Static variables in multithreading

[wallaceoc80]

Hi, I have a question regarding the use of static variables in a multithreading application. I have an application that will be parsing 2 different XML files on different threads. I then want to have a class (say Object1) that has a map containing other objects (Object2).

Items of Object2 can be created by both threads so my question is whether they can both be added to the same map or does the multithreading mean that the map is not accessible accross threads?

I hope I have explained this clearly enough and any help would be appreciated.

Regards,
Wallace

 

[ArkM]

Multi-threading is irrelevant to variable scope. It's not a thread can (or cant) see the variable. So you may access a map from all threads (as global or via reference etc) - but be careful: a map (usually it's some kind of a tree structure) is not thread-safe data structure.

You must protect map insert operations from concurrent threads. Use mutexes or critical sections or semaphores (Windows synchronization primitives). Probably, packed into the special insert function critical section synchronization is the best choice in that case.