1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/dom/base/MessagePort.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,526 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#include "MessagePort.h"
1.10 +#include "MessageEvent.h"
1.11 +#include "mozilla/dom/Event.h"
1.12 +#include "mozilla/dom/MessageChannel.h"
1.13 +#include "mozilla/dom/MessagePortBinding.h"
1.14 +#include "mozilla/dom/MessagePortList.h"
1.15 +#include "mozilla/dom/StructuredCloneTags.h"
1.16 +#include "nsContentUtils.h"
1.17 +#include "nsGlobalWindow.h"
1.18 +#include "nsPresContext.h"
1.19 +
1.20 +#include "nsIDocument.h"
1.21 +#include "nsIDOMFile.h"
1.22 +#include "nsIDOMFileList.h"
1.23 +#include "nsIPresShell.h"
1.24 +
1.25 +namespace mozilla {
1.26 +namespace dom {
1.27 +
1.28 +class DispatchEventRunnable : public nsRunnable
1.29 +{
1.30 + friend class MessagePort;
1.31 +
1.32 + public:
1.33 + DispatchEventRunnable(MessagePort* aPort)
1.34 + : mPort(aPort)
1.35 + {
1.36 + }
1.37 +
1.38 + NS_IMETHOD
1.39 + Run()
1.40 + {
1.41 + nsRefPtr<DispatchEventRunnable> mKungFuDeathGrip(this);
1.42 +
1.43 + mPort->mDispatchRunnable = nullptr;
1.44 + mPort->Dispatch();
1.45 +
1.46 + return NS_OK;
1.47 + }
1.48 +
1.49 + private:
1.50 + nsRefPtr<MessagePort> mPort;
1.51 +};
1.52 +
1.53 +class PostMessageRunnable : public nsRunnable
1.54 +{
1.55 + friend class MessagePort;
1.56 +
1.57 + public:
1.58 + NS_DECL_NSIRUNNABLE
1.59 +
1.60 + PostMessageRunnable()
1.61 + {
1.62 + }
1.63 +
1.64 + ~PostMessageRunnable()
1.65 + {
1.66 + }
1.67 +
1.68 + JSAutoStructuredCloneBuffer& Buffer()
1.69 + {
1.70 + return mBuffer;
1.71 + }
1.72 +
1.73 + bool StoreISupports(nsISupports* aSupports)
1.74 + {
1.75 + mSupportsArray.AppendElement(aSupports);
1.76 + return true;
1.77 + }
1.78 +
1.79 + void Dispatch(MessagePort* aPort)
1.80 + {
1.81 + mPort = aPort;
1.82 + NS_DispatchToCurrentThread(this);
1.83 + }
1.84 +
1.85 + private:
1.86 + nsRefPtr<MessagePort> mPort;
1.87 + JSAutoStructuredCloneBuffer mBuffer;
1.88 +
1.89 + nsTArray<nsCOMPtr<nsISupports> > mSupportsArray;
1.90 +};
1.91 +
1.92 +namespace {
1.93 +
1.94 +struct StructuredCloneInfo
1.95 +{
1.96 + PostMessageRunnable* mEvent;
1.97 + MessagePort* mPort;
1.98 + nsRefPtrHashtable<nsRefPtrHashKey<MessagePortBase>, MessagePortBase> mPorts;
1.99 +};
1.100 +
1.101 +static JSObject*
1.102 +PostMessageReadStructuredClone(JSContext* cx,
1.103 + JSStructuredCloneReader* reader,
1.104 + uint32_t tag,
1.105 + uint32_t data,
1.106 + void* closure)
1.107 +{
1.108 + if (tag == SCTAG_DOM_BLOB || tag == SCTAG_DOM_FILELIST) {
1.109 + NS_ASSERTION(!data, "Data should be empty");
1.110 +
1.111 + nsISupports* supports;
1.112 + if (JS_ReadBytes(reader, &supports, sizeof(supports))) {
1.113 + JS::Rooted<JS::Value> val(cx);
1.114 + if (NS_SUCCEEDED(nsContentUtils::WrapNative(cx, supports, &val))) {
1.115 + return JSVAL_TO_OBJECT(val);
1.116 + }
1.117 + }
1.118 + }
1.119 +
1.120 + const JSStructuredCloneCallbacks* runtimeCallbacks =
1.121 + js::GetContextStructuredCloneCallbacks(cx);
1.122 +
1.123 + if (runtimeCallbacks) {
