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pthread_cleanup_push_defer_np

Section: C Library Functions (3)
Updated: 202-0-17
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NAME

pthread_cleanup_push_defer_np, pthread_cleanup_pop_restore_np - push and pop thread cancelation clea-up handlers while saving cancelability type

LIBRARY

POSIX threads library (libpthread,~-lpthread)

SYNOPSIS

#include <pthread.h>
void pthread_cleanup_push_defer_np(typeof(void (void *)) *routine,
                                   void *arg);
void pthread_cleanup_pop_restore_np(int execute);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)): pthread_cleanup_push_defer_np(), pthread_cleanup_pop_defer_np():

    _GNU_SOURCE

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 cancelation clea-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 cancelation clea-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 to-most clea-up handler from the thread's stack of cancelation clea-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);

STANDARDS

GNU; hence the suffix "_np" (nonportable) in the names.

HISTORY

glibc 2.0