Revert of Move content/browser/power_save_blocker to //device/power_save_blocker

content/browser/power_save_blocker_x11.cc

+// 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 <X11/Xlib.h>
+#include <X11/extensions/dpms.h>
+#include <X11/extensions/scrnsaver.h>
+#include <stdint.h>
+
+#include <memory>
+
+#include "content/browser/power_save_blocker_impl.h"
+// Xlib #defines Status, but we can't have that for some of our headers.
+#ifdef Status
+#undef Status
+#endif
+
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/command_line.h"
+#include "base/environment.h"
+#include "base/files/file_path.h"
+#include "base/location.h"
+#include "base/logging.h"
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/singleton.h"
+#include "base/nix/xdg_util.h"
+#include "base/synchronization/lock.h"
+#include "dbus/bus.h"
+#include "dbus/message.h"
+#include "dbus/object_path.h"
+#include "dbus/object_proxy.h"
+#include "ui/gfx/x/x11_types.h"
+
+namespace {
+
+enum DBusAPI {
+  NO_API,           // Disable. No supported API available.
+  GNOME_API,        // Use the GNOME API. (Supports more features.)
+  FREEDESKTOP_API,  // Use the FreeDesktop API, for KDE4, KDE5, and XFCE.
+};
+
+// Inhibit flags defined in the org.gnome.SessionManager interface.
+// Can be OR'd together and passed as argument to the Inhibit() method
+// to specify which power management features we want to suspend.
+enum GnomeAPIInhibitFlags {
+  INHIBIT_LOGOUT            = 1,
+  INHIBIT_SWITCH_USER       = 2,
+  INHIBIT_SUSPEND_SESSION   = 4,
+  INHIBIT_MARK_SESSION_IDLE = 8
+};
+
+const char kGnomeAPIServiceName[] = "org.gnome.SessionManager";
+const char kGnomeAPIInterfaceName[] = "org.gnome.SessionManager";
+const char kGnomeAPIObjectPath[] = "/org/gnome/SessionManager";
+
+const char kFreeDesktopAPIPowerServiceName[] =
+    "org.freedesktop.PowerManagement";
+const char kFreeDesktopAPIPowerInterfaceName[] =
+    "org.freedesktop.PowerManagement.Inhibit";
+const char kFreeDesktopAPIPowerObjectPath[] =
+    "/org/freedesktop/PowerManagement/Inhibit";
+
+const char kFreeDesktopAPIScreenServiceName[] = "org.freedesktop.ScreenSaver";
+const char kFreeDesktopAPIScreenInterfaceName[] = "org.freedesktop.ScreenSaver";
+const char kFreeDesktopAPIScreenObjectPath[] = "/org/freedesktop/ScreenSaver";
+
+}  // namespace
+
+namespace content {
+
+class PowerSaveBlockerImpl::Delegate
+    : public base::RefCountedThreadSafe<PowerSaveBlockerImpl::Delegate> {
+ public:
+  // Picks an appropriate D-Bus API to use based on the desktop environment.
+  Delegate(PowerSaveBlockerType type,
+           const std::string& description,
+           bool freedesktop_only,
+           scoped_refptr<base::SequencedTaskRunner> ui_task_runner,
+           scoped_refptr<base::SingleThreadTaskRunner> blocking_task_runner);
+
+  // Post a task to initialize the delegate on the UI thread, which will itself
+  // then post a task to apply the power save block on the FILE thread.
+  void Init();
+
+  // Post a task to remove the power save block on the FILE thread, unless it
+  // hasn't yet been applied, in which case we just prevent it from applying.
+  void CleanUp();
+
+ private:
+  friend class base::RefCountedThreadSafe<Delegate>;
+  ~Delegate() {}
+
+  // Selects an appropriate D-Bus API to use for this object. Must be called on
+  // the UI thread. Checks enqueue_apply_ once an API has been selected, and
+  // enqueues a call back to ApplyBlock() if it is true. See the comments for
+  // enqueue_apply_ below.
+  void InitOnUIThread();
+
+  // Returns true if ApplyBlock() / RemoveBlock() should be called.
+  bool ShouldBlock() const;
+
+  // Apply or remove the power save block, respectively. These methods should be
+  // called once each, on the same thread, per instance. They block waiting for
+  // the action to complete (with a timeout); the thread must thus allow I/O.
