From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Original-To: caml-list@yquem.inria.fr Delivered-To: caml-list@yquem.inria.fr Received: from nez-perce.inria.fr (nez-perce.inria.fr [192.93.2.78]) by yquem.inria.fr (Postfix) with ESMTP id 8F984BB88 for ; Mon, 1 Aug 2005 17:42:15 +0200 (CEST) Received: from pauillac.inria.fr (pauillac.inria.fr [128.93.11.35]) by nez-perce.inria.fr (8.13.0/8.13.0) with ESMTP id j71FgFQC012884 for ; Mon, 1 Aug 2005 17:42:15 +0200 Received: from concorde.inria.fr (concorde.inria.fr [192.93.2.39]) by pauillac.inria.fr (8.7.6/8.7.3) with ESMTP id RAA04004 for ; Mon, 1 Aug 2005 17:42:10 +0200 (MET DST) Received: from mx1.polytechnique.org (mx1.polytechnique.org [129.104.30.34]) by concorde.inria.fr (8.13.0/8.13.0) with ESMTP id j71Fg8LE009383 for ; Mon, 1 Aug 2005 17:42:09 +0200 Received: from [192.168.2.3] (log78-1-82-242-44-42.fbx.proxad.net [82.242.44.42]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (No client certificate requested) by ssl.polytechnique.org (Postfix) with ESMTP id 255E6331A3; Mon, 1 Aug 2005 17:42:08 +0200 (CEST) In-Reply-To: References: Mime-Version: 1.0 (Apple Message framework v733) Content-Type: multipart/signed; micalg=sha1; boundary=Apple-Mail-1-722321815; protocol="application/pkcs7-signature" Message-Id: Cc: caml-list@inria.fr From: Damien Bobillot Subject: Re: [Caml-list] Named pipe problem: is this a bug? Date: Mon, 1 Aug 2005 17:42:05 +0200 To: Alan Schmitt X-Mailer: Apple Mail (2.733) X-AV-Checked: ClamAV using ClamSMTP at djali.polytechnique.org (Mon Aug 1 17:42:08 2005 +0200 (CEST)) X-DCC--Metrics: djali 32702; Body=1 Fuz1=1 Fuz2=1 X-Org-Mail: damien.bobillot.2002@polytechnique.org X-Miltered: at nez-perce with ID 42EE42D7.000 by Joe's j-chkmail (http://j-chkmail.ensmp.fr)! X-Miltered: at concorde with ID 42EE42D0.000 by Joe's j-chkmail (http://j-chkmail.ensmp.fr)! X-Spam: no; 0.00; damien:01 damien:01 caml-list:01 bug:01 flowed:01 schmitt:01 bug:01 endline:01 stdout:01 endline:01 stdout:01 ocamlc:01 bytecode:01 foo:01 foo:01 X-Spam-Checker-Version: SpamAssassin 3.0.3 (2005-04-27) on yquem.inria.fr X-Spam-Level: X-Spam-Status: No, score=0.0 required=5.0 tests=none autolearn=disabled version=3.0.3 --Apple-Mail-1-722321815 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=ISO-8859-1; delsp=yes; format=flowed Le 1 ao=FBt 05 =E0 17:03, Alan Schmitt a =E9crit : > Hello, > > I've stumbled