/* * Copyright (C) 2003-2009 The Music Player Daemon Project * http://www.musicpd.org * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "config.h" #include "event_pipe.h" #include "fd_util.h" #include <stdbool.h> #include <assert.h> #include <glib.h> #include <string.h> #include <errno.h> #include <sys/types.h> #include <unistd.h> #ifdef WIN32 /* for _O_BINARY */ #include <fcntl.h> #endif #undef G_LOG_DOMAIN #define G_LOG_DOMAIN "event_pipe" static int event_pipe[2]; static guint event_pipe_source_id; static GMutex *event_pipe_mutex; static bool pipe_events[PIPE_EVENT_MAX]; static event_pipe_callback_t event_pipe_callbacks[PIPE_EVENT_MAX]; /** * Invoke the callback for a certain event. */ static void event_pipe_invoke(enum pipe_event event) { assert((unsigned)event < PIPE_EVENT_MAX); assert(event_pipe_callbacks[event] != NULL); event_pipe_callbacks[event](); } static gboolean main_notify_event(G_GNUC_UNUSED GIOChannel *source, G_GNUC_UNUSED GIOCondition condition, G_GNUC_UNUSED gpointer data) { char buffer[256]; ssize_t r = read(event_pipe[0], buffer, sizeof(buffer)); bool events[PIPE_EVENT_MAX]; if (r < 0 && errno != EAGAIN && errno != EINTR) g_error("error reading from pipe: %s", strerror(errno)); g_mutex_lock(event_pipe_mutex); memcpy(events, pipe_events, sizeof(events)); memset(pipe_events, 0, sizeof(pipe_events)); g_mutex_unlock(event_pipe_mutex); for (unsigned i = 0; i < PIPE_EVENT_MAX; ++i) if (events[i]) /* invoke the event handler */ event_pipe_invoke(i); return true; } void event_pipe_init(void) { GIOChannel *channel; int ret; ret = pipe_cloexec_nonblock(event_pipe); if (ret < 0) g_error("Couldn't open pipe: %s", strerror(errno)); channel = g_io_channel_unix_new(event_pipe[0]); event_pipe_source_id = g_io_add_watch(channel, G_IO_IN, main_notify_event, NULL); g_io_channel_unref(channel); event_pipe_mutex = g_mutex_new(); } void event_pipe_deinit(void) { g_mutex_free(event_pipe_mutex); g_source_remove(event_pipe_source_id); close(event_pipe[0]); close(event_pipe[1]); } void event_pipe_register(enum pipe_event event, event_pipe_callback_t callback) { assert((unsigned)event < PIPE_EVENT_MAX); assert(event_pipe_callbacks[event] == NULL); event_pipe_callbacks[event] = callback; } void event_pipe_emit(enum pipe_event event) { ssize_t w; assert((unsigned)event < PIPE_EVENT_MAX); g_mutex_lock(event_pipe_mutex); if (pipe_events[event]) { /* already set: don't write */ g_mutex_unlock(event_pipe_mutex); return; } pipe_events[event] = true; g_mutex_unlock(event_pipe_mutex); w = write(event_pipe[1], "", 1); if (w < 0 && errno != EAGAIN && errno != EINTR) g_error("error writing to pipe: %s", strerror(errno)); } void event_pipe_emit_fast(enum pipe_event event) { assert((unsigned)event < PIPE_EVENT_MAX); pipe_events[event] = true; (void)write(event_pipe[1], "", 1); }