The Tor Browser: dom/power/WakeLock.cpp@b8a032363ba2 (annotated)

dom/power/WakeLock.cpp@b8a032363ba2 (annotated)

dom/power/WakeLock.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- Mode: C++; tab-width: 40; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "WakeLock.h"
 #include "mozilla/dom/ContentParent.h"
 #include "mozilla/dom/Event.h" // for nsIDOMEvent::InternalDOMEvent()
 #include "mozilla/dom/MozWakeLockBinding.h"
 #include "mozilla/Hal.h"
 #include "mozilla/HalWakeLock.h"
 #include "nsError.h"
 #include "nsIDocument.h"
 #include "nsIDOMWindow.h"
 #include "nsIDOMEvent.h"
 #include "nsPIDOMWindow.h"
 #include "nsIPropertyBag2.h"
 using namespace mozilla::hal;
 namespace mozilla {
 namespace dom {
 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_0(WakeLock)
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(WakeLock)
   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIDOMEventListener)
   NS_INTERFACE_MAP_ENTRY(nsIDOMEventListener)
   NS_INTERFACE_MAP_ENTRY(nsIObserver)
   NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
 NS_INTERFACE_MAP_END
 NS_IMPL_CYCLE_COLLECTING_ADDREF(WakeLock)
 NS_IMPL_CYCLE_COLLECTING_RELEASE(WakeLock)
 WakeLock::WakeLock()
   : mLocked(false)
   , mHidden(true)
   , mContentParentID(CONTENT_PROCESS_ID_UNKNOWN)
 {
   SetIsDOMBinding();
 }
 WakeLock::~WakeLock()
 {
   DoUnlock();
   DetachEventListener();
 }
 JSObject*
 WakeLock::WrapObject(JSContext* aCx)
 {
   return MozWakeLockBinding::Wrap(aCx, this);
 }
 nsresult
 WakeLock::Init(const nsAString &aTopic, nsIDOMWindow *aWindow)
 {
   // Don't Init() a WakeLock twice.
   MOZ_ASSERT(mTopic.IsEmpty());
   if (aTopic.IsEmpty()) {
     return NS_ERROR_INVALID_ARG;
   }
   mTopic.Assign(aTopic);
   mWindow = do_GetWeakReference(aWindow);
   nsCOMPtr<nsPIDOMWindow> window = do_QueryInterface(aWindow);
   /**
    * Null windows are allowed. A wake lock without associated window
    * is always considered invisible.
    */
   if (window) {
     nsCOMPtr<nsIDocument> doc = window->GetExtantDoc();
     NS_ENSURE_STATE(doc);
     mHidden = doc->Hidden();
   }
   AttachEventListener();
   DoLock();
   return NS_OK;
 }
 nsresult
 WakeLock::Init(const nsAString& aTopic, ContentParent* aContentParent)
 {
   // Don't Init() a WakeLock twice.
   MOZ_ASSERT(mTopic.IsEmpty());
   MOZ_ASSERT(aContentParent);
   if (aTopic.IsEmpty()) {
     return NS_ERROR_INVALID_ARG;
   }
   mTopic.Assign(aTopic);
   mContentParentID = aContentParent->ChildID();
   mHidden = false;
   nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
   if (obs) {
     obs->AddObserver(this, "ipc:content-shutdown", /* ownsWeak */ true);
   }
   DoLock();
   return NS_OK;
 }
 NS_IMETHODIMP
 WakeLock::Observe(nsISupports* aSubject, const char* aTopic, const char16_t* data)
 {
   // If this wake lock was acquired on behalf of another process, unlock it
   // when that process dies.
   //
   // Note that we do /not/ call DoUnlock() here!  The wake lock back-end is
   // already listening for ipc:content-shutdown messages and will clear out its
   // tally for the process when it dies.  All we need to do here is ensure that
   // unlock() becomes a nop.
   MOZ_ASSERT(!strcmp(aTopic, "ipc:content-shutdown"));
   nsCOMPtr<nsIPropertyBag2> props = do_QueryInterface(aSubject);
   if (!props) {
     NS_WARNING("ipc:content-shutdown message without property bag as subject");
     return NS_OK;
   }
   uint64_t childID = 0;
   nsresult rv = props->GetPropertyAsUint64(NS_LITERAL_STRING("childID"),
                                            &childID);
   if (NS_SUCCEEDED(rv)) {
     if (childID == mContentParentID) {
       mLocked = false;
     }
   } else {
     NS_WARNING("ipc:content-shutdown message without childID property");
   }
   return NS_OK;
 }
 void
 WakeLock::DoLock()
 {
   if (!mLocked) {
     // Change the flag immediately to prevent recursive reentering
