eventthread.java

jpda例子文件

/*
 * @(#)EventThread.java	1.4 03/01/23
 *
 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright (c) 1997-2001 by Sun Microsystems, Inc. All Rights Reserved.
 * 
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 * 
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
 * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
 * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 * 
 * This software is not designed or intended for use in on-line control of
 * aircraft, air traffic, aircraft navigation or aircraft communications; or in
 * the design, construction, operation or maintenance of any nuclear
 * facility. Licensee represents and warrants that it will not use or
 * redistribute the Software for such purposes.
 */

package com.sun.tools.example.trace;

import com.sun.jdi.*;
import com.sun.jdi.request.*;
import com.sun.jdi.event.*;

import java.util.*;
import java.io.PrintWriter;

/**
 * This class processes incoming JDI events and displays them
 *
 * @version     @(#) EventThread.java 1.4 03/01/23 21:22:26
 * @author Robert Field
 */
public class EventThread extends Thread {

    private final VirtualMachine vm;   // Running VM
    private final String[] excludes;   // Packages to exclude
    private final PrintWriter writer;  // Where output goes

    static String nextBaseIndent = ""; // Starting indent for next thread

    private boolean connected = true;  // Connected to VM
    private boolean vmDied = true;     // VMDeath occurred

    // Maps ThreadReference to ThreadTrace instances
    private Map traceMap = new HashMap();

    EventThread(VirtualMachine vm, String[] excludes, PrintWriter writer) {
        super("event-handler");
        this.vm = vm;
        this.excludes = excludes;
        this.writer = writer;
    }

    /**
     * Run the event handling thread.  
     * As long as we are connected, get event sets off 
     * the queue and dispatch the events within them.
     */
    public void run() { 
        EventQueue queue = vm.eventQueue();
        while (connected) {
            try {
                EventSet eventSet = queue.remove();
                EventIterator it = eventSet.eventIterator();
                while (it.hasNext()) {
                    handleEvent(it.nextEvent());
                }
                eventSet.resume();
            } catch (InterruptedException exc) {
                // Ignore
            } catch (VMDisconnectedException discExc) {
                handleDisconnectedException();
                break;
            }
        }
    }

    /**
     * Create the desired event requests, and enable 
     * them so that we will get events.
     * @param excludes     Class patterns for which we don't want events
     * @param watchFields  Do we want to watch assignments to fields
     */
    void setEventRequests(boolean watchFields) {
        EventRequestManager mgr = vm.eventRequestManager();

        // want all exceptions
        ExceptionRequest excReq = mgr.createExceptionRequest(null, 
                                                             true, true); 
        // suspend so we can step
        excReq.setSuspendPolicy(EventRequest.SUSPEND_ALL);
        excReq.enable();

        MethodEntryRequest menr = mgr.createMethodEntryRequest();
        for (int i=0; i<excludes.length; ++i) {
            menr.addClassExclusionFilter(excludes[i]);
        }
        menr.setSuspendPolicy(EventRequest.SUSPEND_NONE);
        menr.enable();

        MethodExitRequest mexr = mgr.createMethodExitRequest();
        for (int i=0; i<excludes.length; ++i) {
            mexr.addClassExclusionFilter(excludes[i]);
        }
        mexr.setSuspendPolicy(EventRequest.SUSPEND_NONE);
        mexr.enable();

        ThreadDeathRequest tdr = mgr.createThreadDeathRequest();
	// Make sure we sync on thread death
        tdr.setSuspendPolicy(EventRequest.SUSPEND_ALL);
        tdr.enable();

	if (watchFields) {
	    ClassPrepareRequest cpr = mgr.createClassPrepareRequest();
	    for (int i=0; i<excludes.length; ++i) {
		cpr.addClassExclusionFilter(excludes[i]);
	    }
	    cpr.setSuspendPolicy(EventRequest.SUSPEND_ALL);
	    cpr.enable();
	}
    }

    /**
     * This class keeps context on events in one thread.
     * In this implementation, context is the indentation prefix.
     */
    class ThreadTrace {
        final ThreadReference thread;
        final String baseIndent;
	static final String threadDelta = "                     ";
	StringBuffer indent;

	ThreadTrace(ThreadReference thread) {
            this.thread = thread;
            this.baseIndent = nextBaseIndent;
	    indent = new StringBuffer(baseIndent);
	    nextBaseIndent += threadDelta;
	    println("====== " + thread.name() + " ======");
	}

	private void println(String str) {
	    writer.print(indent);
	    writer.println(str);
	}

	void methodEntryEvent(MethodEntryEvent event)  {
	    println(event.method().name() + "  --  " 
                    + event.method().declaringType().name());
	    indent.append("| ");
	}
	
	void methodExitEvent(MethodExitEvent event)  {
	    indent.setLength(indent.length()-2);
	}
	
	void fieldWatchEvent(ModificationWatchpointEvent event)  {
            Field field = event.field();
            Value value = event.valueToBe();
	    println("    " + field.name() + " = " + value);
	}
	
	void exceptionEvent(ExceptionEvent event) {
	    println("Exception: " + event.exception() + 
		    " catch: " + event.catchLocation());

            // Step to the catch
            EventRequestManager mgr = vm.eventRequestManager();
            StepRequest req = mgr.createStepRequest(thread, 
                                                    StepRequest.STEP_MIN,
                                                    StepRequest.STEP_INTO);
            req.addCountFilter(1);  // next step only
            req.setSuspendPolicy(EventRequest.SUSPEND_ALL);
            req.enable();
	}

