NULLOP(9) | Kernel Developer's Manual | NULLOP(9) |
nullop
—
#include <sys/systm.h>
int
nullop
(void
*v);
void
voidop
(void);
int
enodev
(void);
int
enxio
(void);
int
enoioctl
(void);
int
enosys
(void);
int
eopnotsupp
(void);
nullop
() function provides a generic “null
operation”. It always returns the value 0. The
voidop
() function takes no arguments and does nothing.
The enodev
(),
enxio
(), enoioctl
(),
enosys
(), and eopnotsupp
()
functions always fail, returning ENODEV
,
ENXIO
, ENOTTY
,
ENOSYS
, and EOPNOTSUPP
,
respectively.
nullop
()
may be useful:
uint64_t xc; ... xc = xc_broadcast(0, (xcfunc_t)nullop, NULL, NULL); xc_wait(xc);
July 25, 2010 | NetBSD 9.0 |