Legacy Document

Inside Macintosh: Devices /

Chapter 1 - Device Manager / Device Manager Reference

Device Manager Functions / Controlling and Monitoring Device Drivers

KillIO

You can use the KillIO function to terminate all current and pending I/O requests for a device driver.

pascal OSErr KillIO(short refNum); 

refNum

The driver reference number.

DESCRIPTION

The KillIO function stops any current I/O request being processed by the driver specified by the RefNum parameter, and removes all pending requests from the I/O queue for that driver. The Device Manager calls the completion routine, if any, for each pending request, and sets the ioResult field of each request equal to the result code abortErr.

The Device Manager passes KillIO requests to a driver only if the driver is open and enabled for control calls. If the driver returns an error, the I/O queue is left unchanged and no completion routines are called.

WARNING

The KillIO function terminates all pending I/O requests for a driver, including requests initiated by other applications.

SPECIAL CONSIDERATIONS

The Device Manager always executes the KillIO function immediately; that is, it never places a KillIO request in the I/O queue.

Although the Device Manager imposes no restrictions on calling KillIO at interrupt time, you should consult a device driver's documentation to determine if it supports this.

RESULT CODES

noErr	0	No error
controlErr	-17	Driver does not respond to this control request
badUnitErr	-21	Driver reference number does not match unit table
unitEmptyErr	-22	Driver reference number specifies a nil handle in unit table
notOpenErr	-28	Driver not open

SEE ALSO

For information about the low-level function for terminating current and pending I/O requests for a driver, see the next section, which describes the PBKillIO function.