111 lines
3.7 KiB
C
111 lines
3.7 KiB
C
/* LIBPIKA - The PIKA 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 3 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, see
|
|
* <https://www.gnu.org/licenses/>.
|
|
*
|
|
* $Revision$
|
|
*/
|
|
|
|
#include "config.h"
|
|
|
|
#define _GNU_SOURCE /* for the sigaction stuff */
|
|
|
|
#include <glib.h>
|
|
|
|
#include "pikasignal.h"
|
|
|
|
|
|
/**
|
|
* SECTION: pikasignal
|
|
* @title: pikasignal
|
|
* @short_description: Portable signal handling.
|
|
* @see_also: signal(2), signal(5 or 7), sigaction(2).
|
|
*
|
|
* Portable signal handling.
|
|
**/
|
|
|
|
|
|
/* Courtesy of Austin Donnelly 06-04-2000 to address bug #2742 */
|
|
|
|
/**
|
|
* pika_signal_private: (skip)
|
|
* @signum: Selects signal to be handled see man 5 signal (or man 7 signal)
|
|
* @handler: Handler that maps to signum. Invoked by O/S.
|
|
* Handler gets signal that caused invocation. Corresponds
|
|
* to the @sa_handler field of the @sigaction struct.
|
|
* @flags: Preferences. OR'ed SA_<xxx>. See man sigaction. Corresponds
|
|
* to the @sa_flags field of the @sigaction struct.
|
|
*
|
|
* 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 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 handler's environment completely via @flags: some signal(2)
|
|
* implementations differ in their semantics, so we need to nail down
|
|
* exactly what we want. [austin 06.04.2000]
|
|
*
|
|
* Returns: A reference to the signal handling function which was
|
|
* active before the call to pika_signal_private().
|
|
*/
|
|
PikaSignalHandlerFunc
|
|
pika_signal_private (gint signum,
|
|
PikaSignalHandlerFunc handler,
|
|
gint flags)
|
|
{
|
|
#ifndef G_OS_WIN32
|
|
gint ret;
|
|
struct sigaction sa;
|
|
struct sigaction osa;
|
|
|
|
/* The sa_handler (mandated by POSIX.1) and sa_sigaction (a
|
|
* common extension) are often implemented by the OS as members
|
|
* of a union. This means you CAN NOT set both, you set one or
|
|
* the other. Caveat programmer!
|
|
*/
|
|
|
|
/* Passing pika_signal_private a pika_sighandler of NULL is not
|
|
* an error, and generally results in the action for that signal
|
|
* being set to SIG_DFL (default behavior). Many OSes define
|
|
* SIG_DFL as (void (*)()0, so setting sa_handler to NULL is
|
|
* the same thing as passing SIG_DFL to it.
|
|
*/
|
|
sa.sa_handler = handler;
|
|
|
|
/* Mask all signals while handler runs to avoid re-entrancy
|
|
* problems.
|
|
*/
|
|
sigfillset (&sa.sa_mask);
|
|
|
|
sa.sa_flags = flags;
|
|
|
|
ret = sigaction (signum, &sa, &osa);
|
|
|
|
if (ret < 0)
|
|
g_error ("unable to set handler for signal %d\n", signum);
|
|
|
|
return (PikaSignalHandlerFunc) osa.sa_handler;
|
|
#else
|
|
return NULL; /* Or g_error()? Should all calls to
|
|
* this function really be inside
|
|
* #ifdef G_OS_UNIX?
|
|
*/
|
|
#endif
|
|
}
|
