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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/RefPtr.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 "nsCycleCollectionParticipant.h"
#include "nsGlobalWindowInner.h"
#include "nsPIDOMWindow.h"
namespace mozilla::dom {
// AbortSignalImpl
// ----------------------------------------------------------------------------
AbortSignalImpl::AbortSignalImpl(SignalAborted aAborted,
JS::Handle<JS::Value> aReason)
: mReason(aReason), mAborted(aAborted) {
MOZ_ASSERT_IF(!mReason.isUndefined(), Aborted());
}
bool AbortSignalImpl::Aborted() const { return mAborted == SignalAborted::Yes; }
void AbortSignalImpl::GetReason(JSContext* aCx,
JS::MutableHandle<JS::Value> aReason) {
if (!Aborted()) {
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 signal is aborted, then return.
if (Aborted()) {
return;
}
// Step 2: Set signal’s abort reason to reason if it is given; otherwise to a
// new "AbortError" DOMException.
//
// (But given AbortSignalImpl is supposed to run without JS context, the
// DOMException creation is deferred to the getter.)
SetAborted(aReason);
// Step 3 - 6
SignalAbortWithDependents();
}
void AbortSignalImpl::SignalAbortWithDependents() {
// AbortSignalImpl cannot have dependents, so just run abort steps for itself.
RunAbortSteps();
}
// This skips event firing as AbortSignalImpl is not supposed to be exposed to
// JS. It's done instead in AbortSignal::RunAbortSteps.
void AbortSignalImpl::RunAbortSteps() {
// Step 1: For each algorithm of signal’s abort algorithms: run algorithm.
//
// 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 2: Empty signal’s abort algorithms.
UnlinkFollowers();
}
void AbortSignalImpl::SetAborted(JS::Handle<JS::Value> aReason) {
mAborted = SignalAborted::Yes;
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(Aborted());
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)
already_AddRefed<AbortSignal> AbortSignal::Create(
nsIGlobalObject* aGlobalObject, SignalAborted aAborted,
JS::Handle<JS::Value> aReason) {
RefPtr<AbortSignal> signal =
new AbortSignal(aGlobalObject, aAborted, aReason);
signal->Init();
return signal.forget();
}
void AbortSignal::Init() {
// Init is use to separate this HoldJSObjects call to avoid calling
// it in the constructor.
//
// We can't call HoldJSObjects in the constructor because it'll
// addref `this` before the vtable is set up properly, so the parent
// type gets stored in the CC participant table. This is problematic
// for classes that inherit AbortSignal.
mozilla::HoldJSObjects(this);
}
AbortSignal::AbortSignal(nsIGlobalObject* aGlobalObject, SignalAborted aAborted,
JS::Handle<JS::Value> aReason)
: DOMEventTargetHelper(aGlobalObject),
AbortSignalImpl(aAborted, aReason),
mDependent(false) {}
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 =
AbortSignal::Create(global, SignalAborted::Yes, 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 =
nsGlobalWindowInner::Cast(innerWindow)
->GetTimeoutManager()
->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 =
AbortSignal::Create(global, SignalAborted::No, 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());
return Any(global, aSignals, [](nsIGlobalObject* aGlobal) {
return AbortSignal::Create(aGlobal, SignalAborted::No,
JS::UndefinedHandleValue);
});
}
already_AddRefed<AbortSignal> AbortSignal::Any(
nsIGlobalObject* aGlobal,
const Span<const OwningNonNull<AbortSignal>>& aSignals,
FunctionRef<already_AddRefed<AbortSignal>(nsIGlobalObject* aGlobal)>
aCreateResultSignal) {
// Step 1. Let resultSignal be a new object implementing AbortSignal using
// realm
RefPtr<AbortSignal> resultSignal = aCreateResultSignal(aGlobal);
if (!aSignals.IsEmpty()) {
// (Prepare for step 2 which uses the reason of this. Cannot use
// RawReason because that can cause constructing new DOMException for each
// dependent signal instead of sharing the single one.)
AutoJSAPI jsapi;
if (!jsapi.Init(aGlobal)) {
return nullptr;
}
JSContext* cx = jsapi.cx();
// 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(cx);
signal->GetReason(cx, &reason);
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) {
if (!sourceSignal) {
// As signal is not aborted, sourceSignal also wasn't.
// Thus do not depend on it, as it cannot be aborted anymore.
continue;
}
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::SignalAbortWithDependents() {
// Step 3: Let dependentSignalsToAbort be a new list.
nsTArray<RefPtr<AbortSignal>> dependentSignalsToAbort;
// mDependentSignals can go away after this function.
nsTArray<RefPtr<AbortSignal>> dependentSignals = std::move(mDependentSignals);
if (!dependentSignals.IsEmpty()) {
// (Prepare for step 4.1.1 which uses the reason of this. Cannot use
// RawReason because that can cause constructing new DOMException for each
// dependent signal instead of sharing the single one.)
AutoJSAPI jsapi;
if (!jsapi.Init(GetParentObject())) {
return;
}
JSContext* cx = jsapi.cx();
JS::Rooted<JS::Value> reason(cx);
GetReason(cx, &reason);
// Step 4. For each dependentSignal of signal’s dependent signals:
for (const auto& dependentSignal : dependentSignals) {
MOZ_ASSERT(dependentSignal->mSourceSignals.Contains(this));
// Step 4.1: If dependentSignal is not aborted, then:
if (!dependentSignal->Aborted()) {
// Step 4.1.1: Set dependentSignal’s abort reason to signal’s abort
// reason.
dependentSignal->SetAborted(reason);
// Step 4.1.2: Append dependentSignal to dependentSignalsToAbort.
dependentSignalsToAbort.AppendElement(dependentSignal);
}
}
}
// Step 5: Run the abort steps for signal.
RunAbortSteps();
// Step 6: For each dependentSignal of dependentSignalsToAbort, run the abort
// steps for dependentSignal.
for (const auto& dependentSignal : dependentSignalsToAbort) {
dependentSignal->RunAbortSteps();
}
}
void AbortSignal::RunAbortSteps() {
// Step 1 - 2:
AbortSignalImpl::RunAbortSteps();
// Step 3. 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);
}
bool AbortSignal::Dependent() const { return mDependent; }
AbortSignal::~AbortSignal() { mozilla::DropJSObjects(this); }
// AbortFollower
// ----------------------------------------------------------------------------
AbortFollower::~AbortFollower() { Unfollow(); }
void AbortFollower::Follow(AbortSignalImpl* aSignal) {
// Step 1.
if (aSignal->Aborted()) {
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