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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sts=4 et sw=4 tw=99:
* 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/. */
#ifndef builtin_Promise_h
#define builtin_Promise_h
#include "builtin/SelfHostingDefines.h"
#include "vm/NativeObject.h"
namespace js {
enum PromiseSlots {
PromiseSlot_Flags = 0,
PromiseSlot_ReactionsOrResult,
PromiseSlot_RejectFunction,
PromiseSlot_AwaitGenerator = PromiseSlot_RejectFunction,
PromiseSlot_AllocationSite,
PromiseSlot_ResolutionSite,
PromiseSlot_AllocationTime,
PromiseSlot_ResolutionTime,
PromiseSlot_Id,
PromiseSlots,
};
#define PROMISE_FLAG_RESOLVED 0x1
#define PROMISE_FLAG_FULFILLED 0x2
#define PROMISE_FLAG_HANDLED 0x4
#define PROMISE_FLAG_REPORTED 0x8
#define PROMISE_FLAG_DEFAULT_RESOLVE_FUNCTION 0x10
#define PROMISE_FLAG_DEFAULT_REJECT_FUNCTION 0x20
#define PROMISE_FLAG_ASYNC 0x40
class AutoSetNewObjectMetadata;
class PromiseObject : public NativeObject
{
public:
static const unsigned RESERVED_SLOTS = PromiseSlots;
static const Class class_;
static const Class protoClass_;
static PromiseObject* create(JSContext* cx, HandleObject executor,
HandleObject proto = nullptr, bool needsWrapping = false);
static JSObject* unforgeableResolve(JSContext* cx, HandleValue value);
static JSObject* unforgeableReject(JSContext* cx, HandleValue value);
JS::PromiseState state() {
int32_t flags = getFixedSlot(PromiseSlot_Flags).toInt32();
if (!(flags & PROMISE_FLAG_RESOLVED)) {
MOZ_ASSERT(!(flags & PROMISE_FLAG_FULFILLED));
return JS::PromiseState::Pending;
}
if (flags & PROMISE_FLAG_FULFILLED)
return JS::PromiseState::Fulfilled;
return JS::PromiseState::Rejected;
}
Value value() {
MOZ_ASSERT(state() == JS::PromiseState::Fulfilled);
return getFixedSlot(PromiseSlot_ReactionsOrResult);
}
Value reason() {
MOZ_ASSERT(state() == JS::PromiseState::Rejected);
return getFixedSlot(PromiseSlot_ReactionsOrResult);
}
static MOZ_MUST_USE bool resolve(JSContext* cx, Handle<PromiseObject*> promise,
HandleValue resolutionValue);
static MOZ_MUST_USE bool reject(JSContext* cx, Handle<PromiseObject*> promise,
HandleValue rejectionValue);
static void onSettled(JSContext* cx, Handle<PromiseObject*> promise);
double allocationTime() { return getFixedSlot(PromiseSlot_AllocationTime).toNumber(); }
double resolutionTime() { return getFixedSlot(PromiseSlot_ResolutionTime).toNumber(); }
JSObject* allocationSite() {
return getFixedSlot(PromiseSlot_AllocationSite).toObjectOrNull();
}
JSObject* resolutionSite() {
return getFixedSlot(PromiseSlot_ResolutionSite).toObjectOrNull();
}
double lifetime();
double timeToResolution() {
MOZ_ASSERT(state() != JS::PromiseState::Pending);
return resolutionTime() - allocationTime();
}
MOZ_MUST_USE bool dependentPromises(JSContext* cx, MutableHandle<GCVector<Value>> values);
uint64_t getID();
bool isUnhandled() {
MOZ_ASSERT(state() == JS::PromiseState::Rejected);
return !(getFixedSlot(PromiseSlot_Flags).toInt32() & PROMISE_FLAG_HANDLED);
}
void markAsReported() {
MOZ_ASSERT(isUnhandled());
int32_t flags = getFixedSlot(PromiseSlot_Flags).toInt32();
setFixedSlot(PromiseSlot_Flags, Int32Value(flags | PROMISE_FLAG_REPORTED));
}
};
/**
* Unforgeable version of the JS builtin Promise.all.
