignal(signal, target);
 144                     }
 145                 } catch (IllegalArgumentException e) {
 146                     Activator.getDefault().logError("Exception handling signal " + signal + " in method " + method, e); //$NON-NLS-1$ //$NON-NLS-2$
 147                 } catch (IllegalAccessException e) {
 148                     Activator.getDefault().logError("Exception handling signal " + signal + " in method " + method, e); //$NON-NLS-1$ //$NON-NLS-2$
 149                 } catch (InvocationTargetException e) {
 150                     Activator.getDefault().logError("Exception handling signal " + signal + " in method " + method, e); //$NON-NLS-1$ //$NON-NLS-2$
 151                 }
 152             }
 153         }
 154
 155         if (Tracer.isSignalTraced()) Tracer.traceSignal(signal, "(end)"); //$NON-NLS-1$
 156     }
 157
 158 }