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