Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 728 insertions, 0 deletions

diff --git a/dom/workers/WorkerRunnable.cpp b/dom/workers/WorkerRunnable.cpp
new file mode 100644
index 0000000000..ec461d3cfb
--- /dev/null
+++ b/dom/workers/WorkerRunnable.cpp
@@ -0,0 +1,728 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 "WorkerRunnable.h"
+
+#include "WorkerScope.h"
+#include "js/RootingAPI.h"
+#include "jsapi.h"
+#include "jsfriendapi.h"
+#include "mozilla/AlreadyAddRefed.h"
+#include "mozilla/AppShutdown.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/ErrorResult.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/Telemetry.h"
+#include "mozilla/TelemetryHistogramEnums.h"
+#include "mozilla/TimeStamp.h"
+#include "mozilla/Unused.h"
+#include "mozilla/dom/ScriptSettings.h"
+#include "mozilla/dom/Worker.h"
+#include "mozilla/dom/WorkerCommon.h"
+#include "nsDebug.h"
+#include "nsGlobalWindowInner.h"
+#include "nsID.h"
+#include "nsIEventTarget.h"
+#include "nsIGlobalObject.h"
+#include "nsIRunnable.h"
+#include "nsThreadUtils.h"
+#include "nsWrapperCacheInlines.h"
+
+namespace mozilla::dom {
+
+namespace {
+
+const nsIID kWorkerRunnableIID = {
+    0x320cc0b5,
+    0xef12,
+    0x4084,
+    {0x88, 0x6e, 0xca, 0x6a, 0x81, 0xe4, 0x1d, 0x68}};
+
+}  // namespace
+
+#ifdef DEBUG
+WorkerRunnable::WorkerRunnable(WorkerPrivate* aWorkerPrivate,
+                               TargetAndBusyBehavior aBehavior)
+    : mWorkerPrivate(aWorkerPrivate),
+      mBehavior(aBehavior),
+      mCanceled(0),
+      mCallingCancelWithinRun(false) {
+  MOZ_ASSERT(aWorkerPrivate);
+}
+#endif
+
+bool WorkerRunnable::IsDebuggerRunnable() const { return false; }
+
+nsIGlobalObject* WorkerRunnable::DefaultGlobalObject() const {
+  if (IsDebuggerRunnable()) {
+    return mWorkerPrivate->DebuggerGlobalScope();
+  } else {
+    return mWorkerPrivate->GlobalScope();
+  }
+}
+
+bool WorkerRunnable::PreDispatch(WorkerPrivate* aWorkerPrivate) {
+#ifdef DEBUG
+  MOZ_ASSERT(aWorkerPrivate);
+
+  switch (mBehavior) {
+    case ParentThreadUnchangedBusyCount:
+      aWorkerPrivate->AssertIsOnWorkerThread();
+      break;
+
+    case WorkerThreadModifyBusyCount:
+    case WorkerThreadUnchangedBusyCount:
+      aWorkerPrivate->AssertIsOnParentThread();
+      break;
+
+    default:
+      MOZ_ASSERT_UNREACHABLE("Unknown behavior!");
+  }
+#endif
+
+  if (mBehavior == WorkerThreadModifyBusyCount) {
+    return aWorkerPrivate->ModifyBusyCount(true);
+  }
+
+  return true;
+}
+
+bool WorkerRunnable::Dispatch() {
+  bool ok = PreDispatch(mWorkerPrivate);
+  if (ok) {
+    ok = DispatchInternal();
+  }
+  PostDispatch(mWorkerPrivate, ok);
+  return ok;
+}
+
+bool WorkerRunnable::DispatchInternal() {
+  RefPtr<WorkerRunnable> runnable(this);
+
+  if (mBehavior == WorkerThreadModifyBusyCount ||
+      mBehavior == WorkerThreadUnchangedBusyCount) {
+    if (IsDebuggerRunnable()) {
+      return NS_SUCCEEDED(
+          mWorkerPrivate->DispatchDebuggerRunnable(runnable.forget()));
