Filter function problem

[Gintaras]

the variable is shared between by all functions and macros that are called from the first one which declares/initialize it and only by this one.

Not exactly. The variable is shared between all functions of current thread where the variable is declared.

For example, macro A declares int- t_test. Macro A calls function B. Function B also declares int- t_test. This way A and B use the same variable t_test.

Another example. Function C is called multiple times in thread. Function C declares int- t_test or int-- t_test. Variable t_test retains its value between function calls.