From 26ebfc04b0668262976ec4fc38d8780c0937045a Mon Sep 17 00:00:00 2001 From: Max Kellermann Date: Wed, 9 Jan 2013 23:12:53 +0100 Subject: EventPipe: rename to GlobalEvents --- src/GlobalEvents.cxx | 153 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 153 insertions(+) create mode 100644 src/GlobalEvents.cxx (limited to 'src/GlobalEvents.cxx') diff --git a/src/GlobalEvents.cxx b/src/GlobalEvents.cxx new file mode 100644 index 000000000..4bc607dfb --- /dev/null +++ b/src/GlobalEvents.cxx @@ -0,0 +1,153 @@ +/* + * 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 "GlobalEvents.hxx" +#include "thread/Mutex.hxx" +#include "fd_util.h" +#include "mpd_error.h" + +#include +#include +#include +#include +#include + +#undef G_LOG_DOMAIN +#define G_LOG_DOMAIN "global_events" + +namespace GlobalEvents { + static int fds[2]; + static GIOChannel *channel; + static guint source_id; + static Mutex mutex; + static bool flags[MAX]; + static Handler handlers[MAX]; +} + +/** + * Invoke the callback for a certain event. + */ +static void +InvokeGlobalEvent(GlobalEvents::Event event) +{ + assert((unsigned)event < GlobalEvents::MAX); + assert(GlobalEvents::handlers[event] != NULL); + + GlobalEvents::handlers[event](); +} + +static gboolean +GlobalEventCallback(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(GlobalEvents::channel, + buffer, sizeof(buffer), + &bytes_read, &error); + if (status == G_IO_STATUS_ERROR) + MPD_ERROR("error reading from pipe: %s", error->message); + + bool events[GlobalEvents::MAX]; + GlobalEvents::mutex.lock(); + memcpy(events, GlobalEvents::flags, sizeof(events)); + memset(GlobalEvents::flags, 0, + sizeof(GlobalEvents::flags)); + GlobalEvents::mutex.unlock(); + + for (unsigned i = 0; i < GlobalEvents::MAX; ++i) + if (events[i]) + /* invoke the event handler */ + InvokeGlobalEvent(GlobalEvents::Event(i)); + + return true; +} + +void +GlobalEvents::Initialize() +{ + if (pipe_cloexec_nonblock(fds) < 0) + MPD_ERROR("Couldn't open pipe: %s", strerror(errno)); + +#ifndef G_OS_WIN32 + channel = g_io_channel_unix_new(fds[0]); +#else + channel = g_io_channel_win32_new_fd(fds[0]); +#endif + g_io_channel_set_encoding(channel, NULL, NULL); + g_io_channel_set_buffered(channel, false); + + source_id = g_io_add_watch(channel, G_IO_IN, + GlobalEventCallback, NULL); +} + +void +GlobalEvents::Deinitialize() +{ + g_source_remove(source_id); + g_io_channel_unref(channel); + +#ifndef WIN32 + /* By some strange reason this call hangs on Win32 */ + close(fds[0]); +#endif + close(fds[1]); +} + +void +GlobalEvents::Register(Event event, Handler callback) +{ + assert((unsigned)event < MAX); + assert(handlers[event] == NULL); + + handlers[event] = callback; +} + +void +GlobalEvents::Emit(Event event) +{ + assert((unsigned)event < MAX); + + mutex.lock(); + if (flags[event]) { + /* already set: don't write */ + mutex.unlock(); + return; + } + + flags[event] = true; + mutex.unlock(); + + ssize_t w = write(fds[1], "", 1); + if (w < 0 && errno != EAGAIN && errno != EINTR) + MPD_ERROR("error writing to pipe: %s", strerror(errno)); +} + +void +GlobalEvents::FastEmit(Event event) +{ + assert((unsigned)event < MAX); + + flags[event] = true; + + G_GNUC_UNUSED ssize_t nbytes = write(fds[1], "", 1); +} -- cgit v1.2.3