rpc: remove grace period when shutting down the server

The server delayed closing of connections for 3s when stopping. This was
supposed to allow for slow handlers, but it didn't really work. When
geth quits, it will just exit immediately after quitting the server.

Removing the timer makes testing easier because all connections will be
closed after Stop returns.

rpc/server.go

@@ -21,7 +21,6 @@ import (
 	"reflect"
 	"runtime"
 	"sync/atomic"
-	"time"
 
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/logger/glog"
@@ -30,8 +29,6 @@ import (
 )
 
 const (
-	stopPendingRequestTimeout = 3 * time.Second // give pending requests stopPendingRequestTimeout the time to finish when the server is stopped
-
 	notificationBufferSize = 10000 // max buffered notifications before codec is closed
 
 	MetadataApi     = "rpc"
@@ -240,14 +237,12 @@ func (s *Server) ServeSingleRequest(codec ServerCodec, options CodecOption) {
 func (s *Server) Stop() {
 	if atomic.CompareAndSwapInt32(&s.run, 1, 0) {
 		glog.V(logger.Debug).Infoln("RPC Server shutdown initiatied")
-		time.AfterFunc(stopPendingRequestTimeout, func() {
 		s.codecsMu.Lock()
 		defer s.codecsMu.Unlock()
 		s.codecs.Each(func(c interface{}) bool {
 			c.(ServerCodec).Close()
 			return true
 		})
-		})
 	}
 }