view agent/src/os/win32/Monitor.hpp @ 1994:6cd6d394f280

7001033: assert(gch->gc_cause() == GCCause::_scavenge_alot || !gch->incremental_collection_failed()) 7002546: regression on SpecJbb2005 on 7b118 comparing to 7b117 on small heaps Summary: Relaxed assertion checking related to incremental_collection_failed flag to allow for ExplicitGCInvokesConcurrent behaviour where we do not want a failing scavenge to bail to a stop-world collection. Parameterized incremental_collection_will_fail() so we can selectively use, or not use, as appropriate, the statistical prediction at specific use sites. This essentially reverts the scavenge bail-out logic to what it was prior to some recent changes that had inadvertently started using the statistical prediction which can be noisy in the presence of bursty loads. Added some associated verbose non-product debugging messages. Reviewed-by: johnc, tonyp
author ysr
date Tue, 07 Dec 2010 21:55:53 -0800
parents c18cbe5936b8
children
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/*
 * Copyright (c) 2001, 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 _MONITOR_
#define _MONITOR_

#include <windows.h>

class Monitor {
public:
  Monitor();
  ~Monitor();

  void lock();
  void unlock();
  // Default time is forever (i.e, zero). Returns true if it times-out, otherwise
  // false.
  bool wait(long timeout = 0);
  bool notify();
  bool notifyAll();

private:
  HANDLE owner();
  void setOwner(HANDLE owner);
  bool ownedBySelf();

  HANDLE _owner;
  long   _lock_count;
  HANDLE _lock_event;   // Auto-reset event for blocking in lock()
  HANDLE _wait_event;   // Manual-reset event for notifications
  long _counter;        // Current number of notifications
  long _waiters;        // Number of threads waiting for notification
  long _tickets;        // Number of waiters to be notified
};


#endif  // #defined _MONITOR_