LCOV - code coverage report
Current view: directory - ipc/chromium/src/third_party/libevent - signal.c (source / functions) Found Hit Coverage
Test: app.info Lines: 122 36 29.5 %
Date: 2012-06-02 Functions: 9 3 33.3 %

       1                 : /*      $OpenBSD: select.c,v 1.2 2002/06/25 15:50:15 mickey Exp $       */
       2                 : 
       3                 : /*
       4                 :  * Copyright 2000-2002 Niels Provos <provos@citi.umich.edu>
       5                 :  * All rights reserved.
       6                 :  *
       7                 :  * Redistribution and use in source and binary forms, with or without
       8                 :  * modification, are permitted provided that the following conditions
       9                 :  * are met:
      10                 :  * 1. Redistributions of source code must retain the above copyright
      11                 :  *    notice, this list of conditions and the following disclaimer.
      12                 :  * 2. Redistributions in binary form must reproduce the above copyright
      13                 :  *    notice, this list of conditions and the following disclaimer in the
      14                 :  *    documentation and/or other materials provided with the distribution.
      15                 :  * 3. The name of the author may not be used to endorse or promote products
      16                 :  *    derived from this software without specific prior written permission.
      17                 :  *
      18                 :  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
      19                 :  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
      20                 :  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
      21                 :  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
      22                 :  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
      23                 :  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
      24                 :  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
      25                 :  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
      26                 :  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
      27                 :  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
      28                 :  */
      29                 : #ifdef HAVE_CONFIG_H
      30                 : #include "config.h"
      31                 : #endif
      32                 : 
      33                 : #ifdef WIN32
      34                 : #define WIN32_LEAN_AND_MEAN
      35                 : #include <winsock2.h>
      36                 : #include <windows.h>
      37                 : #undef WIN32_LEAN_AND_MEAN
      38                 : #endif
      39                 : #include <sys/types.h>
      40                 : #ifdef HAVE_SYS_TIME_H
      41                 : #include <sys/time.h>
      42                 : #endif
      43                 : #include <sys/queue.h>
      44                 : #ifdef HAVE_SYS_SOCKET_H
      45                 : #include <sys/socket.h>
      46                 : #endif
      47                 : #include <signal.h>
      48                 : #include <stdio.h>
      49                 : #include <stdlib.h>
      50                 : #include <string.h>
      51                 : #ifdef HAVE_UNISTD_H
      52                 : #include <unistd.h>
      53                 : #endif
      54                 : #include <errno.h>
      55                 : #ifdef HAVE_FCNTL_H
      56                 : #include <fcntl.h>
      57                 : #endif
      58                 : #include <assert.h>
      59                 : 
      60                 : #include "event.h"
      61                 : #include "event-internal.h"
      62                 : #include "evsignal.h"
      63                 : #include "evutil.h"
      64                 : #include "log.h"
      65                 : 
      66                 : struct event_base *evsignal_base = NULL;
      67                 : 
      68                 : static void evsignal_handler(int sig);
      69                 : 
      70                 : /* Callback for when the signal handler write a byte to our signaling socket */
      71                 : static void
      72               0 : evsignal_cb(int fd, short what, void *arg)
      73                 : {
      74                 :         static char signals[100];
      75                 : #ifdef WIN32
      76                 :         SSIZE_T n;
      77                 : #else
      78                 :         ssize_t n;
      79                 : #endif
      80                 : 
      81               0 :         n = recv(fd, signals, sizeof(signals), 0);
      82               0 :         if (n == -1)
      83               0 :                 event_err(1, "%s: read", __func__);
      84               0 : }
      85                 : 
      86                 : #ifdef HAVE_SETFD
      87                 : #define FD_CLOSEONEXEC(x) do { \
      88                 :         if (fcntl(x, F_SETFD, 1) == -1) \
      89                 :                 event_warn("fcntl(%d, F_SETFD)", x); \
      90                 : } while (0)
      91                 : #else
      92                 : #define FD_CLOSEONEXEC(x)
      93                 : #endif
      94                 : 
      95                 : void
      96            1420 : evsignal_init(struct event_base *base)
      97                 : {
      98                 :         int i;
      99                 : 
     100                 :         /* 
     101                 :          * Our signal handler is going to write to one end of the socket
     102                 :          * pair to wake up our event loop.  The event loop then scans for
     103                 :          * signals that got delivered.
