mirror of https://github.com/mkerrisk/man-pages
select.2: Clarify that 'timeout' is a *minimum* interval
Make it clear that 'timeout' is a minimum interval; the actual interval will be rounded up to the system clock granularity, and may overrun because of kernel scheduling delays. Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This commit is contained in:
parent
aed1f3b9fb
commit
8c121f4004
|
@ -35,7 +35,7 @@
|
||||||
.\" 2005-03-11, mtk, modified pselect() text (it is now a system
|
.\" 2005-03-11, mtk, modified pselect() text (it is now a system
|
||||||
.\" call in 2.6.16.
|
.\" call in 2.6.16.
|
||||||
.\"
|
.\"
|
||||||
.TH SELECT 2 2010-08-31 "Linux" "Linux Programmer's Manual"
|
.TH SELECT 2 2012-05-02 "Linux" "Linux Programmer's Manual"
|
||||||
.SH NAME
|
.SH NAME
|
||||||
select, pselect, FD_CLR, FD_ISSET, FD_SET, FD_ZERO \-
|
select, pselect, FD_CLR, FD_ISSET, FD_SET, FD_ZERO \-
|
||||||
synchronous I/O multiplexing
|
synchronous I/O multiplexing
|
||||||
|
@ -157,10 +157,14 @@ returns.
|
||||||
.I nfds
|
.I nfds
|
||||||
is the highest-numbered file descriptor in any of the three sets, plus 1.
|
is the highest-numbered file descriptor in any of the three sets, plus 1.
|
||||||
.PP
|
.PP
|
||||||
|
The
|
||||||
.I timeout
|
.I timeout
|
||||||
is an upper bound on the amount of time elapsed before
|
argument specifies the minimum interval that
|
||||||
.BR select ()
|
.BR select ()
|
||||||
returns.
|
should block waiting for a file descriptor to become ready.
|
||||||
|
(This interval will be rounded up to the system clock granularity,
|
||||||
|
and kernel scheduling delays mean that the blocking interval
|
||||||
|
may overrun by a small amount.)
|
||||||
If both fields of the
|
If both fields of the
|
||||||
.I timeval
|
.I timeval
|
||||||
structure are zero, then
|
structure are zero, then
|
||||||
|
|
Loading…
Reference in New Issue