HP-UX 11i June 2004 Release Notes

Programming
HP-UX Shared Memory Extensions Available on Software Pack
Chapter 15
300
HP-UX Shared Memory Extensions Available on
Software Pack
new for June 2004 Now available on the June 2004 Software Pack is the HP-UX Shared Memory
Extensions product, which allows applications limited by System V shared memory
segment usage to support a higher number of concurrent operations or users.
Shared memory is an efficient InterProcess Communications (IPC) mechanism. One
process creates a shared memory segment and attaches it to its address space. Any
processes looking to communicate with this process through the shared memory segment
then attach the shared memory segment to their corresponding address spaces as well.
Once attached, a process can read from or write to the segment depending on the
permissions specified while attaching it. The total number of segments available to the
system is limited, however. The Shared Memory Extensions product is intended to ease
this restriction to allow applications limited only by segment usage to support a higher
number of concurrent operations or users.
Features and Benefits:
The Shared Memory Extensions product allows a four-fold increase in the number of
Shared Memory segments in concurrent usage (over the base OS).
Documentation
For further information on the HP-UX Shared Memory Extensions product, see the
following:
• shmmni (5) manpage
• HP-UX Shared Memory Extensions Product Note, available on the Software Pack
media and at http://docs.hp.com.
For more information about Software Pack and how you can obtain the HP-UX Shared
Memory Extensions product, see “Software Pack (Optional HP-UX 11i v1 Core
Enhancements)” on page 58.