gecko-dev/dom/promise/Promise.cpp
Phil Ringnalda 53745073f0 Back out 13 changesets (bug 1170760) for Gu bustage in homescreen/test/unit/apps_test.js
CLOSED TREE

Backed out changeset 5d84599a8846 (bug 1170760)
Backed out changeset 6104fe33d5f5 (bug 1170760)
Backed out changeset 1dfb229da01d (bug 1170760)
Backed out changeset f380faddfdd8 (bug 1170760)
Backed out changeset 541831dc6b57 (bug 1170760)
Backed out changeset 6a5b7dfab882 (bug 1170760)
Backed out changeset ee514a256922 (bug 1170760)
Backed out changeset 3c2c1acc34ee (bug 1170760)
Backed out changeset dc2a7f5dc5d6 (bug 1170760)
Backed out changeset b312a08fbab5 (bug 1170760)
Backed out changeset cb6aba9b8497 (bug 1170760)
Backed out changeset 39e4f5b1ba40 (bug 1170760)
Backed out changeset 7d79cce3630a (bug 1170760)
2015-11-25 21:02:55 -08:00

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50 KiB
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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 file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozilla/dom/Promise.h"
#include "js/Debug.h"
#include "mozilla/Atomics.h"
#include "mozilla/CycleCollectedJSRuntime.h"
#include "mozilla/OwningNonNull.h"
#include "mozilla/Preferences.h"
#include "mozilla/dom/BindingUtils.h"
#include "mozilla/dom/DOMError.h"
#include "mozilla/dom/MediaStreamError.h"
#include "mozilla/dom/PromiseBinding.h"
#include "mozilla/dom/ScriptSettings.h"
#include "jsfriendapi.h"
#include "js/StructuredClone.h"
#include "nsContentUtils.h"
#include "nsGlobalWindow.h"
#include "nsIScriptObjectPrincipal.h"
#include "nsJSEnvironment.h"
#include "nsJSPrincipals.h"
#include "nsJSUtils.h"
#include "nsPIDOMWindow.h"
#include "PromiseCallback.h"
#include "PromiseDebugging.h"
#include "PromiseNativeHandler.h"
#include "PromiseWorkerProxy.h"
#include "WorkerPrivate.h"
#include "WorkerRunnable.h"
#include "xpcpublic.h"
#ifdef MOZ_CRASHREPORTER
#include "nsExceptionHandler.h"
#endif
namespace mozilla {
namespace dom {
namespace {
// Generator used by Promise::GetID.
Atomic<uintptr_t> gIDGenerator(0);
} // namespace
using namespace workers;
// This class processes the promise's callbacks with promise's result.
class PromiseReactionJob final : public nsRunnable
{
public:
PromiseReactionJob(Promise* aPromise,
PromiseCallback* aCallback,
const JS::Value& aValue)
: mPromise(aPromise)
, mCallback(aCallback)
, mValue(CycleCollectedJSRuntime::Get()->Runtime(), aValue)
{
MOZ_ASSERT(aPromise);
MOZ_ASSERT(aCallback);
MOZ_COUNT_CTOR(PromiseReactionJob);
}
virtual
~PromiseReactionJob()
{
NS_ASSERT_OWNINGTHREAD(PromiseReactionJob);
MOZ_COUNT_DTOR(PromiseReactionJob);
}
protected:
NS_IMETHOD
Run() override
{
NS_ASSERT_OWNINGTHREAD(PromiseReactionJob);
ThreadsafeAutoJSContext cx;
JS::Rooted<JSObject*> wrapper(cx, mPromise->GetWrapper());
MOZ_ASSERT(wrapper); // It was preserved!
JSAutoCompartment ac(cx, wrapper);
JS::Rooted<JS::Value> value(cx, mValue);
if (!MaybeWrapValue(cx, &value)) {
NS_WARNING("Failed to wrap value into the right compartment.");
JS_ClearPendingException(cx);
return NS_OK;
}
JS::Rooted<JSObject*> asyncStack(cx, mPromise->mAllocationStack);
JS::Rooted<JSString*> asyncCause(cx, JS_NewStringCopyZ(cx, "Promise"));
if (!asyncCause) {
JS_ClearPendingException(cx);
return NS_ERROR_OUT_OF_MEMORY;
}
{
Maybe<JS::AutoSetAsyncStackForNewCalls> sas;
if (asyncStack) {
sas.emplace(cx, asyncStack, asyncCause);
}
mCallback->Call(cx, value);
}
return NS_OK;
}
private:
RefPtr<Promise> mPromise;
RefPtr<PromiseCallback> mCallback;
JS::PersistentRooted<JS::Value> mValue;
NS_DECL_OWNINGTHREAD;
};
enum {
SLOT_PROMISE = 0,
SLOT_DATA
};
/*
* Utilities for thenable callbacks.
*
* A thenable is a { then: function(resolve, reject) { } }.
* `then` is called with a resolve and reject callback pair.
* Since only one of these should be called at most once (first call wins), the
* two keep a reference to each other in SLOT_DATA. When either of them is
* called, the references are cleared. Further calls are ignored.
*/
namespace {
void
LinkThenableCallables(JSContext* aCx, JS::Handle<JSObject*> aResolveFunc,
JS::Handle<JSObject*> aRejectFunc)
{
js::SetFunctionNativeReserved(aResolveFunc, SLOT_DATA,
JS::ObjectValue(*aRejectFunc));
js::SetFunctionNativeReserved(aRejectFunc, SLOT_DATA,
JS::ObjectValue(*aResolveFunc));
}
/*
* Returns false if callback was already called before, otherwise breaks the
* links and returns true.
*/
bool
MarkAsCalledIfNotCalledBefore(JSContext* aCx, JS::Handle<JSObject*> aFunc)
{
JS::Value otherFuncVal = js::GetFunctionNativeReserved(aFunc, SLOT_DATA);
if (!otherFuncVal.isObject()) {
return false;
}
JSObject* otherFuncObj = &otherFuncVal.toObject();
MOZ_ASSERT(js::GetFunctionNativeReserved(otherFuncObj, SLOT_DATA).isObject());
// Break both references.
js::SetFunctionNativeReserved(aFunc, SLOT_DATA, JS::UndefinedValue());
js::SetFunctionNativeReserved(otherFuncObj, SLOT_DATA, JS::UndefinedValue());
return true;
}
Promise*
GetPromise(JSContext* aCx, JS::Handle<JSObject*> aFunc)
{
JS::Value promiseVal = js::GetFunctionNativeReserved(aFunc, SLOT_PROMISE);
MOZ_ASSERT(promiseVal.isObject());
Promise* promise;
UNWRAP_OBJECT(Promise, &promiseVal.toObject(), promise);
return promise;
}
} // namespace
// Runnable to resolve thenables.
// Equivalent to the specification's ResolvePromiseViaThenableTask.
class PromiseResolveThenableJob final : public nsRunnable
{
public:
PromiseResolveThenableJob(Promise* aPromise,
JS::Handle<JSObject*> aThenable,
PromiseInit* aThen)
: mPromise(aPromise)
, mThenable(CycleCollectedJSRuntime::Get()->Runtime(), aThenable)
, mThen(aThen)
{
MOZ_ASSERT(aPromise);
MOZ_COUNT_CTOR(PromiseResolveThenableJob);
}
virtual
~PromiseResolveThenableJob()
{
NS_ASSERT_OWNINGTHREAD(PromiseResolveThenableJob);
MOZ_COUNT_DTOR(PromiseResolveThenableJob);
}
protected:
NS_IMETHOD
Run() override
{
NS_ASSERT_OWNINGTHREAD(PromiseResolveThenableJob);
ThreadsafeAutoJSContext cx;
JS::Rooted<JSObject*> wrapper(cx, mPromise->GetWrapper());
MOZ_ASSERT(wrapper); // It was preserved!
