1 /* Copyright (C) 1998-2016 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <http://www.gnu.org/licenses/>. */
22 #include <string.h> /* For the real memset prototype. */
25 /* Set the disposition for SIG. */
27 sigset (int sig
, __sighandler_t disp
)
30 struct sigaction oact
;
35 /* Handle SIG_HOLD first. */
38 /* Create an empty signal set. */
39 if (__sigemptyset (&set
) < 0)
42 /* Add the specified signal. */
43 if (__sigaddset (&set
, sig
) < 0)
46 /* Add the signal set to the current signal mask. */
47 if (__sigprocmask (SIG_BLOCK
, &set
, &oset
) < 0)
50 /* If the signal was already blocked signal this to the caller. */
51 if (__sigismember (&oset
, sig
))
54 /* We need to determine whether a specific handler is installed. */
55 if (__sigaction (sig
, NULL
, &oact
) < 0)
58 return oact
.sa_handler
;
62 /* Check signal extents to protect __sigismember. */
63 if (disp
== SIG_ERR
|| sig
< 1 || sig
>= NSIG
)
69 act
.sa_handler
= disp
;
70 if (__sigemptyset (&act
.sa_mask
) < 0)
73 if (__sigaction (sig
, &act
, &oact
) < 0)
76 /* Create an empty signal set. */
77 if (__sigemptyset (&set
) < 0)
80 /* Add the specified signal. */
81 if (__sigaddset (&set
, sig
) < 0)
84 /* Remove the signal set from the current signal mask. */
85 if (__sigprocmask (SIG_UNBLOCK
, &set
, &oset
) < 0)
88 /* If the signal was already blocked return SIG_HOLD. */
89 return __sigismember (&oset
, sig
) ? SIG_HOLD
: oact
.sa_handler
;