Release SpdySession socket read buffer

net/spdy/spdy_session.cc

Index: net/spdy/spdy_session.cc
diff --git a/net/spdy/spdy_session.cc b/net/spdy/spdy_session.cc
index 79257d7795f2247d66cea021942970f24158d888..4cd6bd2b5f3746f3ce250dc0ac5152fe3f335710 100644
--- a/net/spdy/spdy_session.cc
+++ b/net/spdy/spdy_session.cc
@@ -737,7 +737,7 @@ SpdySession::SpdySession(const SpdySessionKey& spdy_session_key,
       pool_(NULL),
       http_server_properties_(http_server_properties),
       transport_security_state_(transport_security_state),
-      read_buffer_(new IOBuffer(kReadBufferSize)),
+      // read_buffer_(new IOBuffer(kReadBufferSize)),
       stream_hi_water_mark_(kFirstStreamId),
       last_accepted_push_stream_id_(0),
       unclaimed_pushed_streams_(this),
@@ -1369,8 +1369,9 @@ size_t SpdySession::DumpMemoryStats(StreamSocket::SocketMemoryStats* stats,
   connection_->DumpMemoryStats(stats);
 
   // |connection_| is estimated in stats->total_size. |read_buffer_| is
-  // estimated in kReadBufferSize. TODO(xunjieli): Make them use EMU().
-  return stats->total_size + kReadBufferSize +
+  // estimated in |read_buffer_size|. TODO(xunjieli): Make them use EMU().
+  size_t read_buffer_size = read_buffer_ ? kReadBufferSize : 0;
+  return stats->total_size + read_buffer_size +
          SpdyEstimateMemoryUsage(spdy_session_key_) +
          SpdyEstimateMemoryUsage(pooled_aliases_) +
          SpdyEstimateMemoryUsage(active_streams_) +
@@ -1860,19 +1861,21 @@ int SpdySession::DoReadLoop(ReadState expected_read_state, int result) {
 }
 
 int SpdySession::DoRead() {
+  DCHECK(!read_buffer_);
   CHECK(in_io_loop_);
 
   CHECK(connection_);
   CHECK(connection_->socket());
   read_state_ = READ_STATE_DO_READ_COMPLETE;
   int rv = ERR_READ_IF_READY_NOT_IMPLEMENTED;
+  read_buffer_ = new IOBuffer(kReadBufferSize);
   if (base::FeatureList::IsEnabled(Socket::kReadIfReadyExperiment)) {
     rv = connection_->socket()->ReadIfReady(
         read_buffer_.get(), kReadBufferSize,
         base::Bind(&SpdySession::PumpReadLoop, weak_factory_.GetWeakPtr(),
                    READ_STATE_DO_READ));
-    // TODO(xunjieli): Follow-up CL to release |read_buffer_|.
-    // https://crbug.com/690915.
+    if (rv == ERR_IO_PENDING)

[DmitrySkiba, 2017/03/06 21:42:37]

Are we killing buffer with read operation in progress? I thought read_buffer_
should be alive until DoReadComplete() is called.

[xunjieli, 2017/03/06 21:58:59]

Great question. The new ReadIfReady() method that I implemented allows us to
release |read_buffer_| if a read is pending.

The CL is at https://codereview.chromium.org/2593063003/, which is expected to
land soon.

[xunjieli, 2017/03/06 22:00:51]

Btw, if you apply the CL linked above and start Chrome with
"--enable-features=SocketReadIfReady", all BIOAdapter buffers will be gone. 

+      read_buffer_ = nullptr;
   }
   if (rv == ERR_READ_IF_READY_NOT_IMPLEMENTED) {
     // Fallback to regular Read().
@@ -1881,12 +1884,15 @@ int SpdySession::DoRead() {
         base::Bind(&SpdySession::PumpReadLoop, weak_factory_.GetWeakPtr(),
                    READ_STATE_DO_READ_COMPLETE));
   }
-  if (rv == ERR_IO_PENDING)
+  if (rv == ERR_IO_PENDING) {
     read_state_ = READ_STATE_DO_READ;
+    return ERR_IO_PENDING;
+  }
   return rv;
 }
 
 int SpdySession::DoReadComplete(int result) {
+  DCHECK(read_buffer_);
   CHECK(in_io_loop_);
 
   // Parse a frame.  For now this code requires that the frame fit into our
@@ -1924,6 +1930,7 @@ int SpdySession::DoReadComplete(int result) {
               SpdyFramer::SPDY_NO_ERROR);
   }
 
+  read_buffer_ = nullptr;
   read_state_ = READ_STATE_DO_READ;
   return OK;
 }