// SPDX-License-Identifier: Apache-2.0
//
// Copyright 2008-2016 Conrad Sanderson (http://conradsanderson.id.au)
// Copyright 2008-2016 National ICT Australia (NICTA)
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ------------------------------------------------------------------------

//! \addtogroup mp_misc
//! @{

template <typename eT, const bool use_smaller_thresh = false>
struct mp_gate {
  arma_inline static bool eval(const uword n_elem) {
#if defined(ARMA_USE_OPENMP)
    {
      const bool length_ok = (is_cx<eT>::yes || use_smaller_thresh)
                                 ? (n_elem >= (arma_config::mp_threshold / uword(2)))
                                 : (n_elem >= arma_config::mp_threshold);

      if (length_ok) {
        if (omp_in_parallel()) {
          return false;
        }
      }

      return length_ok;
    }
#else
    {
      arma_ignore(n_elem);

      return false;
    }
#endif
  }
};

struct mp_thread_limit {
  arma_inline static int get() {
#if defined(ARMA_USE_OPENMP)
    int n_threads = (std::min)(int(arma_config::mp_threads),
                               int((std::max)(int(1), int(omp_get_max_threads()))));
#else
    int n_threads = int(1);
#endif

    return n_threads;
  }

  arma_inline static bool in_parallel() {
#if defined(ARMA_USE_OPENMP)
    { return bool(omp_in_parallel()); }
#else
    { return false; }
#endif
  }
};

//! @}
