Dear SCO Customer,

The ipcs utility prints information about active inter-process
communication (IPC) facilities. IPC mechanisms in UnixWare are message
queues, semaphores and shared-memory segments.

Support Level Supplement (SLS) ptf7448a, the UnixWare 7.1.0 ipc Driver 
Supplement, addresses the following problem:

ipcs -qa sets the message queue to R, but once msgrcv is completed, the 
flag is not reset. Thus, ipcs -qa may not show a true representation of
the message queues.

msgrcv() sets the MSG_RWAIT flag when a message receiver waits for a message.
However, the driver never clears this flag. SLS ptf7448a clears the MSG_RWAIT
bit in the msgsnd and wakes up all the processes sleeping on the message
queue. Also, if a process sleeping in msgrcv() gets interrupted, SLS ptf7448a
clears the bit and signals all the processes waiting on the message queue to
retry.


Contents
--------

        /etc/conf/pack.d/ipc/Driver_atup.o
        /etc/conf/pack.d/ipc/Driver_mp.o


Software Notes and Recommendations
----------------------------------

SLS ptf7448a should only be installed on:

        UnixWare 7 Release 7.1.0


Installation Instructions
-------------------------

1. Download the ptf7448a.Z file to the /tmp directory on your machine.

2. As root, uncompress the file and add the SLS package to your system
   using these commands:

        $ su
        Password: <type your root password>
        # uncompress /tmp/ptf7448a.Z
        # pkgadd -d /tmp/ptf7448a
        # rm /tmp/ptf7448a

Alternatively, this SLS package may be installed in quiet mode, 
that is, without displaying the release notes and asking for 
installation confirmation.  To do this, use these commands:

        $ su
        Password: <type your root password>
        # uncompress /tmp/ptf7448a.Z
        # pkgadd -qd /tmp/ptf7448a all
        # rm /tmp/ptf7448a

3. Reboot the system after installing this SLS package.

The release notes displayed prior to installation can be found in:

        /var/sadm/pkg/ptf7448/install/ptf7448.txt


Removal Instructions
--------------------

1. As root, remove the SLS package using these commands:

        $ su
        Password: <type your root password>
        # pkgrm ptf7448

2. Reboot the system after removing this SLS package.


If you have questions regarding this SLS, or the product on which 
it is installed, please contact your software supplier.