langtools/src/jdk.jshell/share/classes/jdk/jshell/JDIEventHandler.java
changeset 33362 65ec6de1d6b4
child 34752 9c262a013456
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/src/jdk.jshell/share/classes/jdk/jshell/JDIEventHandler.java	Mon Oct 19 19:15:16 2015 +0200
@@ -0,0 +1,181 @@
+/*
+ * Copyright (c) 1998, 2011, 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.jshell;
+
+import com.sun.jdi.*;
+import com.sun.jdi.event.*;
+
+/**
+ * Handler of Java Debug Interface events.
+ * Adapted from jdb EventHandler; Handling of events not used by JShell stubbed out.
+ */
+class JDIEventHandler implements Runnable {
+
+    Thread thread;
+    volatile boolean connected = true;
+    boolean completed = false;
+    String shutdownMessageKey;
+    final JDIEnv env;
+
+    JDIEventHandler(JDIEnv env) {
+        this.env = env;
+        this.thread = new Thread(this, "event-handler");
+        this.thread.start();
+    }
+
+    synchronized void shutdown() {
+        connected = false;  // force run() loop termination
+        thread.interrupt();
+        while (!completed) {
+            try {wait();} catch (InterruptedException exc) {}
+        }
+    }
+
+    @Override
+    public void run() {
+        EventQueue queue = env.vm().eventQueue();
+        while (connected) {
+            try {
+                EventSet eventSet = queue.remove();
+                boolean resumeStoppedApp = false;
+                EventIterator it = eventSet.eventIterator();
+                while (it.hasNext()) {
+                    resumeStoppedApp |= handleEvent(it.nextEvent());
+                }
+
+                if (resumeStoppedApp) {
+                    eventSet.resume();
+                }
+            } catch (InterruptedException exc) {
+                // Do nothing. Any changes will be seen at top of loop.
+            } catch (VMDisconnectedException discExc) {
+                handleDisconnectedException();
+                break;
+            }
+        }
+        synchronized (this) {
+            completed = true;
+            notifyAll();
+        }
+    }
+
+    private boolean handleEvent(Event event) {
+        if (event instanceof ExceptionEvent) {
+            exceptionEvent(event);
+        } else if (event instanceof WatchpointEvent) {
+            fieldWatchEvent(event);
+        } else if (event instanceof MethodEntryEvent) {
+            methodEntryEvent(event);
+        } else if (event instanceof MethodExitEvent) {
+            methodExitEvent(event);
+        } else if (event instanceof ClassPrepareEvent) {
+            classPrepareEvent(event);
+        } else if (event instanceof ThreadStartEvent) {
+            threadStartEvent(event);
+        } else if (event instanceof ThreadDeathEvent) {
+            threadDeathEvent(event);
+        } else if (event instanceof VMStartEvent) {
+            vmStartEvent(event);
+            return true;
+        } else {
+            handleExitEvent(event);
+        }
+        return true;
+    }
+
+    private boolean vmDied = false;
+
+    private void handleExitEvent(Event event) {
+        if (event instanceof VMDeathEvent) {
+            vmDied = true;
+            shutdownMessageKey = "The application exited";
+        } else if (event instanceof VMDisconnectEvent) {
+            connected = false;
+            if (!vmDied) {
+                shutdownMessageKey = "The application has been disconnected";
+            }
+        } else {
+            throw new InternalError("Unexpected event type: " +
+                    event.getClass());
+        }
+        env.shutdown();
+    }
+
+    synchronized void handleDisconnectedException() {
+        /*
+         * A VMDisconnectedException has happened while dealing with
+         * another event. We need to flush the event queue, dealing only
+         * with exit events (VMDeath, VMDisconnect) so that we terminate
+         * correctly.
+         */
+        EventQueue queue = env.vm().eventQueue();
+        while (connected) {
+            try {
+                EventSet eventSet = queue.remove();
+                EventIterator iter = eventSet.eventIterator();
+                while (iter.hasNext()) {
+                    handleExitEvent(iter.next());
+                }
+            } catch (InterruptedException exc) {
+                // ignore
+            } catch (InternalError exc) {
+                // ignore
+            }
+        }
+    }
+
+    private void vmStartEvent(Event event)  {
+        VMStartEvent se = (VMStartEvent)event;
+    }
+
+    private void methodEntryEvent(Event event)  {
+        MethodEntryEvent me = (MethodEntryEvent)event;
+    }
+
+    private void methodExitEvent(Event event)  {
+        MethodExitEvent me = (MethodExitEvent)event;
+    }
+
+    private void fieldWatchEvent(Event event)  {
+        WatchpointEvent fwe = (WatchpointEvent)event;
+    }
+
+    private void classPrepareEvent(Event event)  {
+        ClassPrepareEvent cle = (ClassPrepareEvent)event;
+    }
+
+    private void exceptionEvent(Event event) {
+        ExceptionEvent ee = (ExceptionEvent)event;
+    }
+
+    private void threadDeathEvent(Event event) {
+        ThreadDeathEvent tee = (ThreadDeathEvent)event;
+    }
+
+    private void threadStartEvent(Event event) {
+        ThreadStartEvent tse = (ThreadStartEvent)event;
+    }
+}