+    } else {
+      return NS_SUCCEEDED(mWorkerPrivate->Dispatch(runnable.forget()));
+    }
+  }
+
+  MOZ_ASSERT(mBehavior == ParentThreadUnchangedBusyCount);
+
+  if (WorkerPrivate* parent = mWorkerPrivate->GetParent()) {
+    return NS_SUCCEEDED(parent->Dispatch(runnable.forget()));
+  }
+
+  if (IsDebuggeeRunnable()) {
+    RefPtr<WorkerDebuggeeRunnable> debuggeeRunnable =
+        runnable.forget().downcast<WorkerDebuggeeRunnable>();
+    return NS_SUCCEEDED(mWorkerPrivate->DispatchDebuggeeToMainThread(
+        debuggeeRunnable.forget(), NS_DISPATCH_NORMAL));
+  }
+
+  return NS_SUCCEEDED(mWorkerPrivate->DispatchToMainThread(runnable.forget()));
+}
+
+void WorkerRunnable::PostDispatch(WorkerPrivate* aWorkerPrivate,
+                                  bool aDispatchResult) {
+  MOZ_ASSERT(aWorkerPrivate);
+
+#ifdef DEBUG
+  switch (mBehavior) {
+    case ParentThreadUnchangedBusyCount:
+      aWorkerPrivate->AssertIsOnWorkerThread();
+      break;
+
+    case WorkerThreadModifyBusyCount:
+      aWorkerPrivate->AssertIsOnParentThread();
+      break;
+
+    case WorkerThreadUnchangedBusyCount:
+      aWorkerPrivate->AssertIsOnParentThread();
+      break;
+
+    default:
+      MOZ_ASSERT_UNREACHABLE("Unknown behavior!");
+  }
+#endif
+
+  if (!aDispatchResult) {
+    if (mBehavior == WorkerThreadModifyBusyCount) {
+      aWorkerPrivate->ModifyBusyCount(false);
+    }
+  }
+}
+
+bool WorkerRunnable::PreRun(WorkerPrivate* aWorkerPrivate) { return true; }
+
+void WorkerRunnable::PostRun(JSContext* aCx, WorkerPrivate* aWorkerPrivate,
+                             bool aRunResult) {
+  MOZ_ASSERT(aCx);
+  MOZ_ASSERT(aWorkerPrivate);
+
+#ifdef DEBUG
+  switch (mBehavior) {
+    case ParentThreadUnchangedBusyCount:
+      aWorkerPrivate->AssertIsOnParentThread();
+      break;
+
+    case WorkerThreadModifyBusyCount:
+      aWorkerPrivate->AssertIsOnWorkerThread();
+      break;
+
+    case WorkerThreadUnchangedBusyCount:
+      aWorkerPrivate->AssertIsOnWorkerThread();
+      break;
+
+    default:
+      MOZ_ASSERT_UNREACHABLE("Unknown behavior!");
+  }
+#endif
+
+  if (mBehavior == WorkerThreadModifyBusyCount) {
+    aWorkerPrivate->ModifyBusyCountFromWorker(false);
+  }
+}
+
+// static
+WorkerRunnable* WorkerRunnable::FromRunnable(nsIRunnable* aRunnable) {
+  MOZ_ASSERT(aRunnable);
+
+  WorkerRunnable* runnable;
+  nsresult rv = aRunnable->QueryInterface(kWorkerRunnableIID,
+                                          reinterpret_cast<void**>(&runnable));
+  if (NS_FAILED(rv)) {
+    return nullptr;
+  }
+
+  MOZ_ASSERT(runnable);
+  return runnable;
+}
+
+NS_IMPL_ADDREF(WorkerRunnable)
+NS_IMPL_RELEASE(WorkerRunnable)
+
+NS_INTERFACE_MAP_BEGIN(WorkerRunnable)
+  NS_INTERFACE_MAP_ENTRY(nsIRunnable)
+  NS_INTERFACE_MAP_ENTRY(nsICancelableRunnable)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIRunnable)
+  // kWorkerRunnableIID is special in that it does not AddRef its result.
