dom/workers/WorkerDocumentListener.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "WorkerDocumentListener.h"
   8 #include "mozilla/dom/Document.h"
   9 #include "mozilla/dom/WorkerPrivate.h"
  10 #include "mozilla/dom/WorkerRef.h"
  11 #include "mozilla/dom/WorkerRunnable.h"
  12 #include "mozilla/dom/WorkerScope.h"
  13 #include "nsGlobalWindowInner.h"
  14
  15 namespace mozilla::dom {
  16
  17 WorkerDocumentListener::WorkerDocumentListener()
  18     : mMutex("mozilla::dom::WorkerDocumentListener::mMutex") {}
  19
  20 WorkerDocumentListener::~WorkerDocumentListener() = default;
  21
  22 RefPtr<WorkerDocumentListener> WorkerDocumentListener::Create(
  23     WorkerPrivate* aWorkerPrivate) {
  24   MOZ_ASSERT(aWorkerPrivate);
  25   aWorkerPrivate->AssertIsOnWorkerThread();
  26
  27   auto listener = MakeRefPtr<WorkerDocumentListener>();
  28
  29   RefPtr<StrongWorkerRef> strongWorkerRef =
  30       StrongWorkerRef::Create(aWorkerPrivate, "WorkerDocumentListener",
  31                               [listener]() { listener->Destroy(); });
  32   if (NS_WARN_IF(!strongWorkerRef)) {
  33     return nullptr;
  34   }
  35
  36   listener->mWorkerRef = new ThreadSafeWorkerRef(strongWorkerRef);
  37   uint64_t windowID = aWorkerPrivate->WindowID();
  38
  39   aWorkerPrivate->DispatchToMainThread(NS_NewRunnableFunction(
  40       "WorkerDocumentListener::Create",
  41       [listener, windowID] { listener->SetListening(windowID, true); }));
  42
  43   return listener;
  44 }
  45
  46 void WorkerDocumentListener::OnVisible(bool aVisible) {
  47   MOZ_ASSERT(NS_IsMainThread());
  48
  49   MutexAutoLock lock(mMutex);
  50   if (!mWorkerRef) {
  51     // We haven't handled the runnable to release this yet.
  52     return;
  53   }
  54
  55   class VisibleRunnable final : public WorkerThreadRunnable {
  56    public:
  57     VisibleRunnable(WorkerPrivate* aWorkerPrivate, bool aVisible)
  58         : WorkerThreadRunnable("VisibleRunnable"), mVisible(aVisible) {}
  59
  60     bool WorkerRun(JSContext* aCx, WorkerPrivate* aWorkerPrivate) {
  61       WorkerGlobalScope* scope = aWorkerPrivate->GlobalScope();
  62       MOZ_ASSERT(scope);
  63       scope->OnDocumentVisible(mVisible);
  64       return true;
  65     }
  66
  67    private:
  68     const bool mVisible;
  69   };
  70
  71   auto runnable = MakeRefPtr<VisibleRunnable>(mWorkerRef->Private(), aVisible);
  72   runnable->Dispatch(mWorkerRef->Private());
  73 }
  74
  75 void WorkerDocumentListener::SetListening(uint64_t aWindowID, bool aListen) {
  76   MOZ_ASSERT(NS_IsMainThread());
  77
  78   auto* window = nsGlobalWindowInner::GetInnerWindowWithId(aWindowID);
  79   Document* doc = window->GetExtantDoc();
  80   if (NS_WARN_IF(!doc)) {
  81     // This would typically happen during shutdown if there is an active worker
  82     // listening for document events. The Document may already be freed when we
  83     // try to deregister for notifications.
  84     return;
  85   }
  86
  87   if (aListen) {
  88     doc->AddWorkerDocumentListener(this);
  89   } else {
  90     doc->RemoveWorkerDocumentListener(this);
  91   }
  92 }
  93
  94 void WorkerDocumentListener::Destroy() {
  95   MutexAutoLock lock(mMutex);
  96
  97   MOZ_ASSERT(mWorkerRef);
  98   WorkerPrivate* workerPrivate = mWorkerRef->Private();
  99   MOZ_ASSERT(workerPrivate);
 100   workerPrivate->AssertIsOnWorkerThread();
 101
 102   uint64_t windowID = workerPrivate->WindowID();
 103   workerPrivate->DispatchToMainThread(NS_NewRunnableFunction(
 104       "WorkerDocumentListener::Destroy", [self = RefPtr{this}, windowID] {
 105         self->SetListening(windowID, false);
 106       }));
 107   mWorkerRef = nullptr;
 108 }
 109
 110 }  // namespace mozilla::dom