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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "dbus/object_proxy.h"
#include <stddef.h>
#include <utility>
#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/debug/leak_annotations.h"
#include "base/logging.h"
#include "base/metrics/histogram_macros.h"
#include "base/strings/string_piece.h"
#include "base/strings/stringprintf.h"
#include "base/task_runner.h"
#include "base/task_runner_util.h"
#include "base/threading/thread.h"
#include "base/threading/thread_restrictions.h"
#include "dbus/bus.h"
#include "dbus/dbus_statistics.h"
#include "dbus/message.h"
#include "dbus/object_path.h"
#include "dbus/scoped_dbus_error.h"
#include "dbus/util.h"
namespace dbus {
namespace {
constexpr char kErrorServiceUnknown[] =
"org.freedesktop.DBus.Error.ServiceUnknown";
constexpr char kErrorObjectUnknown[] =
"org.freedesktop.DBus.Error.UnknownObject";
// Used for success ratio histograms. 1 for success, 0 for failure.
constexpr int kSuccessRatioHistogramMaxValue = 2;
// The path of D-Bus Object sending NameOwnerChanged signal.
constexpr char kDBusSystemObjectPath[] = "/org/freedesktop/DBus";
// The D-Bus Object interface.
constexpr char kDBusSystemObjectInterface[] = "org.freedesktop.DBus";
// The D-Bus Object address.
constexpr char kDBusSystemObjectAddress[] = "org.freedesktop.DBus";
// The NameOwnerChanged member in |kDBusSystemObjectInterface|.
constexpr char kNameOwnerChangedMember[] = "NameOwnerChanged";
} // namespace
ObjectProxy::ReplyCallbackHolder::ReplyCallbackHolder(
scoped_refptr<base::TaskRunner> origin_task_runner,
ResponseOrErrorCallback callback)
: origin_task_runner_(origin_task_runner), callback_(std::move(callback)) {
DCHECK(origin_task_runner_.get());
DCHECK(!callback_.is_null());
}
ObjectProxy::ReplyCallbackHolder::ReplyCallbackHolder(
ReplyCallbackHolder&& other) = default;
ObjectProxy::ReplyCallbackHolder::~ReplyCallbackHolder() {
if (callback_.is_null()) {
// This is the regular case.
// CallMethod and its family creates this object on the origin thread,
// PostTask()s to the D-Bus thread for actual D-Bus communication,
// then PostTask()s back to the origin thread to invoke the |callback_|.
// At that timing, the ownership of callback should be released via
// ReleaseCallback().
// Otherwise, this instance was moved to another one. Do nothing in
// either case.
return;
}
// The only case where |origin_task_runner_| becomes nullptr is that
// this is moved. In such a case, |callback_| should be nullptr, too, so it
// should be handled above. Thus, here |origin_task_runner_| must not be
// nullptr.
DCHECK(origin_task_runner_.get());
if (origin_task_runner_->RunsTasksInCurrentSequence()) {
// Destroyed on the origin thread. This happens when PostTask()ing to
// the D-Bus thread fails. The |callback_| can be destroyed on the
// current thread safely. Do nothing here, and let member destruction
// destroy the callback.
return;
}
// Here is on D-Bus thread, so try to PostTask() to destroy the callback.
// to the origin thread.
// The |origin_task_runner_| may already have stopped. E.g., on Chrome's
// shutdown the message loop of the UI thread (= the origin thread) stops
// before D-Bus threaed's. In such a case, PostTask() fails. Because we
// cannot do much thing here, instead, simply leak the callback rather than
// destroying it on the D-Bus thread, which could be unexpected from the
// direct or indirect caller of CallMethod.
