What kind of code can be called “re-entrant”?

Question

Could someone tell me what code can be called \"re-entrant\" code?

I came across this word when reading some real time operating system. What disciplines must be st

Answer 1

Simply saying, a re-entrant code is a code which can be shared among multiple process.

This is possible when the following conditions are satisfied:

1. It should not have global and static data.
2. It should not modify it's own code.
3. It should not call another re-entrant function or code segment.

So, a code following these conditions can be called re-entrant code.