pthread_setcanceltype() atomically sets the calling thread's cancellation type to the specified type and, if oldtype is not NULL, stores the previous cancellation type in oldtype. The type can be either of the following:

PTHREAD_CANCEL_DEFERRED

This is the default. When cancellation is enabled (enabled cancellation is also the default), cancellation occurs when the target thread reaches a cancellation point and a cancel is pending. When cancellation is disabled, all cancellation requests to the target thread are held pending.

PTHREAD_CANCEL_ASYNCHRONOUS

When cancellation is enabled, receipt of a pthread_cancel(3THR) call causes immediate cancellation. When cancellation is disabled, all cancellation requests to the target thread are held pending; as soon as cancellation is re-enabled, pending cancellations are executed immediately.

See cancellation(3THR) for the definition of a cancellation point and a discussion of cancellation concepts. See pthread_setcancelstate(3THR) for explanations of enabling and disabling cancellation.

pthread_setcanceltype() is a cancellation point if type is called with PTHREAD_CANCEL_ASYNCHRONOUS and the cancellation state is PTHREAD_CANCEL_ENABLE.

Upon successful completion, the pthread_setcanceltype() function returns 0. Otherwise, an error number is returned to indicate the error.

The pthread_setcanceltype() function will fail if:

EINVAL

The specified type is not PTHREAD_CANCEL_DEFERRED or PTHREAD_CANCEL_ASYNCHRONOUS.

See attributes(5) for descriptions of the following attributes:

cancellation(3THR), condition(3THR), pthread_cancel(3THR), pthread_cleanup_pop(3THR), pthread_cleanup_push(3THR), pthread_exit(3THR), pthread_join(3THR), pthread_setcancelstate(3THR), pthread_testcancel(3THR), setjmp(3C), attributes(5)