From mboxrd@z Thu Jan  1 00:00:00 1970
From: erik quanstrom <quanstro@quanstro.net>
Date: Mon, 26 Jan 2015 06:13:04 -0800
To: 9fans@9fans.net
Message-ID: <4c37cf728d5b0e7ae4ebd3c2e0c2cee4@brasstown.quanstro.net>
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	<44900c0d4896622fa8a9411b05efe730@brasstown.quanstro.net>
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Subject: Re: [9fans] protection against resource exhaustion
Topicbox-Message-UUID: 3b8270a4-ead9-11e9-9d60-3106f5b1d025

On Mon Jan 26 03:43:36 PST 2015, arisawa@ar.aichi-u.ac.jp wrote:
> Hello,
>=20
> I have been playing the following program.
> I tried on official plan9, 9front, and 9atom.
> none of them showed messages that come from:
> 		sysfatal("fork: %r=E2=80=9D);
> 		sysfatal("exec: %r");
> I suspect that
> 	fork()
> does not return -1 even if it failed in creating new process.

exactly.

the reason it never returns -1, is that introduces a new failure case in
every program running, and testing seems like a huge pain.  just
testing for "handles fork returning -1" is not good enough, it has to hav=
e
a reasonable strategy for deailing with no procs.  this is hard to get ri=
ght.
just reboot.  i have never been able to recover a system that hit noprocs=
.
i ended up wasting people's time trying.

- erik

ps.  how may lines like this have you seen.

	p =3D malloc(n);
	if(p =3D=3D nil){
		...
	}

is this really useful in most tools?