+  void ApplyBlock();
+  void RemoveBlock();
+
+  // Asynchronous callback functions for ApplyBlock and RemoveBlock.
+  // Functions do not receive ownership of |response|.
+  void ApplyBlockFinished(dbus::Response* response);
+  void RemoveBlockFinished(dbus::Response* response);
+
+  // Wrapper for XScreenSaverSuspend. Checks whether the X11 Screen Saver
+  // Extension is available first. If it isn't, this is a no-op.
+  // Must be called on the UI thread.
+  void XSSSuspendSet(bool suspend);
+
+  // If DPMS (the power saving system in X11) is not enabled, then we don't want
+  // to try to disable power saving, since on some desktop environments that may
+  // enable DPMS with very poor default settings (e.g. turning off the display
+  // after only 1 second). Must be called on the UI thread.
+  bool DPMSEnabled();
+
+  // If no other method is available (i.e. not running under a Desktop
+  // Environment) check whether the X11 Screen Saver Extension can be used
+  // to disable the screen saver. Must be called on the UI thread.
+  bool XSSAvailable();
+
+  // Returns an appropriate D-Bus API to use based on the desktop environment.
+  // Must be called on the UI thread, as it may call DPMSEnabled() above.
+  DBusAPI SelectAPI();
+
+  const PowerSaveBlockerType type_;
+  const std::string description_;
+  const bool freedesktop_only_;
+
+  // Initially, we post a message to the UI thread to select an API. When it
+  // finishes, it will post a message to the FILE thread to perform the actual
+  // application of the block, unless enqueue_apply_ is false. We set it to
+  // false when we post that message, or when RemoveBlock() is called before
+  // ApplyBlock() has run. Both api_ and enqueue_apply_ are guarded by lock_.
+  DBusAPI api_;
+  bool enqueue_apply_;
+  base::Lock lock_;
+
+  // Indicates that a D-Bus power save blocking request is in flight.
+  bool block_inflight_;
+  // Used to detect erronous redundant calls to RemoveBlock().
+  bool unblock_inflight_;
+  // Indicates that RemoveBlock() is called before ApplyBlock() has finished.
+  // If it's true, then the RemoveBlock() call will be processed immediately
+  // after ApplyBlock() has finished.
+  bool enqueue_unblock_;
+
+  scoped_refptr<dbus::Bus> bus_;
+
+  // The cookie that identifies our inhibit request,
+  // or 0 if there is no active inhibit request.
+  uint32_t inhibit_cookie_;
+
+  scoped_refptr<base::SequencedTaskRunner> ui_task_runner_;
+  scoped_refptr<base::SingleThreadTaskRunner> blocking_task_runner_;
+
+  DISALLOW_COPY_AND_ASSIGN(Delegate);
+};
+
+PowerSaveBlockerImpl::Delegate::Delegate(
+    PowerSaveBlockerType type,
+    const std::string& description,
+    bool freedesktop_only,
+    scoped_refptr<base::SequencedTaskRunner> ui_task_runner,
+    scoped_refptr<base::SingleThreadTaskRunner> blocking_task_runner)
+    : type_(type),
+      description_(description),
+      freedesktop_only_(freedesktop_only),
+      api_(NO_API),
+      enqueue_apply_(false),
+      inhibit_cookie_(0),
+      ui_task_runner_(ui_task_runner),
+      blocking_task_runner_(blocking_task_runner) {
+  // We're on the client's thread here, so we don't allocate the dbus::Bus
+  // object yet. We'll do it later in ApplyBlock(), on the FILE thread.
+}
+
+void PowerSaveBlockerImpl::Delegate::Init() {
+  base::AutoLock lock(lock_);
+  DCHECK(!enqueue_apply_);
+  enqueue_apply_ = true;
+  block_inflight_ = false;
+  unblock_inflight_ = false;
+  enqueue_unblock_ = false;
+  ui_task_runner_->PostTask(FROM_HERE,
+                            base::Bind(&Delegate::InitOnUIThread, this));
+}
+
+void PowerSaveBlockerImpl::Delegate::CleanUp() {
+  base::AutoLock lock(lock_);
+  if (enqueue_apply_) {
+    // If a call to ApplyBlock() has not yet been enqueued because we are still
+    // initializing on the UI thread, then just cancel it. We don't need to
+    // remove the block because we haven't even applied it yet.
