#include <sys/lwp.h>void _lwp_exit(void);
The _lwp_exit() function causes the calling LWP to terminate. If it is the last LWP in the process, then the process exits with a status of 0 (see exit(2)).
If the LWP was created undetached, it is transformed into a “zombie LWP” that retains at least the LWP's ID until it is waited for (see _lwp_wait(2)). Otherwise, its ID and system resources may be reclaimed immediately.