auto* callback_to_be_deleted =
new ResponseOrErrorCallback(std::move(callback_));
ANNOTATE_LEAKING_OBJECT_PTR(callback_to_be_deleted);
origin_task_runner_->PostTask(
FROM_HERE, base::BindOnce(&base::DeletePointer<ResponseOrErrorCallback>,
callback_to_be_deleted));
}
ObjectProxy::ResponseOrErrorCallback
ObjectProxy::ReplyCallbackHolder::ReleaseCallback() {
DCHECK(origin_task_runner_->RunsTasksInCurrentSequence());
return std::move(callback_);
}
ObjectProxy::ObjectProxy(Bus* bus,
const std::string& service_name,
const ObjectPath& object_path,
int options)
: bus_(bus),
service_name_(service_name),
object_path_(object_path),
ignore_service_unknown_errors_(
options & IGNORE_SERVICE_UNKNOWN_ERRORS) {
LOG_IF(FATAL, !object_path_.IsValid()) << object_path_.value();
}
ObjectProxy::~ObjectProxy() {
DCHECK(pending_calls_.empty());
}
// Originally we tried to make |method_call| a const reference, but we
// gave up as dbus_connection_send_with_reply_and_block() takes a
// non-const pointer of DBusMessage as the second parameter.
std::unique_ptr<Response> ObjectProxy::CallMethodAndBlockWithErrorDetails(
MethodCall* method_call,
int timeout_ms,
ScopedDBusError* error) {
bus_->AssertOnDBusThread();
if (!bus_->Connect() ||
!method_call->SetDestination(service_name_) ||
!method_call->SetPath(object_path_))
return std::unique_ptr<Response>();
DBusMessage* request_message = method_call->raw_message();
// Send the message synchronously.
const base::TimeTicks start_time = base::TimeTicks::Now();
DBusMessage* response_message =
bus_->SendWithReplyAndBlock(request_message, timeout_ms, error->get());
// Record if the method call is successful, or not. 1 if successful.
UMA_HISTOGRAM_ENUMERATION("DBus.SyncMethodCallSuccess",
response_message ? 1 : 0,
kSuccessRatioHistogramMaxValue);
statistics::AddBlockingSentMethodCall(service_name_,
method_call->GetInterface(),
method_call->GetMember());
if (!response_message) {
LogMethodCallFailure(method_call->GetInterface(),
method_call->GetMember(),
error->is_set() ? error->name() : "unknown error type",
error->is_set() ? error->message() : "");
return std::unique_ptr<Response>();
}
// Record time spent for the method call. Don't include failures.
UMA_HISTOGRAM_TIMES("DBus.SyncMethodCallTime",
base::TimeTicks::Now() - start_time);
return Response::FromRawMessage(response_message);
}
std::unique_ptr<Response> ObjectProxy::CallMethodAndBlock(
MethodCall* method_call,
int timeout_ms) {
ScopedDBusError error;
return CallMethodAndBlockWithErrorDetails(method_call, timeout_ms, &error);
}
void ObjectProxy::CallMethod(MethodCall* method_call,
int timeout_ms,
ResponseCallback callback) {
auto internal_callback = base::BindOnce(
&ObjectProxy::OnCallMethod, this, method_call->GetInterface(),
method_call->GetMember(), std::move(callback));
CallMethodWithErrorResponse(method_call, timeout_ms,
std::move(internal_callback));
}
void ObjectProxy::CallMethodWithErrorResponse(
MethodCall* method_call,
int timeout_ms,
ResponseOrErrorCallback callback) {
bus_->AssertOnOriginThread();
const base::TimeTicks start_time = base::TimeTicks::Now();
ReplyCallbackHolder callback_holder(bus_->GetOriginTaskRunner(),
std::move(callback));
if (!method_call->SetDestination(service_name_) ||
!method_call->SetPath(object_path_)) {
// In case of a failure, run the error callback with nullptr.
base::OnceClosure task =
base::BindOnce(&ObjectProxy::RunResponseOrErrorCallback, this,
std::move(callback_holder), start_time,
nullptr /* response */, nullptr /* error_response */);
bus_->GetOriginTaskRunner()->PostTask(FROM_HERE, std::move(task));
return;
}
// Increment the reference count so we can safely reference the
// underlying request message until the method call is complete. This
// will be unref'ed in StartAsyncMethodCall().
