/*

 * Copyright 2004-2007 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.

 *

 * 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 sun.jvm.hotspot.utilities.soql;

import java.util.*;

import sun.jvm.hotspot.debugger.*;

import sun.jvm.hotspot.oops.*;

import sun.jvm.hotspot.runtime.*;

/**

 * Wraps a JavaThread instance in the target VM.

 */

public class JSJavaThread extends JSJavaInstance {

    public JSJavaThread(Instance threadOop, JSJavaFactory fac) {

        super(threadOop, fac);

        // JavaThread retrieved from java.lang.Thread instance may be null.

        // This is the case for threads not-started and for zombies. Wherever

        // appropriate, check for null instead of resulting in NullPointerException.

        this.jthread = OopUtilities.threadOopGetJavaThread(threadOop);

    }

    public JSJavaThread(JavaThread jt, JSJavaFactory fac) {

        super((Instance) jt.getThreadObj(), fac);

        this.jthread = jt;

    }

    public String toString() {

        String name = getName();

        StringBuffer buf = new StringBuffer();

        buf.append("Thread (address=");

        buf.append(getOop().getHandle());

        buf.append(", name=");

        if (name != null) {

            buf.append(name);

        } else {

            buf.append("<unnamed>");

        }

        buf.append(')');

        return buf.toString();

    }

    protected Object getFieldValue(String name) {

        if (name.equals("name")) {

            return getName();

        } else if (name.equals("frames")) {

            return getFrames();

        } else if (name.equals("monitors")) {

            return getOwnedMonitors();

        } else {

            return super.getFieldValue(name);

        }

    }

    protected String[] getFieldNames() {

        String[] flds = super.getFieldNames();

        String[] res = new String[flds.length + 2];

        System.arraycopy(flds, 0, res, 0, flds.length);

        res[flds.length] = "frames";

        res[flds.length + 1] = "monitors";

        return res;

    }

    protected boolean hasField(String name) {

        if (name.equals("frames") || name.equals("monitors")) {

            return true;

        } else {

            return super.hasField(name);

        }

    }

    //-- Internals only below this point

    private String getName() {

        return OopUtilities.threadOopGetName(getOop());

    }

    private synchronized JSList getFrames() {

        if (framesCache == null) {

            final List list = new ArrayList(0);

            if (jthread != null) {

                JavaVFrame jvf = jthread.getLastJavaVFrameDbg();

                while (jvf != null) {

                    list.add(jvf);

                    jvf = jvf.javaSender();

                }

            }

            framesCache = factory.newJSList(list);

        }

        return framesCache;

    }

    private synchronized JSList getOwnedMonitors() {

        if (monitorsCache == null) {

            final List ownedMonitors = new ArrayList(0);

            if (jthread != null) {

                List lockedObjects = new ArrayList(); // List<OopHandle>

                ObjectMonitor waitingMonitor = jthread.getCurrentWaitingMonitor();

                OopHandle waitingObj = null;

                if (waitingMonitor != null) {

                   // save object of current wait() call (if any) for later comparison

                   waitingObj = waitingMonitor.object();

                }

                ObjectMonitor pendingMonitor = jthread.getCurrentPendingMonitor();

                OopHandle pendingObj = null;

                if (pendingMonitor != null) {

                    // save object of current enter() call (if any) for later comparison

                    pendingObj = pendingMonitor.object();

                }

                JavaVFrame frame = jthread.getLastJavaVFrameDbg();

                while (frame != null) {

                    List frameMonitors = frame.getMonitors();  // List<MonitorInfo>

                    for (Iterator miItr = frameMonitors.iterator(); miItr.hasNext(); ) {

                        MonitorInfo mi = (MonitorInfo) miItr.next();

                        OopHandle obj = mi.owner();

                        if (obj == null) {

                            // this monitor doesn't have an owning object so skip it

                            continue;

                        }

                        if (obj.equals(waitingObj)) {

                           // the thread is waiting on this monitor so it isn't really owned

                           continue;

                        }

                        if (obj.equals(pendingObj)) {

                            // the thread is pending on this monitor so it isn't really owned

                            continue;

                        }

                        boolean found = false;

                        for (Iterator loItr = lockedObjects.iterator(); loItr.hasNext(); ) {

                            // check for recursive locks

                            if (obj.equals(loItr.next())) {

                                found = true;

                                break;

                            }

                        }

                        if (found) {

                            // already have this object so don't include it

                            continue;

                        }

                        // add the owning object to our list

                        lockedObjects.add(obj);

                    }

                    frame = (JavaVFrame) frame.javaSender();

                }

                // now convert List<OopHandle> to List<Oop>

                ObjectHeap heap = VM.getVM().getObjectHeap();

                for (Iterator loItr = lockedObjects.iterator(); loItr.hasNext(); ) {

                    ownedMonitors.add(heap.newOop((OopHandle)loItr.next()));

                }

            }

            monitorsCache = factory.newJSList(ownedMonitors);

        }

        return monitorsCache;

    }

    private JavaThread jthread;

    private JSList framesCache;

    private JSList monitorsCache;

}