Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 15 Oct 2002 17:55:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 15 Oct 2002 17:55:39 -0400 Received: from mtao-m02.ehs.aol.com ([64.12.52.8]:18641 "EHLO mtao-m02.ehs.aol.com") by vger.kernel.org with ESMTP id ; Tue, 15 Oct 2002 17:55:37 -0400 Date: Tue, 15 Oct 2002 15:01:25 -0700 From: John Gardiner Myers Subject: Re: [PATCH] async poll for 2.5 To: Davide Libenzi Cc: Benjamin LaHaise , Dan Kegel , Shailabh Nagar , linux-kernel , linux-aio , Andrew Morton , David Miller , Linus Torvalds , Stephen Tweedie Message-id: <3DAC9035.2010208@netscape.com> MIME-version: 1.0 Content-type: multipart/signed; boundary=------------ms010305020802070404020400; micalg=sha1; protocol="application/x-pkcs7-signature" X-Accept-Language: en-us, en User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.2a) Gecko/20020910 References: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6087 Lines: 103 This is a cryptographically signed message in MIME format. --------------ms010305020802070404020400 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Davide Libenzi wrote: >Why would you need to use threads with a multiplex-like interface like >/dev/epoll ? > Because in some applications processing an event can cause the thread to block, potentially for a long time. Multiple threads are needed to isolate that block to the context associated with the event. > while (read() == EGAIN) > wait(POLLIN); > > Assuming registration of interest is inside wait(), this has a race. If the file becomes readable between the time that read() returns and the time that wait() can register interest, the connection will hang. --------------ms010305020802070404020400 Content-Type: application/x-pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIK7TCC A4UwggLuoAMCAQICAlvfMA0GCSqGSIb3DQEBBAUAMIGTMQswCQYDVQQGEwJVUzELMAkGA1UE CBMCQ0ExFjAUBgNVBAcTDU1vdW50YWluIFZpZXcxGzAZBgNVBAoTEkFtZXJpY2EgT25saW5l IEluYzEZMBcGA1UECxMQQU9MIFRlY2hub2xvZ2llczEnMCUGA1UEAxMeSW50cmFuZXQgQ2Vy dGlmaWNhdGUgQXV0aG9yaXR5MB4XDTAyMDYwMTIwMjIyM1oXDTAyMTEyODIwMjIyM1owfTEL MAkGA1UEBhMCVVMxGzAZBgNVBAoTEkFtZXJpY2EgT25saW5lIEluYzEXMBUGCgmSJomT8ixk AQETB2pnbXllcnMxIzAhBgkqhkiG9w0BCQEWFGpnbXllcnNAbmV0c2NhcGUuY29tMRMwEQYD VQQDEwpKb2huIE15ZXJzMIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDsB5tbTLWFycke 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