DBusMessage* request_message = method_call->raw_message();
dbus_message_ref(request_message);
statistics::AddSentMethodCall(service_name_,
method_call->GetInterface(),
method_call->GetMember());
// Wait for the response in the D-Bus thread.
base::OnceClosure task =
base::BindOnce(&ObjectProxy::StartAsyncMethodCall, this, timeout_ms,
request_message, std::move(callback_holder), start_time);
bus_->GetDBusTaskRunner()->PostTask(FROM_HERE, std::move(task));
}
void ObjectProxy::CallMethodWithErrorCallback(MethodCall* method_call,
int timeout_ms,
ResponseCallback callback,
ErrorCallback error_callback) {
auto internal_callback = base::BindOnce(
[](ResponseCallback callback, ErrorCallback error_callback,
Response* response, ErrorResponse* error_response) {
if (response) {
std::move(callback).Run(response);
} else {
std::move(error_callback).Run(error_response);
}
},
std::move(callback), std::move(error_callback));
CallMethodWithErrorResponse(method_call, timeout_ms,
std::move(internal_callback));
}
void ObjectProxy::ConnectToSignal(const std::string& interface_name,
const std::string& signal_name,
SignalCallback signal_callback,
OnConnectedCallback on_connected_callback) {
bus_->AssertOnOriginThread();
if (bus_->HasDBusThread()) {
base::PostTaskAndReplyWithResult(
bus_->GetDBusTaskRunner(), FROM_HERE,
base::BindOnce(&ObjectProxy::ConnectToSignalInternal, this,
interface_name, signal_name, signal_callback),
base::BindOnce(std::move(on_connected_callback), interface_name,
signal_name));
} else {
// If the bus doesn't have a dedicated dbus thread we need to call
// ConnectToSignalInternal directly otherwise we might miss a signal
// that is currently queued if we do a PostTask.
const bool success =
ConnectToSignalInternal(interface_name, signal_name, signal_callback);
std::move(on_connected_callback).Run(interface_name, signal_name, success);
}
}
void ObjectProxy::SetNameOwnerChangedCallback(
NameOwnerChangedCallback callback) {
bus_->AssertOnOriginThread();
name_owner_changed_callback_ = callback;
}
void ObjectProxy::WaitForServiceToBeAvailable(
WaitForServiceToBeAvailableCallback callback) {
bus_->AssertOnOriginThread();
wait_for_service_to_be_available_callbacks_.push_back(std::move(callback));
bus_->GetDBusTaskRunner()->PostTask(
FROM_HERE,
base::BindOnce(&ObjectProxy::WaitForServiceToBeAvailableInternal, this));
}
void ObjectProxy::Detach() {
bus_->AssertOnDBusThread();
if (bus_->is_connected())
bus_->RemoveFilterFunction(&ObjectProxy::HandleMessageThunk, this);
for (const auto& match_rule : match_rules_) {
ScopedDBusError error;
bus_->RemoveMatch(match_rule, error.get());
if (error.is_set()) {
// There is nothing we can do to recover, so just print the error.
LOG(ERROR) << "Failed to remove match rule: " << match_rule;
}
}
match_rules_.clear();
for (auto* pending_call : pending_calls_) {
dbus_pending_call_cancel(pending_call);
dbus_pending_call_unref(pending_call);
}
pending_calls_.clear();
}
void ObjectProxy::StartAsyncMethodCall(int timeout_ms,
DBusMessage* request_message,
ReplyCallbackHolder callback_holder,
base::TimeTicks start_time) {
bus_->AssertOnDBusThread();
if (!bus_->Connect() || !bus_->SetUpAsyncOperations()) {
// In case of a failure, run the error callback with nullptr.