*
* Takes an AutoObjectVector of Promise objects and returns a promise that's
* resolved with an array of resolution values when all those promises have
* been resolved, or rejected with the rejection value of the first rejected
* promise.
*
* Asserts that all objects in the `promises` vector are, maybe wrapped,
* instances of `Promise` or a subclass of `Promise`.
*/
MOZ_MUST_USE JSObject*
GetWaitForAllPromise(JSContext* cx, const JS::AutoObjectVector& promises);
/**
* Enqueues resolve/reject reactions in the given Promise's reactions lists
* as though calling the original value of Promise.prototype.then.
*
* If the `createDependent` flag is not set, no dependent Promise will be
* created. This is used internally to implement DOM functionality.
* Note: In this case, the reactions pushed using this function contain a
* `promise` field that can contain null. That field is only ever used by
* devtools, which have to treat these reactions specially.
*/
MOZ_MUST_USE bool
OriginalPromiseThen(JSContext* cx, Handle<PromiseObject*> promise,
HandleValue onFulfilled, HandleValue onRejected,
MutableHandleObject dependent, bool createDependent);
/**
* PromiseResolve ( C, x )
*
* The abstract operation PromiseResolve, given a constructor and a value,
* returns a new promise resolved with that value.
*/
MOZ_MUST_USE JSObject*
PromiseResolve(JSContext* cx, HandleObject constructor, HandleValue value);
MOZ_MUST_USE PromiseObject*
CreatePromiseObjectForAsync(JSContext* cx, HandleValue generatorVal);
MOZ_MUST_USE bool
AsyncFunctionReturned(JSContext* cx, Handle<PromiseObject*> resultPromise, HandleValue value);
MOZ_MUST_USE bool
AsyncFunctionThrown(JSContext* cx, Handle<PromiseObject*> resultPromise);
MOZ_MUST_USE bool
AsyncFunctionAwait(JSContext* cx, Handle<PromiseObject*> resultPromise, HandleValue value);
/**
* A PromiseTask represents a task that can be dispatched to a helper thread
* (via StartPromiseTask), executed (by implementing PromiseTask::execute()),
* and then resolved back on the original JSContext owner thread.
* Because it contains a PersistentRooted, a PromiseTask will only be destroyed
* on the JSContext's owner thread.
*/
class PromiseTask : public JS::AsyncTask
{
JSRuntime* runtime_;
PersistentRooted<PromiseObject*> promise_;
// PromiseTask implements JS::AsyncTask and prevents derived classes from
// overriding; derived classes should implement the new pure virtual
// functions introduced below. Both of these methods 'delete this'.
void finish(JSContext* cx) override final;
void cancel(JSContext* cx) override final;
protected:
// Called by PromiseTask on the JSContext's owner thread after execute()
// completes on the helper thread, assuming JS::FinishAsyncTaskCallback
// succeeds. After this method returns, the task will be deleted.
virtual bool finishPromise(JSContext* cx, Handle<PromiseObject*> promise) = 0;
public:
PromiseTask(JSContext* cx, Handle<PromiseObject*> promise);
~PromiseTask();
JSRuntime* runtime() const { return runtime_; }
// Called on a helper thread after StartAsyncTask. After execute()
// completes, the JS::FinishAsyncTaskCallback will be called. If this fails
// the task will be enqueued for deletion at some future point without ever
// calling finishPromise().
virtual void execute() = 0;
// May be called in the absence of helper threads to synchronously execute
// and finish a PromiseTask.
bool executeAndFinish(JSContext* cx);
};
bool
Promise_static_resolve(JSContext* cx, unsigned argc, Value* vp);
bool
Promise_reject(JSContext* cx, unsigned argc, Value* vp);
bool
Promise_then(JSContext* cx, unsigned argc, Value* vp);
} // namespace js
#endif /* builtin_Promise_h */
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