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Diffstat (limited to '')
-rw-r--r-- | src/IOThread.cxx | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/src/IOThread.cxx b/src/IOThread.cxx new file mode 100644 index 000000000..192d4cc49 --- /dev/null +++ b/src/IOThread.cxx @@ -0,0 +1,163 @@ +/* + * 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 "IOThread.hxx" +#include "thread/Mutex.hxx" +#include "thread/Cond.hxx" +#include "event/Loop.hxx" + +#include <assert.h> + +static struct { + Mutex mutex; + Cond cond; + + EventLoop *loop; + GThread *thread; +} io; + +void +io_thread_run(void) +{ + assert(io_thread_inside()); + assert(io.loop != NULL); + + io.loop->Run(); +} + +static gpointer +io_thread_func(G_GNUC_UNUSED gpointer arg) +{ + /* lock+unlock to synchronize with io_thread_start(), to be + sure that io.thread is set */ + io.mutex.lock(); + io.mutex.unlock(); + + io_thread_run(); + return NULL; +} + +void +io_thread_init(void) +{ + assert(io.loop == NULL); + assert(io.thread == NULL); + + io.loop = new EventLoop(); +} + +bool +io_thread_start(GError **error_r) +{ + assert(io.loop != NULL); + assert(io.thread == NULL); + + io.mutex.lock(); + io.thread = g_thread_create(io_thread_func, NULL, true, error_r); + io.mutex.unlock(); + if (io.thread == NULL) + return false; + + return true; +} + +void +io_thread_quit(void) +{ + assert(io.loop != NULL); + + io.loop->Break(); +} + +void +io_thread_deinit(void) +{ + if (io.thread != NULL) { + io_thread_quit(); + + g_thread_join(io.thread); + } + + delete io.loop; +} + +EventLoop & +io_thread_get() +{ + assert(io.loop != nullptr); + + return *io.loop; +} + +bool +io_thread_inside(void) +{ + return io.thread != NULL && g_thread_self() == io.thread; +} + +struct call_data { + GThreadFunc function; + gpointer data; + bool done; + gpointer result; +}; + +static gboolean +io_thread_call_func(gpointer _data) +{ + struct call_data *data = (struct call_data *)_data; + + gpointer result = data->function(data->data); + + io.mutex.lock(); + data->done = true; + data->result = result; + io.cond.broadcast(); + io.mutex.unlock(); + + return false; +} + +gpointer +io_thread_call(GThreadFunc function, gpointer _data) +{ + assert(io.thread != NULL); + + if (io_thread_inside()) + /* we're already in the I/O thread - no + synchronization needed */ + return function(_data); + + struct call_data data = { + function, + _data, + false, + nullptr, + }; + + io.loop->AddIdle(io_thread_call_func, &data); + + io.mutex.lock(); + while (!data.done) + io.cond.wait(io.mutex); + io.mutex.unlock(); + + return data.result; +} |