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Diffstat (limited to 'lib/libc/gen/sleep.3')
| -rw-r--r-- | lib/libc/gen/sleep.3 | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/lib/libc/gen/sleep.3 b/lib/libc/gen/sleep.3 index a56a80e..1016a3d 100644 --- a/lib/libc/gen/sleep.3 +++ b/lib/libc/gen/sleep.3 @@ -72,10 +72,29 @@ such a function would not restart after signals, but would not interfere with other uses of .Xr setitimer 2 . .Sh RETURN VALUES +The +.Fn sleep +function returns the number of seconds remaining to complete the operation. If +sleep is interrupted or cannot allocate a timer it may will return the value +needed to be passed to a subsequent sleep to complete the necessary delay. +.Fn sleep +repeatedly until it returns zero may busy-wait until a timer +is available. .Sh SEE ALSO .Xr setitimer 2 , .Xr sigpause 2 , .Xr usleep 3 +.Sh CAVEAT +In practice the FreeBSD implementation will not be interrupted: it will +always return the original argument or zero. Code that depends on +sleep being interrupted (using it as a timed pause, for example) needs +to be recoded to use +.Xr select 2 +or some other delay mechanism. Code that +calls +.Fn sleep +repeatedly until it returns zero may busy-wait until a timer +is available. .Sh HISTORY A .Fn sleep |