1.124 + return runtimeCallbacks->read(cx, reader, tag, data, nullptr);
1.125 + }
1.126 +
1.127 + return nullptr;
1.128 +}
1.129 +
1.130 +static bool
1.131 +PostMessageWriteStructuredClone(JSContext* cx,
1.132 + JSStructuredCloneWriter* writer,
1.133 + JS::Handle<JSObject*> obj,
1.134 + void *closure)
1.135 +{
1.136 + StructuredCloneInfo* scInfo = static_cast<StructuredCloneInfo*>(closure);
1.137 + NS_ASSERTION(scInfo, "Must have scInfo!");
1.138 +
1.139 + nsCOMPtr<nsIXPConnectWrappedNative> wrappedNative;
1.140 + nsContentUtils::XPConnect()->
1.141 + GetWrappedNativeOfJSObject(cx, obj, getter_AddRefs(wrappedNative));
1.142 + if (wrappedNative) {
1.143 + uint32_t scTag = 0;
1.144 + nsISupports* supports = wrappedNative->Native();
1.145 +
1.146 + nsCOMPtr<nsIDOMBlob> blob = do_QueryInterface(supports);
1.147 + if (blob) {
1.148 + scTag = SCTAG_DOM_BLOB;
1.149 + }
1.150 +
1.151 + nsCOMPtr<nsIDOMFileList> list = do_QueryInterface(supports);
1.152 + if (list) {
1.153 + scTag = SCTAG_DOM_FILELIST;
1.154 + }
1.155 +
1.156 + if (scTag) {
1.157 + return JS_WriteUint32Pair(writer, scTag, 0) &&
1.158 + JS_WriteBytes(writer, &supports, sizeof(supports)) &&
1.159 + scInfo->mEvent->StoreISupports(supports);
1.160 + }
1.161 + }
1.162 +
1.163 + const JSStructuredCloneCallbacks* runtimeCallbacks =
1.164 + js::GetContextStructuredCloneCallbacks(cx);
1.165 +
1.166 + if (runtimeCallbacks) {
1.167 + return runtimeCallbacks->write(cx, writer, obj, nullptr);
1.168 + }
1.169 +
1.170 + return false;
1.171 +}
1.172 +
1.173 +static bool
1.174 +PostMessageReadTransferStructuredClone(JSContext* aCx,
1.175 + JSStructuredCloneReader* reader,
1.176 + uint32_t tag, void* data,
1.177 + uint64_t unused,
1.178 + void* aClosure,
1.179 + JS::MutableHandle<JSObject*> returnObject)
1.180 +{
1.181 + StructuredCloneInfo* scInfo = static_cast<StructuredCloneInfo*>(aClosure);
1.182 + NS_ASSERTION(scInfo, "Must have scInfo!");
1.183 +
1.184 + if (tag == SCTAG_DOM_MAP_MESSAGEPORT) {
1.185 + MessagePort* port = static_cast<MessagePort*>(data);
1.186 + port->BindToOwner(scInfo->mPort->GetOwner());
1.187 + scInfo->mPorts.Put(port, nullptr);
1.188 +
1.189 + JS::Rooted<JSObject*> obj(aCx, port->WrapObject(aCx));
1.190 + if (JS_WrapObject(aCx, &obj)) {
1.191 + MOZ_ASSERT(port->GetOwner() == scInfo->mPort->GetOwner());
1.192 + returnObject.set(obj);
1.193 + }
1.194 + return true;
1.195 + }
1.196 +
1.197 + return false;
1.198 +}
1.199 +
1.200 +static bool
1.201 +PostMessageTransferStructuredClone(JSContext* aCx,
1.202 + JS::Handle<JSObject*> aObj,
1.203 + void* aClosure,
1.204 + uint32_t* aTag,
1.205 + JS::TransferableOwnership* aOwnership,
1.206 + void** aContent,
1.207 + uint64_t *aExtraData)
1.208 +{
1.209 + StructuredCloneInfo* scInfo = static_cast<StructuredCloneInfo*>(aClosure);
1.210 + NS_ASSERTION(scInfo, "Must have scInfo!");
1.211 +
1.212 + MessagePortBase *port = nullptr;
1.213 + nsresult rv = UNWRAP_OBJECT(MessagePort, aObj, port);
1.214 + if (NS_SUCCEEDED(rv)) {
1.215 + nsRefPtr<MessagePortBase> newPort;
1.216 + if (scInfo->mPorts.Get(port, getter_AddRefs(newPort))) {
1.217 + // No duplicate.