     104                 :          */
     105            1420 :         if (evutil_socketpair(
     106                 :                     AF_UNIX, SOCK_STREAM, 0, base->sig.ev_signal_pair) == -1)
     107               0 :                 event_err(1, "%s: socketpair", __func__);
     108                 : 
     109            1420 :         FD_CLOSEONEXEC(base->sig.ev_signal_pair[0]);
     110            1420 :         FD_CLOSEONEXEC(base->sig.ev_signal_pair[1]);
     111            1420 :         base->sig.sh_old = NULL;
     112            1420 :         base->sig.sh_old_max = 0;
     113            1420 :         base->sig.evsignal_caught = 0;
     114            1420 :         memset(&base->sig.evsigcaught, 0, sizeof(sig_atomic_t)*NSIG);
     115                 :         /* initialize the queues for all events */
     116           93720 :         for (i = 0; i < NSIG; ++i)
     117           92300 :                 TAILQ_INIT(&base->sig.evsigevents[i]);
     118                 : 
     119            1420 :         evutil_make_socket_nonblocking(base->sig.ev_signal_pair[0]);
     120                 : 
     121            1420 :         event_set(&base->sig.ev_signal, base->sig.ev_signal_pair[1],
     122            1420 :                 EV_READ | EV_PERSIST, evsignal_cb, &base->sig.ev_signal);
     123            1420 :         base->sig.ev_signal.ev_base = base;
     124            1420 :         base->sig.ev_signal.ev_flags |= EVLIST_INTERNAL;
     125            1420 : }
     126                 : 
     127                 : /* Helper: set the signal handler for evsignal to handler in base, so that
     128                 :  * we can restore the original handler when we clear the current one. */
     129                 : int
     130               0 : _evsignal_set_handler(struct event_base *base,
     131                 :                       int evsignal, void (*handler)(int))
     132                 : {
     133                 : #ifdef HAVE_SIGACTION
     134                 :         struct sigaction sa;
     135                 : #else
     136                 :         ev_sighandler_t sh;
     137                 : #endif
     138               0 :         struct evsignal_info *sig = &base->sig;
     139                 :         void *p;
     140                 : 
     141                 :         /*
     142                 :          * resize saved signal handler array up to the highest signal number.
     143                 :          * a dynamic array is used to keep footprint on the low side.
     144                 :          */
     145               0 :         if (evsignal >= sig->sh_old_max) {
     146               0 :                 int new_max = evsignal + 1;
     147                 :                 event_debug(("%s: evsignal (%d) >= sh_old_max (%d), resizing",
     148                 :                             __func__, evsignal, sig->sh_old_max));
     149               0 :                 p = realloc(sig->sh_old, new_max * sizeof(*sig->sh_old));
     150               0 :                 if (p == NULL) {
     151               0 :                         event_warn("realloc");
     152               0 :                         return (-1);
     153                 :                 }
     154                 : 
     155               0 :                 memset((char *)p + sig->sh_old_max * sizeof(*sig->sh_old),
     156               0 :                     0, (new_max - sig->sh_old_max) * sizeof(*sig->sh_old));
     157                 : 
     158               0 :                 sig->sh_old_max = new_max;
     159               0 :                 sig->sh_old = p;
     160                 :         }
     161                 : 
     162                 :         /* allocate space for previous handler out of dynamic array */
     163               0 :         sig->sh_old[evsignal] = malloc(sizeof *sig->sh_old[evsignal]);
     164               0 :         if (sig->sh_old[evsignal] == NULL) {
     165               0 :                 event_warn("malloc");
     166               0 :                 return (-1);
     167                 :         }
     168                 : 
     169                 :         /* save previous handler and setup new handler */
     170                 : #ifdef HAVE_SIGACTION
     171               0 :         memset(&sa, 0, sizeof(sa));
     172               0 :         sa.sa_handler = handler;
     173               0 :         sa.sa_flags |= SA_RESTART;
     174               0 :         sigfillset(&sa.sa_mask);
     175                 : 
     176               0 :         if (sigaction(evsignal, &sa, sig->sh_old[evsignal]) == -1) {
     177               0 :                 event_warn("sigaction");