+    enqueue_apply_ = false;
+  } else {
+    if (ShouldBlock()) {
+      blocking_task_runner_->PostTask(FROM_HERE,
+                                      base::Bind(&Delegate::RemoveBlock, this));
+    }
+
+    ui_task_runner_->PostTask(
+        FROM_HERE, base::Bind(&Delegate::XSSSuspendSet, this, false));
+  }
+}
+
+void PowerSaveBlockerImpl::Delegate::InitOnUIThread() {
+  DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
+  base::AutoLock lock(lock_);
+  api_ = SelectAPI();
+
+  if (enqueue_apply_) {
+    if (ShouldBlock()) {
+      // The thread we use here becomes the origin and D-Bus thread for the
+      // D-Bus library, so we need to use the same thread above for
+      // RemoveBlock(). It must be a thread that allows I/O operations, so we
+      // use the FILE thread.
+      blocking_task_runner_->PostTask(FROM_HERE,
+                                      base::Bind(&Delegate::ApplyBlock, this));
+    }
+    XSSSuspendSet(true);
+  }
+  enqueue_apply_ = false;
+}
+
+bool PowerSaveBlockerImpl::Delegate::ShouldBlock() const {
+  return freedesktop_only_ ? api_ == FREEDESKTOP_API : api_ != NO_API;
+}
+
+void PowerSaveBlockerImpl::Delegate::ApplyBlock() {
+  DCHECK(blocking_task_runner_->RunsTasksOnCurrentThread());
+  DCHECK(!bus_);  // ApplyBlock() should only be called once.
+  DCHECK(!block_inflight_);
+
+  dbus::Bus::Options options;
+  options.bus_type = dbus::Bus::SESSION;
+  options.connection_type = dbus::Bus::PRIVATE;
+  bus_ = new dbus::Bus(options);
+
+  scoped_refptr<dbus::ObjectProxy> object_proxy;
+  std::unique_ptr<dbus::MethodCall> method_call;
+  std::unique_ptr<dbus::MessageWriter> message_writer;
+
+  switch (api_) {
+    case NO_API:
+      NOTREACHED();  // We should never call this method with this value.
+      return;
+    case GNOME_API:
+      object_proxy = bus_->GetObjectProxy(
+          kGnomeAPIServiceName,
+          dbus::ObjectPath(kGnomeAPIObjectPath));
+      method_call.reset(
+          new dbus::MethodCall(kGnomeAPIInterfaceName, "Inhibit"));
+      message_writer.reset(new dbus::MessageWriter(method_call.get()));
+      // The arguments of the method are:
+      //     app_id:        The application identifier
+      //     toplevel_xid:  The toplevel X window identifier
+      //     reason:        The reason for the inhibit
+      //     flags:         Flags that spefify what should be inhibited
+      message_writer->AppendString(
+          base::CommandLine::ForCurrentProcess()->GetProgram().value());
+      message_writer->AppendUint32(0);  // should be toplevel_xid
+      message_writer->AppendString(description_);
+      {
+        uint32_t flags = 0;
+        switch (type_) {
+          case kPowerSaveBlockPreventDisplaySleep:
+            flags |= INHIBIT_MARK_SESSION_IDLE;
+            flags |= INHIBIT_SUSPEND_SESSION;
+            break;
+          case kPowerSaveBlockPreventAppSuspension:
+            flags |= INHIBIT_SUSPEND_SESSION;
+            break;
+        }
+        message_writer->AppendUint32(flags);
+      }
+      break;
+    case FREEDESKTOP_API:
+      switch (type_) {
+        case kPowerSaveBlockPreventDisplaySleep:
+          object_proxy = bus_->GetObjectProxy(
+              kFreeDesktopAPIScreenServiceName,
+              dbus::ObjectPath(kFreeDesktopAPIScreenObjectPath));
+          method_call.reset(new dbus::MethodCall(
+              kFreeDesktopAPIScreenInterfaceName, "Inhibit"));
+          break;
+        case kPowerSaveBlockPreventAppSuspension:
+          object_proxy = bus_->GetObjectProxy(
+              kFreeDesktopAPIPowerServiceName,
+              dbus::ObjectPath(kFreeDesktopAPIPowerObjectPath));
+          method_call.reset(new dbus::MethodCall(
+              kFreeDesktopAPIPowerInterfaceName, "Inhibit"));
+          break;
+      }
+      message_writer.reset(new dbus::MessageWriter(method_call.get()));
+      // The arguments of the method are:
