utimensat.2, wait.2, end.3: srcfix: remove duplicate words in comments

[thirdparty/man-pages.git] / man3 / pthread_cleanup_push_defer_np.3

.\" Copyright (c) 2008 Linux Foundation, written by Michael Kerrisk
.\"     <mtk.manpages@gmail.com>
.\"
.\" Permission is granted to make and distribute verbatim copies of this
.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
.\" Permission is granted to copy and distribute modified versions of this
.\" manual under the conditions for verbatim copying, provided that the
.\" entire resulting derived work is distributed under the terms of a
.\" permission notice identical to this one.
.\"
.\" Since the Linux kernel and libraries are constantly changing, this
.\" manual page may be incorrect or out-of-date.  The author(s) assume no
.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein.  The author(s) may not
.\" have taken the same level of care in the production of this manual,
.\" which is licensed free of charge, as they might when working
.\" professionally.
.\"
.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
.\"
.TH PTHREAD_CLEANUP_PUSH_DEFER_NP 3 2008-12-04 "Linux" "Linux Programmer's Manual"
.SH NAME
pthread_cleanup_push_defer_np, pthread_cleanup_pop_restore_np \- push and pop
thread cancellation clean-up handlers while saving cancelability type
.SH SYNOPSIS
.nf
.B #include <pthread.h>

.BI "void pthread_cleanup_push_defer_np(void (*" routine ")(void *),"
.BI "                                   void *" arg );
.BI "void pthread_cleanup_pop_restore_np(int " execute );
.sp
Compile and link with \fI\-pthread\fP.
.SH DESCRIPTION
These functions are the same as
.BR pthread_cleanup_push (3)
and
.BR pthread_cleanup_pop (3),
except for the differences noted on this page.

Like
.BR pthread_cleanup_push (3),
.BR pthread_cleanup_push_defer_np ()
pushes
.I 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
.BR 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
.BR pthread_cleanup_pop (3),
.BR 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
.BR 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
.BR pthread_cleanup_push (3).

This sequence of calls:

.in +4n
.nf
pthread_cleanup_push_defer_np(routine, arg);
pthread_cleanup_pop_restore_np(execute);
.fi
.in

is equivalent to (but shorter and more efficient than):

.\" As far as I can see, LinuxThreads reverses the two substeps
.\" in the push and pop below.
.in +4n
.nf
int oldtype;

pthread_cleanup_push(routine, arg);
pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, &oldtype);
\&...
pthread_setcanceltype(oldtype, NULL);
pthread_cleanup_pop(execute);
.fi
.in
.\" SH VERSIONS
.\" Available since glibc 2.0
.SH CONFORMING TO
These functions are nonstandard GNU extensions;
hence the suffix "_np" (nonportable) in the names.
.SH SEE ALSO
.BR pthread_cancel (3),
.BR pthread_cleanup_push (3),
.BR pthread_setcancelstate (3),
.BR pthread_testcancel (3),
.BR pthreads (7)