src/jdk.jdi/share/classes/com/sun/tools/jdi/VMState.java

*** 1,7 ****
  /*
!  * Copyright (c) 1999, 2017, 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.  Oracle designates this
--- 1,7 ----
  /*
!  * Copyright (c) 1999, 2018, 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.  Oracle designates this
*** 24,37 ****
   */
  
  package com.sun.tools.jdi;
  
  import java.lang.ref.WeakReference;
! import java.util.ArrayList;
! import java.util.Arrays;
! import java.util.Iterator;
! import java.util.List;
  
  import com.sun.jdi.ThreadGroupReference;
  import com.sun.jdi.ThreadReference;
  import com.sun.jdi.VirtualMachine;
  
--- 24,34 ----
   */
  
  package com.sun.tools.jdi;
  
  import java.lang.ref.WeakReference;
! import java.util.*;
  
  import com.sun.jdi.ThreadGroupReference;
  import com.sun.jdi.ThreadReference;
  import com.sun.jdi.VirtualMachine;
  
*** 42,57 ****
      private final List<WeakReference<VMListener>> listeners = new ArrayList<>(); // synchronized (this)
      private boolean notifyingListeners = false;  // synchronized (this)
  
      /*
       * Certain information can be cached only when the entire VM is
!      * suspended and there are no pending resumes. The fields below
!      * are used to track whether there are pending resumes. (There
!      * is an assumption that JDWP command ids are increasing over time.)
       */
!     private int lastCompletedCommandId = 0;   // synchronized (this)
!     private int lastResumeCommandId = 0;      // synchronized (this)
  
      // This is cached only while the VM is suspended
      private static class Cache {
          List<ThreadGroupReference> groups = null;  // cached Top Level ThreadGroups
          List<ThreadReference> threads = null; // cached Threads
--- 39,52 ----
      private final List<WeakReference<VMListener>> listeners = new ArrayList<>(); // synchronized (this)
      private boolean notifyingListeners = false;  // synchronized (this)
  
      /*
       * Certain information can be cached only when the entire VM is
!      * suspended and there are no pending resumes. The field below
!      * is used to track whether there are pending resumes.
       */
!     private final Set<Integer> pendingResumeCommands = Collections.synchronizedSet(new HashSet<>());
  
      // This is cached only while the VM is suspended
      private static class Cache {
          List<ThreadGroupReference> groups = null;  // cached Top Level ThreadGroups
          List<ThreadReference> threads = null; // cached Threads
*** 95,110 ****
  
      /*
       * A JDWP command has been completed (reply has been received).
       * Update data that tracks pending resume commands.
       */
!     synchronized void notifyCommandComplete(int id) {
!         lastCompletedCommandId = id;
      }
  
      synchronized void freeze() {
!         if (cache == null && (lastCompletedCommandId >= lastResumeCommandId)) {
              /*
               * No pending resumes to worry about. The VM is suspended
               * and additional state can be cached. Notify all
               * interested listeners.
               */
--- 90,105 ----
  
      /*
       * A JDWP command has been completed (reply has been received).
       * Update data that tracks pending resume commands.
       */
!     void notifyCommandComplete(int id) {
!         pendingResumeCommands.remove(id);
      }
  
      synchronized void freeze() {
!         if (cache == null && (pendingResumeCommands.isEmpty())) {
              /*
               * No pending resumes to worry about. The VM is suspended
               * and additional state can be cached. Notify all
               * interested listeners.
               */
*** 113,123 ****
          }
      }
  
      synchronized PacketStream thawCommand(CommandSender sender) {
          PacketStream stream = sender.send();
!         lastResumeCommandId = stream.id();
          thaw();
          return stream;
      }
  
      /**
--- 108,118 ----
          }
      }
  
      synchronized PacketStream thawCommand(CommandSender sender) {
          PacketStream stream = sender.send();
!         pendingResumeCommands.add(stream.id());
          thaw();
          return stream;
      }
  
      /**