+  if (aIID.Equals(kWorkerRunnableIID)) {
+    *aInstancePtr = this;
+    return NS_OK;
+  } else
+NS_INTERFACE_MAP_END
+
+NS_IMETHODIMP
+WorkerRunnable::Run() {
+  bool targetIsWorkerThread = mBehavior == WorkerThreadModifyBusyCount ||
+                              mBehavior == WorkerThreadUnchangedBusyCount;
+
+#ifdef DEBUG
+  MOZ_ASSERT_IF(mCallingCancelWithinRun, targetIsWorkerThread);
+  if (targetIsWorkerThread) {
+    mWorkerPrivate->AssertIsOnWorkerThread();
+  } else {
+    MOZ_ASSERT(mBehavior == ParentThreadUnchangedBusyCount);
+    mWorkerPrivate->AssertIsOnParentThread();
+  }
+#endif
+
+  if (IsCanceled() && !mCallingCancelWithinRun) {
+    return NS_OK;
+  }
+
+  if (targetIsWorkerThread &&
+      mWorkerPrivate->AllPendingRunnablesShouldBeCanceled() && !IsCanceled() &&
+      !mCallingCancelWithinRun) {
+    // Prevent recursion.
+    mCallingCancelWithinRun = true;
+
+    Cancel();
+
+    MOZ_ASSERT(mCallingCancelWithinRun);
+    mCallingCancelWithinRun = false;
+
+    MOZ_ASSERT(IsCanceled(), "Subclass Cancel() didn't set IsCanceled()!");
+
+    if (mBehavior == WorkerThreadModifyBusyCount) {
+      mWorkerPrivate->ModifyBusyCountFromWorker(false);
+    }
+
+    return NS_OK;
+  }
+
+  bool result = PreRun(mWorkerPrivate);
+  if (!result) {
+    MOZ_ASSERT(targetIsWorkerThread,
+               "The only PreRun implementation that can fail is "
+               "ScriptExecutorRunnable");
+    mWorkerPrivate->AssertIsOnWorkerThread();
+    MOZ_ASSERT(!JS_IsExceptionPending(mWorkerPrivate->GetJSContext()));
+    // We can't enter a useful realm on the JSContext here; just pass it
+    // in as-is.
+    PostRun(mWorkerPrivate->GetJSContext(), mWorkerPrivate, false);
+    return NS_ERROR_FAILURE;
+  }
+
+  // Track down the appropriate global, if any, to use for the AutoEntryScript.
+  nsCOMPtr<nsIGlobalObject> globalObject;
+  bool isMainThread = !targetIsWorkerThread && !mWorkerPrivate->GetParent();
+  MOZ_ASSERT(isMainThread == NS_IsMainThread());
+  RefPtr<WorkerPrivate> kungFuDeathGrip;
+  if (targetIsWorkerThread) {
+    globalObject = mWorkerPrivate->GetCurrentEventLoopGlobal();
+    if (!globalObject) {
+      globalObject = DefaultGlobalObject();
+      // Our worker thread may not be in a good state here if there is no
+      // JSContext avaliable.  The way this manifests itself is that
+      // globalObject ends up null (though it's not clear to me how we can be
+      // running runnables at all when DefaultGlobalObject() is returning
+      // false!) and then when we try to init the AutoJSAPI either
+      // CycleCollectedJSContext::Get() returns null or it has a null JSContext.
+      // In any case, we used to have a check for
+      // GetCurrentWorkerThreadJSContext() being non-null here and that seems to
+      // avoid the problem, so let's keep doing that check even if we don't need
+      // the JSContext here at all.
