code.delx.au - pulseaudio/blob - src/pulse/mainloop-signal.c

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of PulseAudio.
   5
   6   Copyright 2004-2006 Lennart Poettering
   7   Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
   8
   9   PulseAudio is free software; you can redistribute it and/or modify
  10   it under the terms of the GNU Lesser General Public License as published
  11   by the Free Software Foundation; either version 2 of the License,
  12   or (at your option) any later version.
  13
  14   PulseAudio is distributed in the hope that it will be useful, but
  15   WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17   General Public License for more details.
  18
  19   You should have received a copy of the GNU Lesser General Public License
  20   along with PulseAudio; if not, write to the Free Software
  21   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  22   USA.
  23 ***/
  24
  25 #ifdef HAVE_CONFIG_H
  26 #include <config.h>
  27 #endif
  28
  29 #include <stdio.h>
  30 #include <assert.h>
  31 #include <signal.h>
  32 #include <errno.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35 #include <unistd.h>
  36 #include <fcntl.h>
  37
  38 #ifdef HAVE_WINDOWS_H
  39 #include <windows.h>
  40 #endif
  41
  42 #include <pulsecore/core-error.h>
  43 #include <pulse/xmalloc.h>
  44
  45 #include <pulsecore/core-util.h>
  46 #include <pulsecore/log.h>
  47 #include <pulsecore/gccmacro.h>
  48
  49 #include "mainloop-signal.h"
  50
  51 struct pa_signal_event {
  52     int sig;
  53 #ifdef HAVE_SIGACTION
  54     struct sigaction saved_sigaction;
  55 #else
  56     void (*saved_handler)(int sig);
  57 #endif
  58     void (*callback) (pa_mainloop_api*a, pa_signal_event *e, int sig, void *userdata);
  59     void *userdata;
  60     void (*destroy_callback) (pa_mainloop_api*a, pa_signal_event*e, void *userdata);
  61     pa_signal_event *previous, *next;
  62 };
  63
  64 static pa_mainloop_api *api = NULL;
  65 static int signal_pipe[2] = { -1, -1 };
  66 static pa_io_event* io_event = NULL;
  67 static pa_signal_event *signals = NULL;
  68
  69 static void signal_handler(int sig) {
  70 #ifndef HAVE_SIGACTION
  71     signal(sig, signal_handler);
  72 #endif
  73     pa_write(signal_pipe[1], &sig, sizeof(sig), NULL);
  74 }
  75
  76 static void dispatch(pa_mainloop_api*a, int sig) {
  77     pa_signal_event*s;
  78
  79     for (s = signals; s; s = s->next)
  80         if (s->sig == sig) {
  81             assert(s->callback);
  82             s->callback(a, s, sig, s->userdata);
  83             break;
  84         }
  85 }
  86
  87 static void callback(pa_mainloop_api*a, pa_io_event*e, int fd, pa_io_event_flags_t f, PA_GCC_UNUSED void *userdata) {
  88     ssize_t r;
  89     int sig;
  90     assert(a && e && f == PA_IO_EVENT_INPUT && e == io_event && fd == signal_pipe[0]);
  91
  92     if ((r = pa_read(signal_pipe[0], &sig, sizeof(sig), NULL)) < 0) {
  93         if (errno == EAGAIN)
  94             return;
  95
  96         pa_log("read(): %s", pa_cstrerror(errno));
  97         return;
  98     }
  99
 100     if (r != sizeof(sig)) {
 101         pa_log("short read()");
 102         return;
 103     }
 104
 105     dispatch(a, sig);
 106 }
 107
 108 int pa_signal_init(pa_mainloop_api *a) {
 109
 110     assert(!api && a && signal_pipe[0] == -1 && signal_pipe[1] == -1 && !io_event);
 111
 112     if (pipe(signal_pipe) < 0) {
 113         pa_log("pipe(): %s", pa_cstrerror(errno));
 114         return -1;
 115     }
 116
 117     pa_make_nonblock_fd(signal_pipe[0]);
 118     pa_make_nonblock_fd(signal_pipe[1]);
 119     pa_fd_set_cloexec(signal_pipe[0], 1);
 120     pa_fd_set_cloexec(signal_pipe[1], 1);
 121
 122     api = a;
 123
 124     io_event = api->io_new(api, signal_pipe[0], PA_IO_EVENT_INPUT, callback, NULL);
 125     assert(io_event);
 126
 127     return 0;
 128 }
 129
 130 void pa_signal_done(void) {
 131     assert(api && signal_pipe[0] >= 0 && signal_pipe[1] >= 0 && io_event);
 132
 133     while (signals)
 134         pa_signal_free(signals);
 135
 136     api->io_free(io_event);
 137     io_event = NULL;
 138
 139     close(signal_pipe[0]);
 140     close(signal_pipe[1]);
 141     signal_pipe[0] = signal_pipe[1] = -1;
 142
 143     api = NULL;
 144 }
 145
 146 pa_signal_event* pa_signal_new(int sig, void (*_callback) (pa_mainloop_api *api, pa_signal_event*e, int sig, void *userdata), void *userdata) {
 147     pa_signal_event *e = NULL;
 148
 149 #ifdef HAVE_SIGACTION
 150     struct sigaction sa;
 151 #endif
 152
 153     assert(sig > 0 && _callback);
 154
 155     for (e = signals; e; e = e->next)
 156         if (e->sig == sig)
 157             goto fail;
 158
 159     e = pa_xmalloc(sizeof(pa_signal_event));
 160     e->sig = sig;
 161     e->callback = _callback;
 162     e->userdata = userdata;
 163     e->destroy_callback = NULL;
 164
 165 #ifdef HAVE_SIGACTION
 166     memset(&sa, 0, sizeof(sa));
 167     sa.sa_handler = signal_handler;
 168     sigemptyset(&sa.sa_mask);
 169     sa.sa_flags = SA_RESTART;
 170
 171     if (sigaction(sig, &sa, &e->saved_sigaction) < 0)
 172 #else
 173     if ((e->saved_handler = signal(sig, signal_handler)) == SIG_ERR)
 174 #endif
 175         goto fail;
 176
 177     e->previous = NULL;
 178     e->next = signals;
 179     signals = e;
 180
 181     return e;
 182 fail:
 183     if (e)
 184         pa_xfree(e);
 185     return NULL;
 186 }
 187
 188 void pa_signal_free(pa_signal_event *e) {
 189     assert(e);
 190
 191     if (e->next)
 192         e->next->previous = e->previous;
 193     if (e->previous)
 194         e->previous->next = e->next;
 195     else
 196         signals = e->next;
 197
 198 #ifdef HAVE_SIGACTION
 199     sigaction(e->sig, &e->saved_sigaction, NULL);
 200 #else
 201     signal(e->sig, e->saved_handler);
 202 #endif
 203
 204     if (e->destroy_callback)
 205         e->destroy_callback(api, e, e->userdata);
 206
 207     pa_xfree(e);
 208 }
 209
 210 void pa_signal_set_destroy(pa_signal_event *e, void (*_callback) (pa_mainloop_api *api, pa_signal_event*e, void *userdata)) {
 211     assert(e);
 212     e->destroy_callback = _callback;
 213 }