cosmopolitan/libc/thread/pthread_attr_setsigmask_np.c

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et 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.      │
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│ 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/str/str.h"
#include "libc/thread/thread2.h"

/**
 * Sets signal mask on thread attributes object.
 *
 * For example, to spawn a thread that won't interfere with signals:
 *
 *     pthread_t id;
 *     sigset_t mask;
 *     pthread_attr_t attr;
 *     sigfillset(&mask);
 *     pthread_attr_init(&attr);
 *     pthread_attr_setsigmask_np(&attr, &mask);
 *     pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 *     pthread_create(&id, &attr, Worker, 0);
 *     pthread_attr_destroy(&attr);
 *
 * @param attr is the thread attributes object
 * @param sigmask will be copied into attributes, or if it's null, then
 *     the existing signal mask presence on the object will be cleared
 * @return 0 on success, or errno on error
 */
errno_t pthread_attr_setsigmask_np(pthread_attr_t *attr,
                                   const sigset_t *sigmask) {
  _Static_assert(sizeof(attr->__sigmask) == sizeof(*sigmask), "");
  if (sigmask) {
    attr->__havesigmask = true;
    attr->__sigmask = *sigmask;
  } else {
    attr->__havesigmask = false;
  }
  return 0;
}