base::OnceClosure task =
base::BindOnce(&ObjectProxy::RunResponseOrErrorCallback, this,
std::move(callback_holder), start_time,
nullptr /* response */, nullptr /* error_response */);
bus_->GetOriginTaskRunner()->PostTask(FROM_HERE, std::move(task));
dbus_message_unref(request_message);
return;
}
DBusPendingCall* dbus_pending_call = nullptr;
bus_->SendWithReply(request_message, &dbus_pending_call, timeout_ms);
using PendingCallback =
base::OnceCallback<void(DBusPendingCall * pending_call)>;
// This returns false only when unable to allocate memory.
const bool success = dbus_pending_call_set_notify(
dbus_pending_call,
[](DBusPendingCall* pending_call, void* user_data) {
std::move(*static_cast<PendingCallback*>(user_data)).Run(pending_call);
},
// PendingCallback instance is owned by libdbus.
new PendingCallback(base::BindOnce(&ObjectProxy::OnPendingCallIsComplete,
this, std::move(callback_holder),
start_time)),
[](void* user_data) { delete static_cast<PendingCallback*>(user_data); });
CHECK(success) << "Unable to allocate memory";
pending_calls_.insert(dbus_pending_call);
// It's now safe to unref the request message.
dbus_message_unref(request_message);
}
void ObjectProxy::OnPendingCallIsComplete(ReplyCallbackHolder callback_holder,
base::TimeTicks start_time,
DBusPendingCall* pending_call) {
bus_->AssertOnDBusThread();
DBusMessage* response_message = dbus_pending_call_steal_reply(pending_call);
// Either |response| or |error_response| takes ownership of the
// |response_message|.
std::unique_ptr<Response> response;
std::unique_ptr<ErrorResponse> error_response;
if (dbus_message_get_type(response_message) == DBUS_MESSAGE_TYPE_ERROR) {
error_response = ErrorResponse::FromRawMessage(response_message);
} else {
response = Response::FromRawMessage(response_message);
}
base::OnceClosure task =
base::BindOnce(&ObjectProxy::RunResponseOrErrorCallback, this,
std::move(callback_holder), start_time, response.get(),
error_response.get());
// The message should be deleted on the D-Bus thread for a complicated
// reason:
//
// libdbus keeps track of the number of bytes in the incoming message
// queue to ensure that the data size in the queue is manageable. The
// bookkeeping is partly done via dbus_message_unref(), and immediately
// asks the client code (Chrome) to stop monitoring the underlying
// socket, if the number of bytes exceeds a certian number, which is set
// to 63MB, per dbus-transport.cc:
//
// /* Try to default to something that won't totally hose the system,
// * but doesn't impose too much of a limitation.
// */
// transport->max_live_messages_size = _DBUS_ONE_MEGABYTE * 63;
//
// The monitoring of the socket is done on the D-Bus thread (see Watch
// class in bus.cc), hence we should stop the monitoring on D-Bus thread.
bus_->GetOriginTaskRunner()->PostTaskAndReply(
FROM_HERE, std::move(task),
base::BindOnce(
[](Response* response, ErrorResponse* error_response) {
// Do nothing.
},
base::Owned(response.release()),
base::Owned(error_response.release())));
// Remove the pending call from the set.
pending_calls_.erase(pending_call);
dbus_pending_call_unref(pending_call);
}
void ObjectProxy::RunResponseOrErrorCallback(
ReplyCallbackHolder callback_holder,
base::TimeTicks start_time,
Response* response,
ErrorResponse* error_response) {
bus_->AssertOnOriginThread();
callback_holder.ReleaseCallback().Run(response, error_response);
if (response) {
// Record time spent for the method call. Don't include failures.
UMA_HISTOGRAM_TIMES("DBus.AsyncMethodCallTime",
base::TimeTicks::Now() - start_time);
}
// Record if the method call is successful, or not. 1 if successful.
