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
  34 #include "mainloop-signal.h"
  35 #include "util.h"
  36 #include "xmalloc.h"
  37 #include "log.h"
  38
  39 struct pa_signal_event {
  40     int sig;
  41     struct sigaction saved_sigaction;
  42     void (*callback) (struct pa_mainloop_api*a, struct pa_signal_event *e, int signal, void *userdata);
  43     void *userdata;
  44     void (*destroy_callback) (struct pa_mainloop_api*a, struct pa_signal_event*e, void *userdata);
  45     struct pa_signal_event *previous, *next;
  46 };
  47
  48 static struct pa_mainloop_api *api = NULL;
  49 static int signal_pipe[2] = { -1, -1 };
  50 static struct pa_io_event* io_event = NULL;
  51 static struct pa_signal_event *signals = NULL;
  52
  53 static void signal_handler(int sig) {
  54     write(signal_pipe[1], &sig, sizeof(sig));
  55 }
  56
  57 static void callback(struct pa_mainloop_api*a, struct pa_io_event*e, int fd, enum pa_io_event_flags f, void *userdata) {
  58     ssize_t r;
  59     int sig;
  60     struct pa_signal_event*s;
  61     assert(a && e && f == PA_IO_EVENT_INPUT && e == io_event && fd == signal_pipe[0]);
  62
  63
  64     if ((r = read(signal_pipe[0], &sig, sizeof(sig))) < 0) {
  65         if (errno == EAGAIN)
  66             return;
  67
  68         pa_log(__FILE__": read(): %s\n", strerror(errno));
  69         return;
  70     }
  71
  72     if (r != sizeof(sig)) {
  73         pa_log(__FILE__": short read()\n");
  74         return;
  75     }
  76
  77     for (s = signals; s; s = s->next)
  78         if (s->sig == sig) {
  79             assert(s->callback);
  80             s->callback(a, s, sig, s->userdata);
  81             break;
  82         }
  83 }
  84
  85 int pa_signal_init(struct pa_mainloop_api *a) {
  86     assert(!api && a && signal_pipe[0] == -1 && signal_pipe[1] == -1 && !io_event);
  87
  88     if (pipe(signal_pipe) < 0) {
  89         pa_log(__FILE__": pipe() failed: %s\n", strerror(errno));
  90         return -1;
  91     }
  92
  93     pa_make_nonblock_fd(signal_pipe[0]);
  94     pa_make_nonblock_fd(signal_pipe[1]);
  95     pa_fd_set_cloexec(signal_pipe[0], 1);
  96     pa_fd_set_cloexec(signal_pipe[1], 1);
  97
  98     api = a;
  99     io_event = api->io_new(api, signal_pipe[0], PA_IO_EVENT_INPUT, callback, NULL);
 100     assert(io_event);
 101     return 0;
 102 }
 103
 104 void pa_signal_done(void) {
 105     assert(api && signal_pipe[0] >= 0 && signal_pipe[1] >= 0 && io_event);
 106
 107     while (signals)
 108         pa_signal_free(signals);
 109
 110
 111         api->io_free(io_event);
 112     io_event = NULL;
 113
 114     close(signal_pipe[0]);
 115     close(signal_pipe[1]);
 116     signal_pipe[0] = signal_pipe[1] = -1;
 117
 118     api = NULL;
 119 }
 120
 121 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) {
 122     struct pa_signal_event *e = NULL;
 123     struct sigaction sa;
 124     assert(sig > 0 && callback);
 125
 126     for (e = signals; e; e = e->next)
 127         if (e->sig == sig)
 128             goto fail;
 129
 130     e = pa_xmalloc(sizeof(struct pa_signal_event));
 131     e->sig = sig;
 132     e->callback = callback;
 133     e->userdata = userdata;
 134     e->destroy_callback = NULL;
 135
 136     memset(&sa, 0, sizeof(sa));
 137     sa.sa_handler = signal_handler;
 138     sigemptyset(&sa.sa_mask);
 139     sa.sa_flags = SA_RESTART;
 140
 141     if (sigaction(sig, &sa, &e->saved_sigaction) < 0)
 142         goto fail;
 143
 144     e->previous = NULL;
 145     e->next = signals;
 146     signals = e;
 147
 148     return e;
 149 fail:
 150     if (e)
 151         pa_xfree(e);
 152     return NULL;
 153 }
 154
 155 void pa_signal_free(struct pa_signal_event *e) {
 156     assert(e);
 157
 158     if (e->next)
 159         e->next->previous = e->previous;
 160     if (e->previous)
 161         e->previous->next = e->next;
 162     else
 163         signals = e->next;
 164
 165     sigaction(e->sig, &e->saved_sigaction, NULL);
 166
 167     if (e->destroy_callback)
 168         e->destroy_callback(api, e, e->userdata);
 169
 170     pa_xfree(e);
 171 }
 172
 173 void pa_signal_set_destroy(struct pa_signal_event *e, void (*callback) (struct pa_mainloop_api *api, struct pa_signal_event*e, void *userdata)) {
 174     assert(e);
 175     e->destroy_callback = callback;
 176 }