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_time_event *time_event = NULL;
  63 static pa_signal_event *signals = NULL;
  64
  65 #ifdef OS_IS_WIN32
  66 static unsigned int waiting_signals = 0;
  67 static CRITICAL_SECTION crit;
  68 #endif
  69
  70 static void signal_handler(int sig) {
  71 #ifndef HAVE_SIGACTION
  72     signal(sig, signal_handler);
  73 #endif
  74     write(signal_pipe[1], &sig, sizeof(sig));
  75
  76 #ifdef OS_IS_WIN32
  77     EnterCriticalSection(&crit);
  78     waiting_signals++;
  79     LeaveCriticalSection(&crit);
  80 #endif
  81 }
  82
  83 static void dispatch(pa_mainloop_api*a, int sig) {
  84     pa_signal_event*s;
  85
  86     for (s = signals; s; s = s->next)
  87         if (s->sig == sig) {
  88             assert(s->callback);
  89             s->callback(a, s, sig, s->userdata);
  90             break;
  91         }
  92 }
  93
  94 #ifdef OS_IS_WIN32
  95 static void timer(pa_mainloop_api*a, pa_time_event*e, PA_GCC_UNUSED const struct timeval *tv, PA_GCC_UNUSED void *userdata) {
  96     ssize_t r;
  97     int sig;
  98     unsigned int sigs;
  99     struct timeval tvnext;
 100
 101     EnterCriticalSection(&crit);
 102     sigs = waiting_signals;
 103     waiting_signals = 0;
 104     LeaveCriticalSection(&crit);
 105
 106     while (sigs) {
 107         if ((r = read(signal_pipe[0], &sig, sizeof(sig))) < 0) {
 108             pa_log(__FILE__": read(): %s", strerror(errno));
 109             return;
 110         }
 111
 112         if (r != sizeof(sig)) {
 113             pa_log(__FILE__": short read()");
 114             return;
 115         }
 116
 117         dispatch(a, sig);
 118
 119         sigs--;
 120     }
 121
 122     pa_timeval_add(pa_gettimeofday(&tvnext), 100000);
 123     a->time_restart(e, &tvnext);
 124 }
 125 #endif
 126
 127 static void callback(pa_mainloop_api*a, pa_io_event*e, int fd, pa_io_event_flags_t f, PA_GCC_UNUSED void *userdata) {
 128     ssize_t r;
 129     int sig;
 130     assert(a && e && f == PA_IO_EVENT_INPUT && e == io_event && fd == signal_pipe[0]);
 131
 132
 133     if ((r = read(signal_pipe[0], &sig, sizeof(sig))) < 0) {
 134         if (errno == EAGAIN)
 135             return;
 136
 137         pa_log(__FILE__": read(): %s", strerror(errno));
 138         return;
 139     }
 140
 141     if (r != sizeof(sig)) {
 142         pa_log(__FILE__": short read()");
 143         return;
 144     }
 145
 146     dispatch(a, sig);
 147 }
 148
 149 int pa_signal_init(pa_mainloop_api *a) {
 150 #ifdef OS_IS_WIN32
 151     struct timeval tv;
 152 #endif
 153
 154     assert(!api && a && signal_pipe[0] == -1 && signal_pipe[1] == -1 && !io_event && !time_event);
 155
 156 #ifdef OS_IS_WIN32
 157     if (_pipe(signal_pipe, 200, _O_BINARY) < 0) {
 158 #else
 159     if (pipe(signal_pipe) < 0) {
 160 #endif
 161         pa_log(__FILE__": pipe() failed: %s", strerror(errno));
 162         return -1;
 163     }
 164
 165     pa_make_nonblock_fd(signal_pipe[0]);
 166     pa_make_nonblock_fd(signal_pipe[1]);
 167     pa_fd_set_cloexec(signal_pipe[0], 1);
 168     pa_fd_set_cloexec(signal_pipe[1], 1);
 169
 170     api = a;
 171
 172 #ifndef OS_IS_WIN32
 173     io_event = api->io_new(api, signal_pipe[0], PA_IO_EVENT_INPUT, callback, NULL);
 174     assert(io_event);
 175 #else
 176     time_event = api->time_new(api, pa_gettimeofday(&tv), timer, NULL);
 177     assert(time_event);
 178
 179     InitializeCriticalSection(&crit);
 180 #endif
 181
 182     return 0;
 183 }
 184
 185 void pa_signal_done(void) {
 186     assert(api && signal_pipe[0] >= 0 && signal_pipe[1] >= 0 && (io_event || time_event));
 187
 188     while (signals)
 189         pa_signal_free(signals);
 190
 191 #ifndef OS_IS_WIN32
 192     api->io_free(io_event);
 193     io_event = NULL;
 194 #else
 195     api->time_free(time_event);
 196     time_event = NULL;
 197
 198     DeleteCriticalSection(&crit);
 199 #endif
 200
 201     close(signal_pipe[0]);
 202     close(signal_pipe[1]);
 203     signal_pipe[0] = signal_pipe[1] = -1;
 204
 205     api = NULL;
 206 }
 207
 208 pa_signal_event* pa_signal_new(int sig, void (*_callback) (pa_mainloop_api *api, pa_signal_event*e, int sig, void *userdata), void *userdata) {
 209     pa_signal_event *e = NULL;
 210
 211 #ifdef HAVE_SIGACTION
 212     struct sigaction sa;
 213 #endif
 214
 215     assert(sig > 0 && _callback);
 216
 217     for (e = signals; e; e = e->next)
 218         if (e->sig == sig)
 219             goto fail;
 220
 221     e = pa_xmalloc(sizeof(pa_signal_event));
 222     e->sig = sig;
 223     e->callback = _callback;
 224     e->userdata = userdata;
 225     e->destroy_callback = NULL;
 226
 227 #ifdef HAVE_SIGACTION
 228     memset(&sa, 0, sizeof(sa));
 229     sa.sa_handler = signal_handler;
 230     sigemptyset(&sa.sa_mask);
 231     sa.sa_flags = SA_RESTART;
 232
 233     if (sigaction(sig, &sa, &e->saved_sigaction) < 0)
 234 #else
 235     if ((e->saved_handler = signal(sig, signal_handler)) == SIG_ERR)
 236 #endif
 237         goto fail;
 238
 239     e->previous = NULL;
 240     e->next = signals;
 241     signals = e;
 242
 243     return e;
 244 fail:
 245     if (e)
 246         pa_xfree(e);
 247     return NULL;
 248 }
 249
 250 void pa_signal_free(pa_signal_event *e) {
 251     assert(e);
 252
 253     if (e->next)
 254         e->next->previous = e->previous;
 255     if (e->previous)
 256         e->previous->next = e->next;
 257     else
 258         signals = e->next;
 259
 260 #ifdef HAVE_SIGACTION
 261     sigaction(e->sig, &e->saved_sigaction, NULL);
 262 #else
 263     signal(e->sig, e->saved_handler);
 264 #endif
 265
 266     if (e->destroy_callback)
 267         e->destroy_callback(api, e, e->userdata);
 268
 269     pa_xfree(e);
 270 }
 271
 272 void pa_signal_set_destroy(pa_signal_event *e, void (*_callback) (pa_mainloop_api *api, pa_signal_event*e, void *userdata)) {
 273     assert(e);
 274     e->destroy_callback = _callback;
 275 }