Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!julius.cs.uiuc.edu!apple!well!jef
From: jef@well.sf.ca.us (Jef Poskanzer)
Newsgroups: comp.unix.internals
Subject: Re: whay can't processes shrink as well as grow?
Message-ID: <20955@well.sf.ca.us>
Date: 5 Oct 90 00:00:00 GMT
References: <1990Oct04.104221.16632@virtech.uucp>
Reply-To: Jef Poskanzer <jef@well.sf.ca.us>
Organization: Paratheo-Anametamystikhood Of Eris Esoteric, Ada Lovelace Cabal
Lines: 20

In the referenced message, cpcahil@virtech.UUCP (Conor P. Cahill) wrote:
}In article <1990Oct3.225943.4691@brolga.cc.uq.oz.au> ggm@brolga.cc.uq.oz.au (George Michaelson) writes:
}>I see some attractive uses of grabbing 5-10 Mb of space, using
}>it and then releasing it without having to exit.
}
}You could probably do with other mechanisms that do not require the jump 
}to 10MB of mem and the fall back to 0, or that use a child program to 
}process the 10MB of data and passes it's output back to the parent and
}exits (thereby freeing the allocated memory).

The child process idea is good.  Another trick that I've used is to have
the program restart itself with an "execvp(*argv, argv);"  This is for
situations when the process's interaction model is "wait for a long time,
do something that needs a lot of memory, go back to waiting".  For example,
a screen saver.
---
Jef

  Jef Poskanzer  jef@well.sf.ca.us  {ucbvax, apple, hplabs}!well!jef
    "Do you think we can use battery operated devices under water?"