+      if (NS_WARN_IF(!globalObject && !GetCurrentWorkerThreadJSContext())) {
+        return NS_ERROR_FAILURE;
+      }
+    }
+
+    // We may still not have a globalObject here: in the case of
+    // CompileScriptRunnable, we don't actually create the global object until
+    // we have the script data, which happens in a syncloop under
+    // CompileScriptRunnable::WorkerRun, so we can't assert that it got created
+    // in the PreRun call above.
+  } else {
+    kungFuDeathGrip = mWorkerPrivate;
+    if (isMainThread) {
+      globalObject = nsGlobalWindowInner::Cast(mWorkerPrivate->GetWindow());
+    } else {
+      globalObject = mWorkerPrivate->GetParent()->GlobalScope();
+    }
+  }
+
+  // We might run script as part of WorkerRun, so we need an AutoEntryScript.
+  // This is part of the HTML spec for workers at:
+  // http://www.whatwg.org/specs/web-apps/current-work/#run-a-worker
+  // If we don't have a globalObject we have to use an AutoJSAPI instead, but
+  // this is OK as we won't be running script in these circumstances.
+  Maybe<mozilla::dom::AutoJSAPI> maybeJSAPI;
+  Maybe<mozilla::dom::AutoEntryScript> aes;
+  JSContext* cx;
+  AutoJSAPI* jsapi;
+  if (globalObject) {
+    aes.emplace(globalObject, "Worker runnable", isMainThread);
+    jsapi = aes.ptr();
+    cx = aes->cx();
+  } else {
+    maybeJSAPI.emplace();
+    maybeJSAPI->Init();
+    jsapi = maybeJSAPI.ptr();
+    cx = jsapi->cx();
+  }
+
+  // Note that we can't assert anything about
+  // mWorkerPrivate->ParentEventTargetRef()->GetWrapper()
+  // existing, since it may in fact have been GCed (and we may be one of the
+  // runnables cleaning up the worker as a result).
+
+  // If we are on the parent thread and that thread is not the main thread,
+  // then we must be a dedicated worker (because there are no
+  // Shared/ServiceWorkers whose parent is itself a worker) and then we
+  // definitely have a globalObject.  If it _is_ the main thread, globalObject
+  // can be null for workers started from JSMs or other non-window contexts,
+  // sadly.
+  MOZ_ASSERT_IF(!targetIsWorkerThread && !isMainThread,
+                mWorkerPrivate->IsDedicatedWorker() && globalObject);
+
+  // If we're on the parent thread we might be in a null realm in the
+  // situation described above when globalObject is null.  Make sure to enter
+  // the realm of the worker's reflector if there is one.  There might
+  // not be one if we're just starting to compile the script for this worker.
+  Maybe<JSAutoRealm> ar;
+  if (!targetIsWorkerThread && mWorkerPrivate->IsDedicatedWorker() &&
+      mWorkerPrivate->ParentEventTargetRef()->GetWrapper()) {
+    JSObject* wrapper = mWorkerPrivate->ParentEventTargetRef()->GetWrapper();
+
+    // If we're on the parent thread and have a reflector and a globalObject,
+    // then the realms of cx, globalObject, and the worker's reflector
+    // should all match.
+    MOZ_ASSERT_IF(globalObject,
+                  js::GetNonCCWObjectRealm(wrapper) == js::GetContextRealm(cx));
+    MOZ_ASSERT_IF(globalObject,
+                  js::GetNonCCWObjectRealm(wrapper) ==
+                      js::GetNonCCWObjectRealm(
+                          globalObject->GetGlobalJSObjectPreserveColor()));
+
+    // If we're on the parent thread and have a reflector, then our
+    // JSContext had better be either in the null realm (and hence
+    // have no globalObject) or in the realm of our reflector.
