1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
|
/* -*- 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);
}
MOZ_MUST_USE bool resolve(JSContext* cx, HandleValue resolutionValue);
MOZ_MUST_USE bool reject(JSContext* cx, HandleValue rejectionValue);
void onSettled(JSContext* cx);
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);
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 */
|
