Does it's safe to use call_defered with or without mutex.lock() ?

[system]

	Attention	Topic was automatically imported from the old Question2Answer platform.
	Asked By	my_person

• I have a function process_score(score) called by _input.

• _input will call process_score(score) again without ended last
  call.

• I use global variables inside process_score(score).

So, call_defered will execute process_score secuently in a list of task or two or more times at once?

May I need to use mutex.lock() to protect my global variables or is unnecesary?