/*

 * Copyright (c) 2002, 2003, 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.

 *

 * 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 sun.jvm.hotspot.runtime.linux_x86;

import java.io.*;

import java.util.*;

import sun.jvm.hotspot.debugger.*;

import sun.jvm.hotspot.debugger.x86.*;

import sun.jvm.hotspot.runtime.*;

import sun.jvm.hotspot.runtime.x86.*;

import sun.jvm.hotspot.types.*;

import sun.jvm.hotspot.utilities.*;

public class LinuxX86JavaThreadPDAccess implements JavaThreadPDAccess {

  private static AddressField  lastJavaFPField;

  private static AddressField  osThreadField;

  // Field from OSThread

  private static CIntegerField osThreadThreadIDField;

  // This is currently unneeded but is being kept in case we change

  // the currentFrameGuess algorithm

  private static final long GUESS_SCAN_RANGE = 128 * 1024;

  static {

    VM.registerVMInitializedObserver(new Observer() {

        public void update(Observable o, Object data) {

          initialize(VM.getVM().getTypeDataBase());

        }

      });

  }

  private static synchronized void initialize(TypeDataBase db) {

    Type type = db.lookupType("JavaThread");

    osThreadField           = type.getAddressField("_osthread");

    Type anchorType = db.lookupType("JavaFrameAnchor");

    lastJavaFPField         = anchorType.getAddressField("_last_Java_fp");

    Type osThreadType = db.lookupType("OSThread");

    osThreadThreadIDField   = osThreadType.getCIntegerField("_thread_id");

  }

  public    Address getLastJavaFP(Address addr) {

    return lastJavaFPField.getValue(addr.addOffsetTo(sun.jvm.hotspot.runtime.JavaThread.getAnchorField().getOffset()));

  }

  public    Address getLastJavaPC(Address addr) {

    return null;

  }

  public    Address getBaseOfStackPointer(Address addr) {

    return null;

  }

  public    Frame getLastFramePD(JavaThread thread, Address addr) {

    Address fp = thread.getLastJavaFP();

    if (fp == null) {

      return null; // no information

    }

    return new X86Frame(thread.getLastJavaSP(), fp);

  }

  public    RegisterMap newRegisterMap(JavaThread thread, boolean updateMap) {

    return new X86RegisterMap(thread, updateMap);

  }

  public    Frame getCurrentFrameGuess(JavaThread thread, Address addr) {

    ThreadProxy t = getThreadProxy(addr);

    X86ThreadContext context = (X86ThreadContext) t.getContext();

    X86CurrentFrameGuess guesser = new X86CurrentFrameGuess(context, thread);

    if (!guesser.run(GUESS_SCAN_RANGE)) {

      return null;

    }

    if (guesser.getPC() == null) {

      return new X86Frame(guesser.getSP(), guesser.getFP());

    } else {

      return new X86Frame(guesser.getSP(), guesser.getFP(), guesser.getPC());

    }

  }

  public    void printThreadIDOn(Address addr, PrintStream tty) {

    tty.print(getThreadProxy(addr));

  }

  public    void printInfoOn(Address threadAddr, PrintStream tty) {

    tty.print("Thread id: ");

    printThreadIDOn(threadAddr, tty);

//    tty.println("\nPostJavaState: " + getPostJavaState(threadAddr));

  }

  public    Address getLastSP(Address addr) {

    ThreadProxy t = getThreadProxy(addr);

    X86ThreadContext context = (X86ThreadContext) t.getContext();

    return context.getRegisterAsAddress(X86ThreadContext.ESP);

  }

  public    ThreadProxy getThreadProxy(Address addr) {

    // Addr is the address of the JavaThread.

    // Fetch the OSThread (for now and for simplicity, not making a

    // separate "OSThread" class in this package)

    Address osThreadAddr = osThreadField.getValue(addr);

    // Get the address of the _thread_id from the OSThread

    Address threadIdAddr = osThreadAddr.addOffsetTo(osThreadThreadIDField.getOffset());

    JVMDebugger debugger = VM.getVM().getDebugger();

    return debugger.getThreadForIdentifierAddress(threadIdAddr);

  }

}