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/* -*- 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
#include "AbortSignal.h"
#include "mozilla/dom/AbortSignalBinding.h"
#include "mozilla/dom/DOMException.h"
#include "mozilla/dom/Event.h"
#include "mozilla/dom/EventBinding.h"
#include "mozilla/dom/TimeoutHandler.h"
#include "mozilla/dom/TimeoutManager.h"
#include "mozilla/dom/ToJSValue.h"
#include "mozilla/dom/WorkerPrivate.h"
#include "mozilla/RefPtr.h"
#include "nsCycleCollectionParticipant.h"
#include "nsPIDOMWindow.h"
namespace mozilla::dom {
// AbortSignalImpl
// ----------------------------------------------------------------------------
AbortSignalImpl::AbortSignalImpl(bool aAborted, JS::Handle<JS::Value> aReason)
: mReason(aReason), mAborted(aAborted) {
MOZ_ASSERT_IF(!mReason.isUndefined(), mAborted);
}
bool AbortSignalImpl::Aborted() const { return mAborted; }
void AbortSignalImpl::GetReason(JSContext* aCx,
JS::MutableHandle<JS::Value> aReason) {
if (!mAborted) {
return;
}
MaybeAssignAbortError(aCx);
aReason.set(mReason);
}
JS::Value AbortSignalImpl::RawReason() const { return mReason.get(); }
void AbortSignalImpl::SignalAbort(JS::Handle<JS::Value> aReason) {
// Step 1.
if (mAborted) {
return;
}
// Step 2.
SetAborted(aReason);
// Step 3.
// When there are multiple followers, the follower removal algorithm
// earlier algorithm to remove a later algorithm, so |mFollowers| must be a
// |nsTObserverArray| to defend against mutation.
for (RefPtr<AbortFollower>& follower : mFollowers.ForwardRange()) {
MOZ_ASSERT(follower->mFollowingSignal == this);
follower->RunAbortAlgorithm();
}
// Step 4.
UnlinkFollowers();
}
void AbortSignalImpl::SetAborted(JS::Handle<JS::Value> aReason) {
mAborted = true;
mReason = aReason;
}
void AbortSignalImpl::Traverse(AbortSignalImpl* aSignal,
nsCycleCollectionTraversalCallback& cb) {
ImplCycleCollectionTraverse(cb, aSignal->mFollowers, "mFollowers", 0);
}
void AbortSignalImpl::Unlink(AbortSignalImpl* aSignal) {
aSignal->mReason.setUndefined();
aSignal->UnlinkFollowers();
}
void AbortSignalImpl::MaybeAssignAbortError(JSContext* aCx) {
MOZ_ASSERT(mAborted);
if (!mReason.isUndefined()) {
return;
}
JS::Rooted<JS::Value> exception(aCx);
RefPtr<DOMException> dom = DOMException::Create(NS_ERROR_DOM_ABORT_ERR);
if (NS_WARN_IF(!ToJSValue(aCx, dom, &exception))) {
return;
}
mReason.set(exception);
}
void AbortSignalImpl::UnlinkFollowers() {
// Manually unlink all followers before destructing the array, or otherwise
// the array will be accessed by Unfollow() while being destructed.
