Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!bloom-beacon!apple!netcom!chris
From: chris@netcom.UUCP (Chris Lakewood)
Newsgroups: comp.bugs.sys5
Subject: Re: What's a system call ( Was: 'what' doesn't use perror...)
Message-ID: <1232@netcom.UUCP>
Date: 14 May 89 02:05:50 GMT
References: <3759@sugar.hackercorp.com] <10156@smoke.BRL.MIL] <1153@aplcen.apl.jhu.edu] <1350@frog.UUCP] <11506@ulysses.homer.nj.att.com] <913@twwells.uucp]
Reply-To: chris@netcom.UUCP (Chris Lakewood)
Organization: NetCom Services - Public Access Unix System (408) 997-9175 guest
Lines: 18

In article <913@twwells.uucp] bill@twwells.UUCP (T. William Wells) writes:
]And then consider sleep(). I know of one system where sleep was
]implemented as a system call (and documented in section 2) because
]the standard version of sleep would hang occasionally. Consider:
]
]	alarm(n);
]	pause();
]
](the guts of sleep) and what happens if the process doesn't run for n
]seconds. Have you ever had tail hang on a heavily loaded system? (I
]have.) Guess why.
]---
]Bill                            { uunet | novavax } !twwells!bill

Don't leave us in suspense...  What happens if the process doesn't run for
n seconds?  Actually, the process won't run for at least n seconds unless
it receives some signal.  The pause causes the process to block until a
signal is received.