Sweden-Number/server/signal.c

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/*
* Server signal handling
*
* Copyright (C) 2003 Alexandre Julliard
*
* 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 2.1 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
* Lesser 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
*/
#include "config.h"
#include <signal.h>
#include <stdio.h>
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#ifdef HAVE_POLL_H
#include <poll.h>
#endif
#ifdef HAVE_SYS_POLL_H
#include <sys/poll.h>
#endif
#include <unistd.h>
#include "file.h"
#include "object.h"
#include "process.h"
#include "thread.h"
#if defined(linux) && defined(__SIGRTMIN)
/* the signal used by linuxthreads as exit signal for clone() threads */
# define SIG_PTHREAD_CANCEL (__SIGRTMIN+1)
#endif
typedef void (*signal_callback)(void);
struct handler
{
struct object obj; /* object header */
struct fd *fd; /* file descriptor for the pipe side */
int pipe_write; /* unix fd for the pipe write side */
volatile int pending; /* is signal pending? */
signal_callback callback; /* callback function */
};
static void handler_dump( struct object *obj, int verbose );
static void handler_destroy( struct object *obj );
static const struct object_ops handler_ops =
{
sizeof(struct handler), /* size */
handler_dump, /* dump */
no_add_queue, /* add_queue */
NULL, /* remove_queue */
NULL, /* signaled */
NULL, /* satisfied */
no_signal, /* signal */
no_get_fd, /* get_fd */
handler_destroy /* destroy */
};
static void handler_poll_event( struct fd *fd, int event );
static const struct fd_ops handler_fd_ops =
{
NULL, /* get_poll_events */
handler_poll_event, /* poll_event */
no_flush, /* flush */
no_get_file_info, /* get_file_info */
no_queue_async, /* queue_async */
no_cancel_async /* cancel_async */
};
static struct handler *handler_sighup;
static struct handler *handler_sigterm;
static struct handler *handler_sigint;
static struct handler *handler_sigchld;
static struct handler *handler_sigio;
static sigset_t blocked_sigset;
/* create a signal handler */
static struct handler *create_handler( signal_callback callback )
{
struct handler *handler;
int fd[2];
if (pipe( fd ) == -1) return NULL;
if (!(handler = alloc_object( &handler_ops )))
{
close( fd[0] );
close( fd[1] );
return NULL;
}
handler->pipe_write = fd[1];
handler->pending = 0;
handler->callback = callback;
if (!(handler->fd = create_anonymous_fd( &handler_fd_ops, fd[0], &handler->obj )))
{
release_object( handler );
return NULL;
}
set_fd_events( handler->fd, POLLIN );
return handler;
}
/* handle a signal received for a given handler */
static void do_signal( struct handler *handler )
{
if (!handler->pending)
{
char dummy = 0;
handler->pending = 1;
write( handler->pipe_write, &dummy, 1 );
}
}
static void handler_dump( struct object *obj, int verbose )
{
struct handler *handler = (struct handler *)obj;
fprintf( stderr, "Signal handler fd=%p\n", handler->fd );
}
static void handler_destroy( struct object *obj )
{
struct handler *handler = (struct handler *)obj;
if (handler->fd) release_object( handler->fd );
close( handler->pipe_write );
}
static void handler_poll_event( struct fd *fd, int event )
{
struct handler *handler = get_fd_user( fd );
if (event & (POLLERR | POLLHUP))
{
/* this is not supposed to happen */
fprintf( stderr, "wineserver: Error on signal handler pipe\n" );
release_object( handler );
}
else if (event & POLLIN)
{
char dummy;
handler->pending = 0;
read( get_unix_fd( handler->fd ), &dummy, 1 );
handler->callback();
}
}
/* SIGHUP callback */
static void sighup_callback(void)
{
#ifdef DEBUG_OBJECTS
dump_objects();
#endif
}
/* SIGTERM callback */
static void sigterm_callback(void)
{
flush_registry();
exit(1);
}
/* SIGINT callback */
static void sigint_callback(void)
{
kill_all_processes( NULL, 1 );
flush_registry();
exit(1);
}
/* SIGHUP handler */
static void do_sighup()
{
do_signal( handler_sighup );
}
/* SIGTERM handler */
static void do_sigterm()
{
do_signal( handler_sigterm );
}
/* SIGINT handler */
static void do_sigint()
{
do_signal( handler_sigint );
}
/* SIGCHLD handler */
static void do_sigchld()
{
do_signal( handler_sigchld );
}
/* SIGIO handler */
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#ifdef HAVE_SIGINFO_T_SI_FD
static void do_sigio( int signum, siginfo_t *si, void *x )
{
do_signal( handler_sigio );
do_change_notify( si->si_fd );
}
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#endif
void init_signals(void)
{
struct sigaction action;
if (!(handler_sighup = create_handler( sighup_callback ))) goto error;
if (!(handler_sigterm = create_handler( sigterm_callback ))) goto error;
if (!(handler_sigint = create_handler( sigint_callback ))) goto error;
if (!(handler_sigchld = create_handler( sigchld_callback ))) goto error;
if (!(handler_sigio = create_handler( sigio_callback ))) goto error;
sigemptyset( &blocked_sigset );
sigaddset( &blocked_sigset, SIGCHLD );
sigaddset( &blocked_sigset, SIGHUP );
sigaddset( &blocked_sigset, SIGINT );
sigaddset( &blocked_sigset, SIGIO );
sigaddset( &blocked_sigset, SIGQUIT );
sigaddset( &blocked_sigset, SIGTERM );
#ifdef SIG_PTHREAD_CANCEL
sigaddset( &blocked_sigset, SIG_PTHREAD_CANCEL );
#endif
action.sa_mask = blocked_sigset;
action.sa_flags = 0;
action.sa_handler = do_sigchld;
sigaction( SIGCHLD, &action, NULL );
#ifdef SIG_PTHREAD_CANCEL
sigaction( SIG_PTHREAD_CANCEL, &action, NULL );
#endif
action.sa_handler = do_sighup;
sigaction( SIGHUP, &action, NULL );
action.sa_handler = do_sigint;
sigaction( SIGINT, &action, NULL );
action.sa_handler = do_sigterm;
sigaction( SIGQUIT, &action, NULL );
sigaction( SIGTERM, &action, NULL );
action.sa_handler = SIG_IGN;
sigaction( SIGXFSZ, &action, NULL );
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#ifdef HAVE_SIGINFO_T_SI_FD
action.sa_sigaction = do_sigio;
action.sa_flags = SA_SIGINFO;
sigaction( SIGIO, &action, NULL );
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#endif
return;
error:
fprintf( stderr, "failed to initialize signal handlers\n" );
exit(1);
}
void close_signals(void)
{
sigprocmask( SIG_BLOCK, &blocked_sigset, NULL );
release_object( handler_sighup );
release_object( handler_sigterm );
release_object( handler_sigint );
release_object( handler_sigchld );
release_object( handler_sigio );
}