for (RefPtr<AbortFollower>& follower : mFollowers.ForwardRange()) {
follower->mFollowingSignal = nullptr;
}
mFollowers.Clear();
}
// AbortSignal
// ----------------------------------------------------------------------------
NS_IMPL_CYCLE_COLLECTION_CLASS(AbortSignal)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(AbortSignal,
DOMEventTargetHelper)
AbortSignalImpl::Traverse(static_cast<AbortSignalImpl*>(tmp), cb);
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDependentSignals)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(AbortSignal,
DOMEventTargetHelper)
AbortSignalImpl::Unlink(static_cast<AbortSignalImpl*>(tmp));
NS_IMPL_CYCLE_COLLECTION_UNLINK(mDependentSignals)
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(AbortSignal)
NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)
NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN_INHERITED(AbortSignal,
DOMEventTargetHelper)
NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mReason)
NS_IMPL_CYCLE_COLLECTION_TRACE_END
NS_IMPL_ADDREF_INHERITED(AbortSignal, DOMEventTargetHelper)
NS_IMPL_RELEASE_INHERITED(AbortSignal, DOMEventTargetHelper)
AbortSignal::AbortSignal(nsIGlobalObject* aGlobalObject, bool aAborted,
JS::Handle<JS::Value> aReason)
: DOMEventTargetHelper(aGlobalObject),
AbortSignalImpl(aAborted, aReason),
mDependent(false) {
mozilla::HoldJSObjects(this);
}
JSObject* AbortSignal::WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) {
return AbortSignal_Binding::Wrap(aCx, this, aGivenProto);
}
already_AddRefed<AbortSignal> AbortSignal::Abort(
GlobalObject& aGlobal, JS::Handle<JS::Value> aReason) {
nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(aGlobal.GetAsSupports());
RefPtr<AbortSignal> abortSignal = new AbortSignal(global, true, aReason);
return abortSignal.forget();
}
class AbortSignalTimeoutHandler final : public TimeoutHandler {
public:
AbortSignalTimeoutHandler(JSContext* aCx, AbortSignal* aSignal)
: TimeoutHandler(aCx), mSignal(aSignal) {}
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_CYCLE_COLLECTION_CLASS(AbortSignalTimeoutHandler)
// Step 3
MOZ_CAN_RUN_SCRIPT bool Call(const char* /* unused */) override {
AutoJSAPI jsapi;
if (NS_WARN_IF(!jsapi.Init(mSignal->GetParentObject()))) {
// (false is only for setInterval, see
// nsGlobalWindowInner::RunTimeoutHandler)
return true;
}
// Step 1. Queue a global task on the timer task source given global to
// signal abort given signal and a new "TimeoutError" DOMException.
JS::Rooted<JS::Value> exception(jsapi.cx());
RefPtr<DOMException> dom = DOMException::Create(NS_ERROR_DOM_TIMEOUT_ERR);
if (NS_WARN_IF(!ToJSValue(jsapi.cx(), dom, &exception))) {
return true;
}
mSignal->SignalAbort(exception);
return true;
}
private:
~AbortSignalTimeoutHandler() override = default;
RefPtr<AbortSignal> mSignal;
};
NS_IMPL_CYCLE_COLLECTION(AbortSignalTimeoutHandler, mSignal)
NS_IMPL_CYCLE_COLLECTING_ADDREF(AbortSignalTimeoutHandler)
NS_IMPL_CYCLE_COLLECTING_RELEASE(AbortSignalTimeoutHandler)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(AbortSignalTimeoutHandler)
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
static void SetTimeoutForGlobal(GlobalObject& aGlobal, TimeoutHandler& aHandler,
int32_t timeout, ErrorResult& aRv) {
if (NS_IsMainThread()) {
nsCOMPtr<nsPIDOMWindowInner> innerWindow =
do_QueryInterface(aGlobal.GetAsSupports());
if (!innerWindow) {
aRv.ThrowInvalidStateError("Could not find window.");
return;
}
int32_t handle;
nsresult rv = innerWindow->TimeoutManager().SetTimeout(
&aHandler, timeout, /* aIsInterval */ false,
Timeout::Reason::eAbortSignalTimeout, &handle);
if (NS_FAILED(rv)) {
aRv.Throw(rv);
return;
}
} else {
WorkerPrivate* workerPrivate =
GetWorkerPrivateFromContext(aGlobal.Context());
workerPrivate->SetTimeout(aGlobal.Context(), &aHandler, timeout,
/* aIsInterval */ false,
Timeout::Reason::eAbortSignalTimeout, aRv);
if (aRv.Failed()) {
return;
}
}
}
already_AddRefed<AbortSignal> AbortSignal::Timeout(GlobalObject& aGlobal,
uint64_t aMilliseconds,
ErrorResult& aRv) {
// Step 2. Let global be signal’s relevant global object.
nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(aGlobal.GetAsSupports());
// Step 1. Let signal be a new AbortSignal object.
RefPtr<AbortSignal> signal =
new AbortSignal(global, false, JS::UndefinedHandleValue);
// Step 3. Run steps after a timeout given global, "AbortSignal-timeout",
// milliseconds, and the following step: ...
