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// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2018 Google Inc. All rights reserved.
// http://ceres-solver.org/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// 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.
// * Neither the name of Google Inc. nor the names of its contributors may be
// used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// Author: vitus@google.com (Michael Vitus)
// This include must come before any #ifndef check on Ceres compile options.
#include "ceres/internal/config.h"
#if defined(CERES_USE_OPENMP)
#include "ceres/parallel_for.h"
#include "ceres/scoped_thread_token.h"
#include "ceres/thread_token_provider.h"
#include "glog/logging.h"
#include "omp.h"
namespace ceres {
namespace internal {
int MaxNumThreadsAvailable() { return omp_get_max_threads(); }
void ParallelFor(ContextImpl* context,
int start,
int end,
int num_threads,
const std::function<void(int)>& function) {
CHECK_GT(num_threads, 0);
CHECK(context != nullptr);
if (end <= start) {
return;
}
#ifdef CERES_USE_OPENMP
#pragma omp parallel for num_threads(num_threads) \
schedule(dynamic) if (num_threads > 1)
#endif // CERES_USE_OPENMP
for (int i = start; i < end; ++i) {
function(i);
}
}
void ParallelFor(ContextImpl* context,
int start,
int end,
int num_threads,
const std::function<void(int thread_id, int i)>& function) {
CHECK(context != nullptr);
ThreadTokenProvider thread_token_provider(num_threads);
ParallelFor(context, start, end, num_threads, [&](int i) {
const ScopedThreadToken scoped_thread_token(&thread_token_provider);
const int thread_id = scoped_thread_token.token();
function(thread_id, i);
});
}
} // namespace internal
} // namespace ceres
#endif // defined(CERES_USE_OPENMP)