code.delx.au - pulseaudio/blob - 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 "mainloop-signal.h"
  40 #include "util.h"
  41 #include "xmalloc.h"
  42 #include "log.h"
  43
  44 struct pa_signal_event {
  45     int sig;
  46 #ifdef HAVE_SIGACTION
  47     struct sigaction saved_sigaction;
  48 #else
  49     void (*saved_handler)(int sig);
  50 #endif
  51     void (*callback) (struct pa_mainloop_api*a, struct pa_signal_event *e, int signal, void *userdata);
  52     void *userdata;
  53     void (*destroy_callback) (struct pa_mainloop_api*a, struct pa_signal_event*e, void *userdata);
  54     struct pa_signal_event *previous, *next;
  55 };
  56
  57 static struct pa_mainloop_api *api = NULL;
  58 static int signal_pipe[2] = { -1, -1 };
  59 static struct pa_io_event* io_event = NULL;
  60 static struct pa_defer_event *defer_event = NULL;
  61 static struct pa_signal_event *signals = NULL;
  62
  63 #ifdef OS_IS_WIN32
  64 static unsigned int waiting_signals = 0;
  65 static CRITICAL_SECTION crit;
  66 #endif
  67
  68 static void signal_handler(int sig) {
  69 #ifndef HAVE_SIGACTION
  70     signal(sig, signal_handler);
  71 #endif
  72     write(signal_pipe[1], &sig, sizeof(sig));
  73
  74 #ifdef OS_IS_WIN32
  75     EnterCriticalSection(&crit);
  76     waiting_signals++;
  77     LeaveCriticalSection(&crit);
  78 #endif
  79 }
  80
  81 static void dispatch(struct pa_mainloop_api*a, int sig) {
  82     struct pa_signal_event*s;
  83
  84     for (s = signals; s; s = s->next)
  85         if (s->sig == sig) {
  86             assert(s->callback);
  87             s->callback(a, s, sig, s->userdata);
  88             break;
  89         }
  90 }
  91
  92 static void defer(struct pa_mainloop_api*a, struct pa_defer_event*e, void *userdata) {
  93     ssize_t r;
  94     int sig;
  95     unsigned int sigs;
  96
  97 #ifdef OS_IS_WIN32
  98     EnterCriticalSection(&crit);
  99     sigs = waiting_signals;
 100     waiting_signals = 0;
 101     LeaveCriticalSection(&crit);
 102 #endif
 103
 104     while (sigs) {
 105         if ((r = read(signal_pipe[0], &sig, sizeof(sig))) < 0) {
 106             pa_log(__FILE__": read(): %s\n", strerror(errno));
 107             return;
 108         }
 109
 110         if (r != sizeof(sig)) {
 111             pa_log(__FILE__": short read()\n");
 112             return;
 113         }
 114
 115         dispatch(a, sig);
 116
 117         sigs--;
 118     }
 119 }
 120
 121 static void callback(struct pa_mainloop_api*a, struct pa_io_event*e, int fd, enum pa_io_event_flags f, void *userdata) {
 122     ssize_t r;
 123     int sig;
 124     assert(a && e && f == PA_IO_EVENT_INPUT && e == io_event && fd == signal_pipe[0]);
 125
 126
 127     if ((r = read(signal_pipe[0], &sig, sizeof(sig))) < 0) {
 128         if (errno == EAGAIN)
 129             return;
 130
 131         pa_log(__FILE__": read(): %s\n", strerror(errno));
 132         return;
 133     }
 134
 135     if (r != sizeof(sig)) {
 136         pa_log(__FILE__": short read()\n");
 137         return;
 138     }
 139
 140     dispatch(a, sig);
 141 }
 142
 143 int pa_signal_init(struct pa_mainloop_api *a) {
 144     assert(!api && a && signal_pipe[0] == -1 && signal_pipe[1] == -1 && !io_event && !defer_event);
 145
 146 #ifdef OS_IS_WIN32
