dom/workers/ChromeWorker.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 "ChromeWorker.h"
   8
   9 #include "mozilla/AppShutdown.h"
  10 #include "mozilla/dom/BindingUtils.h"
  11 #include "mozilla/dom/WorkerBinding.h"
  12 #include "nsContentUtils.h"
  13 #include "nsIXPConnect.h"
  14 #include "WorkerPrivate.h"
  15
  16 namespace mozilla::dom {
  17
  18 /* static */
  19 already_AddRefed<ChromeWorker> ChromeWorker::Constructor(
  20     const GlobalObject& aGlobal, const nsAString& aScriptURL,
  21     const WorkerOptions& aOptions, ErrorResult& aRv) {
  22   // Dump the JS stack if somebody's creating a ChromeWorker after shutdown has
  23   // begun.  See bug 1813353.
  24   if (xpc::IsInAutomation() &&
  25       AppShutdown::IsInOrBeyond(ShutdownPhase::AppShutdown)) {
  26     NS_WARNING("ChromeWorker construction during shutdown");
  27     nsCOMPtr<nsIXPConnect> xpc = nsIXPConnect::XPConnect();
  28     Unused << xpc->DebugDumpJSStack(true, true, false);
  29   }
  30
  31   JSContext* cx = aGlobal.Context();
  32
  33   RefPtr<WorkerPrivate> workerPrivate = WorkerPrivate::Constructor(
  34       cx, aScriptURL, true /* aIsChromeWorker */, WorkerKindDedicated,
  35       RequestCredentials::Omit, aOptions.mType, aOptions.mName, VoidCString(),
  36       nullptr /*aLoadInfo */, aRv);
  37   if (NS_WARN_IF(aRv.Failed())) {
  38     return nullptr;
  39   }
  40
  41   nsCOMPtr<nsIGlobalObject> globalObject =
  42       do_QueryInterface(aGlobal.GetAsSupports());
  43
  44   RefPtr<ChromeWorker> worker =
  45       new ChromeWorker(globalObject, workerPrivate.forget());
  46   return worker.forget();
  47 }
  48
  49 /* static */
  50 bool ChromeWorker::WorkerAvailable(JSContext* aCx, JSObject* /* unused */) {
  51   // Chrome is always allowed to use workers, and content is never
  52   // allowed to use ChromeWorker, so all we have to check is the
  53   // caller.  However, chrome workers apparently might not have a
  54   // system principal, so we have to check for them manually.
  55   if (NS_IsMainThread()) {
  56     return nsContentUtils::IsSystemCaller(aCx);
  57   }
  58
  59   return GetWorkerPrivateFromContext(aCx)->IsChromeWorker();
  60 }
  61
  62 ChromeWorker::ChromeWorker(nsIGlobalObject* aGlobalObject,
  63                            already_AddRefed<WorkerPrivate> aWorkerPrivate)
  64     : Worker(aGlobalObject, std::move(aWorkerPrivate)) {}
  65
  66 ChromeWorker::~ChromeWorker() = default;
  67
  68 JSObject* ChromeWorker::WrapObject(JSContext* aCx,
  69                                    JS::Handle<JSObject*> aGivenProto) {
  70   JS::Rooted<JSObject*> wrapper(
  71       aCx, ChromeWorker_Binding::Wrap(aCx, this, aGivenProto));
  72   if (wrapper) {
  73     // Most DOM objects don't assume they have a reflector. If they don't have
  74     // one and need one, they create it. But in workers code, we assume that the
  75     // reflector is always present.  In order to guarantee that it's always
  76     // present, we have to preserve it. Otherwise the GC will happily collect it
  77     // as needed.
  78     MOZ_ALWAYS_TRUE(TryPreserveWrapper(wrapper));
  79   }
  80
  81   return wrapper;
  82 }
  83
  84 }  // namespace mozilla::dom