diff options
Diffstat (limited to 'lib/libc/gen/usleep.3')
| -rw-r--r-- | lib/libc/gen/usleep.3 | 31 |
1 files changed, 15 insertions, 16 deletions
diff --git a/lib/libc/gen/usleep.3 b/lib/libc/gen/usleep.3 index 66b317a..5b539f9 100644 --- a/lib/libc/gen/usleep.3 +++ b/lib/libc/gen/usleep.3 @@ -52,30 +52,29 @@ of time. System activity or time spent in processing the call may lengthen the sleep slightly. .Pp -If a timer is already running on the process its state is saved. +If a timer is already running on the process its state is unaltered by +this +.Fn usleep +implementation. If the value .Fa microseconds -is more than or equal to the remaining clock time for the saved timer, +is more than or equal to the remaining clock time for the running timer, the sleep time is set to the remaining clock time. -The state of the previous timer -is restored after +.Pp +This function is implemented using +.Xr signanosleep 2 +by pausing for .Fa microseconds -has passed. +of time or until SIGALRM signal occurse. +.Sh NOTES .Pp -This routine is implemented using -.Xr setitimer 2 ; -it requires eight system calls each time it is invoked. -A similar but less compatible function can be obtained with a single -.Xr select 2 ; -such a function would not restart after signals, but would not interfere -with other uses of -.Xr setitimer . +A microsecond is 0.000001 seconds. .Sh SEE ALSO -.Xr getitimer 2 , -.Xr setitimer 2 , -.Xr sigpause 2 , .Xr alarm 3 , +.Xr setitimer 2 , +.Xr signal 3 , +.Xr signanosleep 2 , .Xr sleep 3 , .Xr ualarm 3 .Sh HISTORY |
