jdk/src/share/classes/com/sun/tools/jdi/TargetVM.java
changeset 2 90ce3da70b43
child 51 6fe31bc95bbc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/com/sun/tools/jdi/TargetVM.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,375 @@
+/*
+ * Copyright 1998-2003 Sun Microsystems, Inc.  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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package com.sun.tools.jdi;
+
+import com.sun.jdi.*;
+import com.sun.jdi.event.*;
+import com.sun.jdi.connect.spi.Connection;
+import com.sun.jdi.event.EventSet;
+
+import java.util.*;
+import java.io.IOException;
+
+public class TargetVM implements Runnable {
+    private Map<String, Packet> waitingQueue = new HashMap<String, Packet>(32,0.75f);
+    private boolean shouldListen = true;
+    private List<EventQueue> eventQueues = Collections.synchronizedList(new ArrayList<EventQueue>(2));
+    private VirtualMachineImpl vm;
+    private Connection connection;
+    private Thread readerThread;
+    private EventController eventController = null;
+    private boolean eventsHeld = false;
+
+    /*
+     * TO DO: The limit numbers below are somewhat arbitrary and should
+     * be configurable in the future.
+     */
+    static private final int OVERLOADED_QUEUE = 2000;
+    static private final int UNDERLOADED_QUEUE = 100;
+
+    TargetVM(VirtualMachineImpl vm, Connection connection) {
+        this.vm = vm;
+        this.connection = connection;
+        this.readerThread = new Thread(vm.threadGroupForJDI(),
+                                       this, "JDI Target VM Interface");
+        this.readerThread.setDaemon(true);
+    }
+
+    void start() {
+        readerThread.start();
+    }
+
+    private void dumpPacket(Packet packet, boolean sending) {
+        String direction = sending ? "Sending" : "Receiving";
+        if (sending) {
+            vm.printTrace(direction + " Command. id=" + packet.id +
+                          ", length=" + packet.data.length +
+                          ", commandSet=" + packet.cmdSet +
+                          ", command=" + packet.cmd +
+                          ", flags=" + packet.flags);
+        } else {
+            String type = (packet.flags & Packet.Reply) != 0 ?
+                          "Reply" : "Event";
+            vm.printTrace(direction + " " + type + ". id=" + packet.id +
+                          ", length=" + packet.data.length +
+                          ", errorCode=" + packet.errorCode +
+                          ", flags=" + packet.flags);
+        }
+        StringBuffer line = new StringBuffer(80);
+        line.append("0000: ");
+        for (int i = 0; i < packet.data.length; i++) {
+            if ((i > 0) && (i % 16 == 0)) {
+                vm.printTrace(line.toString());
+                line.setLength(0);
+                line.append(String.valueOf(i));
+                line.append(": ");
+                int len = line.length();
+                for (int j = 0; j < 6 - len; j++) {
+                    line.insert(0, '0');
+                }
+            }
+            int val = 0xff & packet.data[i];
+            String str = Integer.toHexString(val);
+            if (str.length() == 1) {
+                line.append('0');
+            }
+            line.append(str);
+            line.append(' ');
+        }
+        if (line.length() > 6) {
+            vm.printTrace(line.toString());
+        }
+    }
+
+    public void run() {
+        if ((vm.traceFlags & VirtualMachine.TRACE_SENDS) != 0) {
+            vm.printTrace("Target VM interface thread running");
+        }
+        Packet p=null,p2;
+        String idString;
+
+        while(shouldListen) {
+
+            boolean done = false;
+            try {
+                byte b[] = connection.readPacket();
+                if (b.length == 0) {
+                    done = true;
+                }
+                p = Packet.fromByteArray(b);
+            } catch (IOException e) {
+                done = true;
+            }
+
+            if (done) {
+                shouldListen = false;
+                try {
+                    connection.close();
+                } catch (IOException ioe) { }
+                break;
+            }
+
+            if ((vm.traceFlags & VirtualMachineImpl.TRACE_RAW_RECEIVES) != 0)  {
+                dumpPacket(p, false);
+            }
+
+            if((p.flags & Packet.Reply) == 0) {
+                // It's a command
+                handleVMCommand(p);
+            } else {
+                /*if(p.errorCode != Packet.ReplyNoError) {
+                    System.err.println("Packet " + p.id + " returned failure = " + p.errorCode);
+                }*/
+
+                vm.state().notifyCommandComplete(p.id);
+                idString = String.valueOf(p.id);
+
+                synchronized(waitingQueue) {
+                    p2 = (Packet)waitingQueue.get(idString);
+
+                    if (p2 != null)
+                        waitingQueue.remove(idString);
+                }
+
+                if(p2 == null) {
+                    // Whoa! a reply without a sender. Problem.
+                    // FIX ME! Need to post an error.
+
+                    System.err.println("Recieved reply with no sender!");
+                    continue;
+                }
+                p2.errorCode = p.errorCode;
+                p2.data = p.data;
+                p2.replied = true;
+
+                synchronized(p2) {
+                    p2.notify();
+                }
+            }
+        }
+
+        // inform the VM mamager that this VM is history
+        vm.vmManager.disposeVirtualMachine(vm);
+
+        // close down all the event queues
+        // Closing a queue causes a VMDisconnectEvent to
+        // be put onto the queue.
+        synchronized(eventQueues) {
+            Iterator iter = eventQueues.iterator();
+            while (iter.hasNext()) {
+                ((EventQueueImpl)iter.next()).close();
+            }
+        }
+
+        // indirectly throw VMDisconnectedException to
+        // command requesters.
