src/chrome/browser/chromeos/dbus/cros_dbus_service.cc

   1 // Copyright (c) 2012 The Chromium 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 #include "chrome/browser/chromeos/dbus/cros_dbus_service.h"
   6
   7 #include "base/bind.h"
   8 #include "base/stl_util.h"
   9 #include "base/sys_info.h"
  10 #include "base/threading/platform_thread.h"
  11 #include "chrome/browser/chromeos/dbus/display_power_service_provider.h"
  12 #include "chrome/browser/chromeos/dbus/liveness_service_provider.h"
  13 #include "chrome/browser/chromeos/dbus/printer_service_provider.h"
  14 #include "chrome/browser/chromeos/dbus/proxy_resolution_service_provider.h"
  15 #include "chromeos/dbus/dbus_thread_manager.h"
  16 #include "dbus/bus.h"
  17 #include "dbus/exported_object.h"
  18 #include "dbus/object_path.h"
  19 #include "third_party/cros_system_api/dbus/service_constants.h"
  20
  21 namespace chromeos {
  22
  23 namespace {
  24
  25 CrosDBusService* g_cros_dbus_service = NULL;
  26
  27 }  // namespace
  28
  29 // The CrosDBusService implementation used in production, and unit tests.
  30 class CrosDBusServiceImpl : public CrosDBusService {
  31  public:
  32   explicit CrosDBusServiceImpl(dbus::Bus* bus)
  33       : service_started_(false),
  34         origin_thread_id_(base::PlatformThread::CurrentId()),
  35         bus_(bus) {
  36   }
  37
  38   virtual ~CrosDBusServiceImpl() {
  39     STLDeleteElements(&service_providers_);
  40   }
  41
  42   // Starts the D-Bus service.
  43   void Start() {
  44     // Make sure we're running on the origin thread (i.e. the UI thread in
  45     // production).
  46     DCHECK(OnOriginThread());
  47
  48     // Return if the service has been already started.
  49     if (service_started_)
  50       return;
  51
  52     // There are some situations, described in http://crbug.com/234382#c27,
  53     // where processes on Linux can wind up stuck in an uninterruptible state
  54     // for tens of seconds. If this happens when Chrome is trying to exit,
  55     // this unkillable process can wind up clinging to ownership of
  56     // kLibCrosServiceName while the system is trying to restart the browser.
  57     // This leads to a fatal situation if we don't allow the new browser
  58     // instance to replace the old as the owner of kLibCrosServiceName as seen
  59     // in http://crbug.com/234382. Hence, REQUIRE_PRIMARY_ALLOW_REPLACEMENT.
  60     bus_->RequestOwnership(kLibCrosServiceName,
  61                            dbus::Bus::REQUIRE_PRIMARY_ALLOW_REPLACEMENT,
  62                            base::Bind(&CrosDBusServiceImpl::OnOwnership,
  63                                       base::Unretained(this)));
  64
  65     exported_object_ = bus_->GetExportedObject(
  66         dbus::ObjectPath(kLibCrosServicePath));
  67
  68     for (size_t i = 0; i < service_providers_.size(); ++i)
  69       service_providers_[i]->Start(exported_object_);
  70
  71     service_started_ = true;
  72
  73     VLOG(1) << "CrosDBusServiceImpl started.";
  74   }
  75
  76   // Registers a service provider. This must be done before Start().
  77   // |provider| will be owned by CrosDBusService.
  78   void RegisterServiceProvider(ServiceProviderInterface* provider) {
  79     service_providers_.push_back(provider);
  80   }
  81
  82  private:
  83   // Returns true if the current thread is on the origin thread.
  84   bool OnOriginThread() {
  85     return base::PlatformThread::CurrentId() == origin_thread_id_;
  86   }
  87
  88   // Called when an ownership request is completed.
  89   void OnOwnership(const std::string& service_name,
  90                    bool success) {
  91     LOG_IF(FATAL, !success) << "Failed to own: " << service_name;
  92   }
  93
  94   bool service_started_;
  95   base::PlatformThreadId origin_thread_id_;
  96   dbus::Bus* bus_;
  97   scoped_refptr<dbus::ExportedObject> exported_object_;
  98
  99   // Service providers that form CrosDBusService.
 100   std::vector<ServiceProviderInterface*> service_providers_;
 101 };
 102
 103 // The stub CrosDBusService implementation used on Linux desktop,
 104 // which does nothing as of now.
 105 class CrosDBusServiceStubImpl : public CrosDBusService {
 106  public:
 107   CrosDBusServiceStubImpl() {
 108   }
 109
 110   virtual ~CrosDBusServiceStubImpl() {
 111   }
 112 };
 113
 114 // static
 115 void CrosDBusService::Initialize() {
 116   if (g_cros_dbus_service) {
 117     LOG(WARNING) << "CrosDBusService was already initialized";
 118     return;
 119   }
 120   dbus::Bus* bus = DBusThreadManager::Get()->GetSystemBus();
 121   if (base::SysInfo::IsRunningOnChromeOS() && bus) {
 122     CrosDBusServiceImpl* service = new CrosDBusServiceImpl(bus);
 123     service->RegisterServiceProvider(ProxyResolutionServiceProvider::Create());
 124     service->RegisterServiceProvider(new DisplayPowerServiceProvider);
 125     service->RegisterServiceProvider(new LivenessServiceProvider);
 126     service->RegisterServiceProvider(new PrinterServiceProvider);
 127     g_cros_dbus_service = service;
 128     service->Start();
 129   } else {
 130     g_cros_dbus_service = new CrosDBusServiceStubImpl;
 131   }
 132   VLOG(1) << "CrosDBusService initialized";
 133 }
 134
 135 // static
 136 void CrosDBusService::InitializeForTesting(
 137     dbus::Bus* bus,
 138     ServiceProviderInterface* proxy_resolution_service) {
 139   if (g_cros_dbus_service) {
 140     LOG(WARNING) << "CrosDBusService was already initialized";
 141     return;
 142   }
 143   CrosDBusServiceImpl* service =  new CrosDBusServiceImpl(bus);
 144   service->RegisterServiceProvider(proxy_resolution_service);
 145   service->Start();
 146   g_cros_dbus_service = service;
 147   VLOG(1) << "CrosDBusService initialized";
 148 }
 149
 150 // static
 151 void CrosDBusService::Shutdown() {
 152   delete g_cros_dbus_service;
 153   g_cros_dbus_service = NULL;
 154   VLOG(1) << "CrosDBusService Shutdown completed";
 155 }
 156
 157 CrosDBusService::~CrosDBusService() {
 158 }
 159
 160 CrosDBusService::ServiceProviderInterface::~ServiceProviderInterface() {
 161 }
 162
 163 }  // namespace chromeos