+      //     app_id:        The application identifier
+      //     reason:        The reason for the inhibit
+      message_writer->AppendString(
+          base::CommandLine::ForCurrentProcess()->GetProgram().value());
+      message_writer->AppendString(description_);
+      break;
+  }
+
+  block_inflight_ = true;
+  object_proxy->CallMethod(
+      method_call.get(), dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+      base::Bind(&PowerSaveBlockerImpl::Delegate::ApplyBlockFinished, this));
+}
+
+void PowerSaveBlockerImpl::Delegate::ApplyBlockFinished(
+    dbus::Response* response) {
+  DCHECK(blocking_task_runner_->RunsTasksOnCurrentThread());
+  DCHECK(bus_);
+  DCHECK(block_inflight_);
+  block_inflight_ = false;
+
+  if (response) {
+    // The method returns an inhibit_cookie, used to uniquely identify
+    // this request. It should be used as an argument to Uninhibit()
+    // in order to remove the request.
+    dbus::MessageReader message_reader(response);
+    if (!message_reader.PopUint32(&inhibit_cookie_))
+      LOG(ERROR) << "Invalid Inhibit() response: " << response->ToString();
+  } else {
+    LOG(ERROR) << "No response to Inhibit() request!";
+  }
+
+  if (enqueue_unblock_) {
+    enqueue_unblock_ = false;
+    // RemoveBlock() was called while the Inhibit operation was in flight,
+    // so go ahead and remove the block now.
+    blocking_task_runner_->PostTask(FROM_HERE,
+                                    base::Bind(&Delegate::RemoveBlock, this));
+  }
+}
+
+void PowerSaveBlockerImpl::Delegate::RemoveBlock() {
+  DCHECK(blocking_task_runner_->RunsTasksOnCurrentThread());
+  DCHECK(bus_);  // RemoveBlock() should only be called once.
+  DCHECK(!unblock_inflight_);
+
+  if (block_inflight_) {
+    DCHECK(!enqueue_unblock_);
+    // Can't call RemoveBlock until ApplyBlock's async operation has
+    // finished. Enqueue it for execution once ApplyBlock is done.
+    enqueue_unblock_ = true;
+    return;
+  }
+
+  scoped_refptr<dbus::ObjectProxy> object_proxy;
+  std::unique_ptr<dbus::MethodCall> method_call;
+
+  switch (api_) {
+    case NO_API:
+      NOTREACHED();  // We should never call this method with this value.
+      return;
+    case GNOME_API:
+      object_proxy = bus_->GetObjectProxy(
+          kGnomeAPIServiceName,
+          dbus::ObjectPath(kGnomeAPIObjectPath));
+      method_call.reset(
+          new dbus::MethodCall(kGnomeAPIInterfaceName, "Uninhibit"));
+      break;
+    case FREEDESKTOP_API:
+      switch (type_) {
+        case kPowerSaveBlockPreventDisplaySleep:
+          object_proxy = bus_->GetObjectProxy(
+              kFreeDesktopAPIScreenServiceName,
+              dbus::ObjectPath(kFreeDesktopAPIScreenObjectPath));
+          method_call.reset(new dbus::MethodCall(
+              kFreeDesktopAPIScreenInterfaceName, "UnInhibit"));
+          break;
+        case kPowerSaveBlockPreventAppSuspension:
+          object_proxy = bus_->GetObjectProxy(
+              kFreeDesktopAPIPowerServiceName,
+              dbus::ObjectPath(kFreeDesktopAPIPowerObjectPath));
+          method_call.reset(new dbus::MethodCall(
+              kFreeDesktopAPIPowerInterfaceName, "UnInhibit"));
+          break;
+      }
+      break;
+  }
+
+  dbus::MessageWriter message_writer(method_call.get());
+  message_writer.AppendUint32(inhibit_cookie_);
+  unblock_inflight_ = true;
+  object_proxy->CallMethod(
+      method_call.get(), dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+      base::Bind(&PowerSaveBlockerImpl::Delegate::RemoveBlockFinished, this));
+}
+
+void PowerSaveBlockerImpl::Delegate::RemoveBlockFinished(
+    dbus::Response* response) {
+  DCHECK(blocking_task_runner_->RunsTasksOnCurrentThread());
+  DCHECK(bus_);
+  unblock_inflight_ = false;
+
+  if (!response)
+    LOG(ERROR) << "No response to Uninhibit() request!";
+  // We don't care about checking the result. We assume it works; we can't
+  // really do anything about it anyway if it fails.
