pthread_cancel 에 대한 질문입니다..

pthread_cancel을 호출하게 되면..

cancel하기로 한 thread가 완전히 cancel된 후에 리턴 되나요..
아니면 바로 리턴 되고 thread는 따로 종료되나요..??

When a thread eventually honors a cancellation request, it performs as if pthread_exit(PTHREAD_CANCELED) has been called at that point: all cleanup handlers are executed in reverse order, finalization functions
for thread-specific data are called, and finally the thread stops executing with the return value PTHREAD_CANCELED

그리고 pthread_exit 호출 하면 thread가 완전히 종료되나요..??

만약 pthread_exit 수행 중에 외부에서 pthread_cancel을 호출하면 어떻게 되나요..??

PTHREAD_CANCEL_DEFERRED to keep the cancellation request pending until the next cancellation point
......
Threads are always created by pthread_create(3) with cancellation enabled and deferred. That is, the initial cancellation state is PTHREAD_CANCEL_ENABLE and the initial type is PTHREAD_CANCEL_DEFERRED.

Cancellation points are those points in the program execution where a test for pending cancellation requests is performed and cancellation is executed if positive. The following POSIX threads functions are cancellation points:

pthread_join(3)
pthread_cond_wait(3)
pthread_cond_timedwait(3)
pthread_testcancel(3)
sem_wait(3)
sigwait(3)

All other POSIX threads functions are guaranteed not to be cancellation points. That is, they never perform cancellation in deferred cancellation mode.