From dc81eb9c37873e391a927a6f6810239565a91732 Mon Sep 17 00:00:00 2001 From: Ghanan Gowripalan Date: Thu, 27 Aug 2020 12:48:19 -0700 Subject: Add function to get error from a tcpip.Endpoint In an upcoming CL, socket option types are made to implement a marker interface with pointer receivers. Since this results in calling methods of an interface with a pointer, we incur an allocation when attempting to get an Endpoint's last error with the current implementation. When calling the method of an interface, the compiler is unable to determine what the interface implementation does with the pointer (since calling a method on an interface uses virtual dispatch at runtime so the compiler does not know what the interface method will do) so it allocates on the heap to be safe incase an implementation continues to hold the pointer after the functioon returns (the reference escapes the scope of the object). In the example below, the compiler does not know what b.foo does with the reference to a it allocates a on the heap as the reference to a may escape the scope of a. ``` var a int var b someInterface b.foo(&a) ``` This change removes the opportunity for that allocation. RELNOTES: n/a PiperOrigin-RevId: 328796559 --- pkg/tcpip/transport/icmp/endpoint.go | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) (limited to 'pkg/tcpip/transport/icmp') diff --git a/pkg/tcpip/transport/icmp/endpoint.go b/pkg/tcpip/transport/icmp/endpoint.go index bd6f49eb8..c545c8367 100644 --- a/pkg/tcpip/transport/icmp/endpoint.go +++ b/pkg/tcpip/transport/icmp/endpoint.go @@ -415,14 +415,8 @@ func (e *endpoint) GetSockOptInt(opt tcpip.SockOptInt) (int, *tcpip.Error) { } // GetSockOpt implements tcpip.Endpoint.GetSockOpt. -func (e *endpoint) GetSockOpt(opt interface{}) *tcpip.Error { - switch opt.(type) { - case tcpip.ErrorOption: - return nil - - default: - return tcpip.ErrUnknownProtocolOption - } +func (*endpoint) GetSockOpt(interface{}) *tcpip.Error { + return tcpip.ErrUnknownProtocolOption } func send4(r *stack.Route, ident uint16, data buffer.View, ttl uint8, owner tcpip.PacketOwner) *tcpip.Error { @@ -836,3 +830,8 @@ func (e *endpoint) Stats() tcpip.EndpointStats { // Wait implements stack.TransportEndpoint.Wait. func (*endpoint) Wait() {} + +// LastError implements tcpip.Endpoint.LastError. +func (*endpoint) LastError() *tcpip.Error { + return nil +} -- cgit v1.2.3