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-rw-r--r--src/IOThread.cxx197
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diff --git a/src/IOThread.cxx b/src/IOThread.cxx
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+++ b/src/IOThread.cxx
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+/*
+ * 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 "IOThread.hxx"
+#include "thread/Mutex.hxx"
+#include "thread/Cond.hxx"
+
+#include <assert.h>
+
+static struct {
+ Mutex mutex;
+ Cond cond;
+
+ GMainContext *context;
+ GMainLoop *loop;
+ GThread *thread;
+} io;
+
+void
+io_thread_run(void)
+{
+ assert(io_thread_inside());
+ assert(io.context != NULL);
+ assert(io.loop != NULL);
+
+ g_main_loop_run(io.loop);
+}
+
+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.context == NULL);
+ assert(io.loop == NULL);
+ assert(io.thread == NULL);
+
+ io.context = g_main_context_new();
+ io.loop = g_main_loop_new(io.context, false);
+}
+
+bool
+io_thread_start(GError **error_r)
+{
+ assert(io.context != NULL);
+ 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);
+
+ g_main_loop_quit(io.loop);
+}
+
+void
+io_thread_deinit(void)
+{
+ if (io.thread != NULL) {
+ io_thread_quit();
+
+ g_thread_join(io.thread);
+ }
+
+ if (io.loop != NULL)
+ g_main_loop_unref(io.loop);
+
+ if (io.context != NULL)
+ g_main_context_unref(io.context);
+}
+
+GMainContext *
+io_thread_context(void)
+{
+ return io.context;
+}
+
+bool
+io_thread_inside(void)
+{
+ return io.thread != NULL && g_thread_self() == io.thread;
+}
+
+guint
+io_thread_idle_add(GSourceFunc function, gpointer data)
+{
+ GSource *source = g_idle_source_new();
+ g_source_set_callback(source, function, data, NULL);
+ guint id = g_source_attach(source, io.context);
+ g_source_unref(source);
+ return id;
+}
+
+GSource *
+io_thread_timeout_add(guint interval_ms, GSourceFunc function, gpointer data)
+{
+ GSource *source = g_timeout_source_new(interval_ms);
+ g_source_set_callback(source, function, data, NULL);
+ g_source_attach(source, io.context);
+ return source;
+}
+
+GSource *
+io_thread_timeout_add_seconds(guint interval,
+ GSourceFunc function, gpointer data)
+{
+ GSource *source = g_timeout_source_new_seconds(interval);
+ g_source_set_callback(source, function, data, NULL);
+ g_source_attach(source, io.context);
+ return source;
+}
+
+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_thread_idle_add(io_thread_call_func, &data);
+
+ io.mutex.lock();
+ while (!data.done)
+ io.cond.wait(io.mutex);
+ io.mutex.unlock();
+
+ return data.result;
+}