RefPtr<TimeoutHandler> handler =
new AbortSignalTimeoutHandler(aGlobal.Context(), signal);
// Note: We only supports int32_t range intervals
int32_t timeout =
aMilliseconds > uint64_t(std::numeric_limits<int32_t>::max())
? std::numeric_limits<int32_t>::max()
: static_cast<int32_t>(aMilliseconds);
SetTimeoutForGlobal(aGlobal, *handler, timeout, aRv);
if (aRv.Failed()) {
return nullptr;
}
// Step 4. Return signal.
return signal.forget();
}
already_AddRefed<AbortSignal> AbortSignal::Any(
GlobalObject& aGlobal,
const Sequence<OwningNonNull<AbortSignal>>& aSignals) {
nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(aGlobal.GetAsSupports());
// Step 1. Let resultSignal be a new object implementing AbortSignal using
// realm
RefPtr<AbortSignal> resultSignal =
new AbortSignal(global, false, JS::UndefinedHandleValue);
// Step 2. For each signal of signals: if signal is aborted, then set
// resultSignal's abort reason to signal's abort reason and return
// resultSignal.
for (const auto& signal : aSignals) {
if (signal->Aborted()) {
JS::Rooted<JS::Value> reason(RootingCx(), signal->RawReason());
resultSignal->SetAborted(reason);
return resultSignal.forget();
}
}
// Step 3. Set resultSignal's dependent to true
resultSignal->mDependent = true;
// Step 4. For each signal of signals
for (const auto& signal : aSignals) {
if (!signal->Dependent()) {
// Step 4.1. If signal is not dependent, make resultSignal dependent on it
resultSignal->MakeDependentOn(signal);
} else {
// Step 4.2. Otherwise, make resultSignal dependent on its source signals
for (const auto& sourceSignal : signal->mSourceSignals) {
MOZ_ASSERT(!sourceSignal->Aborted() && !sourceSignal->Dependent());
resultSignal->MakeDependentOn(sourceSignal);
}
}
}
// Step 5. Return resultSignal.
return resultSignal.forget();
}
void AbortSignal::MakeDependentOn(AbortSignal* aSignal) {
MOZ_ASSERT(mDependent);
MOZ_ASSERT(aSignal);
// append only if not already contained in list
if (!mSourceSignals.Contains(aSignal)) {
mSourceSignals.AppendElement(aSignal);
}
if (!aSignal->mDependentSignals.Contains(this)) {
aSignal->mDependentSignals.AppendElement(this);
}
}
void AbortSignal::ThrowIfAborted(JSContext* aCx, ErrorResult& aRv) {
aRv.MightThrowJSException();
if (Aborted()) {
JS::Rooted<JS::Value> reason(aCx);
GetReason(aCx, &reason);
aRv.ThrowJSException(aCx, reason);
}
}
void AbortSignal::SignalAbort(JS::Handle<JS::Value> aReason) {
// Step 1, in case "signal abort" algorithm is called directly
if (Aborted()) {
return;
}
// Steps 1-4.
AbortSignalImpl::SignalAbort(aReason);
// Step 5. Fire an event named abort at this signal
EventInit init;
init.mBubbles = false;
init.mCancelable = false;
RefPtr<Event> event = Event::Constructor(this, u"abort"_ns, init);
event->SetTrusted(true);
DispatchEvent(*event);
// Step 6. Abort dependentSignals of this signal
for (const auto& dependant : mDependentSignals) {
MOZ_ASSERT(dependant->mSourceSignals.Contains(this));
dependant->SignalAbort(aReason);
}
// clear dependent signals so that they might be garbage collected
mDependentSignals.Clear();
}
void AbortSignal::RunAbortAlgorithm() {
JS::Rooted<JS::Value> reason(RootingCx(), Signal()->RawReason());
SignalAbort(reason);
}
bool AbortSignal::Dependent() const { return mDependent; }
AbortSignal::~AbortSignal() { mozilla::DropJSObjects(this); }
// AbortFollower
// ----------------------------------------------------------------------------
AbortFollower::~AbortFollower() { Unfollow(); }
void AbortFollower::Follow(AbortSignalImpl* aSignal) {
// Step 1.
if (aSignal->mAborted) {
return;
}
MOZ_DIAGNOSTIC_ASSERT(aSignal);
Unfollow();
// Step 2.
mFollowingSignal = aSignal;
MOZ_ASSERT(!aSignal->mFollowers.Contains(this));
aSignal->mFollowers.AppendElement(this);
}
void AbortFollower::Unfollow() {
if (mFollowingSignal) {
// |Unfollow| is called by cycle-collection unlink code that runs in no
// guaranteed order. So we can't, symmetric with |Follow| above, assert
// that |this| will be found in |mFollowingSignal->mFollowers|.
mFollowingSignal->mFollowers.RemoveElement(this);
mFollowingSignal = nullptr;
}
}
bool AbortFollower::IsFollowing() const { return !!mFollowingSignal; }
} // namespace mozilla::dom