pthreads question

[Thomas Deschepper <thomas deschepper tiscali be>]

Yes, I know, this is a GTK-list, but because recently there were a lot
of posts about creating a worker thread and a thread managing the GUI, I
decided to start learning pthreads.

When a pthread is created with pthread_create(), you should pass in an
argument that defines the function you would like the thread to execute,
this is the 3rd argument.

void *(*start_routine) (void*)

Could someone please explain me this syntax?? Thanks in advance and
sorry if I offended you with a non-GTK-question!

mvg Thomas