Thread Safety in C

Question

imagine I write a library in C. Further, imagine this library to be used from a multi-threaded environment. How do I make it thread-safe? More specific: How do

Answer 1

"imagine I write a library in C. Further, imagine this library to be used from a multi-threaded environment. How do I make it thread-safe? More specific: How do I assure, that certain functions are executed only by one thread at a time?"

You can't -> write a thread-safe or better re-entrant functions. Unless, You would like to write system-wide locks - a very bad idea.

"In opposite to Java or C# for example, C has no means to deal with threads/locks/etc."

This is a joke - right? Long before the Java and C# was developed, the locks were invented and widely used as an synchronization objects...

"I know, that operating systems support threads, but using their api would restrict the compatibility of my library very much."

The thing is, that such libraries already exists - f.e. wxWidgets, which are offering the portable wxThread... (but this is C++)

Anyway, there are 2 main "flavours" of C: the ANSI C and the GNU C -> two different worlds... pick one or the other.