+    MOZ_ASSERT(!js::GetContextRealm(cx) ||
+                   js::GetNonCCWObjectRealm(wrapper) == js::GetContextRealm(cx),
+               "Must either be in the null compartment or in our reflector "
+               "compartment");
+
+    ar.emplace(cx, wrapper);
+  }
+
+  MOZ_ASSERT(!jsapi->HasException());
+  result = WorkerRun(cx, mWorkerPrivate);
+  jsapi->ReportException();
+
+  // We can't even assert that this didn't create our global, since in the case
+  // of CompileScriptRunnable it _does_.
+
+  // It would be nice to avoid passing a JSContext to PostRun, but in the case
+  // of ScriptExecutorRunnable we need to know the current compartment on the
+  // JSContext (the one we set up based on the global returned from PreRun) so
+  // that we can sanely do exception reporting.  In particular, we want to make
+  // sure that we do our JS_SetPendingException while still in that compartment,
+  // because otherwise we might end up trying to create a cross-compartment
+  // wrapper when we try to move the JS exception from our runnable's
+  // ErrorResult to the JSContext, and that's not desirable in this case.
+  //
+  // We _could_ skip passing a JSContext here and then in
+  // ScriptExecutorRunnable::PostRun end up grabbing it from the WorkerPrivate
+  // and looking at its current compartment.  But that seems like slightly weird
+  // action-at-a-distance...
+  //
+  // In any case, we do NOT try to change the compartment on the JSContext at
+  // this point; in the one case in which we could do that
+  // (CompileScriptRunnable) it actually doesn't matter which compartment we're
+  // in for PostRun.
+  PostRun(cx, mWorkerPrivate, result);
+  MOZ_ASSERT(!jsapi->HasException());
+
+  return result ? NS_OK : NS_ERROR_FAILURE;
+}
+
+nsresult WorkerRunnable::Cancel() {
+  uint32_t canceledCount = ++mCanceled;
+
+  MOZ_ASSERT(canceledCount, "Cancel() overflow!");
+
+  // The docs say that Cancel() should not be called more than once and that we
+  // should throw NS_ERROR_UNEXPECTED if it is.
+  return (canceledCount == 1) ? NS_OK : NS_ERROR_UNEXPECTED;
+}
+
+void WorkerDebuggerRunnable::PostDispatch(WorkerPrivate* aWorkerPrivate,
+                                          bool aDispatchResult) {}
+
+WorkerSyncRunnable::WorkerSyncRunnable(WorkerPrivate* aWorkerPrivate,
+                                       nsIEventTarget* aSyncLoopTarget)
+    : WorkerRunnable(aWorkerPrivate, WorkerThreadUnchangedBusyCount),
+      mSyncLoopTarget(aSyncLoopTarget) {
+#ifdef DEBUG
+  if (mSyncLoopTarget) {
+    mWorkerPrivate->AssertValidSyncLoop(mSyncLoopTarget);
+  }
+#endif
+}
+
+WorkerSyncRunnable::WorkerSyncRunnable(
+    WorkerPrivate* aWorkerPrivate, nsCOMPtr<nsIEventTarget>&& aSyncLoopTarget)
+    : WorkerRunnable(aWorkerPrivate, WorkerThreadUnchangedBusyCount),
+      mSyncLoopTarget(std::move(aSyncLoopTarget)) {
+#ifdef DEBUG
+  if (mSyncLoopTarget) {
+    mWorkerPrivate->AssertValidSyncLoop(mSyncLoopTarget);
+  }
+#endif
+}
+
+WorkerSyncRunnable::~WorkerSyncRunnable() = default;
+
+bool WorkerSyncRunnable::DispatchInternal() {
+  if (mSyncLoopTarget) {
+    RefPtr<WorkerSyncRunnable> runnable(this);
+    return NS_SUCCEEDED(
+        mSyncLoopTarget->Dispatch(runnable.forget(), NS_DISPATCH_NORMAL));
+  }
+
+  return WorkerRunnable::DispatchInternal();
+}
+
+void MainThreadWorkerSyncRunnable::PostDispatch(WorkerPrivate* aWorkerPrivate,
+                                                bool aDispatchResult) {}
+
+MainThreadStopSyncLoopRunnable::MainThreadStopSyncLoopRunnable(