// If we ever change which compartment we're working in here, make sure to
// fix the fast-path for resolved-with-a-Promise in ResolveInternal.
JSAutoCompartment ac(cx, wrapper);
JS::Rooted<JSObject*> resolveFunc(cx,
mPromise->CreateThenableFunction(cx, mPromise, PromiseCallback::Resolve));
if (!resolveFunc) {
mPromise->HandleException(cx);
return NS_OK;
}
JS::Rooted<JSObject*> rejectFunc(cx,
mPromise->CreateThenableFunction(cx, mPromise, PromiseCallback::Reject));
if (!rejectFunc) {
mPromise->HandleException(cx);
return NS_OK;
}
LinkThenableCallables(cx, resolveFunc, rejectFunc);
ErrorResult rv;
JS::Rooted<JSObject*> rootedThenable(cx, mThenable);
mThen->Call(rootedThenable, resolveFunc, rejectFunc, rv,
"promise thenable", CallbackObject::eRethrowExceptions,
mPromise->Compartment());
rv.WouldReportJSException();
if (rv.Failed()) {
JS::Rooted<JS::Value> exn(cx);
{ // Scope for JSAutoCompartment
// Convert the ErrorResult to a JS exception object that we can reject
// ourselves with. This will be exactly the exception that would get
// thrown from a binding method whose ErrorResult ended up with
// whatever is on "rv" right now.
JSAutoCompartment ac(cx, mPromise->GlobalJSObject());
DebugOnly<bool> conversionResult = ToJSValue(cx, rv, &exn);
MOZ_ASSERT(conversionResult);
}
bool couldMarkAsCalled = MarkAsCalledIfNotCalledBefore(cx, resolveFunc);
// If we could mark as called, neither of the callbacks had been called
// when the exception was thrown. So we can reject the Promise.
if (couldMarkAsCalled) {
bool ok = JS_WrapValue(cx, &exn);
MOZ_ASSERT(ok);
if (!ok) {
NS_WARNING("Failed to wrap value into the right compartment.");
}
mPromise->RejectInternal(cx, exn);
}
// At least one of resolveFunc or rejectFunc have been called, so ignore
// the exception. FIXME(nsm): This should be reported to the error
// console though, for debugging.
}
return rv.StealNSResult();
}
private:
RefPtr<Promise> mPromise;
JS::PersistentRooted<JSObject*> mThenable;
RefPtr<PromiseInit> mThen;
NS_DECL_OWNINGTHREAD;
};
// Fast version of PromiseResolveThenableJob for use in the cases when we know we're
// calling the canonical Promise.prototype.then on an actual DOM Promise. In
// that case we can just bypass the jumping into and out of JS and call
// AppendCallbacks on that promise directly.
class FastPromiseResolveThenableJob final : public nsRunnable
{
public:
FastPromiseResolveThenableJob(PromiseCallback* aResolveCallback,
PromiseCallback* aRejectCallback,
Promise* aNextPromise)
: mResolveCallback(aResolveCallback)
, mRejectCallback(aRejectCallback)
, mNextPromise(aNextPromise)
{
MOZ_ASSERT(aResolveCallback);
MOZ_ASSERT(aRejectCallback);
MOZ_ASSERT(aNextPromise);
MOZ_COUNT_CTOR(FastPromiseResolveThenableJob);
}
virtual
~FastPromiseResolveThenableJob()
{
NS_ASSERT_OWNINGTHREAD(FastPromiseResolveThenableJob);
MOZ_COUNT_DTOR(FastPromiseResolveThenableJob);
}
protected:
NS_IMETHOD
Run() override
{
NS_ASSERT_OWNINGTHREAD(FastPromiseResolveThenableJob);
mNextPromise->AppendCallbacks(mResolveCallback, mRejectCallback);
return NS_OK;
}
private:
RefPtr<PromiseCallback> mResolveCallback;
RefPtr<PromiseCallback> mRejectCallback;
RefPtr<Promise> mNextPromise;
};
// Promise
NS_IMPL_CYCLE_COLLECTION_CLASS(Promise)
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(Promise)
#if defined(DOM_PROMISE_DEPRECATED_REPORTING)
tmp->MaybeReportRejectedOnce();
#else
tmp->mResult = JS::UndefinedValue();
#endif // defined(DOM_PROMISE_DEPRECATED_REPORTING)
NS_IMPL_CYCLE_COLLECTION_UNLINK(mGlobal)
NS_IMPL_CYCLE_COLLECTION_UNLINK(mResolveCallbacks)
NS_IMPL_CYCLE_COLLECTION_UNLINK(mRejectCallbacks)
NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(Promise)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mGlobal)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mResolveCallbacks)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mRejectCallbacks)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(Promise)
NS_IMPL_CYCLE_COLLECTION_TRACE_JSVAL_MEMBER_CALLBACK(mResult)
NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mAllocationStack)
NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mRejectionStack)
NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mFullfillmentStack)
NS_IMPL_CYCLE_COLLECTION_TRACE_PRESERVED_WRAPPER
NS_IMPL_CYCLE_COLLECTION_TRACE_END
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_BEGIN(Promise)
if (tmp->IsBlack()) {
JS::ExposeValueToActiveJS(tmp->mResult);
if (tmp->mAllocationStack) {
JS::ExposeObjectToActiveJS(tmp->mAllocationStack);
}
if (tmp->mRejectionStack) {
JS::ExposeObjectToActiveJS(tmp->mRejectionStack);
}
if (tmp->mFullfillmentStack) {
JS::ExposeObjectToActiveJS(tmp->mFullfillmentStack);
}
return true;
}
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_END
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_BEGIN(Promise)
return tmp->IsBlackAndDoesNotNeedTracing(tmp);
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_END
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_BEGIN(Promise)
return tmp->IsBlack();
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_END
NS_IMPL_CYCLE_COLLECTING_ADDREF(Promise)
NS_IMPL_CYCLE_COLLECTING_RELEASE(Promise)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(Promise)
NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_ENTRY(Promise)
NS_INTERFACE_MAP_END
Promise::Promise(nsIGlobalObject* aGlobal)
: mGlobal(aGlobal)
, mResult(JS::UndefinedValue())
, mAllocationStack(nullptr)
, mRejectionStack(nullptr)
, mFullfillmentStack(nullptr)
, mState(Pending)
#if defined(DOM_PROMISE_DEPRECATED_REPORTING)
, mHadRejectCallback(false)
#endif // defined(DOM_PROMISE_DEPRECATED_REPORTING)
, mTaskPending(false)
, mResolvePending(false)
, mIsLastInChain(true)
, mWasNotifiedAsUncaught(false)
, mID(0)
{
MOZ_ASSERT(mGlobal);
mozilla::HoldJSObjects(this);
mCreationTimestamp = TimeStamp::Now();
}
Promise::~Promise()
{
#if defined(DOM_PROMISE_DEPRECATED_REPORTING)
MaybeReportRejectedOnce();
#endif // defined(DOM_PROMISE_DEPRECATED_REPORTING)
mozilla::DropJSObjects(this);
}
JSObject*
Promise::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
{
return PromiseBinding::Wrap(aCx, this, aGivenProto);
}
already_AddRefed<Promise>
Promise::Create(nsIGlobalObject* aGlobal, ErrorResult& aRv,
JS::Handle<JSObject*> aDesiredProto)
{
RefPtr<Promise> p = new Promise(aGlobal);
p->CreateWrapper(aDesiredProto, aRv);
if (aRv.Failed()) {
return nullptr;
}
return p.forget();
}
void
Promise::CreateWrapper(JS::Handle<JSObject*> aDesiredProto, ErrorResult& aRv)
