1 /* 2 * Copyright (c) 2000, 2013, 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. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 package sun.jvm.hotspot.runtime; 26 27 import java.io.*; 28 import java.util.*; 29 import sun.jvm.hotspot.debugger.*; 30 import sun.jvm.hotspot.oops.*; 31 import sun.jvm.hotspot.types.*; 32 33 /** <P> ThreadLocalAllocBuffer: a descriptor for thread-local storage 34 used by the threads for allocation. </P> 35 36 <P> It is thread-private at any time, but maybe multiplexed over 37 time across multiple threads. </P> */ 38 39 public class ThreadLocalAllocBuffer extends VMObject { 40 private static AddressField startField; 41 private static AddressField topField; 42 private static AddressField fastPathEndField; 43 private static CIntegerField desired_sizeField; 44 45 static { 46 VM.registerVMInitializedObserver(new Observer() { 47 public void update(Observable o, Object data) { 48 initialize(VM.getVM().getTypeDataBase()); 49 } 50 }); 51 } 52 53 private static synchronized void initialize(TypeDataBase db) { 54 Type type = db.lookupType("ThreadLocalAllocBuffer"); 55 56 startField = type.getAddressField("_start"); 57 topField = type.getAddressField("_top"); 58 fastPathEndField = type.getAddressField("_fast_path_end"); 59 desired_sizeField = type.getCIntegerField("_desired_size"); 60 } 61 62 public ThreadLocalAllocBuffer(Address addr) { 63 super(addr); 64 } 65 66 public Address start() { return startField.getValue(addr); } 67 public Address fastPathEnd() { return fastPathEndField.getValue(addr); } 68 public Address top() { return topField.getValue(addr); } 69 public Address hardEnd() { return fastPathEnd().addOffsetTo(alignmentReserve()); } 70 71 private long alignmentReserve() { 72 return Oop.alignObjectSize(endReserve()); 73 } 74 75 private long endReserve() { 76 long minFillerArraySize = Array.baseOffsetInBytes(BasicType.T_INT); 77 long reserveForAllocationPrefetch = VM.getVM().getReserveForAllocationPrefetch(); 78 long heapWordSize = VM.getVM().getHeapWordSize(); 79 80 return Math.max(minFillerArraySize, reserveForAllocationPrefetch * heapWordSize); 81 } 82 83 /** Support for iteration over heap -- not sure how this will 84 interact with GC in reflective system, but necessary for the 85 debugging mechanism */ 86 public OopHandle startAsOopHandle() { 87 return startField.getOopHandle(addr); 88 } 89 90 /** Support for iteration over heap -- not sure how this will 91 interact with GC in reflective system, but necessary for the 92 debugging mechanism */ 93 public OopHandle nextOopHandle(OopHandle handle, long size) { 94 return handle.addOffsetToAsOopHandle(size); 95 } 96 97 // public int size(); // FIXME: must adjust this to be in bytes 98 // public int availableSize(); // FIXME: must adjust this to be in bytes 99 public void print() { 100 printOn(System.out); 101 } 102 103 public boolean contains(Address p) { 104 if (top() == null) { 105 return false; 106 } 107 return (start().lessThanOrEqual(p) && top().greaterThan(p)); 108 } 109 110 public void printOn(PrintStream tty) { 111 tty.println(" [" + start() + "," + 112 top() + "," + fastPathEnd() + ",{" + hardEnd() + "})"); 113 } 114 }