blob: 312bad05099c956083033e105594936ea22ecb8e [file] [log] [blame]
/*
* Copyright 2004 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifdef HAVE_DBUS_GLIB
#include "webrtc/base/dbus.h"
#include <glib.h>
#include "webrtc/base/logging.h"
#include "webrtc/base/thread.h"
namespace rtc {
// Avoid static object construction/destruction on startup/shutdown.
static pthread_once_t g_dbus_init_once = PTHREAD_ONCE_INIT;
static LibDBusGlibSymbolTable *g_dbus_symbol = NULL;
// Releases DBus-Glib symbols.
static void ReleaseDBusGlibSymbol() {
if (g_dbus_symbol != NULL) {
delete g_dbus_symbol;
g_dbus_symbol = NULL;
}
}
// Loads DBus-Glib symbols.
static void InitializeDBusGlibSymbol() {
// This is thread safe.
if (NULL == g_dbus_symbol) {
g_dbus_symbol = new LibDBusGlibSymbolTable();
// Loads dbus-glib
if (NULL == g_dbus_symbol || !g_dbus_symbol->Load()) {
LOG(LS_WARNING) << "Failed to load dbus-glib symbol table.";
ReleaseDBusGlibSymbol();
} else {
// Nothing we can do if atexit() failed. Just ignore its returned value.
atexit(ReleaseDBusGlibSymbol);
}
}
}
inline static LibDBusGlibSymbolTable *GetSymbols() {
return DBusMonitor::GetDBusGlibSymbolTable();
}
// Implementation of class DBusSigMessageData
DBusSigMessageData::DBusSigMessageData(DBusMessage *message)
: TypedMessageData<DBusMessage *>(message) {
GetSymbols()->dbus_message_ref()(data());
}
DBusSigMessageData::~DBusSigMessageData() {
GetSymbols()->dbus_message_unref()(data());
}
// Implementation of class DBusSigFilter
// Builds a DBus filter string from given DBus path, interface and member.
std::string DBusSigFilter::BuildFilterString(const std::string &path,
const std::string &interface,
const std::string &member) {
std::string ret(DBUS_TYPE "='" DBUS_SIGNAL "'");
if (!path.empty()) {
ret += ("," DBUS_PATH "='");
ret += path;
ret += "'";
}
if (!interface.empty()) {
ret += ("," DBUS_INTERFACE "='");
ret += interface;
ret += "'";
}
if (!member.empty()) {
ret += ("," DBUS_MEMBER "='");
ret += member;
ret += "'";
}
return ret;
}
// Forwards the message to the given instance.
DBusHandlerResult DBusSigFilter::DBusCallback(DBusConnection *dbus_conn,
DBusMessage *message,
void *instance) {
ASSERT(instance);
if (instance) {
return static_cast<DBusSigFilter *>(instance)->Callback(message);
}
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
// Posts a message to caller thread.
DBusHandlerResult DBusSigFilter::Callback(DBusMessage *message) {
if (caller_thread_) {
caller_thread_->Post(this, DSM_SIGNAL, new DBusSigMessageData(message));
}
// Don't "eat" the message here. Let it pop up.
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
// From MessageHandler.
void DBusSigFilter::OnMessage(Message *message) {
if (message != NULL && DSM_SIGNAL == message->message_id) {
DBusSigMessageData *msg =
static_cast<DBusSigMessageData *>(message->pdata);
if (msg) {
ProcessSignal(msg->data());
delete msg;
}
}
}
// Definition of private class DBusMonitoringThread.