UMA_HISTOGRAM_ENUMERATION("DBus.AsyncMethodCallSuccess", response ? 1 : 0,
kSuccessRatioHistogramMaxValue);
}
bool ObjectProxy::ConnectToNameOwnerChangedSignal() {
bus_->AssertOnDBusThread();
if (!bus_->Connect() || !bus_->SetUpAsyncOperations())
return false;
bus_->AddFilterFunction(&ObjectProxy::HandleMessageThunk, this);
// Add a match_rule listening NameOwnerChanged for the well-known name
// |service_name_|.
const std::string name_owner_changed_match_rule =
base::StringPrintf(
"type='signal',interface='org.freedesktop.DBus',"
"member='NameOwnerChanged',path='/org/freedesktop/DBus',"
"sender='org.freedesktop.DBus',arg0='%s'",
service_name_.c_str());
const bool success =
AddMatchRuleWithoutCallback(name_owner_changed_match_rule,
"org.freedesktop.DBus.NameOwnerChanged");
// Try getting the current name owner. It's not guaranteed that we can get
// the name owner at this moment, as the service may not yet be started. If
// that's the case, we'll get the name owner via NameOwnerChanged signal,
// as soon as the service is started.
UpdateNameOwnerAndBlock();
return success;
}
bool ObjectProxy::ConnectToSignalInternal(const std::string& interface_name,
const std::string& signal_name,
SignalCallback signal_callback) {
bus_->AssertOnDBusThread();
if (!ConnectToNameOwnerChangedSignal())
return false;
const std::string absolute_signal_name =
GetAbsoluteMemberName(interface_name, signal_name);
// Add a match rule so the signal goes through HandleMessage().
const std::string match_rule = base::StringPrintf(
"type='signal', sender='%s', interface='%s', path='%s'",
service_name_.c_str(), interface_name.c_str(),
object_path_.value().c_str());
return AddMatchRuleWithCallback(match_rule,
absolute_signal_name,
signal_callback);
}
void ObjectProxy::WaitForServiceToBeAvailableInternal() {
bus_->AssertOnDBusThread();
if (!ConnectToNameOwnerChangedSignal()) { // Failed to connect to the signal.
const bool service_is_ready = false;
bus_->GetOriginTaskRunner()->PostTask(
FROM_HERE,
base::BindOnce(&ObjectProxy::RunWaitForServiceToBeAvailableCallbacks,
this, service_is_ready));
return;
}
const bool service_is_available = !service_name_owner_.empty();
if (service_is_available) { // Service is already available.
bus_->GetOriginTaskRunner()->PostTask(
FROM_HERE,
base::BindOnce(&ObjectProxy::RunWaitForServiceToBeAvailableCallbacks,
this, service_is_available));
return;
}
}
DBusHandlerResult ObjectProxy::HandleMessage(
DBusConnection* connection,
DBusMessage* raw_message) {
bus_->AssertOnDBusThread();
if (dbus_message_get_type(raw_message) != DBUS_MESSAGE_TYPE_SIGNAL)
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
// raw_message will be unrefed on exit of the function. Increment the
// reference so we can use it in Signal.
dbus_message_ref(raw_message);
std::unique_ptr<Signal> signal(Signal::FromRawMessage(raw_message));
// Verify the signal comes from the object we're proxying for, this is
// our last chance to return DBUS_HANDLER_RESULT_NOT_YET_HANDLED and
// allow other object proxies to handle instead.
const ObjectPath path = signal->GetPath();
if (path != object_path_) {
if (path.value() == kDBusSystemObjectPath &&
signal->GetMember() == kNameOwnerChangedMember) {
// Handle NameOwnerChanged separately
return HandleNameOwnerChanged(std::move(signal));
}
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
const std::string interface = signal->GetInterface();
const std::string member = signal->GetMember();
statistics::AddReceivedSignal(service_name_, interface, member);
// Check if we know about the signal.
const std::string absolute_signal_name = GetAbsoluteMemberName(
interface, member);
MethodTable::const_iterator iter = method_table_.find(absolute_signal_name);
if (iter == method_table_.end()) {
// Don't know about the signal.
