/*
 * Copyright (c) 1997, 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.
 *
 */

#include "precompiled.hpp"
#include "gc/shared/barrierSet.hpp"
#include "gc/shared/barrierSetAssembler.hpp"
#include "runtime/thread.hpp"
#include "utilities/macros.hpp"

BarrierSet* BarrierSet::_barrier_set = NULL;

class SetBarrierSetNonJavaThread : public ThreadClosure {
  BarrierSet* _barrier_set;
  size_t _count;

public:
  SetBarrierSetNonJavaThread(BarrierSet* barrier_set) :
    _barrier_set(barrier_set), _count(0) {}

  virtual void do_thread(Thread* thread) {
    _barrier_set->on_thread_create(thread);
    ++_count;
  }

  size_t count() const { return _count; }
};

void BarrierSet::set_barrier_set(BarrierSet* barrier_set) {
  assert(_barrier_set == NULL, "Already initialized");
  _barrier_set = barrier_set;

  // Some threads are created before the barrier set, so the call to
  // BarrierSet::on_thread_create had to be deferred for them.  Now that
  // we have the barrier set, do those deferred calls.

  // First do any non-JavaThreads.
  SetBarrierSetNonJavaThread njt_closure(_barrier_set);
  Threads::non_java_threads_do(&njt_closure);

  // Do the current (main) thread.  Ensure it's the one and only
  // JavaThread so far.  Also verify that it isn't yet on the thread
  // list, else we'd also need to call BarrierSet::on_thread_attach.
  assert(Thread::current()->is_Java_thread(),
         "Expected main thread to be a JavaThread");
  assert((njt_closure.count() + 1) == Threads::threads_before_barrier_set(),
         "Unexpected JavaThreads before barrier set initialization: "
         "Non-JavaThreads: " SIZE_FORMAT ", all: " SIZE_FORMAT,
         njt_closure.count(), Threads::threads_before_barrier_set());
  assert(!JavaThread::current()->on_thread_list(),
         "Main thread already on thread list.");
  _barrier_set->on_thread_create(Thread::current());
}

// Called from init.cpp
void gc_barrier_stubs_init() {
  BarrierSet* bs = BarrierSet::barrier_set();
#ifndef ZERO
  BarrierSetAssembler* bs_assembler = bs->barrier_set_assembler();
  bs_assembler->barrier_stubs_init();
#endif
}