+  inhibit_cookie_ = 0;
+
+  bus_->ShutdownAndBlock();
+  bus_ = nullptr;
+}
+
+void PowerSaveBlockerImpl::Delegate::XSSSuspendSet(bool suspend) {
+  DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
+
+  if (!XSSAvailable())
+    return;
+
+  XDisplay* display = gfx::GetXDisplay();
+  XScreenSaverSuspend(display, suspend);
+}
+
+bool PowerSaveBlockerImpl::Delegate::DPMSEnabled() {
+  DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
+  XDisplay* display = gfx::GetXDisplay();
+  BOOL enabled = false;
+  int dummy;
+  if (DPMSQueryExtension(display, &dummy, &dummy) && DPMSCapable(display)) {
+    CARD16 state;
+    DPMSInfo(display, &state, &enabled);
+  }
+  return enabled;
+}
+
+bool PowerSaveBlockerImpl::Delegate::XSSAvailable() {
+  DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
+  XDisplay* display = gfx::GetXDisplay();
+  int dummy;
+  int major;
+  int minor;
+
+  if (!XScreenSaverQueryExtension(display, &dummy, &dummy))
+    return false;
+
+  if (!XScreenSaverQueryVersion(display, &major, &minor))
+    return false;
+
+  return major > 1 || (major == 1 && minor >= 1);
+}
+
+DBusAPI PowerSaveBlockerImpl::Delegate::SelectAPI() {
+  DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
+  std::unique_ptr<base::Environment> env(base::Environment::Create());
+  switch (base::nix::GetDesktopEnvironment(env.get())) {
+    case base::nix::DESKTOP_ENVIRONMENT_GNOME:
+    case base::nix::DESKTOP_ENVIRONMENT_UNITY:
+      if (DPMSEnabled())
+        return GNOME_API;
+      break;
+    case base::nix::DESKTOP_ENVIRONMENT_XFCE:
+    case base::nix::DESKTOP_ENVIRONMENT_KDE4:
+    case base::nix::DESKTOP_ENVIRONMENT_KDE5:
+      if (DPMSEnabled())
+        return FREEDESKTOP_API;
+      break;
+    case base::nix::DESKTOP_ENVIRONMENT_KDE3:
+    case base::nix::DESKTOP_ENVIRONMENT_OTHER:
+      // Not supported.
+      break;
+  }
+  return NO_API;
+}
+
+PowerSaveBlockerImpl::PowerSaveBlockerImpl(
+    PowerSaveBlockerType type,
+    Reason reason,
+    const std::string& description,
+    scoped_refptr<base::SequencedTaskRunner> ui_task_runner,
+    scoped_refptr<base::SingleThreadTaskRunner> blocking_task_runner)
+    : delegate_(new Delegate(type,
+                             description,
+                             false /* freedesktop_only */,
+                             ui_task_runner,
+                             blocking_task_runner)),
+      ui_task_runner_(ui_task_runner),
+      blocking_task_runner_(blocking_task_runner) {
+  delegate_->Init();
+
+  if (type == kPowerSaveBlockPreventDisplaySleep) {
+    freedesktop_suspend_delegate_ = new Delegate(
+        kPowerSaveBlockPreventAppSuspension, description,
+        true /* freedesktop_only */, ui_task_runner, blocking_task_runner);
+    freedesktop_suspend_delegate_->Init();
+  }
+}
+
+PowerSaveBlockerImpl::~PowerSaveBlockerImpl() {
+  delegate_->CleanUp();
+  if (freedesktop_suspend_delegate_)
+    freedesktop_suspend_delegate_->CleanUp();
+}
+
+}  // namespace content