@startuml
!pragma useVerticalIf on
start
partition readHreg() {
if (no request is alreaty running) then (yes)
 :readHreg;
endif
}
while (request is active)
partition task() {
if (responce arrived) then (yes)
  #palegreen:Execute Transactional Callback;
  :fill result data;
endif
if (responce timeout) then (yes)
  #palegreen:Execute Transactional Callback;
endif
}
endwhile (no request)
stop
@enduml