{
AutoJSAPI jsapi;
if (!jsapi.Init(mGlobal)) {
aRv.Throw(NS_ERROR_UNEXPECTED);
return;
}
JSContext* cx = jsapi.cx();
JS::Rooted<JS::Value> wrapper(cx);
if (!GetOrCreateDOMReflector(cx, this, &wrapper, aDesiredProto)) {
JS_ClearPendingException(cx);
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return;
}
dom::PreserveWrapper(this);
// Now grab our allocation stack
if (!CaptureStack(cx, mAllocationStack)) {
JS_ClearPendingException(cx);
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return;
}
JS::RootedObject obj(cx, &wrapper.toObject());
JS::dbg::onNewPromise(cx, obj);
}
void
Promise::MaybeResolve(JSContext* aCx,
JS::Handle<JS::Value> aValue)
{
MaybeResolveInternal(aCx, aValue);
}
void
Promise::MaybeReject(JSContext* aCx,
JS::Handle<JS::Value> aValue)
{
MaybeRejectInternal(aCx, aValue);
}
void
Promise::MaybeReject(const RefPtr<MediaStreamError>& aArg) {
MaybeSomething(aArg, &Promise::MaybeReject);
}
bool
Promise::PerformMicroTaskCheckpoint()
{
CycleCollectedJSRuntime* runtime = CycleCollectedJSRuntime::Get();
std::queue<nsCOMPtr<nsIRunnable>>& microtaskQueue =
runtime->GetPromiseMicroTaskQueue();
if (microtaskQueue.empty()) {
return false;
}
Maybe<AutoSafeJSContext> cx;
if (NS_IsMainThread()) {
cx.emplace();
}
do {
nsCOMPtr<nsIRunnable> runnable = microtaskQueue.front();
MOZ_ASSERT(runnable);
// This function can re-enter, so we remove the element before calling.
microtaskQueue.pop();
nsresult rv = runnable->Run();
if (NS_WARN_IF(NS_FAILED(rv))) {
return false;
}
if (cx.isSome()) {
JS_CheckForInterrupt(cx.ref());
}
runtime->AfterProcessMicrotask();
} while (!microtaskQueue.empty());
return true;
}
/* static */ bool
Promise::JSCallback(JSContext* aCx, unsigned aArgc, JS::Value* aVp)
{
JS::CallArgs args = CallArgsFromVp(aArgc, aVp);
JS::Rooted<JS::Value> v(aCx,
js::GetFunctionNativeReserved(&args.callee(),
SLOT_PROMISE));
MOZ_ASSERT(v.isObject());
Promise* promise;
if (NS_FAILED(UNWRAP_OBJECT(Promise, &v.toObject(), promise))) {
return Throw(aCx, NS_ERROR_UNEXPECTED);
}
v = js::GetFunctionNativeReserved(&args.callee(), SLOT_DATA);
PromiseCallback::Task task = static_cast<PromiseCallback::Task>(v.toInt32());
if (task == PromiseCallback::Resolve) {
if (!promise->CaptureStack(aCx, promise->mFullfillmentStack)) {
return false;
}
promise->MaybeResolveInternal(aCx, args.get(0));
} else {
promise->MaybeRejectInternal(aCx, args.get(0));
if (!promise->CaptureStack(aCx, promise->mRejectionStack)) {
return false;
}
}
args.rval().setUndefined();
return true;
}
/*
* Common bits of (JSCallbackThenableResolver/JSCallbackThenableRejecter).
* Resolves/rejects the Promise if it is ok to do so, based on whether either of
* the callbacks have been called before or not.
*/
/* static */ bool
Promise::ThenableResolverCommon(JSContext* aCx, uint32_t aTask,
unsigned aArgc, JS::Value* aVp)
{
JS::CallArgs args = CallArgsFromVp(aArgc, aVp);
JS::Rooted<JSObject*> thisFunc(aCx, &args.callee());
if (!MarkAsCalledIfNotCalledBefore(aCx, thisFunc)) {
// A function from this pair has been called before.
args.rval().setUndefined();
return true;
}
Promise* promise = GetPromise(aCx, thisFunc);
MOZ_ASSERT(promise);
if (aTask == PromiseCallback::Resolve) {
promise->ResolveInternal(aCx, args.get(0));
} else {
promise->RejectInternal(aCx, args.get(0));
}
args.rval().setUndefined();
return true;
}
/* static */ bool
Promise::JSCallbackThenableResolver(JSContext* aCx,
unsigned aArgc, JS::Value* aVp)
{
return ThenableResolverCommon(aCx, PromiseCallback::Resolve, aArgc, aVp);
}
/* static */ bool
Promise::JSCallbackThenableRejecter(JSContext* aCx,
unsigned aArgc, JS::Value* aVp)
{
return ThenableResolverCommon(aCx, PromiseCallback::Reject, aArgc, aVp);
}
/* static */ JSObject*
Promise::CreateFunction(JSContext* aCx, Promise* aPromise, int32_t aTask)
{
JSFunction* func = js::NewFunctionWithReserved(aCx, JSCallback,
1 /* nargs */, 0 /* flags */,
nullptr);
if (!func) {
return nullptr;
}
JS::Rooted<JSObject*> obj(aCx, JS_GetFunctionObject(func));
JS::Rooted<JS::Value> promiseObj(aCx);
if (!dom::GetOrCreateDOMReflector(aCx, aPromise, &promiseObj)) {
return nullptr;
}
JS::ExposeValueToActiveJS(promiseObj);
js::SetFunctionNativeReserved(obj, SLOT_PROMISE, promiseObj);
js::SetFunctionNativeReserved(obj, SLOT_DATA, JS::Int32Value(aTask));
return obj;
}
/* static */ JSObject*
Promise::CreateThenableFunction(JSContext* aCx, Promise* aPromise, uint32_t aTask)
{
JSNative whichFunc =
aTask == PromiseCallback::Resolve ? JSCallbackThenableResolver :
JSCallbackThenableRejecter ;
JSFunction* func = js::NewFunctionWithReserved(aCx, whichFunc,
1 /* nargs */, 0 /* flags */,
nullptr);
if (!func) {
return nullptr;
}
JS::Rooted<JSObject*> obj(aCx, JS_GetFunctionObject(func));
JS::Rooted<JS::Value> promiseObj(aCx);
if (!dom::GetOrCreateDOMReflector(aCx, aPromise, &promiseObj)) {
return nullptr;
}
JS::ExposeValueToActiveJS(promiseObj);
js::SetFunctionNativeReserved(obj, SLOT_PROMISE, promiseObj);
return obj;
}
/* static */ already_AddRefed<Promise>
Promise::Constructor(const GlobalObject& aGlobal, PromiseInit& aInit,
ErrorResult& aRv, JS::Handle<JSObject*> aDesiredProto)
{
nsCOMPtr<nsIGlobalObject> global;
global = do_QueryInterface(aGlobal.GetAsSupports());
if (!global) {
aRv.Throw(NS_ERROR_UNEXPECTED);
return nullptr;
}
RefPtr<Promise> promise = Create(global, aRv, aDesiredProto);
if (aRv.Failed()) {
return nullptr;
}
promise->CallInitFunction(aGlobal, aInit, aRv);
if (aRv.Failed()) {
return nullptr;
}
return promise.forget();
}
void
Promise::CallInitFunction(const GlobalObject& aGlobal,
PromiseInit& aInit, ErrorResult& aRv)
{
JSContext* cx = aGlobal.Context();
JS::Rooted<JSObject*> resolveFunc(cx,
CreateFunction(cx, this,
PromiseCallback::Resolve));
if (!resolveFunc) {
aRv.Throw(NS_ERROR_UNEXPECTED);
return;
}
JS::Rooted<JSObject*> rejectFunc(cx,
CreateFunction(cx, this,
PromiseCallback::Reject));
if (!rejectFunc) {
aRv.Throw(NS_ERROR_UNEXPECTED);
return;
}
aInit.Call(resolveFunc, rejectFunc, aRv, "promise initializer",
CallbackObject::eRethrowExceptions, Compartment());
aRv.WouldReportJSException();
if (aRv.Failed()) {
// We want the same behavior as this JS implementation:
//
// function Promise(arg) { try { arg(a, b); } catch (e) { this.reject(e); }}
//
// In particular, that means not using MaybeReject(aRv) here, since that
// would create the exception object in our reflector compartment, while we
// want to create it in whatever the current compartment on cx is.
