First my apologizes. It was not my intention to complain about the low quality or whatsoever of your – in overall – good article. I find great that you share your Pthreads knowledge, and as I am also fervently interested in this topic, I thought you would appreciate feedbacks about your little mistake.

Yes, there is a problem with your code. The fact that the “right things” come out is merely an artifact of many Pthreads library implementation. But nevertheless it is incorrect, and yes, it can fail. I learned it the hard way…

To remove this implementation artifact, add between line 22 and 23 the following:
pthread_detach(pthread_self())

After about 10 runs, I got the following output on my machine (intel Core Duo, running Linux 2.6.27 SMP):
Initializing thread!
This is coming from a thread:
arg.i = 547295120
arg.y = 32767

If you want, we can discuss it off-line

Cheers and keep-up the good work!
Loïc.

You are passing a pointer to the bar object, which located on the stack of the main’s thread. But, main() may terminate before the thread hello() executes. On some systems, bar can become invalid, which shall cause you trouble in hello() when you access it.

May I suggest the following post from me:
Pthreads arguments passing

Cheers,
Loïc.