// 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 "content/browser/power_save_blocker_impl.h"
#include <X11/Xlib.h>
#include <X11/extensions/dpms.h>
// Xlib #defines Status, but we can't have that for some of our headers.
#ifdef Status
#undef Status
#endif
#include "base/basictypes.h"
#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/logging.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/singleton.h"
#include "base/message_loop/message_loop_proxy.h"
#include "base/nix/xdg_util.h"
#include "base/synchronization/lock.h"
#include "content/public/browser/browser_thread.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"
#if defined(TOOLKIT_GTK)
#include "base/message_loop/message_pump_gtk.h"
#else
#include "base/message_loop/message_pump_x11.h"
#endif
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 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 kFreeDesktopAPIServiceName[] = "org.freedesktop.PowerManagement";
const char kFreeDesktopAPIInterfaceName[] =
"org.freedesktop.PowerManagement.Inhibit";
const char kFreeDesktopAPIObjectPath[] =
"/org/freedesktop/PowerManagement/Inhibit";
} // 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& reason);
// 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();
// 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(DBusAPI api);
void RemoveBlock(DBusAPI api);
// 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.
static bool DPMSEnabled();
// 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.
static DBusAPI SelectAPI();
const PowerSaveBlockerType type_;
const std::string reason_;
// 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_;
scoped_refptr<dbus::Bus> bus_;
// The cookie that identifies our inhibit request,
// or 0 if there is no active inhibit request.
uint32 inhibit_cookie_;
DISALLOW_COPY_AND_ASSIGN(Delegate);
};
PowerSaveBlockerImpl::Delegate::Delegate(PowerSaveBlockerType type,
const std::string& reason)
: type_(type),
reason_(reason),
api_(NO_API),
enqueue_apply_(false),
inhibit_cookie_(0) {
// 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;
BrowserThread::PostTask(BrowserThread::UI, 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 (api_ != NO_API) {
BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
base::Bind(&Delegate::RemoveBlock, this, api_));
}
}
void PowerSaveBlockerImpl::Delegate::InitOnUIThread() {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
base::AutoLock lock(lock_);
api_ = SelectAPI();
if (enqueue_apply_ && api_ != NO_API) {
// 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.
BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
base::Bind(&Delegate::ApplyBlock, this, api_));
}
enqueue_apply_ = false;
}
void PowerSaveBlockerImpl::Delegate::ApplyBlock(DBusAPI api) {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
DCHECK(!bus_.get()); // ApplyBlock() should only be called once.
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;
scoped_ptr<dbus::MethodCall> method_call;
scoped_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(
CommandLine::ForCurrentProcess()->GetProgram().value());
message_writer->AppendUint32(0); // should be toplevel_xid
message_writer->AppendString(reason_);
{
uint32 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:
object_proxy = bus_->GetObjectProxy(
kFreeDesktopAPIServiceName,
dbus::ObjectPath(kFreeDesktopAPIObjectPath));
method_call.reset(
new dbus::MethodCall(kFreeDesktopAPIInterfaceName, "Inhibit"));
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(
CommandLine::ForCurrentProcess()->GetProgram().value());
message_writer->AppendString(reason_);
break;
}
// We could do this method call asynchronously, but if we did, we'd need to
// handle the case where we want to cancel the block before we get a reply.
// We're on the FILE thread so it should be OK to block briefly here.
scoped_ptr<dbus::Response> response(object_proxy->CallMethodAndBlock(
method_call.get(), dbus::ObjectProxy::TIMEOUT_USE_DEFAULT));
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.get());
if (!message_reader.PopUint32(&inhibit_cookie_))
LOG(ERROR) << "Invalid Inhibit() response: " << response->ToString();
} else {
LOG(ERROR) << "No response to Inhibit() request!";
}
}
void PowerSaveBlockerImpl::Delegate::RemoveBlock(DBusAPI api) {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
DCHECK(bus_.get()); // RemoveBlock() should only be called once.
scoped_refptr<dbus::ObjectProxy> object_proxy;
scoped_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:
object_proxy = bus_->GetObjectProxy(
kFreeDesktopAPIServiceName,
dbus::ObjectPath(kFreeDesktopAPIObjectPath));
method_call.reset(
new dbus::MethodCall(kFreeDesktopAPIInterfaceName, "UnInhibit"));
break;
}
dbus::MessageWriter message_writer(method_call.get());
message_writer.AppendUint32(inhibit_cookie_);
scoped_ptr<dbus::Response> response(object_proxy->CallMethodAndBlock(
method_call.get(), dbus::ObjectProxy::TIMEOUT_USE_DEFAULT));
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_ = NULL;
}
// static
bool PowerSaveBlockerImpl::Delegate::DPMSEnabled() {
XDisplay* display = base::MessagePumpForUI::GetDefaultXDisplay();
BOOL enabled = false;
int dummy;
if (DPMSQueryExtension(display, &dummy, &dummy) && DPMSCapable(display)) {
CARD16 state;
DPMSInfo(display, &state, &enabled);
}
return enabled;
}
// static
DBusAPI PowerSaveBlockerImpl::Delegate::SelectAPI() {
scoped_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:
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, const std::string& reason)
: delegate_(new Delegate(type, reason)) {
delegate_->Init();
}
PowerSaveBlockerImpl::~PowerSaveBlockerImpl() {
delegate_->CleanUp();
}
} // namespace content