+    WorkerPrivate* aWorkerPrivate, nsCOMPtr<nsIEventTarget>&& aSyncLoopTarget,
+    nsresult aResult)
+    : WorkerSyncRunnable(aWorkerPrivate, std::move(aSyncLoopTarget)),
+      mResult(aResult) {
+  AssertIsOnMainThread();
+#ifdef DEBUG
+  mWorkerPrivate->AssertValidSyncLoop(mSyncLoopTarget);
+#endif
+}
+
+nsresult MainThreadStopSyncLoopRunnable::Cancel() {
+  // We need to check first if cancel is called twice
+  nsresult rv = WorkerSyncRunnable::Cancel();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = Run();
+  NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "Run() failed");
+
+  return rv;
+}
+
+bool MainThreadStopSyncLoopRunnable::WorkerRun(JSContext* aCx,
+                                               WorkerPrivate* aWorkerPrivate) {
+  aWorkerPrivate->AssertIsOnWorkerThread();
+  MOZ_ASSERT(mSyncLoopTarget);
+
+  nsCOMPtr<nsIEventTarget> syncLoopTarget;
+  mSyncLoopTarget.swap(syncLoopTarget);
+
+  aWorkerPrivate->StopSyncLoop(syncLoopTarget, mResult);
+  return true;
+}
+
+bool MainThreadStopSyncLoopRunnable::DispatchInternal() {
+  MOZ_ASSERT(mSyncLoopTarget);
+
+  RefPtr<MainThreadStopSyncLoopRunnable> runnable(this);
+  return NS_SUCCEEDED(
+      mSyncLoopTarget->Dispatch(runnable.forget(), NS_DISPATCH_NORMAL));
+}
+
+void MainThreadStopSyncLoopRunnable::PostDispatch(WorkerPrivate* aWorkerPrivate,
+                                                  bool aDispatchResult) {}
+
+#ifdef DEBUG
+WorkerControlRunnable::WorkerControlRunnable(WorkerPrivate* aWorkerPrivate,
+                                             TargetAndBusyBehavior aBehavior)
+    : WorkerRunnable(aWorkerPrivate, aBehavior) {
+  MOZ_ASSERT(aWorkerPrivate);
+  MOZ_ASSERT(aBehavior == ParentThreadUnchangedBusyCount ||
+                 aBehavior == WorkerThreadUnchangedBusyCount,
+             "WorkerControlRunnables should not modify the busy count");
+}
+#endif
+
+nsresult WorkerControlRunnable::Cancel() {
+  // We need to check first if cancel is called twice
+  nsresult rv = WorkerRunnable::Cancel();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (NS_FAILED(Run())) {
+    NS_WARNING("WorkerControlRunnable::Run() failed.");
+  }
+
+  return NS_OK;
+}
+
+bool WorkerControlRunnable::DispatchInternal() {
+  RefPtr<WorkerControlRunnable> runnable(this);
+
+  if (mBehavior == WorkerThreadUnchangedBusyCount) {
+    return NS_SUCCEEDED(
+        mWorkerPrivate->DispatchControlRunnable(runnable.forget()));
+  }
+
+  if (WorkerPrivate* parent = mWorkerPrivate->GetParent()) {
+    return NS_SUCCEEDED(parent->DispatchControlRunnable(runnable.forget()));
+  }
+
+  return NS_SUCCEEDED(mWorkerPrivate->DispatchToMainThread(runnable.forget()));
+}
+
+WorkerMainThreadRunnable::WorkerMainThreadRunnable(
+    WorkerPrivate* aWorkerPrivate, const nsACString& aTelemetryKey)
+    : mozilla::Runnable("dom::WorkerMainThreadRunnable"),
+      mWorkerPrivate(aWorkerPrivate),
+      mTelemetryKey(aTelemetryKey) {
+  mWorkerPrivate->AssertIsOnWorkerThread();
+}
+
+WorkerMainThreadRunnable::~WorkerMainThreadRunnable() = default;
+
+void WorkerMainThreadRunnable::Dispatch(WorkerStatus aFailStatus,
+                                        mozilla::ErrorResult& aRv) {
+  mWorkerPrivate->AssertIsOnWorkerThread();
+
+  TimeStamp startTime = TimeStamp::NowLoRes();
+
+  AutoSyncLoopHolder syncLoop(mWorkerPrivate, aFailStatus);
+
+  mSyncLoopTarget = syncLoop.GetSerialEventTarget();
+  if (!mSyncLoopTarget) {
+    // SyncLoop creation can fail if the worker is shutting down.
