content/child/threaded_data_provider.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/child/threaded_data_provider.h"
   6
   7 #include "base/location.h"
   8 #include "base/single_thread_task_runner.h"
   9 #include "components/scheduler/child/webthread_impl_for_worker_scheduler.h"
  10 #include "content/child/child_process.h"
  11 #include "content/child/child_thread_impl.h"
  12 #include "content/child/resource_dispatcher.h"
  13 #include "content/child/thread_safe_sender.h"
  14 #include "content/common/resource_messages.h"
  15 #include "ipc/ipc_sync_channel.h"
  16 #include "third_party/WebKit/public/platform/WebThread.h"
  17 #include "third_party/WebKit/public/platform/WebThreadedDataReceiver.h"
  18
  19 namespace content {
  20
  21 namespace {
  22
  23 class DataProviderMessageFilter : public IPC::MessageFilter {
  24  public:
  25   DataProviderMessageFilter(
  26       scoped_refptr<base::SingleThreadTaskRunner> io_task_runner,
  27       scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner,
  28       const scheduler::WebThreadImplForWorkerScheduler& background_thread,
  29       const base::WeakPtr<ThreadedDataProvider>&
  30           background_thread_resource_provider,
  31       const base::WeakPtr<ThreadedDataProvider>& main_thread_resource_provider,
  32       int request_id);
  33
  34   // IPC::ChannelProxy::MessageFilter
  35   void OnFilterAdded(IPC::Sender* sender) final;
  36   bool OnMessageReceived(const IPC::Message& message) final;
  37
  38  private:
  39   ~DataProviderMessageFilter() override {}
  40
  41   void OnReceivedData(int request_id, int data_offset, int data_length,
  42                       int encoded_data_length);
  43
  44   const scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
  45   scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner_;
  46   const scheduler::WebThreadImplForWorkerScheduler& background_thread_;
  47   // This weakptr can only be dereferenced on the background thread.
  48   base::WeakPtr<ThreadedDataProvider>
  49       background_thread_resource_provider_;
  50   // This weakptr can only be dereferenced on the main thread.
  51   base::WeakPtr<ThreadedDataProvider>
  52       main_thread_resource_provider_;
  53   int request_id_;
  54 };
  55
  56 DataProviderMessageFilter::DataProviderMessageFilter(
  57     scoped_refptr<base::SingleThreadTaskRunner> io_task_runner,
  58     scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner,
  59     const scheduler::WebThreadImplForWorkerScheduler& background_thread,
  60     const base::WeakPtr<ThreadedDataProvider>&
  61         background_thread_resource_provider,
  62     const base::WeakPtr<ThreadedDataProvider>& main_thread_resource_provider,
  63     int request_id)
  64     : io_task_runner_(io_task_runner),
  65       main_thread_task_runner_(main_thread_task_runner),
  66       background_thread_(background_thread),
  67       background_thread_resource_provider_(background_thread_resource_provider),
  68       main_thread_resource_provider_(main_thread_resource_provider),
  69       request_id_(request_id) {
  70   DCHECK(main_thread_task_runner_.get());
  71 }
  72
  73 void DataProviderMessageFilter::OnFilterAdded(IPC::Sender* sender) {
  74   DCHECK(io_task_runner_->BelongsToCurrentThread());
  75
  76   main_thread_task_runner_->PostTask(
  77       FROM_HERE,
  78       base::Bind(&ThreadedDataProvider::OnResourceMessageFilterAddedMainThread,
  79                  main_thread_resource_provider_));
  80 }
  81
  82 bool DataProviderMessageFilter::OnMessageReceived(
  83     const IPC::Message& message) {
  84   DCHECK(io_task_runner_->BelongsToCurrentThread());
  85
  86   if (message.type() != ResourceMsg_DataReceived::ID)
  87     return false;
  88
  89   int request_id;
  90
  91   base::PickleIterator iter(message);
  92   if (!iter.ReadInt(&request_id)) {
  93     NOTREACHED() << "malformed resource message";
  94     return true;
  95   }
  96
  97   if (request_id == request_id_) {
  98     ResourceMsg_DataReceived::Schema::Param arg;
  99     if (ResourceMsg_DataReceived::Read(&message, &arg)) {
 100       OnReceivedData(base::get<0>(arg), base::get<1>(arg),
 101                      base::get<2>(arg), base::get<3>(arg));
 102       return true;
 103     }
 104   }
 105
 106   return false;
 107 }
 108
 109 void DataProviderMessageFilter::OnReceivedData(int request_id,
 110                                                int data_offset,
 111                                                int data_length,
 112                                                int encoded_data_length) {
 113   DCHECK(io_task_runner_->BelongsToCurrentThread());
 114   background_thread_.TaskRunner()->PostTask(
 115       FROM_HERE,
 116       base::Bind(&ThreadedDataProvider::OnReceivedDataOnBackgroundThread,
 117                  background_thread_resource_provider_, data_offset, data_length,
 118                  encoded_data_length));
 119 }
 120
 121 }  // anonymous namespace
 122
 123 ThreadedDataProvider::ThreadedDataProvider(
 124     int request_id,
 125     blink::WebThreadedDataReceiver* threaded_data_receiver,
 126     linked_ptr<base::SharedMemory> shm_buffer,
 127     int shm_size,
 128     scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner)
 129     : request_id_(request_id),
 130       shm_buffer_(shm_buffer),
 131       shm_size_(shm_size),