JS::Rooted<JS::Value> value(cx);
DebugOnly<bool> conversionResult = ToJSValue(cx, aRv, &value);
MOZ_ASSERT(conversionResult);
MaybeRejectInternal(cx, value);
}
}
/* static */ already_AddRefed<Promise>
Promise::Resolve(const GlobalObject& aGlobal,
JS::Handle<JS::Value> aValue, ErrorResult& aRv)
{
// If a Promise was passed, just return it.
if (aValue.isObject()) {
JS::Rooted<JSObject*> valueObj(aGlobal.Context(), &aValue.toObject());
Promise* nextPromise;
nsresult rv = UNWRAP_OBJECT(Promise, valueObj, nextPromise);
if (NS_SUCCEEDED(rv)) {
RefPtr<Promise> addRefed = nextPromise;
return addRefed.forget();
}
}
nsCOMPtr<nsIGlobalObject> global =
do_QueryInterface(aGlobal.GetAsSupports());
if (!global) {
aRv.Throw(NS_ERROR_UNEXPECTED);
return nullptr;
}
RefPtr<Promise> p = Resolve(global, aGlobal.Context(), aValue, aRv);
if (p) {
p->mFullfillmentStack = p->mAllocationStack;
}
return p.forget();
}
/* static */ already_AddRefed<Promise>
Promise::Resolve(nsIGlobalObject* aGlobal, JSContext* aCx,
JS::Handle<JS::Value> aValue, ErrorResult& aRv)
{
RefPtr<Promise> promise = Create(aGlobal, aRv);
if (aRv.Failed()) {
return nullptr;
}
promise->MaybeResolveInternal(aCx, aValue);
return promise.forget();
}
/* static */ already_AddRefed<Promise>
Promise::Reject(const GlobalObject& aGlobal,
JS::Handle<JS::Value> aValue, ErrorResult& aRv)
{
nsCOMPtr<nsIGlobalObject> global =
do_QueryInterface(aGlobal.GetAsSupports());
if (!global) {
aRv.Throw(NS_ERROR_UNEXPECTED);
return nullptr;
}
RefPtr<Promise> p = Reject(global, aGlobal.Context(), aValue, aRv);
if (p) {
p->mRejectionStack = p->mAllocationStack;
}
return p.forget();
}
/* static */ already_AddRefed<Promise>
Promise::Reject(nsIGlobalObject* aGlobal, JSContext* aCx,
JS::Handle<JS::Value> aValue, ErrorResult& aRv)
{
RefPtr<Promise> promise = Create(aGlobal, aRv);
if (aRv.Failed()) {
return nullptr;
}
promise->MaybeRejectInternal(aCx, aValue);
return promise.forget();
}
already_AddRefed<Promise>
Promise::Then(JSContext* aCx, AnyCallback* aResolveCallback,
AnyCallback* aRejectCallback, ErrorResult& aRv)
{
RefPtr<Promise> promise = Create(GetParentObject(), aRv);
if (aRv.Failed()) {
return nullptr;
}
JS::Rooted<JSObject*> global(aCx, JS::CurrentGlobalOrNull(aCx));
RefPtr<PromiseCallback> resolveCb =
PromiseCallback::Factory(promise, global, aResolveCallback,
PromiseCallback::Resolve);
RefPtr<PromiseCallback> rejectCb =
PromiseCallback::Factory(promise, global, aRejectCallback,
PromiseCallback::Reject);
AppendCallbacks(resolveCb, rejectCb);
return promise.forget();
}
already_AddRefed<Promise>
Promise::Catch(JSContext* aCx, AnyCallback* aRejectCallback, ErrorResult& aRv)
{
RefPtr<AnyCallback> resolveCb;
return Then(aCx, resolveCb, aRejectCallback, aRv);
}
/**
* The CountdownHolder class encapsulates Promise.all countdown functions and
* the countdown holder parts of the Promises spec. It maintains the result
* array and AllResolveElementFunctions use SetValue() to set the array indices.
*/
class CountdownHolder final : public nsISupports
{
public:
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(CountdownHolder)
CountdownHolder(const GlobalObject& aGlobal, Promise* aPromise,
uint32_t aCountdown)
: mPromise(aPromise), mCountdown(aCountdown)
{
MOZ_ASSERT(aCountdown != 0);
JSContext* cx = aGlobal.Context();
// The only time aGlobal.Context() and aGlobal.Get() are not
// same-compartment is when we're called via Xrays, and in that situation we
// in fact want to create the array in the callee compartment
JSAutoCompartment ac(cx, aGlobal.Get());
mValues = JS_NewArrayObject(cx, aCountdown);
mozilla::HoldJSObjects(this);
}
private:
~CountdownHolder()
{
mozilla::DropJSObjects(this);
}
public:
void SetValue(uint32_t index, const JS::Handle<JS::Value> aValue)
{
MOZ_ASSERT(mCountdown > 0);
ThreadsafeAutoSafeJSContext cx;
JSAutoCompartment ac(cx, mValues);
{
AutoDontReportUncaught silenceReporting(cx);
JS::Rooted<JS::Value> value(cx, aValue);
JS::Rooted<JSObject*> values(cx, mValues);
if (!JS_WrapValue(cx, &value) ||
!JS_DefineElement(cx, values, index, value, JSPROP_ENUMERATE)) {
MOZ_ASSERT(JS_IsExceptionPending(cx));
JS::Rooted<JS::Value> exn(cx);
JS_GetPendingException(cx, &exn);
mPromise->MaybeReject(cx, exn);
}
}
--mCountdown;
if (mCountdown == 0) {
JS::Rooted<JS::Value> result(cx, JS::ObjectValue(*mValues));
mPromise->MaybeResolve(cx, result);
}
}
private:
RefPtr<Promise> mPromise;
uint32_t mCountdown;
JS::Heap<JSObject*> mValues;
};
NS_IMPL_CYCLE_COLLECTING_ADDREF(CountdownHolder)
NS_IMPL_CYCLE_COLLECTING_RELEASE(CountdownHolder)
NS_IMPL_CYCLE_COLLECTION_CLASS(CountdownHolder)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(CountdownHolder)
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(CountdownHolder)
NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mValues)
NS_IMPL_CYCLE_COLLECTION_TRACE_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(CountdownHolder)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPromise)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(CountdownHolder)
NS_IMPL_CYCLE_COLLECTION_UNLINK(mPromise)
tmp->mValues = nullptr;
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
/**
* An AllResolveElementFunction is the per-promise
* part of the Promise.all() algorithm.
