diff options
Diffstat (limited to 'lib/libc/gen')
| -rw-r--r-- | lib/libc/gen/nice.3 | 36 | ||||
| -rw-r--r-- | lib/libc/gen/nice.c | 16 |
2 files changed, 43 insertions, 9 deletions
diff --git a/lib/libc/gen/nice.3 b/lib/libc/gen/nice.3 index 9c39b78..8ce13af 100644 --- a/lib/libc/gen/nice.3 +++ b/lib/libc/gen/nice.3 @@ -28,7 +28,7 @@ .\" @(#)nice.3 8.1 (Berkeley) 6/4/93 .\" $FreeBSD$ .\" -.Dd June 4, 1993 +.Dd February 28, 2015 .Dt NICE 3 .Os .Sh NAME @@ -48,20 +48,48 @@ This interface is obsoleted by .Pp The .Fn nice -function obtains the scheduling priority of the process -from the system and sets it to the priority value specified in -.Fa incr . +function adds +.Fa incr +to the scheduling priority of the process. The priority is a value in the range -20 to 20. The default priority is 0; lower priorities cause more favorable scheduling. Only the super-user may lower priorities. .Pp Children inherit the priority of their parent processes via .Xr fork 2 . +.Sh RETURN VALUES +Upon successful completion, +.Fn nice +returns 0, and +.Va errno +is unchanged. +Otherwise, \-1 is returned, the process' nice value is not changed, and +.Va errno +is set to indicate the error. +.Sh ERRORS +The +.Fn nice +function will fail if: +.Bl -tag -width Er +.It Bq Er EPERM +The +.Fa incr +argument is negative and the caller does not have appropriate privileges. +.El .Sh SEE ALSO .Xr nice 1 , .Xr fork 2 , .Xr setpriority 2 , .Xr renice 8 +.Sh STANDARDS +The +.Fn nice +function conforms to +.St -p1003.1-2008 +except for the return value. +This implementation returns 0 upon successful completion but +the standard requires returning the new nice value, +which could be \-1. .Sh HISTORY A .Fn nice diff --git a/lib/libc/gen/nice.c b/lib/libc/gen/nice.c index e8375e8..ba9524b 100644 --- a/lib/libc/gen/nice.c +++ b/lib/libc/gen/nice.c @@ -43,14 +43,20 @@ __FBSDID("$FreeBSD$"); * Backwards compatible nice. */ int -nice(incr) - int incr; +nice(int incr) { - int prio; + int saverrno, prio; + saverrno = errno; errno = 0; prio = getpriority(PRIO_PROCESS, 0); - if (prio == -1 && errno) + if (prio == -1 && errno != 0) return (-1); - return (setpriority(PRIO_PROCESS, 0, prio + incr)); + if (setpriority(PRIO_PROCESS, 0, prio + incr) == -1) { + if (errno == EACCES) + errno = EPERM; + return (-1); + } + errno = saverrno; + return (0); } |