 132       background_thread_(
 133           static_cast<scheduler::WebThreadImplForWorkerScheduler&>(
 134               *threaded_data_receiver->backgroundThread())),
 135       ipc_channel_(ChildThreadImpl::current()->channel()),
 136       threaded_data_receiver_(threaded_data_receiver),
 137       resource_filter_active_(false),
 138       main_thread_task_runner_(main_thread_task_runner),
 139       main_thread_weak_factory_(this) {
 140   DCHECK(ChildThreadImpl::current());
 141   DCHECK(ipc_channel_);
 142   DCHECK(threaded_data_receiver_);
 143   DCHECK(main_thread_task_runner_.get());
 144
 145   background_thread_weak_factory_.reset(
 146       new base::WeakPtrFactory<ThreadedDataProvider>(this));
 147
 148   filter_ = new DataProviderMessageFilter(
 149       ChildProcess::current()->io_task_runner(), main_thread_task_runner_,
 150       background_thread_, background_thread_weak_factory_->GetWeakPtr(),
 151       main_thread_weak_factory_.GetWeakPtr(), request_id);
 152
 153   ChildThreadImpl::current()->channel()->AddFilter(filter_.get());
 154 }
 155
 156 ThreadedDataProvider::~ThreadedDataProvider() {
 157   DCHECK(ChildThreadImpl::current());
 158
 159   ChildThreadImpl::current()->channel()->RemoveFilter(filter_.get());
 160
 161   delete threaded_data_receiver_;
 162 }
 163
 164 void ThreadedDataProvider::DestructOnMainThread() {
 165   DCHECK(ChildThreadImpl::current());
 166
 167   // The ThreadedDataProvider must be destructed on the main thread to
 168   // be threadsafe when removing the message filter and releasing the shared
 169   // memory buffer.
 170   delete this;
 171 }
 172
 173 void ThreadedDataProvider::Stop() {
 174   DCHECK(ChildThreadImpl::current());
 175
 176   // Make sure we don't get called by on the main thread anymore via weak
 177   // pointers we've passed to the filter.
 178   main_thread_weak_factory_.InvalidateWeakPtrs();
 179
 180   blink::WebThread* current_background_thread =
 181       threaded_data_receiver_->backgroundThread();
 182
 183   // We can't destroy this instance directly; we need to bounce a message over
 184   // to the background thread and back to make sure nothing else will access it
 185   // there, before we can destruct it. We also need to make sure the background
 186   // thread is still alive, since Blink could have shut down at this point
 187   // and freed the thread.
 188   if (current_background_thread) {
 189     // We should never end up with a different parser thread than from when the
 190     // ThreadedDataProvider gets created.
 191     DCHECK(current_background_thread ==
 192            static_cast<scheduler::WebThreadImplForWorkerScheduler*>(
 193                &background_thread_));
 194     background_thread_.TaskRunner()->PostTask(
 195         FROM_HERE, base::Bind(&ThreadedDataProvider::StopOnBackgroundThread,
 196                               base::Unretained(this)));
 197   }
 198 }
 199
 200 void ThreadedDataProvider::StopOnBackgroundThread() {
 201   DCHECK(background_thread_.isCurrentThread());
 202   DCHECK(background_thread_weak_factory_);
 203
 204   // When this happens, the provider should no longer be called on the
 205   // background thread as it's about to be destroyed on the main thread.
 206   // Destructing the weak pointer factory means invalidating the weak pointers
 207   // which means no callbacks from the filter will happen and nothing else will
 208   // use this instance on the background thread.
 209   background_thread_weak_factory_.reset(NULL);
 210   main_thread_task_runner_->PostTask(FROM_HERE,
 211       base::Bind(&ThreadedDataProvider::DestructOnMainThread,
 212                  base::Unretained(this)));
 213 }
 214
 215 void ThreadedDataProvider::OnRequestCompleteForegroundThread(
 216       base::WeakPtr<ResourceDispatcher> resource_dispatcher,
 217       const ResourceMsg_RequestCompleteData& request_complete_data,
 218       const base::TimeTicks& renderer_completion_time) {
 219   DCHECK(ChildThreadImpl::current());
 220
 221   background_thread_.TaskRunner()->PostTask(
 222       FROM_HERE,
 223       base::Bind(&ThreadedDataProvider::OnRequestCompleteBackgroundThread,
 224                  base::Unretained(this), resource_dispatcher,
 225                  request_complete_data, renderer_completion_time));
 226 }
 227
 228 void ThreadedDataProvider::OnRequestCompleteBackgroundThread(
 229       base::WeakPtr<ResourceDispatcher> resource_dispatcher,
 230       const ResourceMsg_RequestCompleteData& request_complete_data,
 231       const base::TimeTicks& renderer_completion_time) {
 232   DCHECK(background_thread_.isCurrentThread());
 233
 234   main_thread_task_runner_->PostTask(FROM_HERE,
 235       base::Bind(
 236           &ResourceDispatcher::CompletedRequestAfterBackgroundThreadFlush,
 237           resource_dispatcher,
 238           request_id_,
 239           request_complete_data,
 240           renderer_completion_time));
 241 }
 242
 243 void ThreadedDataProvider::OnResourceMessageFilterAddedMainThread() {
 244   DCHECK(ChildThreadImpl::current());
 245   DCHECK(background_thread_weak_factory_);
 246
 247   // We bounce this message from the I/O thread via the main thread and then
 248   // to our background thread, following the same path as incoming data before
 249   // our filter gets added, to make sure there's nothing still incoming.
