1 files changed, 191 insertions, 0 deletions
diff --git a/js/src/builtin/Promise.h b/js/src/builtin/Promise.h
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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);
+    }
+
+    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 */