view src/share/vm/memory/genMarkSweep.hpp @ 12301:2c022e432e10

8024974: Incorrect use of GC_locker::is_active() Summary: SymbolTable and StringTable can make calls to GC_locker::is_active() outside a safepoint. This isn't safe because the GC_locker active state (lock count) is only updated at a safepoint and only remains valid as long as _needs_gc is true. However, outside a safepoint_needs_gc can change to false at any time, which makes it impossible to do a correct call to is_active() in that context. In this case these calls can just be removed since the input argument to basic_add() should never be on the heap and so there's no need to check the GC_locker state. This change also adjusts the assert() in is_active() to makes sure all calls to this function are always done under a safepoint. Reviewed-by: brutisso, dcubed Contributed-by: per.liden@oracle.com
author stefank
date Fri, 20 Sep 2013 10:53:28 +0200
parents f95d63e2154a
children
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/*
 * Copyright (c) 2001, 2010, 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.
 *
 */

#ifndef SHARE_VM_MEMORY_GENMARKSWEEP_HPP
#define SHARE_VM_MEMORY_GENMARKSWEEP_HPP

#include "gc_implementation/shared/markSweep.hpp"

class GenMarkSweep : public MarkSweep {
  friend class VM_MarkSweep;
  friend class G1MarkSweep;
 public:
  static void invoke_at_safepoint(int level, ReferenceProcessor* rp,
                                  bool clear_all_softrefs);

 private:

  // Mark live objects
  static void mark_sweep_phase1(int level, bool clear_all_softrefs);
  // Calculate new addresses
  static void mark_sweep_phase2();
  // Update pointers
  static void mark_sweep_phase3(int level);
  // Move objects to new positions
  static void mark_sweep_phase4();

  // Temporary data structures for traversal and storing/restoring marks
  static void allocate_stacks();
  static void deallocate_stacks();
};

#endif // SHARE_VM_MEMORY_GENMARKSWEEP_HPP