lock pattern for global variable in MT4

Does anyone have a good locking pattern for global variables that works in MT4?

I would like only one ea at a time to read, write then update a global variable.

what is a locking pattern?

In programming a pattern is a generaly repeatable solution to a common problem. Sort of like a template that can be used in many places.
I was looking for a locking pattern. In other programming languages there are patterns programmers use to lock a variable so that you can guarantee that only one thing is changing it at a time.

I figured someone has worked out the best way to do this in MT4 with global variables.

Since i made the original post i have found the function GlobalVariableSetOnCondition() which might help to do this unless someone has a better idea.