1.218 + return false;
1.219 + }
1.220 +
1.221 + newPort = port->Clone();
1.222 + scInfo->mPorts.Put(port, newPort);
1.223 +
1.224 + *aTag = SCTAG_DOM_MAP_MESSAGEPORT;
1.225 + *aOwnership = JS::SCTAG_TMO_CUSTOM;
1.226 + *aContent = newPort;
1.227 + *aExtraData = 0;
1.228 +
1.229 + return true;
1.230 + }
1.231 +
1.232 + return false;
1.233 +}
1.234 +
1.235 +static void
1.236 +PostMessageFreeTransferStructuredClone(uint32_t aTag, JS::TransferableOwnership aOwnership,
1.237 + void* aData,
1.238 + uint64_t aExtraData,
1.239 + void* aClosure)
1.240 +{
1.241 + StructuredCloneInfo* scInfo = static_cast<StructuredCloneInfo*>(aClosure);
1.242 + NS_ASSERTION(scInfo, "Must have scInfo!");
1.243 +
1.244 + if (aTag == SCTAG_DOM_MAP_MESSAGEPORT) {
1.245 + MOZ_ASSERT(aOwnership == JS::SCTAG_TMO_CUSTOM);
1.246 + nsRefPtr<MessagePort> port(static_cast<MessagePort*>(aData));
1.247 + scInfo->mPorts.Remove(port);
1.248 + }
1.249 +}
1.250 +
1.251 +JSStructuredCloneCallbacks kPostMessageCallbacks = {
1.252 + PostMessageReadStructuredClone,
1.253 + PostMessageWriteStructuredClone,
1.254 + nullptr,
1.255 + PostMessageReadTransferStructuredClone,
1.256 + PostMessageTransferStructuredClone,
1.257 + PostMessageFreeTransferStructuredClone
1.258 +};
1.259 +
1.260 +} // anonymous namespace
1.261 +
1.262 +static PLDHashOperator
1.263 +PopulateMessagePortList(MessagePortBase* aKey, MessagePortBase* aValue, void* aClosure)
1.264 +{
1.265 + nsTArray<nsRefPtr<MessagePortBase> > *array =
1.266 + static_cast<nsTArray<nsRefPtr<MessagePortBase> > *>(aClosure);
1.267 +
1.268 + array->AppendElement(aKey);
1.269 + return PL_DHASH_NEXT;
1.270 +}
1.271 +
1.272 +NS_IMETHODIMP
1.273 +PostMessageRunnable::Run()
1.274 +{
1.275 + MOZ_ASSERT(mPort);
1.276 +
1.277 + // Get the JSContext for the target window
1.278 + nsCOMPtr<nsIScriptGlobalObject> sgo = do_QueryInterface(mPort->GetOwner());
1.279 + NS_ENSURE_STATE(sgo);
1.280 + nsCOMPtr<nsIScriptContext> scriptContext = sgo->GetContext();
1.281 + AutoPushJSContext cx(scriptContext ? scriptContext->GetNativeContext()
1.282 + : nsContentUtils::GetSafeJSContext());
1.283 +
1.284 + MOZ_ASSERT(cx);
1.285 +
1.286 + // Deserialize the structured clone data
1.287 + JS::Rooted<JS::Value> messageData(cx);
1.288 + StructuredCloneInfo scInfo;
1.289 + scInfo.mEvent = this;
1.290 + scInfo.mPort = mPort;
1.291 +
1.292 + if (!mBuffer.read(cx, &messageData, &kPostMessageCallbacks, &scInfo)) {
1.293 + return NS_ERROR_DOM_DATA_CLONE_ERR;
1.294 + }
1.295 +
1.296 + // Create the event
1.297 + nsCOMPtr<mozilla::dom::EventTarget> eventTarget =
1.298 + do_QueryInterface(mPort->GetOwner());
1.299 + nsRefPtr<MessageEvent> event =
1.300 + new MessageEvent(eventTarget, nullptr, nullptr);
1.301 +
1.302 + event->InitMessageEvent(NS_LITERAL_STRING("message"), false /* non-bubbling */,
1.303 + false /* cancelable */, messageData, EmptyString(),
1.304 + EmptyString(), nullptr);
1.305 + event->SetTrusted(true);
1.306 + event->SetSource(mPort);
1.307 +
1.308 + nsTArray<nsRefPtr<MessagePortBase> > ports;
1.309 + scInfo.mPorts.EnumerateRead(PopulateMessagePortList, &ports);
1.310 + event->SetPorts(new MessagePortList(static_cast<dom::Event*>(event.get()), ports));
1.311 +
1.312 + bool status;
1.313 + mPort->DispatchEvent(static_cast<dom::Event*>(event.get()), &status);
1.314 + return status ? NS_OK : NS_ERROR_FAILURE;
1.315 +}
1.316 +
1.317 +MessagePortBase::MessagePortBase(nsPIDOMWindow* aWindow)
1.318 + : DOMEventTargetHelper(aWindow)
1.319 +{
1.320 + // SetIsDOMBinding() is called by DOMEventTargetHelper's ctor.
