PTHREAD_CLEANUP_PUSH_DEFER_NP(3)                    Linux Programmer's Manual                   PTHREAD_CLEANUP_PUSH_DEFER_NP(3)



NAME
       pthread_cleanup_push_defer_np,  pthread_cleanup_pop_restore_np - push and pop thread cancellation clean-up handlers while
       saving cancelability type

SYNOPSIS
       #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.

DESCRIPTION
       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 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);

CONFORMING TO
       These functions are nonstandard GNU extensions; hence the suffix "_np" (nonportable) in the names.

SEE ALSO
       pthread_cancel(3), pthread_cleanup_push(3), pthread_setcancelstate(3), pthread_testcancel(3), pthreads(7)

COLOPHON
       This  page  is  part of release 3.25 of the Linux man-pages project.  A description of the project, and information about
       reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.



Linux                                                      2008-12-04                           PTHREAD_CLEANUP_PUSH_DEFER_NP(3)