diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-24 04:52:22 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-24 04:52:22 +0000 |
commit | 3d08cd331c1adcf0d917392f7e527b3f00511748 (patch) | |
tree | 312f0d1e1632f48862f044b8bb87e602dcffb5f9 /man/man3/ualarm.3 | |
parent | Adding debian version 6.7-2. (diff) | |
download | manpages-3d08cd331c1adcf0d917392f7e527b3f00511748.tar.xz manpages-3d08cd331c1adcf0d917392f7e527b3f00511748.zip |
Merging upstream version 6.8.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'man/man3/ualarm.3')
-rw-r--r-- | man/man3/ualarm.3 | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/man/man3/ualarm.3 b/man/man3/ualarm.3 new file mode 100644 index 0000000..66359dd --- /dev/null +++ b/man/man3/ualarm.3 @@ -0,0 +1,140 @@ +'\" t +.\" Copyright (c) 2003 Andries Brouwer (aeb@cwi.nl) +.\" +.\" SPDX-License-Identifier: GPL-2.0-or-later +.\" +.TH ualarm 3 2024-05-02 "Linux man-pages (unreleased)" +.SH NAME +ualarm \- schedule signal after given number of microseconds +.SH LIBRARY +Standard C library +.RI ( libc ", " \-lc ) +.SH SYNOPSIS +.nf +.B "#include <unistd.h>" +.P +.BI "useconds_t ualarm(useconds_t " usecs ", useconds_t " interval ); +.fi +.P +.RS -4 +Feature Test Macro Requirements for glibc (see +.BR feature_test_macros (7)): +.RE +.P +.BR ualarm (): +.nf + Since glibc 2.12: + (_XOPEN_SOURCE >= 500) && ! (_POSIX_C_SOURCE >= 200809L) + || /* glibc >= 2.19: */ _DEFAULT_SOURCE + || /* glibc <= 2.19: */ _BSD_SOURCE + Before glibc 2.12: + _BSD_SOURCE || _XOPEN_SOURCE >= 500 +.\" || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED +.fi +.SH DESCRIPTION +The +.BR ualarm () +function causes the signal +.B SIGALRM +to be sent to the invoking process after (not less than) +.I usecs +microseconds. +The delay may be lengthened slightly by any system activity +or by the time spent processing the call or by the +granularity of system timers. +.P +Unless caught or ignored, the +.B SIGALRM +signal will terminate the process. +.P +If the +.I interval +argument is nonzero, further +.B SIGALRM +signals will be sent every +.I interval +microseconds after the first. +.SH RETURN VALUE +This function returns the number of microseconds remaining for +any alarm that was previously set, or 0 if no alarm was pending. +.SH ERRORS +.TP +.B EINTR +Interrupted by a signal; see +.BR signal (7). +.TP +.B EINVAL +\fIusecs\fP or \fIinterval\fP is not smaller than 1000000. +(On systems where that is considered an error.) +.SH ATTRIBUTES +For an explanation of the terms used in this section, see +.BR attributes (7). +.TS +allbox; +lbx lb lb +l l l. +Interface Attribute Value +T{ +.na +.nh +.BR ualarm () +T} Thread safety MT-Safe +.TE +.SH STANDARDS +None. +.SH HISTORY +4.3BSD, POSIX.1-2001. +POSIX.1-2001 marks it as obsolete. +Removed in POSIX.1-2008. +.P +4.3BSD, SUSv2, and POSIX do not define any errors. +.P +POSIX.1-2001 does not specify what happens if the +.I usecs +argument is 0. +.\" This case is not documented in HP-US, Solar, FreeBSD, NetBSD, or OpenBSD! +On Linux (and probably most other systems), +the effect is to cancel any pending alarm. +.P +The type +.I useconds_t +is an unsigned integer type capable of holding integers +in the range [0,1000000]. +On the original BSD implementation, and in glibc before glibc 2.1, +the arguments to +.BR ualarm () +were instead typed as +.IR "unsigned int" . +Programs will be more portable if they never mention +.I useconds_t +explicitly. +.P +The interaction of this function with +other timer functions such as +.BR alarm (2), +.BR sleep (3), +.BR nanosleep (2), +.BR setitimer (2), +.BR timer_create (2), +.BR timer_delete (2), +.BR timer_getoverrun (2), +.BR timer_gettime (2), +.BR timer_settime (2), +.BR usleep (3) +is unspecified. +.P +This function is obsolete. +Use +.BR setitimer (2) +or POSIX interval timers +.RB ( timer_create (2), +etc.) +instead. +.SH SEE ALSO +.BR alarm (2), +.BR getitimer (2), +.BR nanosleep (2), +.BR select (2), +.BR setitimer (2), +.BR usleep (3), +.BR time (7) |