* Every Promise in the handler is handed an instance of this as a resolution
* handler and it sets the relevant index in the CountdownHolder.
*/
class AllResolveElementFunction final : public PromiseNativeHandler
{
public:
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_CYCLE_COLLECTION_CLASS(AllResolveElementFunction)
AllResolveElementFunction(CountdownHolder* aHolder, uint32_t aIndex)
: mCountdownHolder(aHolder), mIndex(aIndex)
{
MOZ_ASSERT(aHolder);
}
void
ResolvedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue) override
{
mCountdownHolder->SetValue(mIndex, aValue);
}
void
RejectedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue) override
{
// Should never be attached to Promise as a reject handler.
MOZ_CRASH("AllResolveElementFunction should never be attached to a Promise's reject handler!");
}
private:
~AllResolveElementFunction()
{
}
RefPtr<CountdownHolder> mCountdownHolder;
uint32_t mIndex;
};
NS_IMPL_CYCLE_COLLECTING_ADDREF(AllResolveElementFunction)
NS_IMPL_CYCLE_COLLECTING_RELEASE(AllResolveElementFunction)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(AllResolveElementFunction)
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
NS_IMPL_CYCLE_COLLECTION(AllResolveElementFunction, mCountdownHolder)
/* static */ already_AddRefed<Promise>
Promise::All(const GlobalObject& aGlobal,
const Sequence<JS::Value>& aIterable, ErrorResult& aRv)
{
JSContext* cx = aGlobal.Context();
nsTArray<RefPtr<Promise>> promiseList;
for (uint32_t i = 0; i < aIterable.Length(); ++i) {
JS::Rooted<JS::Value> value(cx, aIterable.ElementAt(i));
RefPtr<Promise> nextPromise = Promise::Resolve(aGlobal, value, aRv);
MOZ_ASSERT(!aRv.Failed());
promiseList.AppendElement(Move(nextPromise));
}
return Promise::All(aGlobal, promiseList, aRv);
}
/* static */ already_AddRefed<Promise>
Promise::All(const GlobalObject& aGlobal,
const nsTArray<RefPtr<Promise>>& aPromiseList, ErrorResult& aRv)
{
nsCOMPtr<nsIGlobalObject> global =
do_QueryInterface(aGlobal.GetAsSupports());
if (!global) {
aRv.Throw(NS_ERROR_UNEXPECTED);
return nullptr;
}
JSContext* cx = aGlobal.Context();
if (aPromiseList.IsEmpty()) {
JS::Rooted<JSObject*> empty(cx, JS_NewArrayObject(cx, 0));
if (!empty) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return nullptr;
}
JS::Rooted<JS::Value> value(cx, JS::ObjectValue(*empty));
// We know "value" is not a promise, so call the Resolve function
// that doesn't have to check for that.
return Promise::Resolve(global, cx, value, aRv);
}
RefPtr<Promise> promise = Create(global, aRv);
if (aRv.Failed()) {
return nullptr;
}
RefPtr<CountdownHolder> holder =
new CountdownHolder(aGlobal, promise, aPromiseList.Length());
JS::Rooted<JSObject*> obj(cx, JS::CurrentGlobalOrNull(cx));
if (!obj) {
aRv.Throw(NS_ERROR_UNEXPECTED);
return nullptr;
}
RefPtr<PromiseCallback> rejectCb = new RejectPromiseCallback(promise, obj);
for (uint32_t i = 0; i < aPromiseList.Length(); ++i) {
RefPtr<PromiseNativeHandler> resolveHandler =
new AllResolveElementFunction(holder, i);
RefPtr<PromiseCallback> resolveCb =
new NativePromiseCallback(resolveHandler, Resolved);
// Every promise gets its own resolve callback, which will set the right
// index in the array to the resolution value.
aPromiseList[i]->AppendCallbacks(resolveCb, rejectCb);
}
return promise.forget();
}
/* static */ already_AddRefed<Promise>
Promise::Race(const GlobalObject& aGlobal,
const Sequence<JS::Value>& aIterable, ErrorResult& aRv)
{
nsCOMPtr<nsIGlobalObject> global =
do_QueryInterface(aGlobal.GetAsSupports());
if (!global) {
aRv.Throw(NS_ERROR_UNEXPECTED);
return nullptr;
}
JSContext* cx = aGlobal.Context();
JS::Rooted<JSObject*> obj(cx, JS::CurrentGlobalOrNull(cx));
if (!obj) {
aRv.Throw(NS_ERROR_UNEXPECTED);
return nullptr;
}
RefPtr<Promise> promise = Create(global, aRv);
if (aRv.Failed()) {
return nullptr;
}
RefPtr<PromiseCallback> resolveCb =
new ResolvePromiseCallback(promise, obj);
RefPtr<PromiseCallback> rejectCb = new RejectPromiseCallback(promise, obj);
for (uint32_t i = 0; i < aIterable.Length(); ++i) {
JS::Rooted<JS::Value> value(cx, aIterable.ElementAt(i));
RefPtr<Promise> nextPromise = Promise::Resolve(aGlobal, value, aRv);
// According to spec, Resolve can throw, but our implementation never does.
// Well it does when window isn't passed on the main thread, but that is an
// implementation detail which should never be reached since we are checking
// for window above. Remove this when subclassing is supported.
MOZ_ASSERT(!aRv.Failed());
nextPromise->AppendCallbacks(resolveCb, rejectCb);
}
return promise.forget();
}
void
Promise::AppendNativeHandler(PromiseNativeHandler* aRunnable)
{
RefPtr<PromiseCallback> resolveCb =
new NativePromiseCallback(aRunnable, Resolved);
RefPtr<PromiseCallback> rejectCb =
new NativePromiseCallback(aRunnable, Rejected);
AppendCallbacks(resolveCb, rejectCb);
}
JSObject*
Promise::GlobalJSObject() const
{
return mGlobal->GetGlobalJSObject();
}
JSCompartment*
Promise::Compartment() const
{
return js::GetObjectCompartment(GlobalJSObject());
}
void
Promise::AppendCallbacks(PromiseCallback* aResolveCallback,
PromiseCallback* aRejectCallback)
{
if (mGlobal->IsDying()) {
return;
}
MOZ_ASSERT(aResolveCallback);
MOZ_ASSERT(aRejectCallback);
if (mIsLastInChain && mState == PromiseState::Rejected) {
// This rejection is now consumed.
PromiseDebugging::AddConsumedRejection(*this);
// Note that we may not have had the opportunity to call
// RunResolveTask() yet, so we may never have called
// `PromiseDebugging:AddUncaughtRejection`.
