NIO CommKit Host Interface Installation and System Administration Manual

6-19
Porting CommKit Applications To Release 4.x
Programmer-Level Compatibility
DIOCQQABO
This function is no longer supported.
The DIOCQQABO ioctl allowed the application to determine the completion
status of the most recent read and was used in earlier implementations to
determine why a read returned fewer than the requested bytes.
Since the STREAMS environment dissociates the application’s read from the
receive performed on the network, this function is no longer necessary. In your
application, use the dkleveld functions to look for level-D or EOF indications.
Refer to the isdkclosed, isdkeof, isdkleveld example later in this chapter and the
dkleveld manual page. This release preserves message boundaries for received
data, except
1. It splits messages larger than 10240 bytes into smaller messages at boundaries
convenient for the dkhs driver.
2. It splits messages at every level-D URP code.
DIOCSIG
In previous releases, your application could perform a form of asynchronous
read with this ioctl request by “Posting a Receiver” on a circuit and being
notified later by a signal when the data arrived.
This function is now provided through the STREAMS poll system call,
providing a cleaner, more portable approach. Refer to the poll example later
inthischapter.
DIOCBSIZE
This directive allowed your application to alter the URP transmit block size
from the default value.
To change the URP block size, you can now use the new library function
dk_info, which also allows you to change the number of outstanding URP
blocks. Refer to the dk_info example later in this chapter.
TCSBRK In earlier releases, the host driver used this ioctl to transmit an URP level-D
BREAK code.
This function is now provided through the dkbreak library function. The TTY
subsystem continues to support the TCSBRK ioctl.
DIOOPEN Certain DT/HYBRID features in the dkserver program used this ioctl to
determine whether a specific channel on the interface was open. This function is
not supported for user-level applications code.
Table 6-5 Previously Supported ioctl System Calls and Their Current Status
System Call Status