Mercurial > hg > truffle
view agent/src/share/classes/sun/jvm/hotspot/runtime/StackFrameStream.java @ 19491:4d66c000d253
Truffle/Instrumentation: more cleanup in Probe
author | Michael Van De Vanter <michael.van.de.vanter@oracle.com> |
---|---|
date | Wed, 18 Feb 2015 18:30:49 -0800 |
parents | c18cbe5936b8 |
children |
line wrap: on
line source
/* * Copyright (c) 2000, 2004, 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.runtime; import sun.jvm.hotspot.utilities.*; /** <P> StackFrameStream iterates through the frames of a thread starting from top most frame. It automatically takes care of updating the location of all (callee-saved) registers. Notice: If a thread is stopped at a safepoint, all registers are saved, not only the callee-saved ones. </P> <P> Use: </P> <PRE> for(StackFrameStream fst = new StackFrameStream(thread); !fst.isDone(); fst.next()) { ... } </PRE> */ public class StackFrameStream { private Frame fr; private RegisterMap regMap; private boolean isDone; /** Equivalent to StackFrameStream(thread, true) */ public StackFrameStream(JavaThread thread) { this(thread, true); } public StackFrameStream(JavaThread thread, boolean update) { if (!VM.getVM().isDebugging()) { if (Assert.ASSERTS_ENABLED) { Assert.that(thread.hasLastJavaFrame(), "sanity check"); } fr = thread.getLastFrame(); regMap = thread.newRegisterMap(update); isDone = false; } else { // Special case code to find the topmost Java frame // FIXME: should check to see whether we're at safepoint, and if // so, skip the "current frame guess" call and unnecessary // stackwalking work fr = thread.getCurrentFrameGuess(); regMap = thread.newRegisterMap(update); while ((fr != null) && (!fr.isJavaFrame())) { if (fr.isFirstFrame()) { fr = null; } else { fr = fr.sender(regMap); } } if (fr == null) { isDone = true; } } } /** Iteration */ public boolean isDone() { if (isDone) { return true; } else { if (fr == null) { isDone = true; return true; } isDone = fr.isFirstFrame(); return false; } } public void next() { if (!isDone) { fr = fr.sender(regMap); } } /** Query */ public Frame getCurrent() { return fr; } public RegisterMap getRegisterMap() { return regMap; } }