Queries keyboard service vector.
#include <sys/inputdd.h>
int ioctl (FileDescriptor, KSQUERYSV, Arg) int FileDescriptor; caddr_t *Arg;
The KSQUERYSV ioctl subroutine call returns the address of the keyboard service vector via the calling argument. The keyboard service vector is provided so that certain services may be invoked by kernel extensions without the occurrence of sleeps or page faults. The services provided by the vector must not be invoked by a user process.
The following offsets into the vector are defined:
#define KSVALARM 0 /* sound alarm */ #define KSVSAK 1 /* disable/enable secure attention key */ #define KSVRFLUSH 2 /* flush input ring */ #define KSVALARM 0 /*......*/ #define KSVSAK 1 /*......*/ #define KSVRFLUSH 2 /*......*/
Service vector routines are invoked using an indirect call as follows:
(*service_vector[service_number])(dev_t devno, caddr_t arg)
A value of zero is returned if the service vector function is successful. Otherwise, an error number defined in the errno.h file is returned. Alarm requests are ignored if the kernel extension's channel is not active; enable/disable SAK and queue flush requests are always processed.
The KSQUERYSV ioctl subroutine call returns a value of -1 and sets the errno global variable to a value of EINVAL when called by a user process.
FileDescriptor | Specifies the open file descriptor for the keyboard. |
Arg | Specifies the address of the location to return the service vector address. |
This ioctl subroutine call is part of Base Operating System (BOS) Runtime.