external/emma 2.0.5312upstream/2.0.5312

1 files changed, 252 insertions, 0 deletions

diff --git a/core/java13/com/vladium/util/exit/ExitHookManager.java b/core/java13/com/vladium/util/exit/ExitHookManager.java
new file mode 100644
index 0000000..c119268
--- /dev/null
+++ b/core/java13/com/vladium/util/exit/ExitHookManager.java
@@ -0,0 +1,252 @@
+/* Copyright (C) 2003 Vladimir Roubtsov. All rights reserved.
+ * 
+ * This program and the accompanying materials are made available under
+ * the terms of the Common Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * $Id: ExitHookManager.java,v 1.1.1.1 2004/05/09 16:57:58 vlad_r Exp $
+ */
+package com.vladium.util.exit;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import sun.misc.Signal;
+import sun.misc.SignalHandler;
+
+import com.vladium.util.IJREVersion;
+import com.vladium.util.Property;
+import com.vladium.emma.IAppConstants;
+
+// ----------------------------------------------------------------------------
+/**
+ * @author Vlad Roubtsov, (C) 2003
+ */
+public
+abstract class ExitHookManager implements IJREVersion
+{
+    // public: ................................................................
+    
+    // TOTO: handle thread groups as well?
+    
+    public abstract boolean addExitHook (Runnable runnable);
+    public abstract boolean removeExitHook (Runnable runnable);
+    
+    public static synchronized ExitHookManager getSingleton ()
+    {
+        if (s_singleton == null)
+        {
+            if (JRE_1_3_PLUS)
+            {
+                s_singleton = new JRE13ExitHookManager ();
+            }
+            else if (JRE_SUN_SIGNAL_COMPATIBLE)
+            {
+                s_singleton = new SunJREExitHookManager ();
+            }
+            else
+            {
+                throw new UnsupportedOperationException ("no shutdown hook manager available [JVM: " + Property.getSystemFingerprint () + "]");
+            }
+        }
+        
+        return s_singleton;
+    }
+    
+    // protected: .............................................................
+    
+    
+    protected ExitHookManager () {}
+
+    // package: ...............................................................
+
+    // private: ...............................................................
+    
+    
+    private static final class JRE13ExitHookManager extends ExitHookManager
+    {
+        public synchronized boolean addExitHook (final Runnable runnable)
+        {
+            if ((runnable != null) && ! m_exitThreadMap.containsKey (runnable))
+            {
+                final Thread exitThread = new Thread (runnable, IAppConstants.APP_NAME + " shutdown handler thread");
+                
+                try
+                {
+                    Runtime.getRuntime ().addShutdownHook (exitThread);
+                    m_exitThreadMap.put (runnable, exitThread); // TODO: use identity here
+                    
+                    return true;
+                }
+                catch (Exception e)
+                {
+                    System.out.println ("exception caught while adding a shutdown hook:");
+                    e.printStackTrace (System.out);
+                }
+            }
+            
+            return false;
+        }
+        
+        public synchronized boolean removeExitHook (final Runnable runnable)
+        {
+            if (runnable != null)
+            {
+                final Thread exitThread = (Thread) m_exitThreadMap.get (runnable);  // TODO: use identity here
+                
+                if (exitThread != null)
+                {
+                    try
+                    {
+                        Runtime.getRuntime ().removeShutdownHook (exitThread);
+                        m_exitThreadMap.remove (runnable);
+                        
+                        return true;
+                    }
+                    catch (Exception e)
+                    {
+                        System.out.println ("exception caught while removing a shutdown hook:");
+                        e.printStackTrace (System.out);
+                    }
+                }
+            }
+            
+            return false;
+        }
+        
+        JRE13ExitHookManager ()
+        {
+            m_exitThreadMap = new HashMap ();
+        }
+        
+        
+        private final Map /* Runnable->Thread */ m_exitThreadMap;
+        
+    } // end of nested class
+    
+    
+    private static final class SunJREExitHookManager extends ExitHookManager
+    {
+        public synchronized boolean addExitHook (final Runnable runnable)
+        {
+            if ((runnable != null) && ! m_signalHandlerMap.containsKey (runnable))
+            {
+                final INTSignalHandler handler = new INTSignalHandler (runnable);
+                
+                try
+                {
+                    handler.register ();
+                    m_signalHandlerMap.put (runnable, handler); // TODO: use identity here
+                    
+                    return true;
+                }
+                catch (Throwable t)
+                {
+                    System.out.println ("exception caught while adding a shutdown hook:");
+                    t.printStackTrace (System.out);
+                }
+            }
+            
+            return false;
+        }
+        
+        public synchronized boolean removeExitHook (final Runnable runnable)
+        {
+            if (runnable != null)
+            {
+                final INTSignalHandler handler = (INTSignalHandler) m_signalHandlerMap.get (runnable);  // TODO: use identity here
+                if (handler != null)
+                {
+                    try
+                    {
+                        handler.unregister ();
+                        m_signalHandlerMap.remove (runnable);
+                        
+                        return true;
+                    }
+                    catch (Exception e)
+                    {
+                        System.out.println ("exception caught while removing a shutdown hook:");
+                        e.printStackTrace (System.out);
+                    }
+                }
+            }
+            
+            return false;
+        }
+        
+        SunJREExitHookManager ()
+        {
+            m_signalHandlerMap = new HashMap ();
+        }
+        
+        
+        private final Map /* Runnable->INTSignalHandler */ m_signalHandlerMap;
+        
+    } // end of nested class
+    
+    
+    private static final class INTSignalHandler implements SignalHandler
+    {
+        public synchronized void handle (final Signal signal)
+        {
+            if (m_runnable != null)
+            {
+                try
+                {
+                    m_runnable.run ();
+                }
+                catch (Throwable ignore) {}
+            }
+            m_runnable = null;
+            
+            if ((m_previous != null) && (m_previous != SIG_DFL) && (m_previous != SIG_IGN))
+            {
+                try
+                {
+                    // this does not work:
+                    //Signal.handle (signal, m_previous);
+                    //Signal.raise (signal);
+                    
+                    m_previous.handle (signal);
+                }
+                catch (Throwable ignore) {}
+            }
+            else
+            {
+                System.exit (0);
+            }
+        }
+        
+        INTSignalHandler (final Runnable runnable)
+        {
+            m_runnable = runnable;
+        }
+       
+        synchronized void register ()
+        {
+            m_previous = Signal.handle (new Signal ("INT"), this);
+        }
+        
+        synchronized void unregister ()
+        {
+//            if (m_previous != null)
+//            {
+//                Signal.handle (new Signal ("INT"), m_previous);
+//                m_previous = null;
+//            }
+
+            m_runnable = null;
+        }
+
+
+        private Runnable m_runnable;
+        private SignalHandler m_previous;
+        
+    } // end of nested class
+    
+    
+    private static ExitHookManager s_singleton;
+    
+} // end of class
+// ----------------------------------------------------------------------------
\ No newline at end of file