pthread_cleanup_push_defer_np, pthread_cleanup_pop_restore_np - push and pop
thread cancellation clean-up handlers while saving cancelability type
#include <pthread.h>
void pthread_cleanup_push_defer_np(void (*routine)(void *),
void *arg);
void pthread_cleanup_pop_restore_np(int execute);
Compile and link with
-pthread.
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
pthread_cleanup_push_defer_np(),
pthread_cleanup_pop_defer_np():
_GNU_SOURCE
These functions are the same as
pthread_cleanup_push(3) and
pthread_cleanup_pop(3), except for the differences noted on this page.
Like
pthread_cleanup_push(3),
pthread_cleanup_push_defer_np()
pushes
routine onto the thread's stack of cancellation clean-up
handlers. In addition, it also saves the thread's current cancelability type,
and sets the cancelability type to "deferred" (see
pthread_setcanceltype(3)); this ensures that cancellation clean-up will
occur even if the thread's cancelability type was "asynchronous"
before the call.
Like
pthread_cleanup_pop(3),
pthread_cleanup_pop_restore_np() pops
the top-most clean-up handler from the thread's stack of cancellation clean-up
handlers. In addition, it restores the thread's cancelability type to its
value at the time of the matching
pthread_cleanup_push_defer_np().
The caller must ensure that calls to these functions are paired within the same
function, and at the same lexical nesting level. Other restrictions apply, as
described in
pthread_cleanup_push(3).
This sequence of calls:
pthread_cleanup_push_defer_np(routine, arg);
pthread_cleanup_pop_restore_np(execute);
is equivalent to (but shorter and more efficient than):
int oldtype;
pthread_cleanup_push(routine, arg);
pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, &oldtype);
...
pthread_setcanceltype(oldtype, NULL);
pthread_cleanup_pop(execute);
These functions are nonstandard GNU extensions; hence the suffix "_np"
(nonportable) in the names.
pthread_cancel(3),
pthread_cleanup_push(3),
pthread_setcancelstate(3),
pthread_testcancel(3),
pthreads(7)