Fix DTLS packet boundary handling in SSLStreamAdapterTests.

webrtc/base/bufferqueue.h

Index: webrtc/base/bufferqueue.h
diff --git a/webrtc/base/bufferqueue.h b/webrtc/base/bufferqueue.h
index 4941fccf2e1c6233584c21588e34991a312e41e3..4adfa29648a18d51f193d242dd06abdd0e950cbc 100644
--- a/webrtc/base/bufferqueue.h
+++ b/webrtc/base/bufferqueue.h
@@ -16,13 +16,35 @@
 
 #include "webrtc/base/buffer.h"
 #include "webrtc/base/criticalsection.h"
+#include "webrtc/base/messagehandler.h"
+#include "webrtc/base/messagequeue.h"
+#include "webrtc/base/sigslot.h"
+#include "webrtc/base/thread.h"
 
 namespace rtc {
 
-class BufferQueue {
+// BufferEvents are used to asynchronously signal state transitionss.  The flags

[torbjorng (webrtc), 2015/11/16 14:05:03]

Nit: "transitionss" is misspelled.

[joachim, 2015/11/16 21:30:16]

No longer applies (removed).

+// may be combined.
+//  BQ_READ: Data is available
+//  BQ_WRITE: Data can be written
+enum BufferEvent { BQ_READ = 1, BQ_WRITE = 2 };
+
+struct BufferEventData : public MessageData {
+  int events;
+  BufferEventData(int ev) : events(ev) { }
+};
+
+class BufferQueue : public MessageHandler {
  public:
+  enum {

[torbjorng (webrtc), 2015/11/16 14:05:03]

Nit: Define enum on one line for consistency. Please use "git cl format" to make
these sort of things consistent.

[joachim, 2015/11/16 21:30:15]

No longer applies (removed).

+    MSG_POST_EVENT = 0x1
+  };
+
   // Creates a buffer queue queue with a given capacity and default buffer size.
   BufferQueue(size_t capacity, size_t default_size);
+  // Creates a buffer queue queue with a given capacity, default buffer size

[torbjorng (webrtc), 2015/11/16 14:05:03]

Nit: "queue queue"

[joachim, 2015/11/16 21:30:15]

Done.

+  // and owner.
+  BufferQueue(size_t capacity, size_t default_size, Thread* owner);
   ~BufferQueue();
 
   // Return number of queued buffers.
@@ -35,9 +57,26 @@ class BufferQueue {
   // WriteBack always writes either the complete memory or nothing.
   bool WriteBack(const void* data, size_t bytes, size_t* bytes_written);
 
+  // BufferQueues may signal one or more BufferEvents to indicate state changes.
+  // The first argument identifies the buffer on which the state change occured.
+  // The second argument is a bit-wise combination of BufferEvents.
+  sigslot::signal2<BufferQueue*, int> SignalEvent;
+
+  // Like calling SignalEvent, but posts a message to the specified thread,
+  // which will call SignalEvent.  This helps unroll the stack and prevent
+  // re-entrancy.

[torbjorng (webrtc), 2015/11/16 14:05:03]

I don't understand the 2nd sentence here. What does "unroll the stack" mean?  By
"prevent re-entrancy", do you mean that this makes sure non-reentrant code is
not re-entered?  (Which code?)

[joachim, 2015/11/16 21:30:15]

By posting the event to a different (or the same) thread, it will be handled the
next time this thread processes the events. This allows the method to return
immediately and prevents the stack from getting too large (if the event handler
calls another method which triggers an event, which calls another method, etc.).

+  void PostEvent(Thread* t, int events);
+  // Like the aforementioned method, but posts to the current thread.
+  void PostEvent(int events);
+
+ protected:
+  // MessageHandler Interface

[torbjorng (webrtc), 2015/11/16 14:05:03]

Nit: The code style asks for a full stop after every comment.

[joachim, 2015/11/16 21:30:16]

Done.

+  void OnMessage(Message* msg) override;
+
  private:
   size_t capacity_;
   size_t default_size_;
+  Thread* owner_;
   std::deque<Buffer*> queue_;
   std::vector<Buffer*> free_list_;
   mutable CriticalSection crit_;  // object lock

[torbjorng (webrtc), 2015/11/16 14:05:03]

Consider using GUARDED_BY here.
See e.g. webrtc/call/rtc_event_log.cc for an example if its use.

Nit: The comment "object lock" seems unnecessary. If you think it is, please
start with Capital letter and end with full stop.

[joachim, 2015/11/16 21:30:16]

Done.