 147     if (_pipe(signal_pipe, 200, _O_BINARY) < 0) {
 148 #else
 149     if (pipe(signal_pipe) < 0) {
 150 #endif
 151         pa_log(__FILE__": pipe() failed: %s\n", strerror(errno));
 152         return -1;
 153     }
 154
 155     pa_make_nonblock_fd(signal_pipe[0]);
 156     pa_make_nonblock_fd(signal_pipe[1]);
 157     pa_fd_set_cloexec(signal_pipe[0], 1);
 158     pa_fd_set_cloexec(signal_pipe[1], 1);
 159
 160     api = a;
 161
 162 #ifndef OS_IS_WIN32
 163     io_event = api->io_new(api, signal_pipe[0], PA_IO_EVENT_INPUT, callback, NULL);
 164     assert(io_event);
 165 #else
 166     defer_event = api->defer_new(api, defer, NULL);
 167     assert(defer_event);
 168
 169     InitializeCriticalSection(&crit);
 170 #endif
 171
 172     return 0;
 173 }
 174
 175 void pa_signal_done(void) {
 176     assert(api && signal_pipe[0] >= 0 && signal_pipe[1] >= 0 && (io_event || defer_event));
 177
 178     while (signals)
 179         pa_signal_free(signals);
 180
 181
 182 #ifndef OS_IS_WIN32
 183     api->io_free(io_event);
 184     io_event = NULL;
 185 #else
 186     api->defer_free(defer_event);
 187     defer_event = NULL;
 188
 189     DeleteCriticalSection(&crit);
 190 #endif
 191
 192     close(signal_pipe[0]);
 193     close(signal_pipe[1]);
 194     signal_pipe[0] = signal_pipe[1] = -1;
 195
 196     api = NULL;
 197 }
 198
 199 struct pa_signal_event* pa_signal_new(int sig, void (*callback) (struct pa_mainloop_api *api, struct pa_signal_event*e, int sig, void *userdata), void *userdata) {
 200     struct pa_signal_event *e = NULL;
 201
 202 #ifdef HAVE_SIGACTION
 203     struct sigaction sa;
 204 #endif
 205
 206     assert(sig > 0 && callback);
 207
 208     for (e = signals; e; e = e->next)
 209         if (e->sig == sig)
 210             goto fail;
 211
 212     e = pa_xmalloc(sizeof(struct pa_signal_event));
 213     e->sig = sig;
 214     e->callback = callback;
 215     e->userdata = userdata;
 216     e->destroy_callback = NULL;
 217
 218 #ifdef HAVE_SIGACTION
 219     memset(&sa, 0, sizeof(sa));
 220     sa.sa_handler = signal_handler;
 221     sigemptyset(&sa.sa_mask);
 222     sa.sa_flags = SA_RESTART;
 223
 224     if (sigaction(sig, &sa, &e->saved_sigaction) < 0)
 225 #else
 226     if ((e->saved_handler = signal(sig, signal_handler)) == SIG_ERR)
 227 #endif
 228         goto fail;
 229
 230     e->previous = NULL;
 231     e->next = signals;
 232     signals = e;
 233
 234     return e;
 235 fail:
 236     if (e)
 237         pa_xfree(e);
 238     return NULL;
 239 }
 240
 241 void pa_signal_free(struct pa_signal_event *e) {
 242     assert(e);
 243
 244     if (e->next)
 245         e->next->previous = e->previous;
 246     if (e->previous)
 247         e->previous->next = e->next;
 248     else
 249         signals = e->next;
 250
 251 #ifdef HAVE_SIGACTION
 252     sigaction(e->sig, &e->saved_sigaction, NULL);
 253 #else
 254     signal(e->sig, e->saved_handler);
 255 #endif
 256
 257     if (e->destroy_callback)
 258         e->destroy_callback(api, e, e->userdata);
 259
 260     pa_xfree(e);
 261 }
 262
 263 void pa_signal_set_destroy(struct pa_signal_event *e, void (*callback) (struct pa_mainloop_api *api, struct pa_signal_event*e, void *userdata)) {
 264     assert(e);
 265     e->destroy_callback = callback;
 266 }