/*

 * Copyright (c) 2018, 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_UTILITIES_GLOBAL_COUNTER_INLINE_HPP

#define SHARE_UTILITIES_GLOBAL_COUNTER_INLINE_HPP

#include "runtime/thread.inline.hpp"

#include "utilities/globalCounter.hpp"

inline void GlobalCounter::critical_section_begin(Thread *thread) {

  assert(thread == Thread::current(), "must be current thread");

  assert(thread->is_VM_thread() || thread->is_Java_thread(), "must be VMThread or JavaThread");

  assert((*thread->get_rcu_counter() & COUNTER_ACTIVE) == 0x0, "nestled critical sections, not supported yet");

  uintx gbl_cnt = OrderAccess::load_acquire(&_global_counter._counter);

  OrderAccess::release_store_fence(thread->get_rcu_counter(), gbl_cnt | COUNTER_ACTIVE);

}

inline void GlobalCounter::critical_section_end(Thread *thread) {

  assert(thread == Thread::current(), "must be current thread");

  assert(thread->is_VM_thread() || thread->is_Java_thread(), "must be VMThread or JavaThread");

  assert((*thread->get_rcu_counter() & COUNTER_ACTIVE) == COUNTER_ACTIVE, "must be in ctitical section");

  // Mainly for debugging we set it to 'now'.

  uintx gbl_cnt = OrderAccess::load_acquire(&_global_counter._counter);

  OrderAccess::release_store(thread->get_rcu_counter(), gbl_cnt);

}

class GlobalCounter::CriticalSection {

 private:

  Thread* _thread;

 public:

  inline CriticalSection(Thread* thread) : _thread(thread) {

    GlobalCounter::critical_section_begin(_thread);

  }

  inline  ~CriticalSection() {

    GlobalCounter::critical_section_end(_thread);

  }

};

#endif // include guard