1 /*
   2  * Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 /*
  27  * This source code is provided to illustrate the usage of a given feature
  28  * or technique and has been deliberately simplified. Additional steps
  29  * required for a production-quality application, such as security checks,
  30  * input validation and proper error handling, might not be present in
  31  * this sample code.
  32  */
  33 
  34 
  35 package com.sun.tools.example.debug.bdi;
  36 
  37 import com.sun.jdi.*;
  38 
  39 //### Should handle target VM death or connection failure cleanly.
  40 
  41 public class ThreadInfo {
  42 
  43     private ThreadReference thread;
  44     private int status;
  45 
  46     private int frameCount;
  47 
  48     Object userObject;  // User-supplied annotation.
  49 
  50     private boolean interrupted = false;
  51 
  52     private void assureInterrupted() throws VMNotInterruptedException {
  53         if (!interrupted) {
  54             throw new VMNotInterruptedException();
  55         }
  56     }
  57 
  58     ThreadInfo (ThreadReference thread) {
  59         this.thread = thread;
  60         this.frameCount = -1;
  61     }
  62 
  63     public ThreadReference thread() {
  64         return thread;
  65     }
  66 
  67     public int getStatus() throws VMNotInterruptedException {
  68         assureInterrupted();
  69         update();
  70         return status;
  71     }
  72 
  73     public int getFrameCount() throws VMNotInterruptedException {
  74         assureInterrupted();
  75         update();
  76         return frameCount;
  77     }
  78 
  79     public StackFrame getFrame(int index) throws VMNotInterruptedException {
  80         assureInterrupted();
  81         update();
  82         try {
  83             return thread.frame(index);
  84         } catch (IncompatibleThreadStateException e) {
  85             // Should not happen
  86             interrupted = false;
  87             throw new VMNotInterruptedException();
  88         }
  89     }
  90 
  91     public Object getUserObject() {
  92         return userObject;
  93     }
  94 
  95     public void setUserObject(Object obj) {
  96         userObject = obj;
  97     }
  98 
  99     // Refresh upon first access after cache is cleared.
 100 
 101     void update() throws VMNotInterruptedException {
 102         if (frameCount == -1) {
 103             try {
 104                 status = thread.status();
 105                 frameCount = thread.frameCount();
 106             } catch (IncompatibleThreadStateException e) {
 107                 // Should not happen
 108                 interrupted = false;
 109                 throw new VMNotInterruptedException();
 110             }
 111         }
 112     }
 113 
 114     // Called from 'ExecutionManager'.
 115 
 116     void validate() {
 117         interrupted = true;
 118     }
 119 
 120     void invalidate() {
 121         interrupted = false;
 122         frameCount = -1;
 123         status = ThreadReference.THREAD_STATUS_UNKNOWN;
 124     }
 125 
 126 }