1 /*
   2  * Copyright (c) 2019, 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 OS_LINUX_WAITBARRIER_LINUX_HPP
  26 #define OS_LINUX_WAITBARRIER_LINUX_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 
  30 class LinuxWaitBarrier : public CHeapObj<mtInternal> {
  31   volatile int _futex_barrier;
  32 
  33   // Prevent copying and assignment of LinuxWaitBarrier instances.
  34   LinuxWaitBarrier(const LinuxWaitBarrier&);
  35   LinuxWaitBarrier& operator=(const LinuxWaitBarrier&);
  36 
  37  public:
  38   LinuxWaitBarrier() : _futex_barrier(0) {};
  39   ~LinuxWaitBarrier() {};
  40 
  41   const char* description() { return "futex"; }
  42 
  43   void arm(int barrier_tag);
  44   void disarm();
  45   void wait(int barrier_tag);
  46 };
  47 
  48 #endif // OS_LINUX_WAITBARRIER_LINUX_HPP