        // Step to exception catch
	void stepEvent(StepEvent event)  {
            // Adjust call depth
            int cnt = 0;
            indent = new StringBuffer(baseIndent);
            try {
                cnt = thread.frameCount();
            } catch (IncompatibleThreadStateException exc) {
            }
            while (cnt-- > 0) {
                indent.append("| ");
            }

            EventRequestManager mgr = vm.eventRequestManager();
            mgr.deleteEventRequest(event.request());
        }

	void threadDeathEvent(ThreadDeathEvent event)  {
            indent = new StringBuffer(baseIndent);
	    println("====== " + thread.name() + " end ======");
        }
    }	

    /**
     * Returns the ThreadTrace instance for the specified thread,
     * creating one if needed.
     */
    ThreadTrace threadTrace(ThreadReference thread) {
	ThreadTrace trace = (ThreadTrace)traceMap.get(thread);
	if (trace == null) {
	    trace = new ThreadTrace(thread);
	    traceMap.put(thread, trace);
	}
	return trace;
    }

    /**
     * Dispatch incoming events
     */
    private void handleEvent(Event event) {
        if (event instanceof ExceptionEvent) {
            exceptionEvent((ExceptionEvent)event);
        } else if (event instanceof ModificationWatchpointEvent) {
            fieldWatchEvent((ModificationWatchpointEvent)event);
        } else if (event instanceof MethodEntryEvent) {
            methodEntryEvent((MethodEntryEvent)event);
        } else if (event instanceof MethodExitEvent) {
            methodExitEvent((MethodExitEvent)event);
        } else if (event instanceof StepEvent) {
            stepEvent((StepEvent)event);
        } else if (event instanceof ThreadDeathEvent) {
            threadDeathEvent((ThreadDeathEvent)event);
        } else if (event instanceof ClassPrepareEvent) {
            classPrepareEvent((ClassPrepareEvent)event);
        } else if (event instanceof VMStartEvent) {
            vmStartEvent((VMStartEvent)event);
        } else if (event instanceof VMDeathEvent) {
            vmDeathEvent((VMDeathEvent)event);
        } else if (event instanceof VMDisconnectEvent) {
            vmDisconnectEvent((VMDisconnectEvent)event);
        } else {
            throw new Error("Unexpected event type");
        }
    }

    /***
     * 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.
     */
    synchronized void handleDisconnectedException() {
        EventQueue queue = vm.eventQueue();
        while (connected) {
            try {
                EventSet eventSet = queue.remove();
                EventIterator iter = eventSet.eventIterator();
                while (iter.hasNext()) {
                    Event event = iter.nextEvent();
                    if (event instanceof VMDeathEvent) {
                        vmDeathEvent((VMDeathEvent)event);
                    } else if (event instanceof VMDisconnectEvent) {
                        vmDisconnectEvent((VMDisconnectEvent)event);
                    } 
                }
                eventSet.resume(); // Resume the VM
            } catch (InterruptedException exc) {
                // ignore
            }
        }
    }

    private void vmStartEvent(VMStartEvent event)  {
         writer.println("-- VM Started --");
    }

    // Forward event for thread specific processing
    private void methodEntryEvent(MethodEntryEvent event)  {
         threadTrace(event.thread()).methodEntryEvent(event);
    }

    // Forward event for thread specific processing
    private void methodExitEvent(MethodExitEvent event)  {
         threadTrace(event.thread()).methodExitEvent(event);
    }

    // Forward event for thread specific processing
    private void stepEvent(StepEvent event)  {
         threadTrace(event.thread()).stepEvent(event);
    }

    // Forward event for thread specific processing
    private void fieldWatchEvent(ModificationWatchpointEvent event)  {
         threadTrace(event.thread()).fieldWatchEvent(event);
    }

    void threadDeathEvent(ThreadDeathEvent event)  {
	ThreadTrace trace = (ThreadTrace)traceMap.get(event.thread());
	if (trace != null) {  // only want threads we care about
            trace.threadDeathEvent(event);   // Forward event
        }
    }

    /**
     * A new class has been loaded.  
     * Set watchpoints on each of its fields
     */
    private void classPrepareEvent(ClassPrepareEvent event)  {
        EventRequestManager mgr = vm.eventRequestManager();
	List fields = event.referenceType().visibleFields();
	for (Iterator it = fields.iterator(); it.hasNext(); ) {
	    Field field = (Field)it.next();
	    ModificationWatchpointRequest req = 
		     mgr.createModificationWatchpointRequest(field);
            for (int i=0; i<excludes.length; ++i) {
                req.addClassExclusionFilter(excludes[i]);
            }
	    req.setSuspendPolicy(EventRequest.SUSPEND_NONE);
	    req.enable();
	}
    }

    private void exceptionEvent(ExceptionEvent event) {
	ThreadTrace trace = (ThreadTrace)traceMap.get(event.thread());
	if (trace != null) {  // only want threads we care about
            trace.exceptionEvent(event);      // Forward event
        }
    }

    public void vmDeathEvent(VMDeathEvent event) {
	vmDied = true;
        writer.println("-- The application exited --");
    }

    public void vmDisconnectEvent(VMDisconnectEvent event) {
        connected = false;
        if (!vmDied) {
	    writer.println("-- The application has been disconnected --");
	}
    }
}