plugin/pprof - add option to enable block profiling (#2729)

* - add an option for block profiling to plugin pprof

* - move option block into nested block

plugin/pprof/pprof.go

@@ -6,12 +6,14 @@ import (
 	"net"
 	"net/http"
 	pp "net/http/pprof"
+	"runtime"
 )
 
 type handler struct {
-	addr string
-	ln   net.Listener
-	mux  *http.ServeMux
+	addr     string
+	rateBloc int
+	ln       net.Listener
+	mux      *http.ServeMux
 }
 
 func (h *handler) Startup() error {
@@ -30,6 +32,8 @@ func (h *handler) Startup() error {
 	h.mux.HandleFunc(path+"/symbol", pp.Symbol)
 	h.mux.HandleFunc(path+"/trace", pp.Trace)
 
+	runtime.SetBlockProfileRate(h.rateBloc)
+
 	go func() {
 		http.Serve(h.ln, h.mux)
 	}()