+        synchronized(waitingQueue) {
+            Iterator iter = waitingQueue.values().iterator();
+            while (iter.hasNext()) {
+                Packet packet = (Packet)iter.next();
+                synchronized(packet) {
+                    packet.notify();
+                }
+            }
+            waitingQueue.clear();
+        }
+
+        if ((vm.traceFlags & VirtualMachine.TRACE_SENDS) != 0) {
+            vm.printTrace("Target VM interface thread exiting");
+        }
+    }
+
+    protected void handleVMCommand(Packet p) {
+        switch (p.cmdSet) {
+            case JDWP.Event.COMMAND_SET:
+                handleEventCmdSet(p);
+                break;
+
+            default:
+                System.err.println("Ignoring cmd " + p.id + "/" +
+                                   p.cmdSet + "/" + p.cmd + " from the VM");
+                return;
+        }
+    }
+
+    /* Events should not be constructed on this thread (the thread
+     * which reads all data from the transport). This means that the
+     * packet cannot be converted to real JDI objects as that may
+     * involve further communications with the back end which would
+     * deadlock.
+     *
+     * Instead the whole packet is passed for lazy eval by a queue
+     * reading thread.
+     */
+    protected void handleEventCmdSet(Packet p) {
+        EventSet eventSet = new EventSetImpl(vm, p);
+
+        if (eventSet != null) {
+            queueEventSet(eventSet);
+        }
+    }
+
+    private EventController eventController() {
+        if (eventController == null) {
+            eventController = new EventController(vm);
+        }
+        return eventController;
+    }
+
+    private synchronized void controlEventFlow(int maxQueueSize) {
+        if (!eventsHeld && (maxQueueSize > OVERLOADED_QUEUE)) {
+            eventController().hold();
+            eventsHeld = true;
+        } else if (eventsHeld && (maxQueueSize < UNDERLOADED_QUEUE)) {
+            eventController().release();
+            eventsHeld = false;
+        }
+    }
+
+    void notifyDequeueEventSet() {
+        int maxQueueSize = 0;
+        synchronized(eventQueues) {
+            Iterator iter = eventQueues.iterator();
+            while (iter.hasNext()) {
+                EventQueueImpl queue = (EventQueueImpl)iter.next();
+                maxQueueSize = Math.max(maxQueueSize, queue.size());
+            }
+        }
+        controlEventFlow(maxQueueSize);
+    }
+
+    private void queueEventSet(EventSet eventSet) {
+        int maxQueueSize = 0;
+
+        synchronized(eventQueues) {
+            Iterator iter = eventQueues.iterator();
+            while (iter.hasNext()) {
+                EventQueueImpl queue = (EventQueueImpl)iter.next();
+                queue.enqueue(eventSet);
+                maxQueueSize = Math.max(maxQueueSize, queue.size());
+            }
+        }
+
+        controlEventFlow(maxQueueSize);
+    }
+
+    void send(Packet packet) {
+        String id = String.valueOf(packet.id);
+
+        synchronized(waitingQueue) {
+            waitingQueue.put(id, packet);
+        }
+
+        if ((vm.traceFlags & VirtualMachineImpl.TRACE_RAW_SENDS) != 0) {
+            dumpPacket(packet, true);
+        }
+
+        try {
+            connection.writePacket(packet.toByteArray());
+        } catch (IOException e) {
+            throw new VMDisconnectedException(e.getMessage());
+        }
+    }
+
+    void waitForReply(Packet packet) {
+        synchronized(packet) {
+            while ((!packet.replied) && shouldListen) {
+                try { packet.wait(); } catch (InterruptedException e) {;}
+            }
+
+            if (!packet.replied) {
+                throw new VMDisconnectedException();
+            }
+        }
+    }
+
+    void addEventQueue(EventQueueImpl queue) {
+        if ((vm.traceFlags & VirtualMachine.TRACE_EVENTS) != 0) {
+            vm.printTrace("New event queue added");
+        }
+        eventQueues.add(queue);
+    }
+
+    void stopListening() {
+        if ((vm.traceFlags & VirtualMachine.TRACE_EVENTS) != 0) {
+            vm.printTrace("Target VM i/f closing event queues");
+        }
+        shouldListen = false;
+        try {
+            connection.close();
+        } catch (IOException ioe) { }
+    }
+
+    static private class EventController extends Thread {
+        VirtualMachineImpl vm;
+        int controlRequest = 0;
+
+        EventController(VirtualMachineImpl vm) {
+            super(vm.threadGroupForJDI(), "JDI Event Control Thread");
+            this.vm = vm;
+            setDaemon(true);
+            setPriority((MAX_PRIORITY + NORM_PRIORITY)/2);
+            super.start();
+        }
+
+        synchronized void hold() {
+            controlRequest++;
+            notifyAll();
+        }
+
+        synchronized void release() {
+            controlRequest--;
+            notifyAll();
+        }
+
+        public void run() {
+            while(true) {
+                int currentRequest;
+                synchronized(this) {
+                    while (controlRequest == 0) {
+                        try {wait();} catch (InterruptedException e) {}
+                    }
+                    currentRequest = controlRequest;
+                    controlRequest = 0;
+                }
+                try {
+                    if (currentRequest > 0) {
+                        JDWP.VirtualMachine.HoldEvents.process(vm);
+                    } else {
+                        JDWP.VirtualMachine.ReleaseEvents.process(vm);
+                    }
+                } catch (JDWPException e) {
+                    /*
+                     * Don't want to terminate the thread, so the
+                     * stack trace is printed and we continue.
+                     */
+                    e.toJDIException().printStackTrace(System.err);
+                }
+            }
+        }
+    }
+
+}