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

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