static variable thread safe?

[Kumar]

Hi,

If i am using static variable in a function, in say a dll. If that dll
is being used by a multi-threaded program, will the static variable be
safe to use? I mean, will it have the problems associated with using
global variables in this case, i.e. same variable being modified by
multiple threads, and hence creating issues...?

Thanks,
Kumar

 

[Peter Pichler]

If i am using static variable in a function, in say a dll. If that dll
is being used by a multi-threaded program, will the static variable be
safe to use? I mean, will it have the problems associated with using
global variables in this case, i.e. same variable being modified by
multiple threads, and hence creating issues...?

Yes.

(The fact that threads, DLLs and similar stuff is off-topical on this
group is irrelevant ;-))

Peter

 

[Peter Pichler]

Yes.

On the second thought, I may not have been as clear as I could have been.

The answer is "no" to your first question and "yes" to the other(s).

Peter

 

[pete]

Yes.

(The fact that threads, DLLs and similar stuff is off-topical on this
group is irrelevant ;-))

Unless the right answer is really "No".

 

[Peter Pichler]

Unless the right answer is really "No".

It depends on the question ;-)

 

[pete]

It depends on the question ;-)

Anyway, you can convert a function from one that uses a
local static variable, to one that doesn't,
simply by replacing the local static variable
with a parameter which points to an
{automatic variable in the calling function}.

 

[CBFalconer]

If i am using static variable in a function, in say a dll. If that
dll is being used by a multi-threaded program, will the static
variable be safe to use? I mean, will it have the problems
associated with using global variables in this case, i.e. same
variable being modified by multiple threads, and hence creating
issues...?

In a word, yes. A static variable is always a 'global', but with
restricted visibility.