     mLocked = true;
     hal::ModifyWakeLock(mTopic,
                         hal::WAKE_LOCK_ADD_ONE,
                         mHidden ? hal::WAKE_LOCK_ADD_ONE : hal::WAKE_LOCK_NO_CHANGE,
                         mContentParentID);
   }
 }
 void
 WakeLock::DoUnlock()
 {
   if (mLocked) {
     // Change the flag immediately to prevent recursive reentering
     mLocked = false;
     hal::ModifyWakeLock(mTopic,
                         hal::WAKE_LOCK_REMOVE_ONE,
                         mHidden ? hal::WAKE_LOCK_REMOVE_ONE : hal::WAKE_LOCK_NO_CHANGE,
                         mContentParentID);
   }
 }
 void
 WakeLock::AttachEventListener()
 {
   nsCOMPtr<nsPIDOMWindow> window = do_QueryReferent(mWindow);
   if (window) {
     nsCOMPtr<nsIDocument> doc = window->GetExtantDoc();
     if (doc) {
       doc->AddSystemEventListener(NS_LITERAL_STRING("visibilitychange"),
                                   this,
                                   /* useCapture = */ true,
                                   /* wantsUntrusted = */ false);
       nsCOMPtr<EventTarget> target = do_QueryInterface(window);
       target->AddSystemEventListener(NS_LITERAL_STRING("pagehide"),
                                      this,
                                      /* useCapture = */ true,
                                      /* wantsUntrusted = */ false);
       target->AddSystemEventListener(NS_LITERAL_STRING("pageshow"),
                                      this,
                                      /* useCapture = */ true,
                                      /* wantsUntrusted = */ false);
     }
   }
 }
 void
 WakeLock::DetachEventListener()
 {
   nsCOMPtr<nsPIDOMWindow> window = do_QueryReferent(mWindow);
   if (window) {
     nsCOMPtr<nsIDocument> doc = window->GetExtantDoc();
     if (doc) {
       doc->RemoveSystemEventListener(NS_LITERAL_STRING("visibilitychange"),
                                      this,
                                      /* useCapture = */ true);
       nsCOMPtr<EventTarget> target = do_QueryInterface(window);
       target->RemoveSystemEventListener(NS_LITERAL_STRING("pagehide"),
                                         this,
                                         /* useCapture = */ true);
       target->RemoveSystemEventListener(NS_LITERAL_STRING("pageshow"),
                                         this,
                                         /* useCapture = */ true);
     }
   }
 }
 void
 WakeLock::Unlock(ErrorResult& aRv)
 {
   /*
    * We throw NS_ERROR_DOM_INVALID_STATE_ERR on double unlock.
    */
   if (!mLocked) {
     aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
     return;
   }
   DoUnlock();
   DetachEventListener();
 }
 void
 WakeLock::GetTopic(nsAString &aTopic)
 {
   aTopic.Assign(mTopic);
 }
 NS_IMETHODIMP
 WakeLock::HandleEvent(nsIDOMEvent *aEvent)
 {
   nsAutoString type;
   aEvent->GetType(type);
   if (type.EqualsLiteral("visibilitychange")) {
     nsCOMPtr<nsIDocument> doc =
       do_QueryInterface(aEvent->InternalDOMEvent()->GetTarget());
     NS_ENSURE_STATE(doc);
     bool oldHidden = mHidden;
     mHidden = doc->Hidden();
     if (mLocked && oldHidden != mHidden) {
       hal::ModifyWakeLock(mTopic,
                           hal::WAKE_LOCK_NO_CHANGE,
                           mHidden ? hal::WAKE_LOCK_ADD_ONE : hal::WAKE_LOCK_REMOVE_ONE,
                           mContentParentID);
     }
     return NS_OK;
   }
   if (type.EqualsLiteral("pagehide")) {
     DoUnlock();
     return NS_OK;
   }
   if (type.EqualsLiteral("pageshow")) {
     DoLock();
     return NS_OK;
   }
   return NS_OK;
 }
 nsISupports*
 WakeLock::GetParentObject() const
 {
   nsCOMPtr<nsPIDOMWindow> window = do_QueryInterface(mWindow);
   return window;
 }
 } // dom
 } // mozilla

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dom/power/WakeLock.cpp@b8a032363ba2 (annotated)

dom/power/WakeLock.cpp