1 /*
   2  * Copyright 2000-2004 Sun Microsystems, Inc.  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.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  20  * CA 95054 USA or visit www.sun.com if you need additional information or
  21  * have any questions.
  22  *
  23  */
  24 
  25 package sun.jvm.hotspot.utilities;
  26 
  27 import sun.jvm.hotspot.code.*;
  28 import sun.jvm.hotspot.debugger.*;
  29 import sun.jvm.hotspot.gc_interface.*;
  30 import sun.jvm.hotspot.interpreter.*;
  31 import sun.jvm.hotspot.runtime.*;
  32 import sun.jvm.hotspot.memory.*;
  33 
  34 /** This class, only intended for use in the debugging system,
  35     provides the functionality of find() in the VM. */
  36 
  37 public class PointerFinder {
  38   public static PointerLocation find(Address a) {
  39     PointerLocation loc = new PointerLocation(a);
  40 
  41     CollectedHeap heap = VM.getVM().getUniverse().heap();
  42     if (heap instanceof GenCollectedHeap) {
  43       GenCollectedHeap genheap = (GenCollectedHeap) heap;
  44       if (genheap.isIn(a)) {
  45         for (int i = 0; i < genheap.nGens(); i++) {
  46           Generation g = genheap.getGen(i);
  47           if (g.isIn(a)) {
  48             loc.gen = g;
  49             break;
  50           }
  51         }
  52 
  53         if (loc.gen == null) {
  54           // Should be in perm gen
  55           Generation permGen = genheap.permGen();
  56           if (Assert.ASSERTS_ENABLED) {
  57             Assert.that(permGen.isIn(a), "should have been in ordinary or perm gens if it's in the heap");
  58           }
  59           loc.permGen = permGen;
  60         }
  61 
  62         if (VM.getVM().getUseTLAB()) {
  63           // Try to find thread containing it
  64           for (JavaThread t = VM.getVM().getThreads().first(); t != null; t = t.next()) {
  65             ThreadLocalAllocBuffer tlab = t.tlab();
  66             if (tlab.contains(a)) {
  67               loc.inTLAB = true;
  68               loc.tlabThread = t;
  69               loc.tlab = tlab;
  70               break;
  71             }
  72           }
  73         }
  74 
  75         return loc;
  76       }
  77     } else {
  78       if (heap.isIn(a)) {
  79         loc.heap = heap;
  80         return loc;
  81       }
  82     }
  83 
  84     Interpreter interp = VM.getVM().getInterpreter();
  85     if (interp.contains(a)) {
  86       loc.inInterpreter = true;
  87       loc.interpreterCodelet = interp.getCodeletContaining(a);
  88       return loc;
  89     }
  90 
  91     if (!VM.getVM().isCore()) {
  92       CodeCache c = VM.getVM().getCodeCache();
  93       if (c.contains(a)) {
  94         loc.inCodeCache = true;
  95         loc.blob = c.findBlobUnsafe(a);
  96         if (Assert.ASSERTS_ENABLED) {
  97           Assert.that(loc.blob != null, "Should have found CodeBlob");
  98         }
  99         loc.inBlobInstructions = loc.blob.instructionsContains(a);
 100         loc.inBlobData         = loc.blob.dataContains(a);
 101         loc.inBlobOops         = loc.blob.oopsContains(a);
 102         loc.inBlobUnknownLocation = (!(loc.inBlobInstructions ||
 103                                        loc.inBlobData ||
 104                                        loc.inBlobOops));
 105         return loc;
 106       }
 107     }
 108 
 109     // Check JNIHandles; both local and global
 110     JNIHandles handles = VM.getVM().getJNIHandles();
 111     JNIHandleBlock handleBlock = handles.globalHandles();
 112     if (handleBlock != null) {
 113       handleBlock = handleBlock.blockContainingHandle(a);
 114     }
 115     if (handleBlock != null) {
 116       loc.inStrongGlobalJNIHandleBlock = true;
 117       loc.handleBlock = handleBlock;
 118       return loc;
 119     } else {
 120       handleBlock = handles.weakGlobalHandles();
 121       if (handleBlock != null) {
 122         handleBlock = handleBlock.blockContainingHandle(a);
 123         if (handleBlock != null) {
 124           loc.inWeakGlobalJNIHandleBlock = true;
 125           loc.handleBlock = handleBlock;
 126           return loc;
 127         } else {
 128           // Look in thread-local handles
 129           for (JavaThread t = VM.getVM().getThreads().first(); t != null; t = t.next()) {
 130             handleBlock = t.activeHandles();
 131             if (handleBlock != null) {
 132               handleBlock = handleBlock.blockContainingHandle(a);
 133               if (handleBlock != null) {
 134                 loc.inLocalJNIHandleBlock = true;
 135                 loc.handleBlock = handleBlock;
 136                 loc.handleThread = t;
 137                 return loc;
 138               }
 139             }
 140           }
 141         }
 142       }
 143     }
 144 
 145 
 146     // Fall through; have to return it anyway.
 147     return loc;
 148   }
 149 }