220 4714 article Path: news.gmane.org!not-for-mail From: Lawrence Crowl Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: lock free traits for functions Date: Wed, 29 May 2013 12:24:55 -0700 Lines: 34 Approved: news@gmane.org Message-ID: References: <4ed4041c-a458-4fc8-ae3d-7534d5d261c2@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 X-Trace: ger.gmane.org 1369855497 23645 80.91.229.3 (29 May 2013 19:24:57 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 29 May 2013 19:24:57 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCY3D77DYUDBBB5MTGGQKGQE4PYWFEA@isocpp.org Wed May 29 21:24:59 2013 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-vb0-f70.google.com ([209.85.212.70]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1UhlzV-0003SU-CM for gclcip-std-proposals@m.gmane.org; Wed, 29 May 2013 21:24:57 +0200 Original-Received: by mail-vb0-f70.google.com with SMTP id f13sf11565081vbg.5 for ; Wed, 29 May 2013 12:24:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlers.com; s=googlers; h=x-beenthere:mime-version:in-reply-to:references:date:message-id :subject:from:to:x-original-sender:x-original-authentication-results :reply-to:precedence:mailing-list:list-id:x-google-group-id :list-post:list-help:list-archive:list-subscribe:list-unsubscribe :content-type; bh=pqmuHjhhh/JxTs/Qc+pH+YQriCPEuZCNUAPJXKqG+7g=; b=XS6+ML5NbBXmQHZ2QXD+seUS0u6MSIkQRH5BiJPrYKFSy+fn7nFpSUbj1wn6tABumZ i2ujfqMf9kkFqKLsH4/cFhF8F68a/YhxzZ8Jptf+NzXKOs5hjtMMBDhT3/cquJRVuNtw sBLnsYo+beoGvaok1BMkrbfwQ8m6JvjC27sc0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-beenthere:mime-version:in-reply-to:references:date:message-id :subject:from:to:x-gm-message-state:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:x-google-group-id:list-post:list-help:list-archive :list-subscribe:list-unsubscribe:content-type; bh=pqmuHjhhh/JxTs/Qc+pH+YQriCPEuZCNUAPJXKqG+7g=; b=WnO52qnhDnURK6d8bl1hS/lOQEW1iq2d0ZhRs+aedjm960oYNP3ChzptXGgPy7KRoK U0m4x5Y2+trD1QbyrSCA6Dz1wsAsH3dB5vbRkZeGlXt/DMz0gkdFcma60Eq5c3BeH0RO qkdiP2Q0dtjoYegceNFAs426wOe2J4WuyMkUXP2UP+MIcOrFyFlZ3d9NIDeRUZguoq1C Q5G78U5EqHzSvhcPUfqVb9PQ9JdFlflchhxNrwj7cP44bmuZ9olL3s/Jb4vlWfRONkNh 4Xk55LK6rla0aYK9PxoEbhj9/Jz5WGfpUht2h1H0pjDqg+87UcAoEDN6PgMWe4/kdt9T LNlg== X-Received: by 10.236.15.34 with SMTP id e22mr2064375yhe.16.1369855496323; Wed, 29 May 2013 12:24:56 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.49.122.102 with SMTP id lr6ls32686qeb.13.gmail; Wed, 29 May 2013 12:24:55 -0700 (PDT) X-Received: by 10.49.81.193 with SMTP id c1mr4531504qey.56.1369855495357; Wed, 29 May 2013 12:24:55 -0700 (PDT) Original-Received: from mail-qc0-x22d.google.com (mail-qc0-x22d.google.com [2607:f8b0:400d:c01::22d]) by mx.google.com with ESMTPS id k1si31250236qaz.67.2013.05.29.12.24.55 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 29 May 2013 12:24:55 -0700 (PDT) Received-SPF: pass (google.com: domain of crowl@google.com designates 2607:f8b0:400d:c01::22d as permitted sender) client-ip=2607:f8b0:400d:c01::22d; Original-Received: by mail-qc0-f173.google.com with SMTP id c11so4954096qcv.18 for ; Wed, 29 May 2013 12:24:55 -0700 (PDT) X-Received: by 10.229.125.20 with SMTP id w20mr1524245qcr.85.1369855495104; Wed, 29 May 2013 12:24:55 -0700 (PDT) Original-Received: by 10.229.1.196 with HTTP; Wed, 29 May 2013 12:24:55 -0700 (PDT) In-Reply-To: <4ed4041c-a458-4fc8-ae3d-7534d5d261c2@isocpp.org> X-Gm-Message-State: ALoCoQm0uO4uz0Lb9Kql5/6t5l8qccneGSoD4nBWTOfXGfu0zzuDiR2uRxYz0+rzF+eAOKdZxNqkyFwy0SarJT5qdQsjDQlICEHTfGN8VN2atWD2TKF3J6ANEyh/rlLMZKUgJUscDYQKeSxf6tlee5ndai9v6ubvlQx8nDw9Lv2kxfw7Jv5kWu8adAzbPBtMlO8mZ9vkTei4 X-Original-Sender: crowl@googlers.com X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of crowl@google.com designates 2607:f8b0:400d:c01::22d as permitted sender) smtp.mail=crowl@google.com; dkim=pass header.i=@googlers.com; dmarc=pass (p=QUARANTINE dis=none) d=googlers.com Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: X-Google-Group-Id: 399137483710 List-Post: , List-Help: , List-Archive: List-Subscribe: , List-Unsubscribe: , Xref: news.gmane.org gmane.comp.lang.c++.isocpp.proposals:4714 Archived-At: On 5/29/13, adrien courdavault wrote: > This seams to be a very simplistic request but I think it would be > nice to have some traits to know if a function call is lock free > or not. It is not usefull for every function, but it could be > for the class like thread obviously. Clearly launching a thread > is not, but depending on the implementation get_id could be; > > I say that because in time critical thread you want to know it > it is safe to do that. In my case i want to know if I am in the > time critical thread, ... problem, if asking for the id of the > thread is not lock free I might just have break the rule I wanted > to inforce by asking if I was in this thread, what do you think? We might be able to provide this query definitively for a pre-determined set of functions. In general, though, I think we would need to be able to answer "don't know". Do you have a list of other functions for which you must know? Do you need a dynamic test, i.e. on a function pointer, or can you live with a static test, i.e. on a template argument? -- Lawrence Crowl -- --- You received this message because you are subscribed to the Google Groups "ISO C++ Standard - Future Proposals" group. To unsubscribe from this group and stop receiving emails from it, send an email to std-proposals+unsubscribe@isocpp.org. To post to this group, send email to std-proposals@isocpp.org. Visit this group at http://groups.google.com/a/isocpp.org/group/std-proposals/?hl=en. .