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

.\" Copyright (c) 2008, Linux Foundation, written by Michael Kerrisk
.\"     <mtk.manpages@gmail.com>
.\"
.\" %%%LICENSE_START(VERBATIM)
.\" 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.\" manual page may be incorrect or out-of-date.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.
.\" %%%LICENSE_END
.\"
.TH SCHED_GETCPU 3 2017-09-15 "Linux" "Linux Programmer's Manual"
.SH NAME
sched_getcpu \- determine CPU on which the calling thread is running
.SH SYNOPSIS
.nf
.B #include <sched.h>
.PP
.B int sched_getcpu(void);
.fi
.PP
.in -4n
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.in
.PP
.BR sched_getcpu ():
.ad l
.RS 4
.PD 0
.TP 4
Since glibc 2.14:
_GNU_SOURCE
.TP 4
Before glibc 2.14:
_BSD_SOURCE || _SVID_SOURCE
    /* _GNU_SOURCE also suffices */
.PD
.RE
.ad b
.SH DESCRIPTION
.BR sched_getcpu ()
returns the number of the CPU on which the calling thread is currently executing.
.SH RETURN VALUE
On success,
.BR sched_getcpu ()
returns a nonnegative CPU number.
On error, \-1 is returned and
.I errno
is set to indicate the error.
.SH ERRORS
.TP
.B ENOSYS
This kernel does not implement
.BR getcpu (2).
.SH VERSIONS
This function is available since glibc 2.6.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lb lb lb
l l l.
Interface	Attribute	Value
T{
.BR sched_getcpu ()
T}	Thread safety	MT-Safe
.TE
.SH CONFORMING TO
.BR sched_getcpu ()
is glibc-specific.
.SH NOTES
The call
.PP
.in +4n
.EX
cpu = sched_getcpu();
.EE
.in
.PP
is equivalent to the following
.BR getcpu (2)
call:
.PP
.in +4n
.EX
int c, s;
s = getcpu(&c, NULL, NULL);
cpu = (s == \-1) ? s : c;
.EE
.in
.SH SEE ALSO
.BR getcpu (2),
.BR sched (7)
Commit	Line	Data
	1	.\" Copyright (c) 2008, Linux Foundation, written by Michael Kerrisk
	2	.\" <mtk.manpages@gmail.com>
	3	.\"
	4	.\" %%%LICENSE_START(VERBATIM)
	5	.\" Permission is granted to make and distribute verbatim copies of this
	6	.\" manual provided the copyright notice and this permission notice are
	7	.\" preserved on all copies.
	8	.\"
	9	.\" Permission is granted to copy and distribute modified versions of this
	10	.\" manual under the conditions for verbatim copying, provided that the
	11	.\" entire resulting derived work is distributed under the terms of a
	12	.\" permission notice identical to this one.
	13	.\"
	14	.\" Since the Linux kernel and libraries are constantly changing, this
	15	.\" manual page may be incorrect or out-of-date. The author(s) assume no
	16	.\" responsibility for errors or omissions, or for damages resulting from
	17	.\" the use of the information contained herein. The author(s) may not
	18	.\" have taken the same level of care in the production of this manual,
	19	.\" which is licensed free of charge, as they might when working
	20	.\" professionally.
	21	.\"
	22	.\" Formatted or processed versions of this manual, if unaccompanied by
	23	.\" the source, must acknowledge the copyright and authors of this work.
	24	.\" %%%LICENSE_END
	25	.\"
	26	.TH SCHED_GETCPU 3 2017-09-15 "Linux" "Linux Programmer's Manual"
	27	.SH NAME
	28	sched_getcpu \- determine CPU on which the calling thread is running
	29	.SH SYNOPSIS
	30	.nf
	31	.B #include <sched.h>
	32	.PP
	33	.B int sched_getcpu(void);
	34	.fi
	35	.PP
	36	.in -4n
	37	Feature Test Macro Requirements for glibc (see
	38	.BR feature_test_macros (7)):
	39	.in
	40	.PP
	41	.BR sched_getcpu ():
	42	.ad l
	43	.RS 4
	44	.PD 0
	45	.TP 4
	46	Since glibc 2.14:
	47	_GNU_SOURCE
	48	.TP 4
	49	Before glibc 2.14:
	50	_BSD_SOURCE \|\| _SVID_SOURCE
	51	/* _GNU_SOURCE also suffices */
	52	.PD
	53	.RE
	54	.ad b
	55	.SH DESCRIPTION
	56	.BR sched_getcpu ()
	57	returns the number of the CPU on which the calling thread is currently executing.
	58	.SH RETURN VALUE
	59	On success,
	60	.BR sched_getcpu ()
	61	returns a nonnegative CPU number.
	62	On error, \-1 is returned and
	63	.I errno
	64	is set to indicate the error.
	65	.SH ERRORS
	66	.TP
	67	.B ENOSYS
	68	This kernel does not implement
	69	.BR getcpu (2).
	70	.SH VERSIONS
	71	This function is available since glibc 2.6.
	72	.SH ATTRIBUTES
	73	For an explanation of the terms used in this section, see
	74	.BR attributes (7).
	75	.TS
	76	allbox;
	77	lb lb lb
	78	l l l.
	79	Interface Attribute Value
	80	T{
	81	.BR sched_getcpu ()
	82	T} Thread safety MT-Safe
	83	.TE
	84	.SH CONFORMING TO
	85	.BR sched_getcpu ()
	86	is glibc-specific.
	87	.SH NOTES
	88	The call
	89	.PP
	90	.in +4n
	91	.EX
	92	cpu = sched_getcpu();
	93	.EE
	94	.in
	95	.PP
	96	is equivalent to the following
	97	.BR getcpu (2)
	98	call:
	99	.PP
	100	.in +4n
	101	.EX
	102	int c, s;
	103	s = getcpu(&c, NULL, NULL);
	104	cpu = (s == \-1) ? s : c;
	105	.EE
	106	.in
	107	.SH SEE ALSO
	108	.BR getcpu (2),
	109	.BR sched (7)