// It creates a worker-thread to listen signals on DBus. The worker-thread will
// be running in a priate GMainLoop forever until either Stop() has been invoked
// or it hits an error.
class DBusMonitor::DBusMonitoringThread : public rtc::Thread {
public:
explicit DBusMonitoringThread(DBusMonitor *monitor,
GMainContext *context,
GMainLoop *mainloop,
std::vector<DBusSigFilter *> *filter_list)
: monitor_(monitor),
context_(context),
mainloop_(mainloop),
connection_(NULL),
idle_source_(NULL),
filter_list_(filter_list) {
ASSERT(monitor_);
ASSERT(context_);
ASSERT(mainloop_);
ASSERT(filter_list_);
}
virtual ~DBusMonitoringThread() {
Stop();
}
// Override virtual method of Thread. Context: worker-thread.
virtual void Run() {
ASSERT(NULL == connection_);
// Setup DBus connection and start monitoring.
monitor_->OnMonitoringStatusChanged(DMS_INITIALIZING);
if (!Setup()) {
LOG(LS_ERROR) << "DBus monitoring setup failed.";
monitor_->OnMonitoringStatusChanged(DMS_FAILED);
CleanUp();
return;
}
monitor_->OnMonitoringStatusChanged(DMS_RUNNING);
g_main_loop_run(mainloop_);
monitor_->OnMonitoringStatusChanged(DMS_STOPPED);
// Done normally. Clean up DBus connection.
CleanUp();
return;
}
// Override virtual method of Thread. Context: caller-thread.
virtual void Stop() {
ASSERT(NULL == idle_source_);
// Add an idle source and let the gmainloop quit on idle.
idle_source_ = g_idle_source_new();
if (idle_source_) {
g_source_set_callback(idle_source_, &Idle, this, NULL);
g_source_attach(idle_source_, context_);
} else {
LOG(LS_ERROR) << "g_idle_source_new() failed.";
QuitGMainloop(); // Try to quit anyway.
}
Thread::Stop(); // Wait for the thread.
}
private:
// Registers all DBus filters.
void RegisterAllFilters() {
ASSERT(NULL != GetSymbols()->dbus_g_connection_get_connection()(
connection_));
for (std::vector<DBusSigFilter *>::iterator it = filter_list_->begin();
it != filter_list_->end(); ++it) {
DBusSigFilter *filter = (*it);
if (!filter) {
LOG(LS_ERROR) << "DBusSigFilter list corrupted.";
continue;
}
GetSymbols()->dbus_bus_add_match()(
GetSymbols()->dbus_g_connection_get_connection()(connection_),
filter->filter().c_str(), NULL);
if (!GetSymbols()->dbus_connection_add_filter()(
GetSymbols()->dbus_g_connection_get_connection()(connection_),
&DBusSigFilter::DBusCallback, filter, NULL)) {
LOG(LS_ERROR) << "dbus_connection_add_filter() failed."
<< "Filter: " << filter->filter();
continue;
}
}
}
// Unregisters all DBus filters.
void UnRegisterAllFilters() {
ASSERT(NULL != GetSymbols()->dbus_g_connection_get_connection()(
connection_));
for (std::vector<DBusSigFilter *>::iterator it = filter_list_->begin();
it != filter_list_->end(); ++it) {
DBusSigFilter *filter = (*it);
if (!filter) {
LOG(LS_ERROR) << "DBusSigFilter list corrupted.";
continue;
}
GetSymbols()->dbus_connection_remove_filter()(
GetSymbols()->dbus_g_connection_get_connection()(connection_),
&DBusSigFilter::DBusCallback, filter);
}
}
// Sets up the monitoring thread.
bool Setup() {
g_main_context_push_thread_default(context_);
// Start connection to dbus.
// If dbus daemon is not running, returns false immediately.
connection_ = GetSymbols()->dbus_g_bus_get_private()(monitor_->type_,
context_, NULL);
if (NULL == connection_) {
LOG(LS_ERROR) << "dbus_g_bus_get_private() unable to get connection.";
return false;
}
if (NULL == GetSymbols()->dbus_g_connection_get_connection()(connection_)) {
LOG(LS_ERROR) << "dbus_g_connection_get_connection() returns NULL. "
<< "DBus daemon is probably not running.";
return false;
}
// Application don't exit if DBus daemon die.
GetSymbols()->dbus_connection_set_exit_on_disconnect()(
GetSymbols()->dbus_g_connection_get_connection()(connection_), FALSE);
// Connect all filters.
