runtime/JSPromise.cpp

   1 /*
   2  * Copyright (C) 2013 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  14  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  15  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  17  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  18  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  19  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  20  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  21  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  22  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  23  * THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "config.h"
  27 #include "JSPromise.h"
  28
  29 #if ENABLE(PROMISES)
  30
  31 #include "Error.h"
  32 #include "JSCJSValueInlines.h"
  33 #include "JSCellInlines.h"
  34 #include "JSPromiseConstructor.h"
  35 #include "JSPromiseReaction.h"
  36 #include "Microtask.h"
  37 #include "SlotVisitorInlines.h"
  38 #include "StructureInlines.h"
  39
  40 namespace JSC {
  41
  42 static void triggerPromiseReactions(VM&, JSGlobalObject*, Vector<WriteBarrier<JSPromiseReaction>>&, JSValue);
  43
  44 const ClassInfo JSPromise::s_info = { "Promise", &Base::s_info, 0, 0, CREATE_METHOD_TABLE(JSPromise) };
  45
  46 JSPromise* JSPromise::create(VM& vm, JSGlobalObject* globalObject, JSPromiseConstructor* constructor)
  47 {
  48     JSPromise* promise = new (NotNull, allocateCell<JSPromise>(vm.heap)) JSPromise(vm, globalObject->promiseStructure());
  49     promise->finishCreation(vm, constructor);
  50     return promise;
  51 }
  52
  53 Structure* JSPromise::createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
  54 {
  55     return Structure::create(vm, globalObject, prototype, TypeInfo(ObjectType, StructureFlags), info());
  56 }
  57
  58 JSPromise::JSPromise(VM& vm, Structure* structure)
  59     : JSDestructibleObject(vm, structure)
  60     , m_status(Status::Unresolved)
  61 {
  62 }
  63
  64 void JSPromise::finishCreation(VM& vm, JSPromiseConstructor* constructor)
  65 {
  66     Base::finishCreation(vm);
  67     ASSERT(inherits(info()));
  68
  69     m_constructor.set(vm, this, constructor);
  70 }
  71
  72 void JSPromise::destroy(JSCell* cell)
  73 {
  74     static_cast<JSPromise*>(cell)->JSPromise::~JSPromise();
  75 }
  76
  77 void JSPromise::visitChildren(JSCell* cell, SlotVisitor& visitor)
  78 {
  79     JSPromise* thisObject = jsCast<JSPromise*>(cell);
  80     ASSERT_GC_OBJECT_INHERITS(thisObject, info());
  81     COMPILE_ASSERT(StructureFlags & OverridesVisitChildren, OverridesVisitChildrenWithoutSettingFlag);
  82     ASSERT(thisObject->structure()->typeInfo().overridesVisitChildren());
  83
  84     Base::visitChildren(thisObject, visitor);
  85
  86     visitor.append(&thisObject->m_result);
  87     visitor.append(&thisObject->m_constructor);
  88     visitor.append(thisObject->m_resolveReactions.begin(), thisObject->m_resolveReactions.end());
  89     visitor.append(thisObject->m_rejectReactions.begin(), thisObject->m_rejectReactions.end());
  90 }
  91
  92 void JSPromise::reject(VM& vm, JSValue reason)
  93 {
  94     // 1. If the value of promise's internal slot [[PromiseStatus]] is not "unresolved", return.
  95     if (m_status != Status::Unresolved)
  96         return;
  97
  98     DeferGC deferGC(vm.heap);
  99
 100     // 2. Let 'reactions' be the value of promise's [[RejectReactions]] internal slot.
 101     Vector<WriteBarrier<JSPromiseReaction>> reactions;
 102     reactions.swap(m_rejectReactions);
 103
 104     // 3. Set the value of promise's [[Result]] internal slot to reason.
 105     m_result.set(vm, this, reason);
 106
 107     // 4. Set the value of promise's [[ResolveReactions]] internal slot to undefined.
 108     m_resolveReactions.clear();
 109
 110     // 5. Set the value of promise's [[RejectReactions]] internal slot to undefined.
 111     // NOTE: Handled by the swap above.
 112
 113     // 6. Set the value of promise's [[PromiseStatus]] internal slot to "has-rejection".
 114     m_status = Status::HasRejection;
 115
 116     // 7. Return the result of calling TriggerPromiseReactions(reactions, reason).
 117     triggerPromiseReactions(vm, globalObject(), reactions, reason);
 118 }
 119
 120 void JSPromise::resolve(VM& vm, JSValue resolution)
 121 {
 122     // 1. If the value of promise's internal slot [[PromiseStatus]] is not "unresolved", return.
 123     if (m_status != Status::Unresolved)
 124         return;
 125
 126     DeferGC deferGC(vm.heap);
 127
 128     // 2. Let 'reactions' be the value of promise's [[ResolveReactions]] internal slot.
 129     Vector<WriteBarrier<JSPromiseReaction>> reactions;
 130     reactions.swap(m_resolveReactions);
 131
 132     // 3. Set the value of promise's [[Result]] internal slot to resolution.
 133     m_result.set(vm, this, resolution);
 134
 135     // 4. Set the value of promise's [[ResolveReactions]] internal slot to undefined.
 136     // NOTE: Handled by the swap above.
 137
 138     // 5. Set the value of promise's [[RejectReactions]] internal slot to undefined.
 139     m_rejectReactions.clear();
 140
 141     // 6. Set the value of promise's [[PromiseStatus]] internal slot to "has-resolution".
 142     m_status = Status::HasResolution;
 143
 144     // 7. Return the result of calling TriggerPromiseReactions(reactions, resolution).
 145     triggerPromiseReactions(vm, globalObject(), reactions, resolution);
 146 }
 147
 148 void JSPromise::appendResolveReaction(VM& vm, JSPromiseReaction* reaction)
 149 {
 150     m_resolveReactions.append(WriteBarrier<JSPromiseReaction>(vm, this, reaction));
 151 }
 152
 153 void JSPromise::appendRejectReaction(VM& vm, JSPromiseReaction* reaction)
 154 {
 155     m_rejectReactions.append(WriteBarrier<JSPromiseReaction>(vm, this, reaction));
 156 }
 157
 158 void triggerPromiseReactions(VM& vm, JSGlobalObject* globalObject, Vector<WriteBarrier<JSPromiseReaction>>& reactions, JSValue argument)
 159 {
 160     // 1. Repeat for each reaction in reactions, in original insertion order
 161     for (auto& reaction : reactions) {
 162         // i. Call QueueMicrotask(ExecutePromiseReaction, (reaction, argument)).
 163         globalObject->queueMicrotask(createExecutePromiseReactionMicrotask(vm, reaction.get(), argument));
 164     }
 165
 166     // 2. Return.
 167 }
 168
 169 } // namespace JSC
 170
 171 #endif // ENABLE(PROMISES)