}
mIsLastInChain = false;
#if defined(DOM_PROMISE_DEPRECATED_REPORTING)
// Now that there is a callback, we don't need to report anymore.
mHadRejectCallback = true;
RemoveFeature();
#endif // defined(DOM_PROMISE_DEPRECATED_REPORTING)
mResolveCallbacks.AppendElement(aResolveCallback);
mRejectCallbacks.AppendElement(aRejectCallback);
// If promise's state is fulfilled, queue a task to process our fulfill
// callbacks with promise's result. If promise's state is rejected, queue a
// task to process our reject callbacks with promise's result.
if (mState != Pending) {
TriggerPromiseReactions();
}
}
class WrappedWorkerRunnable final : public WorkerSameThreadRunnable
{
public:
WrappedWorkerRunnable(workers::WorkerPrivate* aWorkerPrivate, nsIRunnable* aRunnable)
: WorkerSameThreadRunnable(aWorkerPrivate)
, mRunnable(aRunnable)
{
MOZ_ASSERT(aRunnable);
MOZ_COUNT_CTOR(WrappedWorkerRunnable);
}
bool
WorkerRun(JSContext* aCx, workers::WorkerPrivate* aWorkerPrivate) override
{
NS_ASSERT_OWNINGTHREAD(WrappedWorkerRunnable);
mRunnable->Run();
return true;
}
private:
virtual
~WrappedWorkerRunnable()
{
MOZ_COUNT_DTOR(WrappedWorkerRunnable);
NS_ASSERT_OWNINGTHREAD(WrappedWorkerRunnable);
}
nsCOMPtr<nsIRunnable> mRunnable;
NS_DECL_OWNINGTHREAD
};
/* static */ void
Promise::DispatchToMicroTask(nsIRunnable* aRunnable)
{
MOZ_ASSERT(aRunnable);
CycleCollectedJSRuntime* runtime = CycleCollectedJSRuntime::Get();
std::queue<nsCOMPtr<nsIRunnable>>& microtaskQueue =
runtime->GetPromiseMicroTaskQueue();
microtaskQueue.push(aRunnable);
}
#if defined(DOM_PROMISE_DEPRECATED_REPORTING)
void
Promise::MaybeReportRejected()
{
if (mState != Rejected || mHadRejectCallback || mResult.isUndefined()) {
return;
}
AutoJSAPI jsapi;
// We may not have a usable global by now (if it got unlinked
// already), so don't init with it.
jsapi.Init();
JSContext* cx = jsapi.cx();
JS::Rooted<JSObject*> obj(cx, GetWrapper());
MOZ_ASSERT(obj); // We preserve our wrapper, so should always have one here.
JS::Rooted<JS::Value> val(cx, mResult);
JS::ExposeValueToActiveJS(val);
JSAutoCompartment ac(cx, obj);
if (!JS_WrapValue(cx, &val)) {
JS_ClearPendingException(cx);
return;
}
js::ErrorReport report(cx);
if (!report.init(cx, val)) {
JS_ClearPendingException(cx);
return;
}
RefPtr<xpc::ErrorReport> xpcReport = new xpc::ErrorReport();
bool isMainThread = MOZ_LIKELY(NS_IsMainThread());
bool isChrome = isMainThread ? nsContentUtils::IsSystemPrincipal(nsContentUtils::ObjectPrincipal(obj))
: GetCurrentThreadWorkerPrivate()->IsChromeWorker();
nsPIDOMWindow* win = isMainThread ? xpc::WindowGlobalOrNull(obj) : nullptr;
xpcReport->Init(report.report(), report.message(), isChrome, win ? win->WindowID() : 0);
// Now post an event to do the real reporting async
// Since Promises preserve their wrapper, it is essential to RefPtr<> the
// AsyncErrorReporter, otherwise if the call to DispatchToMainThread fails, it
// will leak. See Bug 958684. So... don't use DispatchToMainThread()
nsCOMPtr<nsIThread> mainThread = do_GetMainThread();
if (NS_WARN_IF(!mainThread)) {
// Would prefer NS_ASSERTION, but that causes failure in xpcshell tests
NS_WARNING("!!! Trying to report rejected Promise after MainThread shutdown");
}
if (mainThread) {
RefPtr<AsyncErrorReporter> r = new AsyncErrorReporter(xpcReport);
mainThread->Dispatch(r.forget(), NS_DISPATCH_NORMAL);
}
}
#endif // defined(DOM_PROMISE_DEPRECATED_REPORTING)
void
Promise::MaybeResolveInternal(JSContext* aCx,
JS::Handle<JS::Value> aValue)
{
if (mResolvePending) {
return;
}
ResolveInternal(aCx, aValue);
}
void
Promise::MaybeRejectInternal(JSContext* aCx,
JS::Handle<JS::Value> aValue)
{
if (mResolvePending) {
return;
}
RejectInternal(aCx, aValue);
}
void
Promise::HandleException(JSContext* aCx)
{
JS::Rooted<JS::Value> exn(aCx);
if (JS_GetPendingException(aCx, &exn)) {
JS_ClearPendingException(aCx);
RejectInternal(aCx, exn);
}
}
void
Promise::ResolveInternal(JSContext* aCx,
JS::Handle<JS::Value> aValue)
{
mResolvePending = true;
if (aValue.isObject()) {
AutoDontReportUncaught silenceReporting(aCx);
JS::Rooted<JSObject*> valueObj(aCx, &aValue.toObject());
// Thenables.
JS::Rooted<JS::Value> then(aCx);
if (!JS_GetProperty(aCx, valueObj, "then", &then)) {
HandleException(aCx);
return;
}
if (then.isObject() && JS::IsCallable(&then.toObject())) {
// This is the then() function of the thenable aValueObj.
JS::Rooted<JSObject*> thenObj(aCx, &then.toObject());
// Add a fast path for the case when we're resolved with an actual
// Promise. This has two requirements:
//
// 1) valueObj is a Promise.
// 2) thenObj is a JSFunction backed by our actual Promise::Then
// implementation.
//
// If those requirements are satisfied, then we know exactly what
// thenObj.call(valueObj) will do, so we can optimize a bit and avoid ever
// entering JS for this stuff.
Promise* nextPromise;
if (PromiseBinding::IsThenMethod(thenObj) &&
NS_SUCCEEDED(UNWRAP_OBJECT(Promise, valueObj, nextPromise))) {
// If we were taking the codepath that involves PromiseResolveThenableJob and
// PromiseInit below, then eventually, in PromiseResolveThenableJob::Run, we
// would create some JSFunctions in the compartment of
// this->GetWrapper() and pass them to the PromiseInit. So by the time
// we'd see the resolution value it would be wrapped into the
// compartment of this->GetWrapper(). The global of that compartment is
// this->GetGlobalJSObject(), so use that as the global for
// ResolvePromiseCallback/RejectPromiseCallback.