RegisterAllFilters();
return true;
}
// Cleans up the monitoring thread.
void CleanUp() {
if (idle_source_) {
// We did an attach() with the GSource, so we need to destroy() it.
g_source_destroy(idle_source_);
// We need to unref() the GSource to end the last reference we got.
g_source_unref(idle_source_);
idle_source_ = NULL;
}
if (connection_) {
if (GetSymbols()->dbus_g_connection_get_connection()(connection_)) {
UnRegisterAllFilters();
GetSymbols()->dbus_connection_close()(
GetSymbols()->dbus_g_connection_get_connection()(connection_));
}
GetSymbols()->dbus_g_connection_unref()(connection_);
connection_ = NULL;
}
g_main_loop_unref(mainloop_);
mainloop_ = NULL;
g_main_context_unref(context_);
context_ = NULL;
}
// Handles callback on Idle. We only add this source when ready to stop.
static gboolean Idle(gpointer data) {
static_cast<DBusMonitoringThread *>(data)->QuitGMainloop();
return TRUE;
}
// We only hit this when ready to quit.
void QuitGMainloop() {
g_main_loop_quit(mainloop_);
}
DBusMonitor *monitor_;
GMainContext *context_;
GMainLoop *mainloop_;
DBusGConnection *connection_;
GSource *idle_source_;
std::vector<DBusSigFilter *> *filter_list_;
};
// Implementation of class DBusMonitor
// Returns DBus-Glib symbol handle. Initialize it first if hasn't.
LibDBusGlibSymbolTable *DBusMonitor::GetDBusGlibSymbolTable() {
// This is multi-thread safe.
pthread_once(&g_dbus_init_once, InitializeDBusGlibSymbol);
return g_dbus_symbol;
};
// Creates an instance of DBusMonitor
DBusMonitor *DBusMonitor::Create(DBusBusType type) {
if (NULL == DBusMonitor::GetDBusGlibSymbolTable()) {
return NULL;
}
return new DBusMonitor(type);
}
DBusMonitor::DBusMonitor(DBusBusType type)
: type_(type),
status_(DMS_NOT_INITIALIZED),
monitoring_thread_(NULL) {
ASSERT(type_ == DBUS_BUS_SYSTEM || type_ == DBUS_BUS_SESSION);
}
DBusMonitor::~DBusMonitor() {
StopMonitoring();
}
bool DBusMonitor::AddFilter(DBusSigFilter *filter) {
if (monitoring_thread_) {
return false;
}
if (!filter) {
return false;
}
filter_list_.push_back(filter);
return true;
}
bool DBusMonitor::StartMonitoring() {
if (!monitoring_thread_) {
g_type_init();
// g_thread_init API is deprecated since glib 2.31.0, see release note:
// http://mail.gnome.org/archives/gnome-announce-list/2011-October/msg00041.html
#if !GLIB_CHECK_VERSION(2, 31, 0)
g_thread_init(NULL);
#endif
GetSymbols()->dbus_g_thread_init()();
GMainContext *context = g_main_context_new();
if (NULL == context) {
LOG(LS_ERROR) << "g_main_context_new() failed.";
return false;
}
GMainLoop *mainloop = g_main_loop_new(context, FALSE);
if (NULL == mainloop) {
LOG(LS_ERROR) << "g_main_loop_new() failed.";
g_main_context_unref(context);
return false;
}
monitoring_thread_ = new DBusMonitoringThread(this, context, mainloop,
&filter_list_);
if (monitoring_thread_ == NULL) {
LOG(LS_ERROR) << "Failed to create DBus monitoring thread.";
g_main_context_unref(context);
g_main_loop_unref(mainloop);
return false;
}
monitoring_thread_->Start();
}
return true;
}
bool DBusMonitor::StopMonitoring() {
if (monitoring_thread_) {
monitoring_thread_->Stop();
monitoring_thread_ = NULL;
}
return true;
}
DBusMonitor::DBusMonitorStatus DBusMonitor::GetStatus() {
return status_;
}
void DBusMonitor::OnMonitoringStatusChanged(DBusMonitorStatus status) {
status_ = status;
}
#undef LATE
} // namespace rtc
#endif // HAVE_DBUS_GLIB