De-Clientize UDPSocket service

mojo/services/network/udp_socket_impl.cc

Index: mojo/services/network/udp_socket_impl.cc
diff --git a/mojo/services/network/udp_socket_impl.cc b/mojo/services/network/udp_socket_impl.cc
index 524136a32744b49fd542a1c1a468485cc605f2bf..d46d3da533e9bd8671f6c9979b47970a5d5b752d 100644
--- a/mojo/services/network/udp_socket_impl.cc
+++ b/mojo/services/network/udp_socket_impl.cc
@@ -34,8 +34,9 @@ UDPSocketImpl::PendingSendRequest::PendingSendRequest() {}
 
 UDPSocketImpl::PendingSendRequest::~PendingSendRequest() {}
 
-UDPSocketImpl::UDPSocketImpl()
-    : socket_(net::DatagramSocket::DEFAULT_BIND, net::RandIntCallback(),
+UDPSocketImpl::UDPSocketImpl(InterfaceRequest<UDPSocket> request)
+    : binding_(this, request.Pass()),
+      socket_(net::DatagramSocket::DEFAULT_BIND, net::RandIntCallback(),
               nullptr, net::NetLog::Source()),
       state_(NOT_BOUND_OR_CONNECTED),
       allow_address_reuse_(false),
@@ -215,6 +216,15 @@ void UDPSocketImpl::NegotiateMaxPendingSendRequests(
   }
 }
 
+void UDPSocketImpl::SetReceiver(UDPSocketReceiverPtr receiver) {
+  receiver_ = receiver.Pass();
+
+  // If there is a pending RecvFrom completion, we can continue it now.
+  if (recvfrom_buffer_.get()) {
+    OnRecvFromCompleted(recvfrom_result_);
+  }
+}
+
 void UDPSocketImpl::ReceiveMore(uint32_t datagram_number) {
   if (datagram_number == 0)
     return;
@@ -323,6 +333,13 @@ void UDPSocketImpl::DoSendTo(NetAddressPtr addr,
 void UDPSocketImpl::OnRecvFromCompleted(int net_result) {
   DCHECK(recvfrom_buffer_.get());
 
+  // If no receiver is set yet, leave this RecvFrom operation in a pending
+  // state, preventing additional RecvFroms as well.

[yzshen1, 2015/01/28 19:31:06]

This is a pretty clever way. :)

+  if (!receiver_) {
+    recvfrom_result_ = net_result;
+    return;
+  }
+
   NetAddressPtr net_address;
   Array<uint8_t> array;
   if (net_result >= 0) {
@@ -337,9 +354,8 @@ void UDPSocketImpl::OnRecvFromCompleted(int net_result) {
   }
   recvfrom_buffer_ = nullptr;
 
-  client()->OnReceived(MakeNetworkError(net_result), net_address.Pass(),
-                       array.Pass());
-
+  receiver_->OnReceived(MakeNetworkError(net_result), net_address.Pass(),
+                        array.Pass());
   DCHECK_GT(remaining_recv_slots_, 0u);
   remaining_recv_slots_--;
   if (remaining_recv_slots_ > 0)