JS::Rooted<JSObject*> glob(aCx, GlobalJSObject());
RefPtr<PromiseCallback> resolveCb = new ResolvePromiseCallback(this, glob);
RefPtr<PromiseCallback> rejectCb = new RejectPromiseCallback(this, glob);
RefPtr<FastPromiseResolveThenableJob> task =
new FastPromiseResolveThenableJob(resolveCb, rejectCb, nextPromise);
DispatchToMicroTask(task);
return;
}
RefPtr<PromiseInit> thenCallback =
new PromiseInit(nullptr, thenObj, mozilla::dom::GetIncumbentGlobal());
RefPtr<PromiseResolveThenableJob> task =
new PromiseResolveThenableJob(this, valueObj, thenCallback);
DispatchToMicroTask(task);
return;
}
}
MaybeSettle(aValue, Resolved);
}
void
Promise::RejectInternal(JSContext* aCx,
JS::Handle<JS::Value> aValue)
{
mResolvePending = true;
MaybeSettle(aValue, Rejected);
}
void
Promise::Settle(JS::Handle<JS::Value> aValue, PromiseState aState)
{
MOZ_ASSERT(mGlobal,
"We really should have a global here. Except we sometimes don't "
"in the wild for some odd reason");
if (!mGlobal || mGlobal->IsDying()) {
return;
}
mSettlementTimestamp = TimeStamp::Now();
SetResult(aValue);
SetState(aState);
AutoJSAPI jsapi;
jsapi.Init();
JSContext* cx = jsapi.cx();
JS::RootedObject wrapper(cx, GetWrapper());
MOZ_ASSERT(wrapper); // We preserved it
JSAutoCompartment ac(cx, wrapper);
JS::dbg::onPromiseSettled(cx, wrapper);
if (aState == PromiseState::Rejected &&
mIsLastInChain) {
// The Promise has just been rejected, and it is last in chain.
// We need to inform PromiseDebugging.
// If the Promise is eventually not the last in chain anymore,
// we will need to inform PromiseDebugging again.
PromiseDebugging::AddUncaughtRejection(*this);
}
#if defined(DOM_PROMISE_DEPRECATED_REPORTING)
// If the Promise was rejected, and there is no reject handler already setup,
// watch for thread shutdown.
if (aState == PromiseState::Rejected &&
!mHadRejectCallback &&
!NS_IsMainThread()) {
workers::WorkerPrivate* worker = GetCurrentThreadWorkerPrivate();
MOZ_ASSERT(worker);
worker->AssertIsOnWorkerThread();
mFeature = new PromiseReportRejectFeature(this);
if (NS_WARN_IF(!worker->AddFeature(worker->GetJSContext(), mFeature))) {
// To avoid a false RemoveFeature().
mFeature = nullptr;
// Worker is shutting down, report rejection immediately since it is
// unlikely that reject callbacks will be added after this point.
MaybeReportRejectedOnce();
}
}
#endif // defined(DOM_PROMISE_DEPRECATED_REPORTING)
TriggerPromiseReactions();
}
void
Promise::MaybeSettle(JS::Handle<JS::Value> aValue,
PromiseState aState)
{
// Promise.all() or Promise.race() implementations will repeatedly call
// Resolve/RejectInternal rather than using the Maybe... forms. Stop SetState
// from asserting.
if (mState != Pending) {
return;
}
Settle(aValue, aState);
}
void
Promise::TriggerPromiseReactions()
{
nsTArray<RefPtr<PromiseCallback>> callbacks;
callbacks.SwapElements(mState == Resolved ? mResolveCallbacks
: mRejectCallbacks);
mResolveCallbacks.Clear();
mRejectCallbacks.Clear();
for (uint32_t i = 0; i < callbacks.Length(); ++i) {
RefPtr<PromiseReactionJob> task =
new PromiseReactionJob(this, callbacks[i], mResult);
DispatchToMicroTask(task);
}
}
#if defined(DOM_PROMISE_DEPRECATED_REPORTING)
void
Promise::RemoveFeature()
{
if (mFeature) {
workers::WorkerPrivate* worker = GetCurrentThreadWorkerPrivate();
MOZ_ASSERT(worker);
worker->RemoveFeature(worker->GetJSContext(), mFeature);
mFeature = nullptr;
}
}
bool
PromiseReportRejectFeature::Notify(JSContext* aCx, workers::Status aStatus)
{
MOZ_ASSERT(aStatus > workers::Running);
mPromise->MaybeReportRejectedOnce();
// After this point, `this` has been deleted by RemoveFeature!
return true;
}
#endif // defined(DOM_PROMISE_DEPRECATED_REPORTING)
bool
Promise::CaptureStack(JSContext* aCx, JS::Heap<JSObject*>& aTarget)
{
JS::Rooted<JSObject*> stack(aCx);
if (!JS::CaptureCurrentStack(aCx, &stack)) {
return false;
}
aTarget = stack;
return true;
}
void
Promise::GetDependentPromises(nsTArray<RefPtr<Promise>>& aPromises)
{
// We want to return promises that correspond to then() calls, Promise.all()
// calls, and Promise.race() calls.
//
// For the then() case, we have both resolve and reject callbacks that know
// what the next promise is.
//
// For the race() case, likewise.
//
// For the all() case, our reject callback knows what the next promise is, but
// our resolve callback just knows it needs to notify some
// PromiseNativeHandler, which itself only has an indirect relationship to the
// next promise.
//
// So we walk over our _reject_ callbacks and ask each of them what promise
// its dependent promise is.
for (size_t i = 0; i < mRejectCallbacks.Length(); ++i) {
Promise* p = mRejectCallbacks[i]->GetDependentPromise();
if (p) {
aPromises.AppendElement(p);
}
}
}
// A WorkerRunnable to resolve/reject the Promise on the worker thread.
// Calling thread MUST hold PromiseWorkerProxy's mutex before creating this.
class PromiseWorkerProxyRunnable : public workers::WorkerRunnable
{
public:
PromiseWorkerProxyRunnable(PromiseWorkerProxy* aPromiseWorkerProxy,
PromiseWorkerProxy::RunCallbackFunc aFunc)
: WorkerRunnable(aPromiseWorkerProxy->GetWorkerPrivate(),
WorkerThreadUnchangedBusyCount)
, mPromiseWorkerProxy(aPromiseWorkerProxy)
, mFunc(aFunc)
{
MOZ_ASSERT(NS_IsMainThread());
MOZ_ASSERT(mPromiseWorkerProxy);
}
virtual bool
WorkerRun(JSContext* aCx, workers::WorkerPrivate* aWorkerPrivate)
{
MOZ_ASSERT(aWorkerPrivate);
aWorkerPrivate->AssertIsOnWorkerThread();
MOZ_ASSERT(aWorkerPrivate == mWorkerPrivate);
MOZ_ASSERT(mPromiseWorkerProxy);
RefPtr<Promise> workerPromise = mPromiseWorkerProxy->WorkerPromise();
// Here we convert the buffer to a JS::Value.
JS::Rooted<JS::Value> value(aCx);
if (!mPromiseWorkerProxy->Read(aCx, &value)) {
JS_ClearPendingException(aCx);
return false;
}
(workerPromise->*mFunc)(aCx, value);
// Release the Promise because it has been resolved/rejected for sure.
mPromiseWorkerProxy->CleanUp(aCx);
return true;
}
protected:
~PromiseWorkerProxyRunnable() {}
private:
RefPtr<PromiseWorkerProxy> mPromiseWorkerProxy;
// Function pointer for calling Promise::{ResolveInternal,RejectInternal}.
