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view agent/src/share/classes/sun/jvm/hotspot/utilities/MarkBits.java @ 17716:cdb71841f4bc
6498581: ThreadInterruptTest3 produces wrong output on Windows
Summary: There is race condition between os::interrupt and os::is_interrupted on Windows. In JVM_Sleep(Thread.sleep), check if thread gets interrupted, it may see interrupted but not really interrupted so cause spurious waking up (early return from sleep). Fix by checking if interrupt event really gets set thus prevent false return. For intrinsic of _isInterrupted, on Windows, go fastpath only on bit not set.
Reviewed-by: acorn, kvn
Contributed-by: david.holmes@oracle.com, yumin.qi@oracle.com
author | minqi |
---|---|
date | Wed, 26 Feb 2014 15:20:41 -0800 |
parents | c18cbe5936b8 |
children |
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/* * Copyright (c) 2001, 2003, 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.utilities; import sun.jvm.hotspot.debugger.*; import sun.jvm.hotspot.gc_interface.*; import sun.jvm.hotspot.memory.*; import sun.jvm.hotspot.oops.*; import sun.jvm.hotspot.runtime.*; /** Helper class which covers the reserved area of the heap with an (object-external) set of mark bits, used for GC-like scans through the heap like liveness analysis. */ public class MarkBits { public MarkBits(CollectedHeap heap) { MemRegion reserved = heap.reservedRegion(); // Must cover "reserved" with one bit for each OopHandle start = reserved.start(); end = reserved.end(); long numOopHandles = end.minus(start) / VM.getVM().getOopSize(); // FIXME: will have trouble with larger heap sizes bits = new BitMap((int) numOopHandles); } public void clear() { bits.clear(); } /** Returns true if a mark was newly placed for the given Oop, or false if the Oop was already marked. If the Oop happens to lie outside the heap (should not happen), prints a warning and returns false. */ public boolean mark(Oop obj) { if (obj == null) { System.err.println("MarkBits: WARNING: null object, ignoring"); return false; } OopHandle handle = obj.getHandle(); // FIXME: will have trouble with larger heap sizes long idx = handle.minus(start) / VM.getVM().getOopSize(); if ((idx < 0) || (idx >= bits.size())) { System.err.println("MarkBits: WARNING: object " + handle + " outside of heap, ignoring"); return false; } int intIdx = (int) idx; if (bits.at(intIdx)) { return false; // already marked } bits.atPut(intIdx, true); return true; } /** Forces clearing of a given mark bit. */ public void clear(Oop obj) { OopHandle handle = obj.getHandle(); // FIXME: will have trouble with larger heap sizes long idx = handle.minus(start) / VM.getVM().getOopSize(); if ((idx < 0) || (idx >= bits.size())) { System.err.println("MarkBits: WARNING: object " + handle + " outside of heap, ignoring"); return; } int intIdx = (int) idx; bits.atPut(intIdx, false); } private BitMap bits; private Address start; private Address end; }