/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 Justine Alexandra Roberts Tunney                              │
│                                                                              │
│ Permission to use, copy, modify, and/or distribute this software for         │
│ any purpose with or without fee is hereby granted, provided that the         │
│ above copyright notice and this permission notice appear in all copies.      │
│                                                                              │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
│ PERFORMANCE OF THIS SOFTWARE.                                                │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/errno.h"
#include "libc/thread/thread.h"
#include "third_party/nsync/counter.h"

/**
 * Initializes barrier.
 *
 * @param attr may be null
 * @param count is how many threads need to call pthread_barrier_wait()
 *     before the barrier is released, which must be greater than zero
 * @return 0 on success, or error number on failure
 * @raise EINVAL if `count` isn't greater than zero
 * @raise ENOMEM if insufficient memory exists
 */
int pthread_barrier_init(pthread_barrier_t *barrier,
                         const pthread_barrierattr_t *attr, unsigned count) {
  nsync_counter c;
  if (!count) return EINVAL;
  if (!(c = nsync_counter_new(count))) return ENOMEM;
  *barrier = (pthread_barrier_t){._nsync = c};
  return 0;
}