PromiseWorkerProxy::RunCallbackFunc mFunc;
};
/* static */
already_AddRefed<PromiseWorkerProxy>
PromiseWorkerProxy::Create(workers::WorkerPrivate* aWorkerPrivate,
Promise* aWorkerPromise,
const PromiseWorkerProxyStructuredCloneCallbacks* aCb)
{
MOZ_ASSERT(aWorkerPrivate);
aWorkerPrivate->AssertIsOnWorkerThread();
MOZ_ASSERT(aWorkerPromise);
MOZ_ASSERT_IF(aCb, !!aCb->Write && !!aCb->Read);
RefPtr<PromiseWorkerProxy> proxy =
new PromiseWorkerProxy(aWorkerPrivate, aWorkerPromise, aCb);
// We do this to make sure the worker thread won't shut down before the
// promise is resolved/rejected on the worker thread.
if (!proxy->AddRefObject()) {
// Probably the worker is terminating. We cannot complete the operation
// and we have to release all the resources.
proxy->CleanProperties();
return nullptr;
}
return proxy.forget();
}
NS_IMPL_ISUPPORTS0(PromiseWorkerProxy)
PromiseWorkerProxy::PromiseWorkerProxy(workers::WorkerPrivate* aWorkerPrivate,
Promise* aWorkerPromise,
const PromiseWorkerProxyStructuredCloneCallbacks* aCallbacks)
: mWorkerPrivate(aWorkerPrivate)
, mWorkerPromise(aWorkerPromise)
, mCleanedUp(false)
, mCallbacks(aCallbacks)
, mCleanUpLock("cleanUpLock")
, mFeatureAdded(false)
{
}
PromiseWorkerProxy::~PromiseWorkerProxy()
{
MOZ_ASSERT(mCleanedUp);
MOZ_ASSERT(!mFeatureAdded);
MOZ_ASSERT(!mWorkerPromise);
MOZ_ASSERT(!mWorkerPrivate);
}
void
PromiseWorkerProxy::CleanProperties()
{
#ifdef DEBUG
workers::WorkerPrivate* worker = GetCurrentThreadWorkerPrivate();
MOZ_ASSERT(worker);
worker->AssertIsOnWorkerThread();
#endif
// Ok to do this unprotected from Create().
// CleanUp() holds the lock before calling this.
mCleanedUp = true;
mWorkerPromise = nullptr;
mWorkerPrivate = nullptr;
// Clear the StructuredCloneHolderBase class.
Clear();
}
bool
PromiseWorkerProxy::AddRefObject()
{
MOZ_ASSERT(mWorkerPrivate);
mWorkerPrivate->AssertIsOnWorkerThread();
MOZ_ASSERT(!mFeatureAdded);
if (!mWorkerPrivate->AddFeature(mWorkerPrivate->GetJSContext(),
this)) {
return false;
}
mFeatureAdded = true;
// Maintain a reference so that we have a valid object to clean up when
// removing the feature.
AddRef();
return true;
}
workers::WorkerPrivate*
PromiseWorkerProxy::GetWorkerPrivate() const
{
#ifdef DEBUG
if (NS_IsMainThread()) {
mCleanUpLock.AssertCurrentThreadOwns();
}
#endif
// Safe to check this without a lock since we assert lock ownership on the
// main thread above.
MOZ_ASSERT(!mCleanedUp);
MOZ_ASSERT(mFeatureAdded);
return mWorkerPrivate;
}
Promise*
PromiseWorkerProxy::WorkerPromise() const
{
#ifdef DEBUG
workers::WorkerPrivate* worker = GetCurrentThreadWorkerPrivate();
MOZ_ASSERT(worker);
worker->AssertIsOnWorkerThread();
#endif
MOZ_ASSERT(mWorkerPromise);
return mWorkerPromise;
}
void
PromiseWorkerProxy::StoreISupports(nsISupports* aSupports)
{
MOZ_ASSERT(NS_IsMainThread());
nsMainThreadPtrHandle<nsISupports> supports(
new nsMainThreadPtrHolder<nsISupports>(aSupports));
mSupportsArray.AppendElement(supports);
}
void
PromiseWorkerProxy::RunCallback(JSContext* aCx,
JS::Handle<JS::Value> aValue,
RunCallbackFunc aFunc)
{
MOZ_ASSERT(NS_IsMainThread());
MutexAutoLock lock(Lock());
// If the worker thread's been cancelled we don't need to resolve the Promise.
if (CleanedUp()) {
return;
}
// The |aValue| is written into the StructuredCloneHolderBase.
if (!Write(aCx, aValue)) {
JS_ClearPendingException(aCx);
MOZ_ASSERT(false, "cannot serialize the value with the StructuredCloneAlgorithm!");
}
RefPtr<PromiseWorkerProxyRunnable> runnable =
new PromiseWorkerProxyRunnable(this, aFunc);
runnable->Dispatch(aCx);
}
void
PromiseWorkerProxy::ResolvedCallback(JSContext* aCx,
JS::Handle<JS::Value> aValue)
{
RunCallback(aCx, aValue, &Promise::ResolveInternal);
}
void
PromiseWorkerProxy::RejectedCallback(JSContext* aCx,
JS::Handle<JS::Value> aValue)
{
RunCallback(aCx, aValue, &Promise::RejectInternal);
}
bool
PromiseWorkerProxy::Notify(JSContext* aCx, Status aStatus)
{
if (aStatus >= Canceling) {
CleanUp(aCx);
}
return true;
}
void
PromiseWorkerProxy::CleanUp(JSContext* aCx)
{
// Can't release Mutex while it is still locked, so scope the lock.
{
MutexAutoLock lock(Lock());
// |mWorkerPrivate| is not safe to use anymore if we have already
// cleaned up and RemoveFeature(), so we need to check |mCleanedUp| first.
if (CleanedUp()) {
return;
}
MOZ_ASSERT(mWorkerPrivate);
mWorkerPrivate->AssertIsOnWorkerThread();
MOZ_ASSERT(mWorkerPrivate->GetJSContext() == aCx);
// Release the Promise and remove the PromiseWorkerProxy from the features of
// the worker thread since the Promise has been resolved/rejected or the
// worker thread has been cancelled.
MOZ_ASSERT(mFeatureAdded);
mWorkerPrivate->RemoveFeature(mWorkerPrivate->GetJSContext(), this);
mFeatureAdded = false;
CleanProperties();
}
Release();
}
JSObject*
PromiseWorkerProxy::CustomReadHandler(JSContext* aCx,
JSStructuredCloneReader* aReader,
uint32_t aTag,
uint32_t aIndex)
{
if (NS_WARN_IF(!mCallbacks)) {
return nullptr;
}
return mCallbacks->Read(aCx, aReader, this, aTag, aIndex);
}
bool
PromiseWorkerProxy::CustomWriteHandler(JSContext* aCx,
JSStructuredCloneWriter* aWriter,
JS::Handle<JSObject*> aObj)
{
if (NS_WARN_IF(!mCallbacks)) {
return false;
}
return mCallbacks->Write(aCx, aWriter, this, aObj);
}
// Specializations of MaybeRejectBrokenly we actually support.
template<>
void Promise::MaybeRejectBrokenly(const RefPtr<DOMError>& aArg) {
MaybeSomething(aArg, &Promise::MaybeReject);
}
template<>
void Promise::MaybeRejectBrokenly(const nsAString& aArg) {
MaybeSomething(aArg, &Promise::MaybeReject);
}
uint64_t
Promise::GetID() {
if (mID != 0) {
return mID;
}
return mID = ++gIDGenerator;
}
} // namespace dom
} // namespace mozilla