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Java example source code file (Win32AMD64JavaThreadPDAccess.java)

This example Java source code file (Win32AMD64JavaThreadPDAccess.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

address, addressfield, amd64currentframeguess, amd64threadcontext, guess_scan_range, javaframeanchor, javathreadpdaccess, jvmdebugger, observer, osthread, printstream, threadproxy, type, util, x86registermap

The Win32AMD64JavaThreadPDAccess.java Java example source code

/*
 * Copyright (c) 2005, 2013, 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.win32_amd64;

import java.io.*;
import java.util.*;
import sun.jvm.hotspot.debugger.*;
import sun.jvm.hotspot.debugger.amd64.*;
import sun.jvm.hotspot.runtime.*;
import sun.jvm.hotspot.runtime.amd64.*;
import sun.jvm.hotspot.runtime.x86.*;
import sun.jvm.hotspot.types.*;
import sun.jvm.hotspot.utilities.*;

/** This class is only public to allow using the VMObjectFactory to
    instantiate these.
*/

public class Win32AMD64JavaThreadPDAccess implements JavaThreadPDAccess {
  private static AddressField  lastJavaFPField;
  private static AddressField  osThreadField;

  // Field from OSThread
  private static Field         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");
    Type anchorType = db.lookupType("JavaFrameAnchor");
    lastJavaFPField         = anchorType.getAddressField("_last_Java_fp");
    osThreadField           = type.getAddressField("_osthread");

    type = db.lookupType("OSThread");
    osThreadThreadIdField = type.getField("_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
    }
    Address pc =  thread.getLastJavaPC();
    if ( pc != null ) {
      return new X86Frame(thread.getLastJavaSP(), fp, pc);
    } else {
      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);
    AMD64ThreadContext context = (AMD64ThreadContext) t.getContext();
    AMD64CurrentFrameGuess guesser = new AMD64CurrentFrameGuess(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) {
  }

  public Address getLastSP(Address addr) {
    ThreadProxy t = getThreadProxy(addr);
    AMD64ThreadContext context = (AMD64ThreadContext) t.getContext();
    return context.getRegisterAsAddress(AMD64ThreadContext.RSP);
  }

  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 within the OSThread
    Address threadIdAddr =
      osThreadAddr.addOffsetTo(osThreadThreadIdField.getOffset());
    JVMDebugger debugger = VM.getVM().getDebugger();
    return debugger.getThreadForIdentifierAddress(threadIdAddr);
  }
}

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