+    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
+    return;
+  }
+
+  DebugOnly<nsresult> rv = mWorkerPrivate->DispatchToMainThread(this);
+  MOZ_ASSERT(
+      NS_SUCCEEDED(rv),
+      "Should only fail after xpcom-shutdown-threads and we're gone by then");
+
+  bool success = NS_SUCCEEDED(syncLoop.Run());
+
+  Telemetry::Accumulate(
+      Telemetry::SYNC_WORKER_OPERATION, mTelemetryKey,
+      static_cast<uint32_t>(
+          (TimeStamp::NowLoRes() - startTime).ToMilliseconds()));
+
+  Unused << startTime;  // Shut the compiler up.
+
+  if (!success) {
+    aRv.ThrowUncatchableException();
+  }
+}
+
+NS_IMETHODIMP
+WorkerMainThreadRunnable::Run() {
+  AssertIsOnMainThread();
+
+  // This shouldn't be necessary once we're better about making sure no workers
+  // are created during shutdown in earlier phases.
+  if (AppShutdown::IsInOrBeyond(ShutdownPhase::XPCOMShutdownThreads)) {
+    return NS_ERROR_ILLEGAL_DURING_SHUTDOWN;
+  }
+
+  bool runResult = MainThreadRun();
+
+  RefPtr<MainThreadStopSyncLoopRunnable> response =
+      new MainThreadStopSyncLoopRunnable(mWorkerPrivate,
+                                         std::move(mSyncLoopTarget),
+                                         runResult ? NS_OK : NS_ERROR_FAILURE);
+
+  MOZ_ALWAYS_TRUE(response->Dispatch());
+
+  return NS_OK;
+}
+
+bool WorkerSameThreadRunnable::PreDispatch(WorkerPrivate* aWorkerPrivate) {
+  // We don't call WorkerRunnable::PreDispatch, because we're using
+  // WorkerThreadModifyBusyCount for mBehavior, and WorkerRunnable will assert
+  // that PreDispatch is on the parent thread in that case.
+  aWorkerPrivate->AssertIsOnWorkerThread();
+  return true;
+}
+
+void WorkerSameThreadRunnable::PostDispatch(WorkerPrivate* aWorkerPrivate,
+                                            bool aDispatchResult) {
+  // We don't call WorkerRunnable::PostDispatch, because we're using
+  // WorkerThreadModifyBusyCount for mBehavior, and WorkerRunnable will assert
+  // that PostDispatch is on the parent thread in that case.
+  aWorkerPrivate->AssertIsOnWorkerThread();
+  if (aDispatchResult) {
+    DebugOnly<bool> willIncrement =
+        aWorkerPrivate->ModifyBusyCountFromWorker(true);
+    // Should never fail since if this thread is still running, so should the
+    // parent and it should be able to process a control runnable.
