david@dcl-cs.UUCP (David Coffield) (06/15/85)
Can anyone feed me some information on the interprocess communication facilities that are available with System V - ie what is the equivalent of the BSD 4.2 socket on Sys V? I believe there exists an equivalent facility, called "streams", but that's about as much as I know. Anyone know any more? Thanks, David. -- UUCP: ...!seismo!mcvax!ukc!icdoc!dcl-cs!david DARPA: david%lancs.comp@ucl-cs | Post: University of Lancaster, JANET: david@uk.ac.lancs.comp | Department of Computing, Phone: +44 524 65201 ext 4150 | Bailrigg, Lancaster, LA1 4YR, UK.
guy@sun.uucp (Guy Harris) (06/17/85)
> Can anyone feed me some information on the interprocess communication > facilities that are available with System V - ie what is the equivalent of > the BSD 4.2 socket on Sys V? I believe there exists an equivalent facility, > called "streams", but that's about as much as I know. There is no equivalent facility on System V as it comes from AT&T. It has an IPC message mechanism that only works between processes on the same processor. A facility based on I/O connections called "streams" was developed by Dennis Ritchie as part of "Eighth Edition" UNIX (which is based on 4.1BSD). This is described in the latest UNIX edition of the AT&T Bell Laboratories Technical Journal (October 1984, Vol. 63 No. 8 Part 2), but it doesn't go into much detail about the networking aspects of streams (i.e., how do you specify a protocol, how do you connect to a given port on a given remote host with a connection-oriented protocol, how do you send a packet to a given port on a given remote host with a connectionless protocol, how do you specify routing, etc.). AT&T has made some statements that a networking mechanism based on streams will be available in a future System V release. They haven't said to what degree it resembles the streams mechanism in Eighth Edition UNIX, nor have they given any more details about that mechanism beyond what's in the BLTJ. Guy Harris
sylvain@lvbull.UUCP (Sylvain Langlois RCG-ARS) (06/17/85)
As far as I know, "streams" are not yet implemented in any SV release. They should be in forthcoming SV R3.0 which has been announced for April 86. Dennis Ritchie wrote a paper on this subject in Bell Technical book (issued October 84) - a special UNIX issue again! -. There is also some papers published by /usr/group about communication facilities which talk (vaguely) about streams (Dave Olander's paper). An other rumor is also saying that streams would be part of 4.4BSD system... BUT THGIS IS ONLY A RUMOR!! If anybody has got some more info on this lattest point, I would appreciate a "More about... " mail. Thanks. -- Sylvain "Panic Trap" Langlois UUCP Address: (...!mcvax!vmucnam!lvbull!sylvain) Postal Address: BULL, PC 33/05, 68 route de Versailles, F-78430 Louveciennes, France.
gwyn@brl-tgr.ARPA (Doug Gwyn <gwyn>) (06/18/85)
> Can anyone feed me some information on the interprocess communication > facilities that are available with System V - ie what is the equivalent of > the BSD 4.2 socket on Sys V? I believe there exists an equivalent facility, > called "streams", but that's about as much as I know. Currently available releases of UNIX System V have the following: - FIFOs (named pipes) - semaphores - shared memory regions - message-passing None of these are equivalent to sockets (and vice-versa). Stream I/O is a nifty invention of Dennis Ritchie that is not yet generally available. It is expected to appear in future releases of both UNIX System V and 4.nBSD. Streams are not sockets either, but they do provide the foundation for nice networking implementations.