pthread_create: Resource temporarily unavailable (errno = 11)

原来是pthread_create后没有调pthread_join或者pthread_detach, 导致memory leak.

A thread may either be joinable or detached. If a thread is joinable,
then another thread can call pthread_join(3) to wait for the thread to
terminate and fetch its exit status. Only when a terminated joinable
thread has been joined are the last of its resources released back to
the system. When a detached thread terminates, its resources are auto-
matically released back to the system: it is not possible to join with
the thread in order to obtain its exit status. Making a thread
detached is useful for some types of daemon threads whose exit status
the application does not need to care about. By default, a new thread
is created in a joinable state, unless attr was set to create the
thread in a detached state (using pthread_attr_setdetachstate(3)).