Mercurial > hg > graal-jvmci-8
view agent/src/share/classes/sun/jvm/hotspot/oops/DataLayout.java @ 6972:bd7a7ce2e264
6830717: replay of compilations would help with debugging
Summary: When java process crashed in compiler thread, repeat the compilation process will help finding root cause. This is done with using SA dump application class data and replay data from core dump, then use debug version of jvm to recompile the problematic java method.
Reviewed-by: kvn, twisti, sspitsyn
Contributed-by: yumin.qi@oracle.com
author | minqi |
---|---|
date | Mon, 12 Nov 2012 14:03:53 -0800 |
parents | da91efe96a93 |
children |
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/* * Copyright (c) 2011, 2012, 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.oops; import java.io.*; import java.util.*; import sun.jvm.hotspot.debugger.*; import sun.jvm.hotspot.runtime.*; import sun.jvm.hotspot.types.*; import sun.jvm.hotspot.utilities.*; public class DataLayout { public static final int noTag = 0; public static final int bitDataTag = 1; public static final int counterDataTag = 2; public static final int jumpDataTag= 3; public static final int receiverTypeDataTag = 4; public static final int virtualCallDataTag = 5; public static final int retDataTag = 6; public static final int branchDataTag = 7; public static final int multiBranchDataTag = 8; // The _struct._flags word is formatted as [trapState:4 | flags:4]. // The trap state breaks down further as [recompile:1 | reason:3]. // This further breakdown is defined in deoptimization.cpp. // See Deoptimization.trapStateReason for an assert that // trapBits is big enough to hold reasons < reasonRecordedLimit. // // The trapState is collected only if ProfileTraps is true. public static final int trapBits = 1+3; // 3: enough to distinguish [0..reasonRecordedLimit]. public static final int trapShift = 8 - trapBits; public static final int trapMask = Bits.rightNBits(trapBits); public static final int trapMaskInPlace = (trapMask << trapShift); public static final int flagLimit = trapShift; public static final int flagMask = Bits.rightNBits(flagLimit); public static final int firstFlag = 0; private Address data; private int offset; private boolean handlized; public DataLayout(MethodData d, int o) { data = d.getAddress(); offset = o; } public DataLayout(Address d, int o) { data = d; offset = o; handlized = true; } public int dp() { return offset; } private int getU11(int at) { return data.getJByteAt(offset + at) & 0xff; } private int getU22(int at) { return data.getJShortAt(offset + at) & 0xffff; } int cellAt(int index) { // Cells are intptr_t sized but only contain ints as raw values return (int)data.getCIntegerAt(offset + cellOffset(index), MethodData.cellSize, false); } public Address addressAt(int index) { OopHandle handle; if (handlized) { return data.getAddressAt(offset + cellOffset(index)); } else { return data.getOopHandleAt(offset + cellOffset(index)); } } // Every data layout begins with a header. This header // contains a tag, which is used to indicate the size/layout // of the data, 4 bits of flags, which can be used in any way, // 4 bits of trap history (none/one reason/many reasons), // and a bci, which is used to tie this piece of data to a // specific bci in the bytecodes. // union { // intptrT _bits; // struct { // u1 _tag; // u1 _flags; // u2 _bci; // } _struct; // } _header; // Some types of data layouts need a length field. static boolean needsArrayLen(int tag) { return (tag == multiBranchDataTag); } public static final int counterIncrement = 1; // Size computation static int headerSizeInBytes() { return MethodData.cellSize; } static int headerSizeInCells() { return 1; } static int computeSizeInBytes(int cellCount) { return headerSizeInBytes() + cellCount * MethodData.cellSize; } // Initialization // void initialize(int tag, int bci, int cellCount); // Accessors public int tag() { return getU11(0); } // Return a few bits of trap state. Range is [0..trapMask]. // The state tells if traps with zero, one, or many reasons have occurred. // It also tells whether zero or many recompilations have occurred. // The associated trap histogram in the MDO itself tells whether // traps are common or not. If a BCI shows that a trap X has // occurred, and the MDO shows N occurrences of X, we make the // simplifying assumption that all N occurrences can be blamed // on that BCI. int trapState() { return (flags() >> trapShift) & trapMask; } int flags() { return getU11(1); } int bci() { return getU22(2); } boolean flagAt(int flagNumber) { // assert(flagNumber < flagLimit, "oob"); return (flags() & (0x1 << flagNumber)) != 0; } // Low-level support for code generation. static int headerOffset() { return 0; } static int tagOffset() { return 0; } static int flagsOffset() { return 1; } static int bciOffset() { return 2; } public static int cellOffset(int index) { return MethodData.cellSize + index * MethodData.cellSize; } // // Return a value which, when or-ed as a byte into _flags, sets the flag. // static int flagNumberToByteConstant(int flagNumber) { // assert(0 <= flagNumber && flagNumber < flagLimit, "oob"); // DataLayout temp; temp.setHeader(0); // temp.setFlagAt(flagNumber); // return temp._header._struct._flags; // } // // Return a value which, when or-ed as a word into _header, sets the flag. // static intptrT flagMaskToHeaderMask(int byteConstant) { // DataLayout temp; temp.setHeader(0); // temp._header._struct._flags = byteConstant; // return temp._header._bits; // } }