doug@ws5.cis.temple.edu (Doug Bagley) (03/01/88)
I have a question about IPC in Ultrix 2.0. I have a distributed (over internet) application that does a lot of message passing. The behavior that I want is for the sender to never block on a send -- the message should just be queued somewhere -- and receivers would just read from the queue. Sockets are just the thing, but in Ultrix 2.0, the high watermark is too low. I can queue about 7K of data before the sender blocks. For my application, I'd like to be able to queue about 100K as a maximum, but more commonly it would be about 20-40K. Well I gave a quick look in include/sys/ioctl.h and there is an ioctl call -- using SIOCSHIWAT -- which supposedly increases the high watermark. However, I am unclear as to when the ioctl call should be made, if it requires root privilege, or what. Whenever I call it I get the error "Can't assign requested address". I'm pretty much in the dark. I can't find anything about this sort of stuff in the regular Ultrix manuals. Obviously I'm looking in the wrong place. Anyway, if someone out there can point me in the right direction on this, I'd be very appreciative. Alternatively, if anyone has ideas about a more fruitful direction to take to get messages queued, I am open to all suggestions. Thank you, Doug Bagley protmiwsia (please reply only to me, i will summarize if appropriate) __________________________________________________________________ CSNET: bagley@temple.edu ARPA(flaky): doug@ws5.cis.temple.edu