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
VLOG(1) << "Signal received: " << signal->ToString();
std::string sender = signal->GetSender();
if (service_name_owner_ != sender) {
LOG(ERROR) << "Rejecting a message from a wrong sender.";
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
const base::TimeTicks start_time = base::TimeTicks::Now();
if (bus_->HasDBusThread()) {
// Post a task to run the method in the origin thread.
// Transfer the ownership of |signal| to RunMethod().
// |released_signal| will be deleted in RunMethod().
Signal* released_signal = signal.release();
bus_->GetOriginTaskRunner()->PostTask(FROM_HERE,
base::Bind(&ObjectProxy::RunMethod,
this,
start_time,
iter->second,
released_signal));
} else {
const base::TimeTicks start_time = base::TimeTicks::Now();
// If the D-Bus thread is not used, just call the callback on the
// current thread. Transfer the ownership of |signal| to RunMethod().
Signal* released_signal = signal.release();
RunMethod(start_time, iter->second, released_signal);
}
// We don't return DBUS_HANDLER_RESULT_HANDLED for signals because other
// objects may be interested in them. (e.g. Signals from org.freedesktop.DBus)
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
void ObjectProxy::RunMethod(base::TimeTicks start_time,
std::vector<SignalCallback> signal_callbacks,
Signal* signal) {
bus_->AssertOnOriginThread();
for (std::vector<SignalCallback>::iterator iter = signal_callbacks.begin();
iter != signal_callbacks.end(); ++iter)
iter->Run(signal);
// Delete the message on the D-Bus thread. See comments in
// RunResponseOrErrorCallback().
bus_->GetDBusTaskRunner()->PostTask(
FROM_HERE,
base::Bind(&base::DeletePointer<Signal>, signal));
// Record time spent for handling the signal.
UMA_HISTOGRAM_TIMES("DBus.SignalHandleTime",
base::TimeTicks::Now() - start_time);
}
DBusHandlerResult ObjectProxy::HandleMessageThunk(
DBusConnection* connection,
DBusMessage* raw_message,
void* user_data) {
ObjectProxy* self = reinterpret_cast<ObjectProxy*>(user_data);
return self->HandleMessage(connection, raw_message);
}
void ObjectProxy::LogMethodCallFailure(
const base::StringPiece& interface_name,
const base::StringPiece& method_name,
const base::StringPiece& error_name,
const base::StringPiece& error_message) const {
if (ignore_service_unknown_errors_ &&
(error_name == kErrorServiceUnknown || error_name == kErrorObjectUnknown))
return;
std::ostringstream msg;
msg << "Failed to call method: " << interface_name << "." << method_name
<< ": object_path= " << object_path_.value()
<< ": " << error_name << ": " << error_message;
// "UnknownObject" indicates that an object or service is no longer available,
// e.g. a Shill network service has gone out of range. Treat these as warnings
// not errors.
if (error_name == kErrorObjectUnknown)
LOG(WARNING) << msg.str();
else
LOG(ERROR) << msg.str();
}
void ObjectProxy::OnCallMethod(const std::string& interface_name,
const std::string& method_name,
ResponseCallback response_callback,
Response* response,
ErrorResponse* error_response) {
if (response) {
// Method call was successful.
std::move(response_callback).Run(response);
return;
}
// Method call failed.
std::string error_name;
std::string error_message;
if (error_response) {
// Error message may contain the error message as string.
