{"id":9090,"url":"https://patchwork.libcamera.org/api/patches/9090/?format=json","web_url":"https://patchwork.libcamera.org/patch/9090/","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":"<20200731133947.84258-4-email@uajain.com>","date":"2020-07-31T13:39:55","name":"[libcamera-devel,v3,3/3] libcamera: camera: Ensure deletion via deleteLater()","commit_ref":null,"pull_url":null,"state":"accepted","archived":false,"hash":"76adf0b1fc2a340921cc567c9b541d639d1abdc5","submitter":{"id":1,"url":"https://patchwork.libcamera.org/api/people/1/?format=json","name":"Umang Jain","email":"email@uajain.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/9090/mbox/","series":[{"id":1168,"url":"https://patchwork.libcamera.org/api/series/1168/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=1168","date":"2020-07-31T13:39:52","name":"Add Object::deleteLater() support","version":3,"mbox":"https://patchwork.libcamera.org/series/1168/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/9090/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/9090/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 0E1CDBD878\n\tfor ;\n\tFri, 31 Jul 2020 13:40:00 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 8EB8761EEF;\n\tFri, 31 Jul 2020 15:39:59 +0200 (CEST)","from o1.f.az.sendgrid.net (o1.f.az.sendgrid.net [208.117.55.132])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id EAA9D61EA4\n\tfor ;\n\tFri, 31 Jul 2020 15:39:56 +0200 (CEST)","by filterdrecv-p3iad2-d8cc6d457-tlvzw with SMTP id\n\tfilterdrecv-p3iad2-d8cc6d457-tlvzw-19-5F241F2B-2A\n\t2020-07-31 13:39:55.67984757 +0000 UTC m=+156690.394921146","from mail.uajain.com (unknown)\n\tby ismtpd0001p1maa1.sendgrid.net (SG) with ESMTP\n\tid APo5bF33SdSYpXkNlB5ZcQ Fri, 31 Jul 2020 13:39:55.235 +0000 (UTC)"],"Authentication-Results":"lancelot.ideasonboard.com;\n\tdkim=fail reason=\"signature verification failed\" (1024-bit key;\n\tunprotected) header.d=uajain.com header.i=@uajain.com\n\theader.b=\"E8HMt7yo\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=uajain.com;\n\th=from:subject:in-reply-to:references:mime-version:to:cc:\n\tcontent-transfer-encoding:content-type;\n\ts=s1; bh=Q13Y/KIA9jXepafD4MdInIVxJgHdpkJml9AgdG7ctRo=;\n\tb=E8HMt7yosv/O5SF43DjkQoJGKN62gtxVzVP1o1zXsDka6fvrK+gLf4WUdmYaxFmhAmO1\n\t8JJuuHGysh31NZZvQm1jwXeT/F8AGDi/k0N7TAvzgSdqJL9ptYF4ZL/Gp/FLBHgrvIGh1l\n\tYgBDhFrrpmA/R0XX8a9wkkztquqm0MXNI=","From":"Umang Jain ","Date":"Fri, 31 Jul 2020 13:39:55 +0000 (UTC)","Message-Id":"<20200731133947.84258-4-email@uajain.com>","In-Reply-To":"<20200731133947.84258-1-email@uajain.com>","References":"<20200731133947.84258-1-email@uajain.com>","Mime-Version":"1.0","X-SG-EID":"1Q40EQ7YGir8a9gjSIAdTjhngY657NMk9ckeo4dbHZDiOpywc/L3L9rFqlwE4KPcREc2X1LpIgLW8oEasGbeg9uPR3HyoPdWA+c8k6xqhnH2yVbMfbMS9MDZuibMw2RmskFzVjMwpfjjA/Ah5AKcr1cMsEQlRCK6Hj8SG1mFRxAHATDOM1J51AiekMHBcBKn6ixU7B4tO1QcPQByENNmqq2CNN0E1GKA4oYfagZAufxjlObs93wSJLD9Ej+mRWZqndUvlHrTBeJdB24nqjqXZA==","To":"libcamera-devel@lists.libcamera.org","Subject":"[libcamera-devel] [PATCH v3 3/3] libcamera: camera: Ensure deletion\n\tvia deleteLater()","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","Content-Type":"text/plain; charset=\"us-ascii\"","Content-Transfer-Encoding":"7bit","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "},"content":"Object::deleteLater() ensures that the deletion of the Object\ntakes place in a thread it is bound to. Deleting the Object\nin a different thread is a violation according to the threading\nmodel.\n\nOn hot-unplug of a currently streaming camera, the last reference\nof Camera when dropped from the application thread (for e.g. QCam's\nthread), the destructor is then called from this thread. This is not\nallowed by the threading model. Camera is meant to be deleted in the\nthread it is bound to - in this case the CameraManager's thread.\n\nSigned-off-by: Umang Jain \nReviewed-by: Laurent Pinchart \n---\n include/libcamera/camera.h | 3 ++-\n src/libcamera/camera.cpp | 2 +-\n src/libcamera/camera_manager.cpp | 6 +++++-\n 3 files changed, 8 insertions(+), 3 deletions(-)","diff":"diff --git a/include/libcamera/camera.h b/include/libcamera/camera.h\nindex 4d1a4a9..7dd23d7 100644\n--- a/include/libcamera/camera.h\n+++ b/include/libcamera/camera.h\n@@ -13,6 +13,7 @@\n #include \n \n #include \n+#include \n #include \n #include \n #include \n@@ -66,7 +67,7 @@ protected:\n \tstd::vector config_;\n };\n \n-class Camera final : public std::enable_shared_from_this\n+class Camera final : public Object, public std::enable_shared_from_this\n {\n public:\n \tstatic std::shared_ptr create(PipelineHandler *pipe,\ndiff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp\nindex 69a1b44..034f341 100644\n--- a/src/libcamera/camera.cpp\n+++ b/src/libcamera/camera.cpp\n@@ -464,7 +464,7 @@ std::shared_ptr Camera::create(PipelineHandler *pipe,\n \tstruct Deleter : std::default_delete {\n \t\tvoid operator()(Camera *camera)\n \t\t{\n-\t\t\tdelete camera;\n+\t\t\tcamera->deleteLater();\n \t\t}\n \t};\n \ndiff --git a/src/libcamera/camera_manager.cpp b/src/libcamera/camera_manager.cpp\nindex f60491d..c45bf33 100644\n--- a/src/libcamera/camera_manager.cpp\n+++ b/src/libcamera/camera_manager.cpp\n@@ -164,9 +164,13 @@ void CameraManager::Private::cleanup()\n \n \t/*\n \t * Release all references to cameras to ensure they all get destroyed\n-\t * before the device enumerator deletes the media devices.\n+\t * before the device enumerator deletes the media devices. Cameras are\n+\t * destroyed via Object::deleteLater() API, hence we need to explicitly\n+\t * process deletion requests from the thread's message queue as the event\n+\t * loop is not in action here.\n \t */\n \tcameras_.clear();\n+\tdispatchMessages(Message::Type::DeferredDelete);\n \n \tenumerator_.reset(nullptr);\n }\n","prefixes":["libcamera-devel","v3","3/3"]}