view src/share/vm/runtime/serviceThread.hpp @ 3293:1f4413413144

7039089: G1: changeset for 7037276 broke heap verification, and related cleanups Summary: In G1 heap verification, we no longer scan perm to G1-collected heap refs as part of process_strong_roots() but rather in a separate explicit oop iteration over the perm gen. This preserves the original perm card-marks. Added a new assertion in younger_refs_iterate() to catch a simple subcase where the user may have forgotten a prior save_marks() call, as happened in the case of G1's attempt to iterate perm to G1 refs when verifying the heap before exit. The assert was deliberately weakened for ParNew+CMS and will be fixed for that combination in a future CR. Also made some (non-G1) cleanups related to code and comments obsoleted by the migration of Symbols to the native heap. Reviewed-by: iveresov, jmasa, tonyp
author ysr
date Tue, 26 Apr 2011 21:17:24 -0700
parents bf8517f4e4d0
children
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/*
 * Copyright (c) 2011, 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_RUNTIME_SERVICETHREAD_HPP
#define SHARE_VM_RUNTIME_SERVICETHREAD_HPP

#include "runtime/thread.hpp"

// A JavaThread for low memory detection support and JVMTI
// compiled-method-load events.
class ServiceThread : public JavaThread {
  friend class VMStructs;
 private:

  static ServiceThread* _instance;

  static void service_thread_entry(JavaThread* thread, TRAPS);
  ServiceThread(ThreadFunction entry_point) : JavaThread(entry_point) {};

 public:
  static void initialize();

  // Hide this thread from external view.
  bool is_hidden_from_external_view() const      { return true; }

  // Returns true if the passed thread is the service thread.
  static bool is_service_thread(Thread* thread);
};

#endif // SHARE_VM_RUNTIME_SERVICETHREAD_HPP