Question

I am coding for a pthread C++ program.

I got error:
“pthread_getunique_np” was not declared in this scope

The pthread_getunique_np or others with “*np” are not portable.

I cannot find solutions from posts online .

I know _np means it is not a POSIX standard.

How to get around this ? I need to include some header files or other substitutes ?

thanks

Answer 1

Like Martin said, on many systems, you can just used the pthread_t of the thread as a unique identifier. You can retrieve this with pthread_self(3), which is POSIX. You can use the function pthread_equal(3) to test two pthread_ts for equivalence.

pthread_t threadID = pthread_self();
if (pthread_equal(threadID, someOtherID) != 0)
    /* Branch based on being the same thread */
else
    /* Branch based on being different threads */

As far as I can tell, pthread_getunique_np() returns a unique integer ID, which is different than using a pthread_t as an identifier. On many systems, the values returned from both pthread_self(3) andf pthread_getunique_np() are the same. In fact, you need the pthread_t to obtain the unique integer.

Either way, pthread_self(3) is required to return the ID of the thread from which it is called, so I believe you should be able to use this portable function the way you want.

(Information about pthread_getunique_np() from IBM)