Article View: comp.sys.next.programmer
Article #1820Shared memory?
From: bjanzen
Date: Wed, 18 Nov 1992 22:57
Date: Wed, 18 Nov 1992 22:57
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2096 bytes
We use /usr/include/system/shm.h to set up a a fairly large shared memory database for our realtime data application that is currently implemented on RS6000's. No such thing on NeXT - it isn't too kosher in an object environment, but I could port an existing app NOW and redesign later if I knew if/where shm.h was. The only reference I found was in librarian - --------------- Although messaging is similar to UNIX 4.3BSD stream sockets in that it permits reliable, kernel-mediated communication between tasks, messaging has a much more fundamental role within Mach. Whereas UNIX processes obtain system services through a variety of interfaces (for example, the open() system call for files, the socket() and bind() system calls for network connections, and numerous access protocols for user-level services), Mach provides all services through messaging. Because of this consistency of interprocess communication, the Mach operating system can easily be extended to incorporate new features. As an alternative to messaging, Mach also supports interprocess communication using shared memory. However, if you use shared memory for interprocess communication, you're responsible for synchronizing the transmission and reception of the message. With the Mach messaging system, Mach itself schedules the transmission and reception of messages, thereby ensuring that no message is read before it's been sent in its entirety. ------------- I'm responsible. Where the heck is it, or just plain is it? Barry Janzen bjanzen@lexmark.com
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Newsgroups: comp.sys.next.programmer Path: arc1-ca.pugleaf.net!sparky!uunet!charon.amdahl.com!pacbell.com!ames!haven.umd.edu!darwin.sura.net!ukma!lexmark!lexmark.com!BJANZEN From: bjanzen@lexmark.com Subject: Shared memory? Message-ID: <168A310A88.BJANZEN@lexmark.com> X-Disclaimer: These views are the poster's and not necessarily those of Lexmark Sender: usenet@lexmark.com (News Dude) Nntp-Posting-Host: lexvmlpp.lexmark.com Organization: Lexmark International, Lexington, KY Date: Wed, 18 Nov 1992 22:57:12 GMT Lines: 32