 250   background_thread_.TaskRunner()->PostTask(
 251       FROM_HERE,
 252       base::Bind(
 253           &ThreadedDataProvider::OnResourceMessageFilterAddedBackgroundThread,
 254           background_thread_weak_factory_->GetWeakPtr()));
 255 }
 256
 257 void ThreadedDataProvider::OnResourceMessageFilterAddedBackgroundThread() {
 258   DCHECK(background_thread_.isCurrentThread());
 259   resource_filter_active_ = true;
 260
 261   // At this point we know no more data is going to arrive from the main thread,
 262   // so we can process any data we've received directly from the I/O thread
 263   // in the meantime.
 264   if (!queued_data_.empty()) {
 265     std::vector<QueuedSharedMemoryData>::iterator iter = queued_data_.begin();
 266     for (; iter != queued_data_.end(); ++iter) {
 267       ForwardAndACKData(iter->data, iter->length, iter->encoded_length);
 268     }
 269
 270     queued_data_.clear();
 271   }
 272 }
 273
 274 void ThreadedDataProvider::OnReceivedDataOnBackgroundThread(
 275     int data_offset, int data_length, int encoded_data_length) {
 276   DCHECK(background_thread_.isCurrentThread());
 277   DCHECK(shm_buffer_ != NULL);
 278
 279   CHECK_GE(shm_size_, data_offset + data_length);
 280   const char* data_ptr = static_cast<char*>(shm_buffer_->memory());
 281   CHECK(data_ptr);
 282   CHECK(data_ptr + data_offset);
 283
 284   if (resource_filter_active_) {
 285     ForwardAndACKData(data_ptr + data_offset, data_length, encoded_data_length);
 286   } else {
 287     // There's a brief interval between the point where we know the filter
 288     // has been installed on the I/O thread, and when we know for sure there's
 289     // no more data coming in from the main thread (from before the filter
 290     // got added). If we get any data during that interval, we need to queue
 291     // it until we're certain we've processed all the main thread data to make
 292     // sure we forward (and ACK) everything in the right order.
 293     QueuedSharedMemoryData queued_data;
 294     queued_data.data = data_ptr + data_offset;
 295     queued_data.length = data_length;
 296     queued_data.encoded_length = encoded_data_length;
 297     queued_data_.push_back(queued_data);
 298   }
 299 }
 300
 301 void ThreadedDataProvider::OnReceivedDataOnForegroundThread(
 302     const char* data, int data_length, int encoded_data_length) {
 303   DCHECK(ChildThreadImpl::current());
 304
 305   background_thread_.TaskRunner()->PostTask(
 306       FROM_HERE, base::Bind(&ThreadedDataProvider::ForwardAndACKData,
 307                             base::Unretained(this), data, data_length,
 308                             encoded_data_length));
 309 }
 310
 311 void ThreadedDataProvider::ForwardAndACKData(const char* data,
 312                                              int data_length,
 313                                              int encoded_data_length) {
 314   DCHECK(background_thread_.isCurrentThread());
 315
 316   threaded_data_receiver_->acceptData(data, data_length);
 317
 318   scoped_ptr<std::vector<char>> data_copy;
 319   if (threaded_data_receiver_->needsMainthreadDataCopy()) {
 320     data_copy.reset(new std::vector<char>(data, data + data_length));
 321   }
 322
 323   main_thread_task_runner_->PostTask(FROM_HERE,
 324       base::Bind(&ThreadedDataProvider::DataNotifyForegroundThread,
 325           base::Unretained(this),
 326           base::Passed(&data_copy),
 327           data_length,
 328           encoded_data_length));
 329
 330   ipc_channel_->Send(new ResourceHostMsg_DataReceived_ACK(request_id_));
 331 }
 332
 333 void ThreadedDataProvider::DataNotifyForegroundThread(
 334     scoped_ptr<std::vector<char> > data_copy,
 335     int data_length,
 336     int encoded_data_length) {
 337   if (data_copy) {
 338     DCHECK(threaded_data_receiver_->needsMainthreadDataCopy());
 339     DCHECK_EQ((size_t)data_length, data_copy->size());
 340   }
 341
 342   threaded_data_receiver_->acceptMainthreadDataNotification(
 343       (data_copy && !data_copy->empty()) ? &data_copy->front() : NULL,
 344       data_length, encoded_data_length);
 345 }
 346
 347 }  // namespace content