/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-â
âvi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :viâ
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â Copyright 2020 Justine Alexandra Roberts Tunney                              â
â                                                                              â
â Permission to use, copy, modify, and/or distribute this software for         â
â any purpose with or without fee is hereby granted, provided that the         â
â above copyright notice and this permission notice appear in all copies.      â
â                                                                              â
â THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                â
â WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                â
â WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             â
â AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         â
â DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        â
â PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               â
â TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             â
â PERFORMANCE OF THIS SOFTWARE.                                                â
ââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââ*/
#include "libc/calls/wait4.h"
#include "libc/calls/calls.h"
#include "libc/calls/cp.internal.h"
#include "libc/calls/struct/rusage.internal.h"
#include "libc/dce.h"
#include "libc/intrin/asan.internal.h"
#include "libc/intrin/strace.internal.h"
#include "libc/sysv/errfuns.h"

/**
 * Waits for status to change on process.
 *
 * @param pid >0 targets specific process, =0 means any proc in a group,
 *     -1 means any child process, <-1 means any proc in specific group
 * @param opt_out_wstatus optionally returns status code, and *wstatus
 *     may be inspected using WEEXITSTATUS(), etc.
 * @param options can have WNOHANG, WUNTRACED, WCONTINUED, etc.
 * @param opt_out_rusage optionally returns accounting data
 * @return process id of terminated child or -1 w/ errno
 * @cancellationpoint
 * @asyncsignalsafe
 * @restartable
 */
int wait4(int pid, int *opt_out_wstatus, int options,
          struct rusage *opt_out_rusage) {
  int rc, ws = 0;
  BEGIN_CANCELLATION_POINT;

  if (IsAsan() &&
      ((opt_out_wstatus &&
        !__asan_is_valid(opt_out_wstatus, sizeof(*opt_out_wstatus))) ||
       (opt_out_rusage &&
        !__asan_is_valid(opt_out_rusage, sizeof(*opt_out_rusage))))) {
    rc = efault();
  } else if (!IsWindows()) {
    rc = sys_wait4(pid, &ws, options, opt_out_rusage);
  } else {
    rc = sys_wait4_nt(pid, &ws, options, opt_out_rusage);
  }
  if (rc != -1 && opt_out_wstatus) *opt_out_wstatus = ws;

  END_CANCELLATION_POINT;
  STRACE("wait4(%d, [%#x], %d, %p) â %d% m", pid, ws, options, opt_out_rusage,
         rc);
  return rc;
}
