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