{"id":2170,"url":"https://patchwork.libcamera.org/api/patches/2170/?format=json","web_url":"https://patchwork.libcamera.org/patch/2170/","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":"<20191012184407.31684-10-laurent.pinchart@ideasonboard.com>","date":"2019-10-12T18:44:02","name":"[libcamera-devel,v2,09/14] libcamera: v4l2_device: Avoid copy of V4L2ControlInfo","commit_ref":null,"pull_url":null,"state":"accepted","archived":false,"hash":"561bca3fcff520c58e42a4526c88bd1c23f0ccb3","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/people/2/?format=json","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/2170/mbox/","series":[{"id":531,"url":"https://patchwork.libcamera.org/api/series/531/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=531","date":"2019-10-12T18:43:53","name":"Use ControlList for both libcamera and V4L2 controls","version":2,"mbox":"https://patchwork.libcamera.org/series/531/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/2170/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/2170/checks/","tags":{},"headers":{"Return-Path":"","Received":["from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id ABCBA61986\n\tfor ;\n\tSat, 12 Oct 2019 20:44:21 +0200 (CEST)","from pendragon.bb.dnainternet.fi\n\t(dfj612yhrgyx302h3jwwy-3.rev.dnainternet.fi\n\t[IPv6:2001:14ba:21f5:5b00:ce28:277f:58d7:3ca4])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 4BDF254C\n\tfor ;\n\tSat, 12 Oct 2019 20:44:21 +0200 (CEST)"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1570905861;\n\tbh=PHukfiupzGP473rBSTqF5QnoGbfpdJ2UyRUkSw3CLyE=;\n\th=From:To:Subject:Date:In-Reply-To:References:From;\n\tb=XngmN1uW8S1A4dATT71Rwpxhu7SfKpd3J0VOMD+y3h0siQNc1BzdLNl2JRCeULix/\n\t3BTkAS9KDMEHTBQ3vzd/dEaACOPCQqRZIawDmJ73fcrRYF9At24NtfzDgYHOcD6m7u\n\t2J+Odn9P4uikEtBn3yEJIDl3tWiSSFKCJozNzJPc=","From":"Laurent Pinchart ","To":"libcamera-devel@lists.libcamera.org","Date":"Sat, 12 Oct 2019 21:44:02 +0300","Message-Id":"<20191012184407.31684-10-laurent.pinchart@ideasonboard.com>","X-Mailer":"git-send-email 2.21.0","In-Reply-To":"<20191012184407.31684-1-laurent.pinchart@ideasonboard.com>","References":"<20191012184407.31684-1-laurent.pinchart@ideasonboard.com>","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","Subject":"[libcamera-devel] [PATCH v2 09/14] libcamera: v4l2_device: Avoid\n\tcopy of V4L2ControlInfo","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","X-List-Received-Date":"Sat, 12 Oct 2019 18:44:21 -0000"},"content":"The V4L2Device::listControls() method creates an instance of\nV4L2ControlInfo and then inserts it in the device's list of controls.\nThe insertion uses std::map::emplace(), but passes the V4L2ControlInfo,\nresulting in a copy being performed (using the copy constructor of\nV4L2ControlInfo).\n\nOptimise this by really constructing the V4L2ControlInfo in-place. The\nuse of std::piecewise_construct is required for gcc-5 that seems to have\ntrouble with std::map::emplace() on non-copyable values in this case.\n\nSigned-off-by: Laurent Pinchart \n---\n src/libcamera/v4l2_device.cpp | 9 +++++----\n 1 file changed, 5 insertions(+), 4 deletions(-)","diff":"diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp\nindex fd4b9c6d5c62..3bd82ff23212 100644\n--- a/src/libcamera/v4l2_device.cpp\n+++ b/src/libcamera/v4l2_device.cpp\n@@ -352,8 +352,7 @@ void V4L2Device::listControls()\n \t\t ctrl.flags & V4L2_CTRL_FLAG_DISABLED)\n \t\t\tcontinue;\n \n-\t\tV4L2ControlInfo info(ctrl);\n-\t\tswitch (info.type()) {\n+\t\tswitch (ctrl.type) {\n \t\tcase V4L2_CTRL_TYPE_INTEGER:\n \t\tcase V4L2_CTRL_TYPE_BOOLEAN:\n \t\tcase V4L2_CTRL_TYPE_MENU:\n@@ -364,12 +363,14 @@ void V4L2Device::listControls()\n \t\t\tbreak;\n \t\t/* \\todo Support compound controls. */\n \t\tdefault:\n-\t\t\tLOG(V4L2, Debug) << \"Control type '\" << info.type()\n+\t\t\tLOG(V4L2, Debug) << \"Control type '\" << ctrl.type\n \t\t\t\t\t << \"' not supported\";\n \t\t\tcontinue;\n \t\t}\n \n-\t\tcontrols_.emplace(ctrl.id, info);\n+\t\tcontrols_.emplace(std::piecewise_construct,\n+\t\t\t\t std::forward_as_tuple(ctrl.id),\n+\t\t\t\t std::forward_as_tuple(ctrl));\n \t}\n }\n \n","prefixes":["libcamera-devel","v2","09/14"]}