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 "chrome/browser/chromeos/dbus/screen_lock_service_provider.h"
  16 #include "chromeos/dbus/dbus_thread_manager.h"
  17 #include "dbus/bus.h"
  18 #include "dbus/exported_object.h"
  19 #include "dbus/object_path.h"
  20 #include "third_party/cros_system_api/dbus/service_constants.h"
  21
  22 namespace chromeos {
  23
  24 namespace {
  25
  26 CrosDBusService* g_cros_dbus_service = NULL;
  27
  28 }  // namespace
  29
  30 // The CrosDBusService implementation used in production, and unit tests.
  31 class CrosDBusServiceImpl : public CrosDBusService {
  32  public:
  33   explicit CrosDBusServiceImpl(dbus::Bus* bus)
  34       : service_started_(false),
  35         origin_thread_id_(base::PlatformThread::CurrentId()),
  36         bus_(bus) {
  37   }
  38
  39   virtual ~CrosDBusServiceImpl() {
  40     STLDeleteElements(&service_providers_);
  41   }
  42
  43   // Starts the D-Bus service.
  44   void Start() {
  45     // Make sure we're running on the origin thread (i.e. the UI thread in
  46     // production).
  47     DCHECK(OnOriginThread());
  48
  49     // Return if the service has been already started.
  50     if (service_started_)
  51       return;
  52
  53     // There are some situations, described in http://crbug.com/234382#c27,
  54     // where processes on Linux can wind up stuck in an uninterruptible state
  55     // for tens of seconds. If this happens when Chrome is trying to exit,
  56     // this unkillable process can wind up clinging to ownership of
  57     // kLibCrosServiceName while the system is trying to restart the browser.
  58     // This leads to a fatal situation if we don't allow the new browser
  59     // instance to replace the old as the owner of kLibCrosServiceName as seen
  60     // in http://crbug.com/234382. Hence, REQUIRE_PRIMARY_ALLOW_REPLACEMENT.
  61     bus_->RequestOwnership(kLibCrosServiceName,
  62                            dbus::Bus::REQUIRE_PRIMARY_ALLOW_REPLACEMENT,
  63                            base::Bind(&CrosDBusServiceImpl::OnOwnership,
  64                                       base::Unretained(this)));
  65
  66     exported_object_ = bus_->GetExportedObject(
  67         dbus::ObjectPath(kLibCrosServicePath));
  68
  69     for (size_t i = 0; i < service_providers_.size(); ++i)
  70       service_providers_[i]->Start(exported_object_);
  71
  72     service_started_ = true;
  73
  74     VLOG(1) << "CrosDBusServiceImpl started.";
  75   }
  76
  77   // Registers a service provider. This must be done before Start().
  78   // |provider| will be owned by CrosDBusService.
  79   void RegisterServiceProvider(ServiceProviderInterface* provider) {
  80     service_providers_.push_back(provider);
  81   }
  82
  83  private:
  84   // Returns true if the current thread is on the origin thread.
  85   bool OnOriginThread() {
  86     return base::PlatformThread::CurrentId() == origin_thread_id_;
  87   }
  88
  89   // Called when an ownership request is completed.
  90   void OnOwnership(const std::string& service_name,
  91                    bool success) {
  92     LOG_IF(FATAL, !success) << "Failed to own: " << service_name;
  93   }
  94
  95   bool service_started_;
  96   base::PlatformThreadId origin_thread_id_;
  97   dbus::Bus* bus_;
  98   scoped_refptr<dbus::ExportedObject> exported_object_;
  99
 100   // Service providers that form CrosDBusService.
 101   std::vector<ServiceProviderInterface*> service_providers_;
 102 };
 103
 104 // The stub CrosDBusService implementation used on Linux desktop,
 105 // which does nothing as of now.
 106 class CrosDBusServiceStubImpl : public CrosDBusService {
 107  public:
 108   CrosDBusServiceStubImpl() {
 109   }
 110
 111   virtual ~CrosDBusServiceStubImpl() {
 112   }
 113 };
 114
 115 // static
 116 void CrosDBusService::Initialize() {
 117   if (g_cros_dbus_service) {
 118     LOG(WARNING) << "CrosDBusService was already initialized";
 119     return;
 120   }
 121   dbus::Bus* bus = DBusThreadManager::Get()->GetSystemBus();
 122   if (base::SysInfo::IsRunningOnChromeOS() && bus) {
 123     CrosDBusServiceImpl* service = new CrosDBusServiceImpl(bus);
 124     service->RegisterServiceProvider(ProxyResolutionServiceProvider::Create());
 125     service->RegisterServiceProvider(new DisplayPowerServiceProvider);
 126     service->RegisterServiceProvider(new LivenessServiceProvider);
 127     service->RegisterServiceProvider(new PrinterServiceProvider);
 128     service->RegisterServiceProvider(new ScreenLockServiceProvider);
 129     g_cros_dbus_service = service;
 130     service->Start();
 131   } else {
 132     g_cros_dbus_service = new CrosDBusServiceStubImpl;
 133   }
 134   VLOG(1) << "CrosDBusService initialized";
 135 }
 136
 137 // static
 138 void CrosDBusService::InitializeForTesting(
 139     dbus::Bus* bus,
 140     ServiceProviderInterface* proxy_resolution_service) {
 141   if (g_cros_dbus_service) {
 142     LOG(WARNING) << "CrosDBusService was already initialized";
 143     return;
 144   }
 145   CrosDBusServiceImpl* service =  new CrosDBusServiceImpl(bus);
 146   service->RegisterServiceProvider(proxy_resolution_service);
 147   service->Start();
 148   g_cros_dbus_service = service;
 149   VLOG(1) << "CrosDBusService initialized";
 150 }
 151
 152 // static
 153 void CrosDBusService::Shutdown() {
 154   delete g_cros_dbus_service;
 155   g_cros_dbus_service = NULL;
 156   VLOG(1) << "CrosDBusService Shutdown completed";
 157 }
 158
 159 CrosDBusService::~CrosDBusService() {
 160 }
 161
 162 CrosDBusService::ServiceProviderInterface::~ServiceProviderInterface() {
 163 }
 164
 165 }  // namespace chromeos