1 /*
   2  * Copyright (c) 2001, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef _MONITOR_
  26 #define _MONITOR_
  27 
  28 #include <windows.h>
  29 
  30 class Monitor {
  31 public:
  32   Monitor();
  33   ~Monitor();
  34 
  35   void lock();
  36   void unlock();
  37   // Default time is forever (i.e, zero). Returns true if it times-out, otherwise
  38   // false.
  39   bool wait(long timeout = 0);
  40   bool notify();
  41   bool notifyAll();
  42 
  43 private:
  44   HANDLE owner();
  45   void setOwner(HANDLE owner);
  46   bool ownedBySelf();
  47 
  48   HANDLE _owner;
  49   long   _lock_count;
  50   HANDLE _lock_event;   // Auto-reset event for blocking in lock()
  51   HANDLE _wait_event;   // Manual-reset event for notifications
  52   long _counter;        // Current number of notifications
  53   long _waiters;        // Number of threads waiting for notification
  54   long _tickets;        // Number of waiters to be notified
  55 };
  56 
  57 
  58 #endif  // #defined _MONITOR_