upon a small bug, and I wonder if it's a OS X bug =20 > (I'm using X.4.2), or a caml bug. The problem is the following: I =20 > create a named pipe, then I open it. The open system call seems to =20 > block until there is data in the pipe. > > Here is a small program illustrating this: > > let _ =3D > Unix.mkfifo "pipe_test" 0o640; > print_endline "pipe created"; > flush stdout; > let chin =3D open_in "pipe_test" in > print_endline "pipe opened"; > flush stdout > > Compile it using "ocamlc unix.cma bug.ml" (the bug occurs both in =20 > bytecode and native code). When a.out is run, one sees: > pipe created > and the program keeps running. If one then does a > echo foo >> pipe_test > then the "pipe opened" line is shown, and the program terminates. Same thing on my computers (Mac OS X & Linux). In fact, a pipe is considered to be opened only if both ends exists =20 (you've created the read end, "echo foo >> .." create the write end). http://www.annodex.net/cgi-bin/man/man2html?fifo+4 says : "The kernel maintains exactly one pipe object for each FIFO special =20 file that is opened by at least one process. The FIFO must be opened =20 on both ends (reading and writing) before data can be passed. =20 Normally, opening the FIFO blocks until the other end is opened also." (it's no use to call flush after print_endline : printf_endline do =20 the flush itself) --=20 Damien Bobillot --Apple-Mail-1-722321815 Content-Transfer-Encoding: base64 Content-Type: application/pkcs7-signature; name=smime.p7s Content-Disposition: attachment; filename=smime.p7s MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIGIjCCAtsw ggJEoAMCAQICAw54xzANBgkqhkiG9w0BAQQFADBiMQswCQYDVQQGEwJaQTElMCMGA1UEChMcVGhh d3RlIENvbnN1bHRpbmcgKFB0eSkgTHRkLjEsMCoGA1UEAxMjVGhhd3RlIFBlcnNvbmFsIEZyZWVt YWlsIElzc3VpbmcgQ0EwHhcNMDUwNDEzMTc1MTAxWhcNMDYwNDEzMTc1MTAxWjBJMR8wHQYDVQQD ExZUaGF3dGUgRnJlZW1haWwgTWVtYmVyMSYwJAYJKoZIhvcNAQkBFhdkYW1pZW4uYm9iaWxsb3RA bTR4Lm9yZzCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAJ1TOYBqwJ42s0Fzz56jY1p0 fplGyikFgoNEUKGnOpqt4vpeoqUppAnORt2yvdQJxfIkhsWkrD/diiPS7MTF73wcxlSJtqYzVzPK G/2WDm6dBinuWCIyWYFhtGedyxbap3kJW44H7cL7HUVVxZ0JhOIOTsjCoEzaeKnML7bctbIJeXEE lErfbDv2jA1PDG1ru5dx+Q+AmbexX92ygnntE6aX3QZLSbhrytg4yCRdV8cOyQ9eFruZBI42RJv3 nJXevjUOr4n+y/7bzijAJj4BFyUU+dllvj6bmk5brnUXheCSOD0Ci20dqGNC1MyJ43b6MoIrbW7j JwYIv12D6KuWoaUCAwEAAaM0MDIwIgYDVR0RBBswGYEXZGFtaWVuLmJvYmlsbG90QG00eC5vcmcw