diff options
Diffstat (limited to 'lib/libc/sys/timer_create.2')
-rw-r--r-- | lib/libc/sys/timer_create.2 | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/lib/libc/sys/timer_create.2 b/lib/libc/sys/timer_create.2 new file mode 100644 index 0000000..9e4bc23 --- /dev/null +++ b/lib/libc/sys/timer_create.2 @@ -0,0 +1,164 @@ +.\" Copyright (c) 2005 David Xu <davidxu@FreeBSD.org> +.\" All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice(s), this list of conditions and the following disclaimer as +.\" the first lines of this file unmodified other than the possible +.\" addition of one or more copyright notices. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice(s), this list of conditions and the following disclaimer in +.\" the documentation and/or other materials provided with the +.\" distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY +.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR +.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE +.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR +.\" BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, +.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE +.\" OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, +.\" EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +.\" +.\" $FreeBSD$ +.\" +.Dd September 11, 2000 +.Dt TIMER_CREATE 2 +.Os +.Sh NAME +.Nm timer_create +.Nd "create a per-process timer (REALTIME)" +.Sh LIBRARY +.Lb libc +.Sh SYNOPSIS +.In time.h +.Ft int +.Fo timer_create +.Fa "clockid_t clockid" "struct sigevent *restrict evp" +.Fa "timer_t *restrict timerid" +.Fc +.Sh DESCRIPTION +The +.Fn timer_create +system call creates a per-process timer using the specified clock, +.Fa clock_id , +as the timing base. +The +.Fn timer_create +system call returns, in the location referenced by +.Fa timerid , +a timer ID of type +.Vt timer_t +used to identify the timer in timer requests. +This timer ID is unique within the calling process until the timer is deleted. +The particular clock, +.Fa clock_id , +is defined in +.In time.h . +The timer whose ID is returned is in a disarmed state upon return from +.Fn timer_create . +.Pp +The +.Fa evp +argument, if +.Pf non- Dv NULL , +points to a +.Vt sigevent +structure. +This structure, +allocated by the application, defines the asynchronous notification to occur +when the timer expires. +If the +.Fa evp +argument is +.Dv NULL , +the effect is as if the +.Fa evp +argument pointed to a +.Vt sigevent +structure with the +.Va sigev_notify +member having the value +.Dv SIGEV_SIGNAL , +the +.Va sigev_signo +having a default signal number, and the +.Va sigev_value +member having +the value of the timer ID. +.Pp +The implementations supports a +.Fa clock_id +of +.Dv CLOCK_REALTIME +or +.Dv CLOCK_MONOTONIC . +.Pp +If +.Fa evp->sigev_sigev_notify +is +.Dv SIGEV_THREAD +and +.Fa sev->sigev_notify_attributes +is not +.Dv NULL , +if the attribute pointed to by +.Fa sev->sigev_notify_attributes +has +a thread stack address specified by a call to +.Fn pthread_attr_setstack +or +.Fn pthread_attr_setstackaddr , +the results are unspecified if the signal is generated more than once. +.Sh RETURN VALUES +If the call succeeds, +.Fn timer_create +returns zero and updates the location referenced by +.Fa timerid +to a +.Vt timer_t , +which can be passed to the per-process timer calls. +If an error +occurs, the system call returns a value of \-1 +and the global variable +.Va errno +is set to indicate the +error. +The value of +.Fa timerid +is undefined if an error occurs. +.Sh ERRORS +The +.Fn timer_create +system call +will fail if: +.Bl -tag -width Er +.It Bq Er EAGAIN +The calling process has already created all of the timers it is allowed by +this implementation. +.It Bq Er EINVAL +The specified clock ID is not supported. +.It Bq Er EFAULT +Any arguments point outside the allocated address space or there is a +memory protection fault. +.El +.Sh SEE ALSO +.Xr clock_getres 2 , +.Xr timer_delete 2 , +.Xr timer_getoverun 2 , +.Xr siginfo 3 +.Sh STANDARDS +The +.Fn timer_create +system call conforms to +.St -p1003.1-2004 +.Sh HISTORY +Support for +.Tn POSIX +per-process timer first appeared in +.Fx 7.0 . |