error_name = error_response->GetErrorName();
MessageReader reader(error_response);
reader.PopString(&error_message);
} else {
error_name = "unknown error type";
}
LogMethodCallFailure(interface_name, method_name, error_name, error_message);
std::move(response_callback).Run(nullptr);
}
bool ObjectProxy::AddMatchRuleWithCallback(
const std::string& match_rule,
const std::string& absolute_signal_name,
SignalCallback signal_callback) {
DCHECK(!match_rule.empty());
DCHECK(!absolute_signal_name.empty());
bus_->AssertOnDBusThread();
if (match_rules_.find(match_rule) == match_rules_.end()) {
ScopedDBusError error;
bus_->AddMatch(match_rule, error.get());
if (error.is_set()) {
LOG(ERROR) << "Failed to add match rule \"" << match_rule << "\". Got "
<< error.name() << ": " << error.message();
return false;
} else {
// Store the match rule, so that we can remove this in Detach().
match_rules_.insert(match_rule);
// Add the signal callback to the method table.
method_table_[absolute_signal_name].push_back(signal_callback);
return true;
}
} else {
// We already have the match rule.
method_table_[absolute_signal_name].push_back(signal_callback);
return true;
}
}
bool ObjectProxy::AddMatchRuleWithoutCallback(
const std::string& match_rule,
const std::string& absolute_signal_name) {
DCHECK(!match_rule.empty());
DCHECK(!absolute_signal_name.empty());
bus_->AssertOnDBusThread();
if (match_rules_.find(match_rule) != match_rules_.end())
return true;
ScopedDBusError error;
bus_->AddMatch(match_rule, error.get());
if (error.is_set()) {
LOG(ERROR) << "Failed to add match rule \"" << match_rule << "\". Got "
<< error.name() << ": " << error.message();
return false;
}
// Store the match rule, so that we can remove this in Detach().
match_rules_.insert(match_rule);
return true;
}
void ObjectProxy::UpdateNameOwnerAndBlock() {
bus_->AssertOnDBusThread();
// Errors should be suppressed here, as the service may not be yet running
// when connecting to signals of the service, which is just fine.
// The ObjectProxy will be notified when the service is launched via
// NameOwnerChanged signal. See also comments in ConnectToSignalInternal().
service_name_owner_ =
bus_->GetServiceOwnerAndBlock(service_name_, Bus::SUPPRESS_ERRORS);
}
DBusHandlerResult ObjectProxy::HandleNameOwnerChanged(
std::unique_ptr<Signal> signal) {
DCHECK(signal);
bus_->AssertOnDBusThread();
// Confirm the validity of the NameOwnerChanged signal.
if (signal->GetMember() == kNameOwnerChangedMember &&
signal->GetInterface() == kDBusSystemObjectInterface &&
signal->GetSender() == kDBusSystemObjectAddress) {
MessageReader reader(signal.get());
std::string name, old_owner, new_owner;
if (reader.PopString(&name) &&
reader.PopString(&old_owner) &&
reader.PopString(&new_owner) &&
name == service_name_) {
service_name_owner_ = new_owner;
bus_->GetOriginTaskRunner()->PostTask(
FROM_HERE,
base::Bind(&ObjectProxy::RunNameOwnerChangedCallback,
this, old_owner, new_owner));
const bool service_is_available = !service_name_owner_.empty();
if (service_is_available) {
bus_->GetOriginTaskRunner()->PostTask(
FROM_HERE,
base::Bind(&ObjectProxy::RunWaitForServiceToBeAvailableCallbacks,
this, service_is_available));
}
}
}
// Always return unhandled to let other object proxies handle the same
// signal.
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
void ObjectProxy::RunNameOwnerChangedCallback(const std::string& old_owner,
const std::string& new_owner) {
bus_->AssertOnOriginThread();
if (!name_owner_changed_callback_.is_null())
name_owner_changed_callback_.Run(old_owner, new_owner);
}
void ObjectProxy::RunWaitForServiceToBeAvailableCallbacks(
bool service_is_available) {
bus_->AssertOnOriginThread();
std::vector<WaitForServiceToBeAvailableCallback> callbacks;
callbacks.swap(wait_for_service_to_be_available_callbacks_);
for (size_t i = 0; i < callbacks.size(); ++i)
std::move(callbacks[i]).Run(service_is_available);
}
} // namespace dbus