+    MOZ_ASSERT(willIncrement);
+  }
+}
+
+WorkerProxyToMainThreadRunnable::WorkerProxyToMainThreadRunnable()
+    : mozilla::Runnable("dom::WorkerProxyToMainThreadRunnable") {}
+
+WorkerProxyToMainThreadRunnable::~WorkerProxyToMainThreadRunnable() = default;
+
+bool WorkerProxyToMainThreadRunnable::Dispatch(WorkerPrivate* aWorkerPrivate) {
+  MOZ_ASSERT(aWorkerPrivate);
+  aWorkerPrivate->AssertIsOnWorkerThread();
+
+  RefPtr<StrongWorkerRef> workerRef = StrongWorkerRef::Create(
+      aWorkerPrivate, "WorkerProxyToMainThreadRunnable");
+  if (NS_WARN_IF(!workerRef)) {
+    RunBackOnWorkerThreadForCleanup(aWorkerPrivate);
+    return false;
+  }
+
+  MOZ_ASSERT(!mWorkerRef);
+  mWorkerRef = new ThreadSafeWorkerRef(workerRef);
+
+  if (ForMessaging()
+          ? NS_WARN_IF(NS_FAILED(
+                aWorkerPrivate->DispatchToMainThreadForMessaging(this)))
+          : NS_WARN_IF(NS_FAILED(aWorkerPrivate->DispatchToMainThread(this)))) {
+    ReleaseWorker();
+    RunBackOnWorkerThreadForCleanup(aWorkerPrivate);
+    return false;
+  }
+
+  return true;
+}
+
+NS_IMETHODIMP
+WorkerProxyToMainThreadRunnable::Run() {
+  AssertIsOnMainThread();
+  RunOnMainThread(mWorkerRef->Private());
+  PostDispatchOnMainThread();
+  return NS_OK;
+}
+
+void WorkerProxyToMainThreadRunnable::PostDispatchOnMainThread() {
+  class ReleaseRunnable final : public MainThreadWorkerControlRunnable {
+    RefPtr<WorkerProxyToMainThreadRunnable> mRunnable;
+
+   public:
+    ReleaseRunnable(WorkerPrivate* aWorkerPrivate,
+                    WorkerProxyToMainThreadRunnable* aRunnable)
+        : MainThreadWorkerControlRunnable(aWorkerPrivate),
+          mRunnable(aRunnable) {
+      MOZ_ASSERT(aRunnable);
+    }
+
+    // We must call RunBackOnWorkerThreadForCleanup() also if the runnable is
+    // canceled.
+    nsresult Cancel() override {
+      WorkerRun(nullptr, mWorkerPrivate);
+      return MainThreadWorkerControlRunnable::Cancel();
+    }
+
+    virtual bool WorkerRun(JSContext* aCx,
+                           WorkerPrivate* aWorkerPrivate) override {
+      MOZ_ASSERT(aWorkerPrivate);
+      aWorkerPrivate->AssertIsOnWorkerThread();
+
+      if (mRunnable) {
+        mRunnable->RunBackOnWorkerThreadForCleanup(aWorkerPrivate);
+
+        // Let's release the worker thread.
+        mRunnable->ReleaseWorker();
+        mRunnable = nullptr;
+      }
+
+      return true;
+    }
+
+   private:
+    ~ReleaseRunnable() = default;
+  };
+
+  RefPtr<WorkerControlRunnable> runnable =
+      new ReleaseRunnable(mWorkerRef->Private(), this);
+  Unused << NS_WARN_IF(!runnable->Dispatch());
+}
+
+void WorkerProxyToMainThreadRunnable::ReleaseWorker() { mWorkerRef = nullptr; }
+
+bool WorkerDebuggeeRunnable::PreDispatch(WorkerPrivate* aWorkerPrivate) {
+  if (mBehavior == ParentThreadUnchangedBusyCount) {
+    RefPtr<StrongWorkerRef> strongRef = StrongWorkerRef::Create(
+        aWorkerPrivate, "WorkerDebuggeeRunnable::mSender");
+    if (!strongRef) {
+      return false;
+    }
+
+    mSender = new ThreadSafeWorkerRef(strongRef);
+  }
+
+  return WorkerRunnable::PreDispatch(aWorkerPrivate);
+}
+
+}  // namespace mozilla::dom