     178               0 :                 free(sig->sh_old[evsignal]);
     179               0 :                 return (-1);
     180                 :         }
     181                 : #else
     182                 :         if ((sh = signal(evsignal, handler)) == SIG_ERR) {
     183                 :                 event_warn("signal");
     184                 :                 free(sig->sh_old[evsignal]);
     185                 :                 return (-1);
     186                 :         }
     187                 :         *sig->sh_old[evsignal] = sh;
     188                 : #endif
     189                 : 
     190               0 :         return (0);
     191                 : }
     192                 : 
     193                 : int
     194               0 : evsignal_add(struct event *ev)
     195                 : {
     196                 :         int evsignal;
     197               0 :         struct event_base *base = ev->ev_base;
     198               0 :         struct evsignal_info *sig = &ev->ev_base->sig;
     199                 : 
     200               0 :         if (ev->ev_events & (EV_READ|EV_WRITE))
     201               0 :                 event_errx(1, "%s: EV_SIGNAL incompatible use", __func__);
     202               0 :         evsignal = EVENT_SIGNAL(ev);
     203               0 :         assert(evsignal >= 0 && evsignal < NSIG);
     204               0 :         if (TAILQ_EMPTY(&sig->evsigevents[evsignal])) {
     205                 :                 event_debug(("%s: %p: changing signal handler", __func__, ev));
     206               0 :                 if (_evsignal_set_handler(
     207                 :                             base, evsignal, evsignal_handler) == -1)
     208               0 :                         return (-1);
     209                 : 
     210                 :                 /* catch signals if they happen quickly */
     211               0 :                 evsignal_base = base;
     212                 : 
     213               0 :                 if (!sig->ev_signal_added) {
     214               0 :                         if (event_add(&sig->ev_signal, NULL))
     215               0 :                                 return (-1);
     216               0 :                         sig->ev_signal_added = 1;
     217                 :                 }
     218                 :         }
     219                 : 
     220                 :         /* multiple events may listen to the same signal */
     221               0 :         TAILQ_INSERT_TAIL(&sig->evsigevents[evsignal], ev, ev_signal_next);
     222                 : 
     223               0 :         return (0);
     224                 : }
     225                 : 
     226                 : int
     227               0 : _evsignal_restore_handler(struct event_base *base, int evsignal)
     228                 : {
     229               0 :         int ret = 0;
     230               0 :         struct evsignal_info *sig = &base->sig;
     231                 : #ifdef HAVE_SIGACTION
     232                 :         struct sigaction *sh;
     233                 : #else
     234                 :         ev_sighandler_t *sh;
     235                 : #endif
     236                 : 
     237                 :         /* restore previous handler */
     238               0 :         sh = sig->sh_old[evsignal];
     239               0 :         sig->sh_old[evsignal] = NULL;
     240                 : #ifdef HAVE_SIGACTION
     241               0 :         if (sigaction(evsignal, sh, NULL) == -1) {
     242               0 :                 event_warn("sigaction");
     243               0 :                 ret = -1;
     244                 :         }
     245                 : #else
     246                 :         if (signal(evsignal, *sh) == SIG_ERR) {
     247                 :                 event_warn("signal");
     248                 :                 ret = -1;
     249                 :         }
     250                 : #endif
     251               0 :         free(sh);
     252                 : 
     253               0 :         return ret;
     254                 : }
     255                 : 
     256                 : int
     257               0 : evsignal_del(struct event *ev)
     258                 : {
     259               0 :         struct event_base *base = ev->ev_base;
     260               0 :         struct evsignal_info *sig = &base->sig;
     261               0 :         int evsignal = EVENT_SIGNAL(ev);
     262                 : 
     263               0 :         assert(evsignal >= 0 && evsignal < NSIG);
     264                 : 
