X-Recipient: archive-cygwin AT delorie DOT com
DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:date:from:to:subject:message-id:reply-to
	:references:mime-version:content-type:in-reply-to; q=dns; s=
	default; b=dLIAwfGaMk7WNrRxAkRGOvrdD9Qh96XMpP8kCKfMO0a92qIksxQSY
	lr39JLuvPA3+Q+ccjOkzJ1Jb9lDXcIeMDR3UbAO9EoeyXObIS36dPfFF8gnpcjnd
	ScmyeaCzfqJ/ZexDccxNtIViWalhrgosQqcXTvDiyg1MdgU+pT/oMg=
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:date:from:to:subject:message-id:reply-to
	:references:mime-version:content-type:in-reply-to; s=default;
	 bh=g+x4dMpf3LJYrKpFo5kqBO5gPZI=; b=L8k36dAoqQYydCLiyXgkOovK0W1T
	k7dRCoGHCI8cKfUYgTLj4XigcoYJvyMx+GJXTxTl35iy3kvfIAPsWst/zBkARZ9F
	4dv3S6v4K+eelibRc3G2lhAy9Li0NZoH1qOgtYNC9PfQeLndzvP0ToON7NZCxXqh
	qZ39UDVI+Hx1VYo=
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id: <cygwin.cygwin.com>
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com
Authentication-Results: sourceware.org; auth=none
X-Spam-SWARE-Status: No, score=-104.0 required=5.0 tests=AWL,BAYES_00,GOOD_FROM_CORINNA_CYGWIN,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 spammy=HX-Languages-Length:1053, pipes
X-HELO: mout.kundenserver.de
Date: Wed, 7 Aug 2019 10:12:42 +0200
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: semget() returns EAGAIN?
Message-ID: <20190807081242.GY11632@calimero.vinschen.de>
Reply-To: cygwin AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
References: <BL0PR0901MB4308D3780798A4941BF944AAA5D40 AT BL0PR0901MB4308 DOT namprd09 DOT prod DOT outlook DOT com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha256;	protocol="application/pgp-signature"; boundary="YGQsgxOP0v8GKjPA"
Content-Disposition: inline
In-Reply-To: <BL0PR0901MB4308D3780798A4941BF944AAA5D40@BL0PR0901MB4308.namprd09.prod.outlook.com>
User-Agent: Mutt/1.11.3 (2019-02-01)

--YGQsgxOP0v8GKjPA
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Aug  7 05:02, Lavrentiev, Anton (NIH/NLM/NCBI) [C] via cygwin wrote:
> I'm noticing that in a high-contention situation (many processes try
> to get ahold of a semaphore) semget() on Cygwin starts to return
> EAGAIN (try again) after about 62 processes has gotten to call
> semget() and are actively competing for the semaphore (i.e. using the
> semaphore ID semget() returned to them).
>=20
> EAGAIN is not documented in any of semget() API documentation that I
> can find.
>=20
> I understand that in Cygwin semget() is implemented as a connection to
> cygserver, and the error probably stems from there, but I don't think
> that such a code is appropriate as a final errno.  And why is there a
> limit, to begin with?  What exactly imposes it?

The number of parallel open pipes, for instance.  By default, 10
worker threads handle the load and up to 62 processes can be handled
in parallel.  If the numbers are too low in your scenario, try to
raise them in /etc/cygserver.conf.


Corinna

--=20
Corinna Vinschen
Cygwin Maintainer

--YGQsgxOP0v8GKjPA
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----
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=pErN
-----END PGP SIGNATURE-----

--YGQsgxOP0v8GKjPA--