glibc/sysdeps/posix/sigwait.c
Siddhesh Poyarekar 30891f35fa Remove "Contributed by" lines
We stopped adding "Contributed by" or similar lines in sources in 2012
in favour of git logs and keeping the Contributors section of the
glibc manual up to date.  Removing these lines makes the license
header a bit more consistent across files and also removes the
possibility of error in attribution when license blocks or files are
copied across since the contributed-by lines don't actually reflect
reality in those cases.

Move all "Contributed by" and similar lines (Written by, Test by,
etc.) into a new file CONTRIBUTED-BY to retain record of these
contributions.  These contributors are also mentioned in
manual/contrib.texi, so we just maintain this additional record as a
courtesy to the earlier developers.

The following scripts were used to filter a list of files to edit in
place and to clean up the CONTRIBUTED-BY file respectively.  These
were not added to the glibc sources because they're not expected to be
of any use in future given that this is a one time task:

https://gist.github.com/siddhesh/b5ecac94eabfd72ed2916d6d8157e7dc
https://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-09-03 22:06:44 +05:30

100 lines
2.7 KiB
C

/* Implementation of sigwait function from POSIX.1c.
Copyright (C) 1996-2021 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;
}