ceres-solver/internal/ceres/thread_token_provider.cc

// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2017 Google Inc. All rights reserved.
// http://ceres-solver.org/
//
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// modification, are permitted provided that the following conditions are met:
//
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//   this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
//   this list of conditions and the following disclaimer in the documentation
//   and/or other materials provided with the distribution.
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//   used to endorse or promote products derived from this software without
//   specific prior written permission.
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// Author: yp@photonscore.de (Yury Prokazov)

#include "ceres/thread_token_provider.h"

#ifdef CERES_USE_OPENMP
#include <omp.h>
#endif

namespace ceres {
namespace internal {

ThreadTokenProvider::ThreadTokenProvider(int num_threads) {
  (void)num_threads;
#ifdef CERES_USE_CXX_THREADS
  for (int i = 0; i < num_threads; i++) {
    pool_.Push(i);
  }
#endif

}

int ThreadTokenProvider::Acquire() {
#ifdef CERES_USE_OPENMP
  return omp_get_thread_num();
#endif

#ifdef CERES_NO_THREADS
  return 0;
#endif

#ifdef CERES_USE_CXX_THREADS
  int thread_id;
  CHECK(pool_.Wait(&thread_id));
  return thread_id;
#endif

}

void ThreadTokenProvider::Release(int thread_id) {
  (void)thread_id;
#ifdef CERES_USE_CXX_THREADS
  pool_.Push(thread_id);
#endif

}

}  // namespace internal
}  // namespace ceres