     265                 :         /* multiple events may listen to the same signal */
     266               0 :         TAILQ_REMOVE(&sig->evsigevents[evsignal], ev, ev_signal_next);
     267                 : 
     268               0 :         if (!TAILQ_EMPTY(&sig->evsigevents[evsignal]))
     269               0 :                 return (0);
     270                 : 
     271                 :         event_debug(("%s: %p: restoring signal handler", __func__, ev));
     272                 : 
     273               0 :         return (_evsignal_restore_handler(ev->ev_base, EVENT_SIGNAL(ev)));
     274                 : }
     275                 : 
     276                 : static void
     277               0 : evsignal_handler(int sig)
     278                 : {
     279               0 :         int save_errno = errno;
     280                 : 
     281               0 :         if (evsignal_base == NULL) {
     282               0 :                 event_warn(
     283                 :                         "%s: received signal %d, but have no base configured",
     284                 :                         __func__, sig);
     285               0 :                 return;
     286                 :         }
     287                 : 
     288               0 :         evsignal_base->sig.evsigcaught[sig]++;
     289               0 :         evsignal_base->sig.evsignal_caught = 1;
     290                 : 
     291                 : #ifndef HAVE_SIGACTION
     292                 :         signal(sig, evsignal_handler);
     293                 : #endif
     294                 : 
     295                 :         /* Wake up our notification mechanism */
     296               0 :         send(evsignal_base->sig.ev_signal_pair[0], "a", 1, 0);
     297               0 :         errno = save_errno;
     298                 : }
     299                 : 
     300                 : void
     301              52 : evsignal_process(struct event_base *base)
     302                 : {
     303              52 :         struct evsignal_info *sig = &base->sig;
     304                 :         struct event *ev, *next_ev;
     305                 :         sig_atomic_t ncalls;
     306                 :         int i;
     307                 :         
     308              52 :         base->sig.evsignal_caught = 0;
     309            3380 :         for (i = 1; i < NSIG; ++i) {
     310            3328 :                 ncalls = sig->evsigcaught[i];
     311            3328 :                 if (ncalls == 0)
     312            3328 :                         continue;
     313                 : 
     314               0 :                 for (ev = TAILQ_FIRST(&sig->evsigevents[i]);
     315               0 :                     ev != NULL; ev = next_ev) {
     316               0 :                         next_ev = TAILQ_NEXT(ev, ev_signal_next);
     317               0 :                         if (!(ev->ev_events & EV_PERSIST))
     318               0 :                                 event_del(ev);
     319               0 :                         event_active(ev, EV_SIGNAL, ncalls);
     320                 :                 }
     321                 : 
     322               0 :                 sig->evsigcaught[i] = 0;
     323                 :         }
     324              52 : }
     325                 : 
     326                 : void
     327            1419 : evsignal_dealloc(struct event_base *base)
     328                 : {
     329            1419 :         int i = 0;
     330            1419 :         if (base->sig.ev_signal_added) {
     331               0 :                 event_del(&base->sig.ev_signal);
     332               0 :                 base->sig.ev_signal_added = 0;
     333                 :         }
     334           93654 :         for (i = 0; i < NSIG; ++i) {
     335           92235 :                 if (i < base->sig.sh_old_max && base->sig.sh_old[i] != NULL)
     336               0 :                         _evsignal_restore_handler(base, i);
     337                 :         }
     338                 : 
     339            1419 :         EVUTIL_CLOSESOCKET(base->sig.ev_signal_pair[0]);
     340            1419 :         base->sig.ev_signal_pair[0] = -1;
     341            1419 :         EVUTIL_CLOSESOCKET(base->sig.ev_signal_pair[1]);
     342            1419 :         base->sig.ev_signal_pair[1] = -1;
     343            1419 :         base->sig.sh_old_max = 0;
     344                 : 
     345                 :         /* per index frees are handled in evsignal_del() */
     346            1419 :         free(base->sig.sh_old);
     347            1419 : }

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