spin_until_impl.hpp

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/*
 * Copyright (c) 2014-2015, Hewlett-Packard Development Company, LP.
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This program 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 for
 * more details. You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * HP designates this particular file as subject to the "Classpath" exception
 * as provided by HP in the LICENSE.txt file that accompanied this code.
 */
#ifndef FOEDUS_ASSORTED_SPIN_UNTIL_IMPL_HPP_
#define FOEDUS_ASSORTED_SPIN_UNTIL_IMPL_HPP_

#include "foedus/assorted/assorted_func.hpp"
#include "foedus/debugging/rdtsc_watch.hpp"

namespace foedus {
namespace assorted {

bool is_running_on_valgrind();

template <typename COND>
inline uint64_t spin_until(COND spin_until_cond) {
  debugging::RdtscWatch watch;

  const bool on_valgrind = is_running_on_valgrind();
  while (!spin_until_cond()) {
    // Valgrind never switches context without this.
    // This if should have a negligible overhead.
    if (on_valgrind) {
      assorted::spinlock_yield();
    }
  }

  watch.stop();
  return watch.elapsed();
}

inline void yield_if_valgrind() {
  const bool on_valgrind = is_running_on_valgrind();
  if (on_valgrind) {
    assorted::spinlock_yield();
  }
}

}  // namespace assorted
}  // namespace foedus

#endif  // FOEDUS_ASSORTED_SPIN_UNTIL_IMPL_HPP_