1.321 +}
1.322 +
1.323 +MessagePortBase::MessagePortBase()
1.324 +{
1.325 + SetIsDOMBinding();
1.326 +}
1.327 +
1.328 +NS_IMPL_CYCLE_COLLECTION_CLASS(MessagePort)
1.329 +
1.330 +NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(MessagePort,
1.331 + DOMEventTargetHelper)
1.332 + NS_IMPL_CYCLE_COLLECTION_UNLINK(mEntangledPort)
1.333 +
1.334 + // Custom unlink loop because this array contains nsRunnable objects
1.335 + // which are not cycle colleactable.
1.336 + while (!tmp->mMessageQueue.IsEmpty()) {
1.337 + NS_IMPL_CYCLE_COLLECTION_UNLINK(mMessageQueue[0]->mPort);
1.338 + NS_IMPL_CYCLE_COLLECTION_UNLINK(mMessageQueue[0]->mSupportsArray);
1.339 + tmp->mMessageQueue.RemoveElementAt(0);
1.340 + }
1.341 +
1.342 + if (tmp->mDispatchRunnable) {
1.343 + NS_IMPL_CYCLE_COLLECTION_UNLINK(mDispatchRunnable->mPort);
1.344 + }
1.345 +
1.346 +NS_IMPL_CYCLE_COLLECTION_UNLINK_END
1.347 +
1.348 +NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(MessagePort,
1.349 + DOMEventTargetHelper)
1.350 + NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mEntangledPort)
1.351 +
1.352 + // Custom unlink loop because this array contains nsRunnable objects
1.353 + // which are not cycle colleactable.
1.354 + for (uint32_t i = 0, len = tmp->mMessageQueue.Length(); i < len; ++i) {
1.355 + NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mMessageQueue[i]->mPort);
1.356 + NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mMessageQueue[i]->mSupportsArray);
1.357 + }
1.358 +
1.359 + if (tmp->mDispatchRunnable) {
1.360 + NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDispatchRunnable->mPort);
1.361 + }
1.362 +
1.363 +NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
1.364 +
1.365 +NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(MessagePort)
1.366 +NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)
1.367 +
1.368 +NS_IMPL_ADDREF_INHERITED(MessagePort, DOMEventTargetHelper)
1.369 +NS_IMPL_RELEASE_INHERITED(MessagePort, DOMEventTargetHelper)
1.370 +
1.371 +MessagePort::MessagePort(nsPIDOMWindow* aWindow)
1.372 + : MessagePortBase(aWindow)
1.373 + , mMessageQueueEnabled(false)
1.374 +{
1.375 +}
1.376 +
1.377 +MessagePort::~MessagePort()
1.378 +{
1.379 + Close();
1.380 +}
1.381 +
1.382 +JSObject*
1.383 +MessagePort::WrapObject(JSContext* aCx)
1.384 +{
1.385 + return MessagePortBinding::Wrap(aCx, this);
1.386 +}
1.387 +
1.388 +void
1.389 +MessagePort::PostMessageMoz(JSContext* aCx, JS::Handle<JS::Value> aMessage,
1.390 + const Optional<Sequence<JS::Value>>& aTransferable,
1.391 + ErrorResult& aRv)
1.392 +{
1.393 + nsRefPtr<PostMessageRunnable> event = new PostMessageRunnable();
1.394 +
1.395 + // We *must* clone the data here, or the JS::Value could be modified
1.396 + // by script
1.397 + StructuredCloneInfo scInfo;
1.398 + scInfo.mEvent = event;
1.399 + scInfo.mPort = this;
1.400 +
1.401 + JS::Rooted<JS::Value> transferable(aCx, JS::UndefinedValue());
1.402 + if (aTransferable.WasPassed()) {
1.403 + const Sequence<JS::Value>& realTransferable = aTransferable.Value();
1.404 +
1.405 + // The input sequence only comes from the generated bindings code, which
1.406 + // ensures it is rooted.
