glibc/sysdeps/posix/sigwait.c
Paul Eggert 581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00

100 lines
2.7 KiB
C

/* Implementation of sigwait function from POSIX.1c.
Copyright (C) 1996-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <signal.h>
#include <stddef.h> /* For NULL. */
#include <sysdep-cancel.h>
/* This is our dummy signal handler we use here. */
static void ignore_signal (int sig);
/* Place where to remember which signal we got. Please note that this
implementation cannot be used for the threaded libc. The
libpthread must provide an own version. */
static int was_sig;
static int
do_sigwait (const sigset_t *set, int *sig)
{
sigset_t tmp_mask;
struct sigaction saved[NSIG];
struct sigaction action;
int save_errno;
int this;
/* Prepare set. */
__sigfillset (&tmp_mask);
/* Unblock all signals in the SET and register our nice handler. */
action.sa_handler = ignore_signal;
action.sa_flags = 0;
__sigfillset (&action.sa_mask); /* Block all signals for handler. */
/* Make sure we recognize error conditions by setting WAS_SIG to a
value which does not describe a legal signal number. */
was_sig = -1;
for (this = 1; this < NSIG; ++this)
if (__sigismember (set, this))
{
/* Unblock this signal. */
__sigdelset (&tmp_mask, this);
/* Register temporary action handler. */
if (__sigaction (this, &action, &saved[this]) != 0)
goto restore_handler;
}
/* Now we can wait for signals. */
__sigsuspend (&tmp_mask);
restore_handler:
save_errno = errno;
while (--this >= 1)
if (__sigismember (set, this))
/* We ignore errors here since we must restore all handlers. */
__sigaction (this, &saved[this], NULL);
__set_errno (save_errno);
/* Store the result and return. */
*sig = was_sig;
return was_sig == -1 ? -1 : 0;
}
int
__sigwait (const sigset_t *set, int *sig)
{
/* __sigsuspend should be a cancellation point. */
return do_sigitid (idtype, id, infop, options);
}
libc_hidden_def (__sigwait)
weak_alias (__sigwait, sigwait)
static void
ignore_signal (int sig)
{
/* Remember the signal. */
was_sig = sig;
}