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..69a19dd1c1be8f01a7568d5d5cb499b081a57514 100644
--- a/net/socket/tcp_socket_posix.cc
+++ b/net/socket/tcp_socket_posix.cc
@@ -14,6 +14,7 @@
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/posix/eintr_wrapper.h"
+#include "base/profiler/scoped_tracker.h"
 #include "base/task_runner_util.h"
 #include "base/threading/worker_pool.h"
 #include "net/base/address_list.h"
@@ -146,8 +147,12 @@ 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),
@@ -524,14 +529,16 @@ 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;
 }
 
 void TCPSocketPosix::ConnectCompleted(const CompletionCallback& callback,
-                                      int rv) const {
+                                      int rv) {
   DCHECK_NE(ERR_IO_PENDING, rv);
+  NotifySocketPerformanceWatcher();
   callback.Run(HandleConnectCompleted(rv));
 }
 
@@ -585,6 +592,7 @@ 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 +630,7 @@ 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 +718,33 @@ int TCPSocketPosix::TcpFastOpenWrite(IOBuffer* buf,
   return socket_->WaitForWrite(buf, buf_len, callback);
 }
 
+void TCPSocketPosix::NotifySocketPerformanceWatcher() {
+#if defined(TCP_INFO)
+  // Check if |socket_performance_watcher_| can be notified of a RTT value.
+  if (!socket_performance_watcher_ ||
+      !socket_performance_watcher_->ShouldNotifyUpdatedRTT()) {
+    return;
+  }
+
+  // TODO(tbansal): Remove ScopedTracker once crbug.com/590254 is fixed.
+  tracked_objects::ScopedTracker tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "590254 TCPSocketPosix::NotifySocketPerformanceWatcher"));

[Ryan Sleevi, 2016/03/04 01:38:38]

Nit: You should move this to cover the full function, since that short-circuit
on 724-726 will affect performance too.

[tbansal1, 2016/03/04 02:37:54]

Done.

+
+  tcp_info info;
+  if (!GetTcpInfo(socket_->socket_fd(), &info))
+    return;
+
+  // Only notify the SocketPerformanceWatcher if the RTT in |tcp_info| struct
+  // was populated. A value of 0 may be valid, but it is not reported to the
+  // SocketPerformanceWatcher in order to maintain high accuracy.
+  if (info.tcpi_rtt > 0) {
+    socket_performance_watcher_->OnUpdatedRTTAvailable(
+        base::TimeDelta::FromMicroseconds(info.tcpi_rtt));
+  }
+#endif  // defined(TCP_INFO)
+}
+
 void TCPSocketPosix::UpdateTCPFastOpenStatusAfterRead() {
   DCHECK(tcp_fastopen_status_ == TCP_FASTOPEN_FAST_CONNECT_RETURN ||
          tcp_fastopen_status_ == TCP_FASTOPEN_SLOW_CONNECT_RETURN);