1.407 + JS::HandleValueArray elements =
1.408 + JS::HandleValueArray::fromMarkedLocation(realTransferable.Length(),
1.409 + realTransferable.Elements());
1.410 +
1.411 + JSObject* array =
1.412 + JS_NewArrayObject(aCx, elements);
1.413 + if (!array) {
1.414 + aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
1.415 + return;
1.416 + }
1.417 + transferable.setObject(*array);
1.418 + }
1.419 +
1.420 + if (!event->Buffer().write(aCx, aMessage, transferable,
1.421 + &kPostMessageCallbacks, &scInfo)) {
1.422 + aRv.Throw(NS_ERROR_DOM_DATA_CLONE_ERR);
1.423 + return;
1.424 + }
1.425 +
1.426 + if (!mEntangledPort) {
1.427 + return;
1.428 + }
1.429 +
1.430 + mEntangledPort->mMessageQueue.AppendElement(event);
1.431 + mEntangledPort->Dispatch();
1.432 +}
1.433 +
1.434 +void
1.435 +MessagePort::Start()
1.436 +{
1.437 + if (mMessageQueueEnabled) {
1.438 + return;
1.439 + }
1.440 +
1.441 + mMessageQueueEnabled = true;
1.442 + Dispatch();
1.443 +}
1.444 +
1.445 +void
1.446 +MessagePort::Dispatch()
1.447 +{
1.448 + if (!mMessageQueueEnabled || mMessageQueue.IsEmpty() || mDispatchRunnable) {
1.449 + return;
1.450 + }
1.451 +
1.452 + nsRefPtr<PostMessageRunnable> event = mMessageQueue.ElementAt(0);
1.453 + mMessageQueue.RemoveElementAt(0);
1.454 +
1.455 + event->Dispatch(this);
1.456 +
1.457 + mDispatchRunnable = new DispatchEventRunnable(this);
1.458 + NS_DispatchToCurrentThread(mDispatchRunnable);
1.459 +}
1.460 +
1.461 +void
1.462 +MessagePort::Close()
1.463 +{
1.464 + if (!mEntangledPort) {
1.465 + return;
1.466 + }
1.467 +
1.468 + // This avoids loops.
1.469 + nsRefPtr<MessagePort> port = mEntangledPort;
1.470 + mEntangledPort = nullptr;
1.471 +
1.472 + // Let's disentangle the 2 ports symmetrically.
1.473 + port->Close();
1.474 +}
1.475 +
1.476 +EventHandlerNonNull*
1.477 +MessagePort::GetOnmessage()
1.478 +{
1.479 + if (NS_IsMainThread()) {
1.480 + return GetEventHandler(nsGkAtoms::onmessage, EmptyString());
1.481 + }
1.482 + return GetEventHandler(nullptr, NS_LITERAL_STRING("message"));
1.483 +}
1.484 +
1.485 +void
1.486 +MessagePort::SetOnmessage(EventHandlerNonNull* aCallback)
1.487 +{
1.488 + if (NS_IsMainThread()) {
1.489 + SetEventHandler(nsGkAtoms::onmessage, EmptyString(), aCallback);
1.490 + } else {
1.491 + SetEventHandler(nullptr, NS_LITERAL_STRING("message"), aCallback);
1.492 + }
1.493 +
1.494 + // When using onmessage, the call to start() is implied.
1.495 + Start();
1.496 +}
1.497 +
1.498 +void
1.499 +MessagePort::Entangle(MessagePort* aMessagePort)
1.500 +{
1.501 + MOZ_ASSERT(aMessagePort);
1.502 + MOZ_ASSERT(aMessagePort != this);
1.503 +
1.504 + Close();
1.505 +
1.506 + mEntangledPort = aMessagePort;
1.507 +}
1.508 +
1.509 +already_AddRefed<MessagePortBase>
1.510 +MessagePort::Clone()
1.511 +{
1.512 + nsRefPtr<MessagePort> newPort = new MessagePort(nullptr);
1.513 +
1.514 + // Move all the events in the port message queue of original port.
1.515 + newPort->mMessageQueue.SwapElements(mMessageQueue);
1.516 +
1.517 + if (mEntangledPort) {
1.518 + nsRefPtr<MessagePort> port = mEntangledPort;
1.519 + mEntangledPort = nullptr;
1.520 +
1.521 + newPort->Entangle(port);
1.522 + port->Entangle(newPort);
1.523 + }
1.524 +
1.525 + return newPort.forget();
1.526 +}
1.527 +
1.528 +} // namespace dom
1.529 +} // namespace mozilla
