diff options
Diffstat (limited to 'src/EventPipe.cxx')
| -rw-r--r-- | src/EventPipe.cxx | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/src/EventPipe.cxx b/src/EventPipe.cxx new file mode 100644 index 000000000..b2c80a3c1 --- /dev/null +++ b/src/EventPipe.cxx @@ -0,0 +1,164 @@ +/* + * Copyright (C) 2003-2013 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 "mpd_error.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 GIOChannel *event_channel; +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]; + gsize bytes_read; + GError *error = NULL; + GIOStatus status = g_io_channel_read_chars(event_channel, + buffer, sizeof(buffer), + &bytes_read, &error); + if (status == G_IO_STATUS_ERROR) + MPD_ERROR("error reading from pipe: %s", error->message); + + bool events[PIPE_EVENT_MAX]; + 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(pipe_event(i)); + + return true; +} + +void event_pipe_init(void) +{ + GIOChannel *channel; + int ret; + + ret = pipe_cloexec_nonblock(event_pipe); + if (ret < 0) + MPD_ERROR("Couldn't open pipe: %s", strerror(errno)); + +#ifndef G_OS_WIN32 + channel = g_io_channel_unix_new(event_pipe[0]); +#else + channel = g_io_channel_win32_new_fd(event_pipe[0]); +#endif + g_io_channel_set_encoding(channel, NULL, NULL); + g_io_channel_set_buffered(channel, false); + + event_pipe_source_id = g_io_add_watch(channel, G_IO_IN, + main_notify_event, NULL); + + event_channel = 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); + g_io_channel_unref(event_channel); + +#ifndef WIN32 + /* By some strange reason this call hangs on Win32 */ + close(event_pipe[0]); +#endif + 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) + MPD_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; + + G_GNUC_UNUSED ssize_t nbytes = write(event_pipe[1], "", 1); +} |