/*

 * Copyright (c) 2015, 2017, 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/z/zCPU.hpp"

#include "logging/log.hpp"

#include "memory/padded.inline.hpp"

#include "runtime/os.hpp"

#include "runtime/thread.inline.hpp"

#include "utilities/debug.hpp"

#define ZCPU_UNKNOWN_AFFINITY (Thread*)-1;

#define ZCPU_UNKNOWN_SELF     (Thread*)-2;

PaddedEnd<ZCPU::ZCPUAffinity>* ZCPU::_affinity = NULL;

__thread Thread*  ZCPU::_self                  = ZCPU_UNKNOWN_SELF;

__thread uint32_t ZCPU::_cpu                   = 0;

void ZCPU::initialize() {

  assert(_affinity == NULL, "Already initialized");

  const uint32_t ncpus = count();

  _affinity = PaddedArray<ZCPUAffinity, mtGC>::create_unfreeable(ncpus);

  for (uint32_t i = 0; i < ncpus; i++) {

    _affinity[i]._thread = ZCPU_UNKNOWN_AFFINITY;

  }

  log_info(gc, init)("CPUs: %u total, %u available",

                     os::processor_count(),

                     os::initial_active_processor_count());

}

uint32_t ZCPU::count() {

  return os::processor_count();

}

uint32_t ZCPU::id() {

  assert(_affinity != NULL, "Not initialized");

  // Fast path

  if (_affinity[_cpu]._thread == _self) {

    return _cpu;

  }

  // Slow path

  _self = Thread::current();

  _cpu = os::processor_id();

  // Update affinity table

  _affinity[_cpu]._thread = _self;

  return _cpu;

}