gimp/libgimp/gimpsignal.c

73 lines
2.8 KiB
C

/* LIBGIMP - The GIMP Library
* Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
*
* This 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 of the License, or (at your option) any later version.
*
* This 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*
* $Revision$
*/
#include "gimpsignal.h"
/**
* gimp_signal:
* @signum: selects signal to be handled see man 5 signal
* @handler: handler that maps to signum. Invoked by O/S.
* handler gets signal that caused invocation.
* @sa_flags: preferences. OR'ed SA_<xxx>. See signal.h
*
* This function furnishes a workalike for signal(2) but
* which internally invokes sigaction(2) after certain
* sa_flags are set; these primarily to ensure restarting
* of interrupted system calls. See sigaction(2) It is a
* aid to transition and not new development: that effort
* should employ sigaction directly. [<gosgood@idt.net> 18.04.2000]
*
* Cause handler to be run when signum is delivered. We
* use sigaction(2) rather than signal(2) so that we can control the
* signal hander's environment completely via sa_flags: some signal(2)
* implementations differ in their sematics, so we need to nail down
* exactly what we want. [<austin@gimp.org> 06.04.2000]
*
* Returns: RetSigType (a reference to a signal handling function)
*
*/
/* Courtesy of Austin Donnelly 06-04-2000 to address bug #2742 */
RetSigType
gimp_signal_private (gint signum, void (*gimp_sighandler)(int), gint sa_flags)
{
int ret;
struct sigaction sa;
struct sigaction osa;
/* this field is a union of sa_sighandler.sa_sighandler1 and */
/* sa_sigaction1 - don't set both at once... */
sa.sa_handler = gimp_sighandler;
/* Mask all signals while handler runs to avoid re-entrancy
* problems. */
sigfillset (&sa.sa_mask);
sa.sa_flags = sa_flags;
ret = sigaction (signum, &sa, &osa);
if (ret < 0)
g_error ("unable to set handler for signal %d\n", signum);
return osa.sa_handler;
}