{"id":17993,"url":"https://patchwork.libcamera.org/api/patches/17993/?format=json","web_url":"https://patchwork.libcamera.org/patch/17993/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/projects/1/?format=json","name":"libcamera","link_name":"libcamera","list_id":"libcamera_core","list_email":"libcamera-devel@lists.libcamera.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20221213093802.704177-3-paul.elder@ideasonboard.com>","date":"2022-12-13T09:38:01","name":"[libcamera-devel,2/3] Documentation: application-developer: Elaborate on request reuse","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"e4202810762bec3ca53d06b36485e76d7e24869c","submitter":{"id":17,"url":"https://patchwork.libcamera.org/api/people/17/?format=json","name":"Paul Elder","email":"paul.elder@ideasonboard.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/17993/mbox/","series":[{"id":3669,"url":"https://patchwork.libcamera.org/api/series/3669/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=3669","date":"2022-12-13T09:37:59","name":"lc-compliance: Fix SimpleCapture test","version":1,"mbox":"https://patchwork.libcamera.org/series/3669/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/17993/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/17993/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id A565EC31E9\n\tfor ;\n\tTue, 13 Dec 2022 09:38:18 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 68B5163369;\n\tTue, 13 Dec 2022 10:38:18 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 9787563354\n\tfor ;\n\tTue, 13 Dec 2022 10:38:15 +0100 (CET)","from pyrite.tail37cf.ts.net (h175-177-042-159.catv02.itscom.jp\n\t[175.177.42.159])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 6D01C7C5;\n\tTue, 13 Dec 2022 10:38:14 +0100 (CET)"],"DKIM-Signature":["v=1; a=rsa-sha256; c=relaxed/simple; d=libcamera.org;\n\ts=mail; t=1670924298;\n\tbh=7d6tePXZ0Z99ZziKOsYZVhwwWsTn9Jj1eOd5UQlwcNo=;\n\th=To:Date:In-Reply-To:References:Subject:List-Id:List-Unsubscribe:\n\tList-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:\n\tFrom;\n\tb=kqM75YZAd+Mlpb/6agawMRho0Ap3U67eG04DQQgxyyR170Hob20SPaYpb2aHZRJ8t\n\tQVTnA9FQo0m34Ojh7zb9pZ9nDGb9Owz6srHcxq6BZqjgYdHB2ORbwzi609cygiJFa1\n\tBvcGmDAzzVM1VvacKHOzPb8XSdvJ+yHT/3ovN9Con2SjEzmLVl8EBOpq7KIb5aPsSm\n\tBoDnVM6KJBf7OmZH6FjdFRE2/IAix37MmEE9u7AfXWxeczHIOnQxF9tyL6j2bSCmFI\n\tSO97lDFQ07tspr9DLGzTUcjbdm1KyDjmUpklSZssRJEaTfjC4g8jQTTmapa5fpfNGt\n\tnm8ECw5iypSww==","v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1670924295;\n\tbh=7d6tePXZ0Z99ZziKOsYZVhwwWsTn9Jj1eOd5UQlwcNo=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=PPV6AGNql92jv31Eq4tvGMcNs3YVcZUpmLA9McFH73k+wyvuZ4PRSePpPE3dDUO+X\n\tNDFj3YXvpMGTbigoaLptr1zVWmqQa0gMLckpN1m2dM2sHYF7COaFztejxtsz7/xqY8\n\tWdymELHoBR7CTZ6mPEKfbxwo0/ojMe6cRBXPn1Ns="],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key; \n\tunprotected) header.d=ideasonboard.com\n\theader.i=@ideasonboard.com\n\theader.b=\"PPV6AGNq\"; dkim-atps=neutral","To":"libcamera-devel@lists.libcamera.org","Date":"Tue, 13 Dec 2022 18:38:01 +0900","Message-Id":"<20221213093802.704177-3-paul.elder@ideasonboard.com>","X-Mailer":"git-send-email 2.35.1","In-Reply-To":"<20221213093802.704177-1-paul.elder@ideasonboard.com>","References":"<20221213093802.704177-1-paul.elder@ideasonboard.com>","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","Subject":"[libcamera-devel] [PATCH 2/3] Documentation: application-developer:\n\tElaborate on request reuse","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","From":"Paul Elder via libcamera-devel ","Reply-To":"Paul Elder ","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "},"content":"It recently came to our attention that marking a Request for reuse and\n*not* queueing it causes segfaults at Request deallocation time, if it\nhappens after framebuffer deallocation. Add a note to warn against this\nin the application-developer documentation.\n\nSigned-off-by: Paul Elder \n---\n Documentation/guides/application-developer.rst | 4 ++++\n 1 file changed, 4 insertions(+)","diff":"diff --git a/Documentation/guides/application-developer.rst b/Documentation/guides/application-developer.rst\nindex 1b2d7727..26d5fc1d 100644\n--- a/Documentation/guides/application-developer.rst\n+++ b/Documentation/guides/application-developer.rst\n@@ -490,6 +490,10 @@ device:\n request->reuse(Request::ReuseBuffers);\n camera->queueRequest(request);\n \n+Note that a request should only be marked for re-use if and only if the request\n+will be re-queued to the camera device. Marking a request for re-use and not\n+queuing it causes undefined behavior.\n+\n Request queueing\n ----------------\n \n","prefixes":["libcamera-devel","2/3"]}