Quellcode-Bibliothek

^© Kompilation durch diese Firma

[Weder Korrektheit noch Funktionsfähigkeit der Software werden zugesichert.]

Datei: spinYield.hpp Sprache: C

/*
* 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_SPINYIELD_HPP
#define SHARE_UTILITIES_SPINYIELD_HPP

#include "memory/allocation.hpp"
#include "utilities/globalDefinitions.hpp"
#include "utilities/ticks.hpp"

class outputStream;

extern "C" int SpinPause();

class SpinYield : public StackObj {
  Tickspan _sleep_time;
  uint _spins;
  uint _yields;
  uint _spin_limit;
  uint _yield_limit;
  uint _sleep_ns;

  void yield_or_sleep();

public:
  static const uint default_spin_limit = 4096;
  static const uint default_yield_limit = 64;
  static const uint default_sleep_ns = 1000;

  // spin_limit is ignored (treated as zero) when !os::is_MP().
  explicit SpinYield(uint spin_limit = default_spin_limit,
                     uint yield_limit = default_yield_limit,
                     uint sleep_ns = default_sleep_ns);

  // Perform next round of delay.
  void wait() {
    // Simple policy: return immediately (spinning) configured number
    // of times, then switch to yield/sleep.  Future work might
    // provide other policies, such as (1) always spin if system is
    // not saturated, or (2) sleeping if yielding is ineffective.
    if (_spins < _spin_limit) {
      ++_spins;
      SpinPause();
    } else {
      yield_or_sleep();
    }
  }

  // Write information about the wait duration to s.
  void report(outputStream* s) const;
};

#endif // SHARE_UTILITIES_SPINYIELD_HPP

¤ Dauer der Verarbeitung: 0.15 Sekunden (vorverarbeitet) ¤

Download des Quellennavigators
Download des sprechenden Kalenders
in der Quellcodebibliothek suchen

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.