DAYDVR0TAQH/BAIwADANBgkqhkiG9w0BAQQFAAOBgQB0u5b6wgwsbcyzDHJTzshlCn4gshxWtU/1 mH77gBCpsY8L554YV4/Tvm1PzmDzErm++drQf5HMy8sEFjmwLvNfBP0BqtkSqsdRFGR4wHzTjMhS EW5LgmlaccqBQzqQrANtzglgBVbtmBDAV92qHjQslwHK4FohCRRzGl4DLQmqBDCCAz8wggKooAMC AQICAQ0wDQYJKoZIhvcNAQEFBQAwgdExCzAJBgNVBAYTAlpBMRUwEwYDVQQIEwxXZXN0ZXJuIENh cGUxEjAQBgNVBAcTCUNhcGUgVG93bjEaMBgGA1UEChMRVGhhd3RlIENvbnN1bHRpbmcxKDAmBgNV BAsTH0NlcnRpZmljYXRpb24gU2VydmljZXMgRGl2aXNpb24xJDAiBgNVBAMTG1RoYXd0ZSBQZXJz b25hbCBGcmVlbWFpbCBDQTErMCkGCSqGSIb3DQEJARYccGVyc29uYWwtZnJlZW1haWxAdGhhd3Rl LmNvbTAeFw0wMzA3MTcwMDAwMDBaFw0xMzA3MTYyMzU5NTlaMGIxCzAJBgNVBAYTAlpBMSUwIwYD VQQKExxUaGF3dGUgQ29uc3VsdGluZyAoUHR5KSBMdGQuMSwwKgYDVQQDEyNUaGF3dGUgUGVyc29u YWwgRnJlZW1haWwgSXNzdWluZyBDQTCBnzANBgkqhkiG9w0BAQEFAAOBjQAwgYkCgYEAxKY8VXNV +065yplaHmjAdQRwnd/p/6Me7L3N9VvyGna9fww6YfK/Uc4B1OVQCjDXAmNaLIkVcI7dyfArhVqq P3FWy688Cwfn8R+RNiQqE88r1fOCdz0Dviv+uxg+B79AgAJk16emu59l0cUqVIUPSAR/p7bRPGEE QB5kGXJgt/sCAwEAAaOBlDCBkTASBgNVHRMBAf8ECDAGAQH/AgEAMEMGA1UdHwQ8MDowOKA2oDSG Mmh0dHA6Ly9jcmwudGhhd3RlLmNvbS9UaGF3dGVQZXJzb25hbEZyZWVtYWlsQ0EuY3JsMAsGA1Ud DwQEAwIBBjApBgNVHREEIjAgpB4wHDEaMBgGA1UEAxMRUHJpdmF0ZUxhYmVsMi0xMzgwDQYJKoZI hvcNAQEFBQADgYEASIzRUIPqCy7MDaNmrGcPf6+svsIXoUOWlJ1/TCG4+DYfqi2fNi/A9BxQIJNw PP2t4WFiw9k6GX6EsZkbAMUaC4J0niVQlGLH2ydxVyWN3amcOY6MIE9lX5Xa9/eH1sYITq726jTl EBpbNU1341YheILcIRk13iSx0x1G/11fZU8xggLnMIIC4wIBATBpMGIxCzAJBgNVBAYTAlpBMSUw IwYDVQQKExxUaGF3dGUgQ29uc3VsdGluZyAoUHR5KSBMdGQuMSwwKgYDVQQDEyNUaGF3dGUgUGVy c29uYWwgRnJlZW1haWwgSXNzdWluZyBDQQIDDnjHMAkGBSsOAwIaBQCgggFTMBgGCSqGSIb3DQEJ AzELBgkqhkiG9w0BBwEwHAYJKoZIhvcNAQkFMQ8XDTA1MDgwMTE1NDIwNlowIwYJKoZIhvcNAQkE MRYEFPSVCIFxjoJ4eashgAxekd7pkmNWMHgGCSsGAQQBgjcQBDFrMGkwYjELMAkGA1UEBhMCWkEx JTAjBgNVBAoTHFRoYXd0ZSBDb25zdWx0aW5nIChQdHkpIEx0ZC4xLDAqBgNVBAMTI1RoYXd0ZSBQ ZXJzb25hbCBGcmVlbWFpbCBJc3N1aW5nIENBAgMOeMcwegYLKoZIhvcNAQkQAgsxa6BpMGIxCzAJ BgNVBAYTAlpBMSUwIwYDVQQKExxUaGF3dGUgQ29uc3VsdGluZyAoUHR5KSBMdGQuMSwwKgYDVQQD EyNUaGF3dGUgUGVyc29uYWwgRnJlZW1haWwgSXNzdWluZyBDQQIDDnjHMA0GCSqGSIb3DQEBAQUA BIIBAFws4jgdkXLAdrknAdmOHSvWFCj0Y5bK4/ddqQj2DUTzwWcEMKxzvhhr35yINrn1iJfhuQlm nz7wpA71dzdqErGx3etKprxI+OxQO2kxqWNAm2dDHQw+Axp9AQZlUPh7v75c+NthoYkBAKC9+rFV N3+wIiuBQNZ9tgMHnOA6UQm1I7EeeVE9ioKnbyefVSSZ1YlFsGVI4UpWET/VkSd87N5fGCn9uAH5 u0+46PZ6CKaNjmwyHfR0oWpdxuwdx5RDr+MS8+HqVF5O4xzPbRtbYYFzYfml8IvxkmQ52xTAcrpy C516s/tss/7a7Zq324brPZa7FA/4059Y9KPltXTx8qIAAAAAAAA= --Apple-Mail-1-722321815--