Trace events for P2P Socket

Trace time spent on IPCs and system socket for sending a packet through
P2P Socket.

Review URL: https://codereview.chromium.org/25648007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229083 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 24 insertions, 2 deletions

diff --git a/content/renderer/p2p/socket_client.cc b/content/renderer/p2p/socket_client.cc
index 68797db..57e0339 100644
--- a/content/renderer/p2p/socket_client.cc
+++ b/content/renderer/p2p/socket_client.cc
@@ -8,6 +8,18 @@
 #include "base/message_loop/message_loop_proxy.h"
 #include "content/common/p2p_messages.h"
 #include "content/renderer/p2p/socket_dispatcher.h"
+#include "crypto/random.h"
+
+namespace {
+
+uint64 GetUniqueId(uint32 random_socket_id, uint32 packet_id) {
+  uint64 uid = random_socket_id;
+  uid <<= 32;
+  uid |= packet_id;
+  return uid;
+}
+
+}  // namespace
 
 namespace content {
 
@@ -16,7 +28,10 @@ P2PSocketClient::P2PSocketClient(P2PSocketDispatcher* dispatcher)
       ipc_message_loop_(dispatcher->message_loop()),
       delegate_message_loop_(base::MessageLoopProxy::current()),
       socket_id_(0), delegate_(NULL),
-      state_(STATE_UNINITIALIZED) {
+      state_(STATE_UNINITIALIZED),
+      random_socket_id_(0),
+      next_packet_id_(0) {
+  crypto::RandBytes(&random_socket_id_, sizeof(random_socket_id_));
 }
 
 P2PSocketClient::~P2PSocketClient() {
@@ -59,7 +74,10 @@ void P2PSocketClient::Send(const net::IPEndPoint& address,
   // Can send data only when the socket is open.
   DCHECK(state_ == STATE_OPEN || state_ == STATE_ERROR);
   if (state_ == STATE_OPEN) {
-    dispatcher_->SendP2PMessage(new P2PHostMsg_Send(socket_id_, address, data));
+    uint64 unique_id = GetUniqueId(random_socket_id_, ++next_packet_id_);
+    TRACE_EVENT_ASYNC_BEGIN0("p2p", "Send", unique_id);
+    dispatcher_->SendP2PMessage(new P2PHostMsg_Send(socket_id_, address, data,
+                                                    unique_id));
   }
 }
 
diff --git a/content/renderer/p2p/socket_client.h b/content/renderer/p2p/socket_client.h
index fd8537e..fbdca27 100644
--- a/content/renderer/p2p/socket_client.h
+++ b/content/renderer/p2p/socket_client.h
@@ -116,6 +116,10 @@ class P2PSocketClient : public base::RefCountedThreadSafe<P2PSocketClient> {
   Delegate* delegate_;
   State state_;
 
+  // These two fields are used to identify packets for tracing.
+  uint32 random_socket_id_;
+  uint32 next_packet_id_;
+
   DISALLOW_COPY_AND_ASSIGN(P2PSocketClient);
 };