Notify NQE of TCP RTT values

net/socket/tcp_socket_posix.cc

Index: net/socket/tcp_socket_posix.cc
diff --git a/net/socket/tcp_socket_posix.cc b/net/socket/tcp_socket_posix.cc
index 0546e6075a57e7663640ac93993b8fa71f1cd3e4..f4275d095d52621277f2d5b849d20b7bbcd0d473 100644
--- a/net/socket/tcp_socket_posix.cc
+++ b/net/socket/tcp_socket_posix.cc
@@ -146,8 +146,12 @@ void CheckSupportAndMaybeEnableTCPFastOpen(bool user_enabled) {
 #endif
 }
 
-TCPSocketPosix::TCPSocketPosix(NetLog* net_log, const NetLog::Source& source)
-    : use_tcp_fastopen_(false),
+TCPSocketPosix::TCPSocketPosix(
+    scoped_ptr<SocketPerformanceWatcher> socket_performance_watcher,
+    NetLog* net_log,
+    const NetLog::Source& source)
+    : socket_performance_watcher_(std::move(socket_performance_watcher)),
+      use_tcp_fastopen_(false),
       tcp_fastopen_write_attempted_(false),
       tcp_fastopen_connected_(false),
       tcp_fastopen_status_(TCP_FASTOPEN_STATUS_UNKNOWN),
@@ -524,7 +528,8 @@ int TCPSocketPosix::BuildTcpSocketPosix(scoped_ptr<TCPSocketPosix>* tcp_socket,
     return ERR_ADDRESS_INVALID;
   }
 
-  tcp_socket->reset(new TCPSocketPosix(net_log_.net_log(), net_log_.source()));
+  tcp_socket->reset(
+      new TCPSocketPosix(nullptr, net_log_.net_log(), net_log_.source()));
   (*tcp_socket)->socket_.reset(accept_socket_.release());
   return OK;
 }
@@ -532,6 +537,7 @@ int TCPSocketPosix::BuildTcpSocketPosix(scoped_ptr<TCPSocketPosix>* tcp_socket,
 void TCPSocketPosix::ConnectCompleted(const CompletionCallback& callback,
                                       int rv) const {
   DCHECK_NE(ERR_IO_PENDING, rv);
+  NotifySocketPerformanceWatcher();
   callback.Run(HandleConnectCompleted(rv));
 }
 
@@ -585,6 +591,7 @@ void TCPSocketPosix::ReadCompleted(const scoped_refptr<IOBuffer>& buf,
                                    const CompletionCallback& callback,
                                    int rv) {
   DCHECK_NE(ERR_IO_PENDING, rv);
+  NotifySocketPerformanceWatcher();
   callback.Run(HandleReadCompleted(buf.get(), rv));
 }
 
@@ -622,6 +629,7 @@ void TCPSocketPosix::WriteCompleted(const scoped_refptr<IOBuffer>& buf,
                                     const CompletionCallback& callback,
                                     int rv) {
   DCHECK_NE(ERR_IO_PENDING, rv);
+  NotifySocketPerformanceWatcher();
   callback.Run(HandleWriteCompleted(buf.get(), rv));
 }
 
@@ -709,6 +717,21 @@ int TCPSocketPosix::TcpFastOpenWrite(IOBuffer* buf,
   return socket_->WaitForWrite(buf, buf_len, callback);
 }
 
+void TCPSocketPosix::NotifySocketPerformanceWatcher() const {
+#if defined(TCP_INFO)
+  if (!socket_performance_watcher_)
+    return;
+
+  tcp_info info;
+  bool getsockopt_success = GetTcpInfo(socket_->socket_fd(), &info);
+  if (!getsockopt_success)
+    return;
+
+  socket_performance_watcher_->OnUpdatedRTTAvailable(
+      base::TimeDelta::FromMicroseconds(info.tcpi_rtt));

[bengr, 2016/02/08 18:51:14]

#include "base/time/time.h"

Also, is tcpi_rtt guaranteed to be valid? How do you tell?

[tbansal1, 2016/02/08 21:33:26]

It is already there in the .tcp_socket_posix.h file
Return value of GetTcpInfo() is expected to be false in the struct is invalid.
But, I added another check just to be sure that I do not report invalid values
(although I have not seen invalid values on linux or on android).

[bengr, 2016/02/08 23:42:06]

Actually, isn't 0 a valid RTT? Perhaps leave it the way you had it.

[tbansal1, 2016/02/09 17:11:22]

Probably not. If RTT computed after doing EWMA is 0, then every TCP packet would
time out as soon as it is sent.

+#endif  // defined(TCP_INFO)
+}
+
 void TCPSocketPosix::UpdateTCPFastOpenStatusAfterRead() {
   DCHECK(tcp_fastopen_status_ == TCP_FASTOPEN_FAST_CONNECT_RETURN ||
          tcp_fastopen_status_ == TCP_FASTOPEN_SLOW_CONNECT_RETURN);