HP-UX 11i Release Notes (December 2000)

Internet and Networking Services

STREAMS/UX (new)

Chapter 10 203

STREAMS/UX (new)

Several enhancements have been made to STREAMS/UX. These include

support for the select() system call, an I/O forwarding mechanism, and

Function Registering:

• The select() system call for STREAMS/UX devices examines the

ﬁles or devices associated with the ﬁle descriptors speciﬁed by the

bitmasks, readfds, writefds, and exceptfds.

select() can detect out-of-band (OOB) data on TCP. select calls an

internal command, hpstreams_select_int2(), which contains a

check in the exception case for T_EXDATA_IND messages.

• STREAMS/UX contains an I/O forwarding mechanism that preserves

the order of messages and forwards those messages. This mechanism

is particularly useful on multi-node systems where driver events can

only be executed on the node where the NIC resides.

• Function Registering enables modules and drivers to work in a mixed

mode system. It provides the modules and drivers within the kernel a

mechanism for correctly translating data that is being sent to and

from the application when STREAMS/UX determines that the

application has been compiled for 32-bit execution, but is operatingon

a 64-bit architecture.

Function registering deﬁnes dynamic data structures and stream

head ﬂags, which will indicate when and if a dynamically speciﬁed

function is to be executed. These data structures and ﬂags can be set

dynamically or on the ﬂy.

NOTE UP Emulation will no longer be supported on HP-UX in a future release.

Therefore, drivers and modules that are conﬁgured as UP emulation

drivers and modules should be made MP scalable in preparation.

For more information about these changes, see the STREAMS/UX for

the HP 9000 Reference Manual.