1 // Copyright 2015 The Chromium OS Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef LIBBRILLO_BRILLO_DBUS_DBUS_SERVICE_WATCHER_H_ 6 #define LIBBRILLO_BRILLO_DBUS_DBUS_SERVICE_WATCHER_H_ 7 8 #include <string> 9 10 #include <base/callback.h> 11 #include <base/macros.h> 12 #include <base/memory/ref_counted.h> 13 #include <base/memory/weak_ptr.h> 14 #include <brillo/brillo_export.h> 15 #include <dbus/bus.h> 16 17 namespace brillo { 18 namespace dbus_utils { 19 20 // DBusServiceWatcher just asks the bus to notify us when the owner of a remote 21 // DBus connection transitions to the empty string. After registering a 22 // callback to be notified of name owner transitions, for the given 23 // |connection_name|, DBusServiceWatcher asks for the current owner. If at any 24 // point an empty string is found for the connection name owner, 25 // DBusServiceWatcher will call back to notify of the connection vanishing. 26 // 27 // The chief value of this class is that it manages the lifetime of the 28 // registered callback in the Bus, because failure to remove callbacks will 29 // cause the Bus to crash the process on destruction. 30 class BRILLO_EXPORT DBusServiceWatcher { 31 public: 32 DBusServiceWatcher(scoped_refptr<dbus::Bus> bus, 33 const std::string& connection_name, 34 const base::Closure& on_connection_vanish); 35 virtual ~DBusServiceWatcher(); 36 virtual std::string connection_name() const { return connection_name_; } 37 38 private: 39 void OnServiceOwnerChange(const std::string& service_owner); 40 41 scoped_refptr<dbus::Bus> bus_; 42 const std::string connection_name_; 43 dbus::Bus::GetServiceOwnerCallback monitoring_callback_; 44 base::Closure on_connection_vanish_; 45 46 base::WeakPtrFactory<DBusServiceWatcher> weak_factory_{this}; 47 DISALLOW_COPY_AND_ASSIGN(DBusServiceWatcher); 48 }; 49 50 } // namespace dbus_utils 51 } // namespace brillo 52 53 #endif // LIBBRILLO_BRILLO_DBUS_DBUS_SERVICE_WATCHER_H_ 54
