Fix DTLS packet boundary handling in SSLStreamAdapterTests.

webrtc/base/bufferqueue.cc

 /*
  *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include "webrtc/base/bufferqueue.h"
 
 namespace rtc {
 
 BufferQueue::BufferQueue(size_t capacity, size_t default_size)
-    : capacity_(capacity), default_size_(default_size) {
+    : capacity_(capacity), default_size_(default_size),
+      owner_(Thread::Current()) {
+}
+
+BufferQueue::BufferQueue(size_t capacity, size_t default_size, Thread* owner)
+    : capacity_(capacity), default_size_(default_size), owner_(owner) {
 }
 
 BufferQueue::~BufferQueue() {
   CritScope cs(&crit_);
 
   for (Buffer* buffer : queue_) {
     delete buffer;
   }
   for (Buffer* buffer : free_list_) {
     delete buffer;
   }
 }
 
 size_t BufferQueue::size() const {
   CritScope cs(&crit_);
   return queue_.size();
 }
 
 bool BufferQueue::ReadFront(void* buffer, size_t bytes, size_t* bytes_read) {
   CritScope cs(&crit_);
   if (queue_.empty()) {
     return false;
   }
 
+  bool was_writable = queue_.size() < capacity_;
   Buffer* packet = queue_.front();
   queue_.pop_front();
 
   size_t next_packet_size = packet->size();
   if (bytes > next_packet_size) {
     bytes = next_packet_size;
   }
 
   memcpy(buffer, packet->data(), bytes);
   if (bytes_read) {
     *bytes_read = bytes;
   }
   free_list_.push_back(packet);
+  if (!was_writable) {
+    PostEvent(owner_, BQ_WRITE);
+  }
   return true;
 }
 
 bool BufferQueue::WriteBack(const void* buffer, size_t bytes,
                             size_t* bytes_written) {
   CritScope cs(&crit_);
   if (queue_.size() == capacity_) {
     return false;
   }
 
+  bool was_readable = !queue_.empty();
   Buffer* packet;
   if (!free_list_.empty()) {
     packet = free_list_.back();
     free_list_.pop_back();
   } else {
     packet = new Buffer(bytes, default_size_);
   }
 
   packet->SetData(static_cast<const uint8_t*>(buffer), bytes);
   if (bytes_written) {
     *bytes_written = bytes;
   }
   queue_.push_back(packet);
+  if (!was_readable) {
+    PostEvent(owner_, BQ_READ);
+  }
   return true;
 }
 
+void BufferQueue::PostEvent(Thread* t, int events) {
+  t->Post(this, MSG_POST_EVENT, new BufferEventData(events));
+}
+
+void BufferQueue::PostEvent(int events) {
+  PostEvent(Thread::Current(), events);
+}
+
+void BufferQueue::OnMessage(Message* msg) {

[tommi, 2015/11/13 08:38:12]

It looks like we allow posting this notification to any thread.  Is that
intentional?  If it's a requirement of an external implementation to receive the
callback on a different thread than the main thread, I would prefer to have that
detail handled in the implementation that depends on it.  If we remove that
capability from BufferQueue, we greatly simplify the threading model.

+  if (MSG_POST_EVENT == msg->message_id) {
+    BufferEventData* pe = static_cast<BufferEventData*>(msg->pdata);
+    SignalEvent(this, pe->events);
+    delete msg->pdata;
+  }
+}
+
 }  // namespace rtc