1#include <unistd.h>
2#include <errno.h>
3#include <sys/resource.h>
4#include <limits.h>
5#include "syscall.h"
6
7int nice(int inc)
8{
9 int prio = inc;
10 // Only query old priority if it can affect the result.
11 // This also avoids issues with integer overflow.
12 if (inc > -2*NZERO && inc < 2*NZERO)
13 prio += getpriority(PRIO_PROCESS, 0);
14 if (prio > NZERO-1) prio = NZERO-1;
15 if (prio < -NZERO) prio = -NZERO;
16 if (setpriority(PRIO_PROCESS, 0, prio)) {
17 if (errno == EACCES)
18 errno = EPERM;
19 return -1;
20 } else {
21 return prio;
22 }
23}