Path: utzoo!utgpu!cunews!bnrgate!brchh104!brchs1!bnr.ca!rice.edu!sun-spots-request
From: TAYBENGH%NUSDISCS.BITNET@cunyvm.cuny.edu (THE AGEIS)
Newsgroups: comp.sys.sun
Subject: lost of SIGIO in SunOS4.1/4.0.3
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Message-ID: <3651@brchh104.bnr.ca>
Date: 5 Jun 91 14:17:00 GMT
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Approved: sun-spots@rice.edu
X-Original-Date:    Thu, 30 May 91 21:05 SST

Hi netlander,
        I am writing some network applications using socket & shared memory.
I used SIGIO to notify the receiver when there is data available in the
shared memory. SIGIO is needed here coz the receiver is polling the socket
using select(2). So I need SIGIO to purposely interrupt the select(2) call.
        This SIGIO signal is sent by the sender using kill(2). However, I
found out SOME (not ALL - the last few sent) SIGIO signals are lost.
I thought SunOS4.1 provides reliable signal as described by Steven in his
Unix network Programming book. Is it true? At last, I suspected the signals
are lost probably because the sender was sending too many signals
too fast. As a result, I purposely slowed down the receiver using sleep(2).
The result turned out to be NO signal was lost. Could somebody please shed
some light on me whether SunOS4.1/4.0.3 DOES deliver the signal reliably?
Or did I missed sth? Anybody has the similar experience?
        Thanks a lot.

- Beng Hang (email: taybengh@nusdiscs.bitnet)
  Dept. Of Info. Syst. and Comp. Sc.
  National University of Singapore