text: /** Lock-free Multiple-Producer Multiple-consumer (MPMC) queue.
   *
   * Based on Dmitry Vyukov#s Bounded MPMC queue:
   *   http://www.1024cores.net/home/lock-free-algorithms/queues/bounded-mpmc-queue
   *
   * @author Steffen Vogel <post@steffenvogel.de>
   * @copyright 2016 Steffen Vogel
   * @copyright 2017 Imperial College London
   * @license BSD 2-Clause License
   * 
   * All rights reserved.
   * 
   * Redistribution and use in source and binary forms, with or without
   * modiffication, 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.
   * 
   * 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 HOLDER 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.
   */
  #ifndef MPMC_QUEUE_H
  #define MPMC_QUEUE_H
  
  struct cell_t {
      size_t seq;
      void *data;
  };
  
  struct mpmcq {
      char pad0[128];
      struct cell_t *buffer;
      size_t buffer_mask;
      char pad1[128];
      size_t enqueue_pos;
      char pad2[128];
      size_t dequeue_pos;
      char pad3[128];
  }  __attribute__((aligned(64)));
  
  
  
  int mpmc_enqueue(volatile struct mpmcq *q, void *data);
  int newmpmcq(struct mpmcq *q,  size_t buffer_bytesize, void *buffer);
  int mpmc_dequeue(volatile struct mpmcq *q, void **data);
  
  #endif /* MPMC_QUEUE_H */
  