{"id":12189,"url":"https://patchwork.libcamera.org/api/patches/12189/?format=json","web_url":"https://patchwork.libcamera.org/patch/12189/","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":"<20210503193307.108607-2-nfraprado@collabora.com>","date":"2021-05-03T19:33:05","name":"[libcamera-devel,RFC,v2,1/3] libcamera: camera: Make stop() idempotent","commit_ref":null,"pull_url":null,"state":"superseded","archived":false,"hash":"33bfc5281041654b44881ecbf922ceac4fef1751","submitter":{"id":84,"url":"https://patchwork.libcamera.org/api/people/84/?format=json","name":"Nícolas F. R. A. Prado","email":"nfraprado@collabora.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/12189/mbox/","series":[{"id":1996,"url":"https://patchwork.libcamera.org/api/series/1996/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=1996","date":"2021-05-03T19:33:04","name":"lc-compliance: Refactor using Googletest","version":2,"mbox":"https://patchwork.libcamera.org/series/1996/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/12189/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/12189/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 A4534BDE78\n\tfor ;\n\tMon, 3 May 2021 19:34:00 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 466E76891E;\n\tMon, 3 May 2021 21:34:00 +0200 (CEST)","from bhuna.collabora.co.uk (bhuna.collabora.co.uk\n\t[IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 47AEE688AE\n\tfor ;\n\tMon, 3 May 2021 21:33:59 +0200 (CEST)","from localhost.localdomain (unknown\n\t[IPv6:2804:14c:1a9:2978:995d:672b:100f:2fd9])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128\n\tbits))\n\t(No client certificate requested) (Authenticated sender: nfraprado)\n\tby bhuna.collabora.co.uk (Postfix) with ESMTPSA id 6C35B1F41E97;\n\tMon, 3 May 2021 20:33:57 +0100 (BST)"],"From":"=?utf-8?b?TsOtY29sYXMgRi4gUi4gQS4gUHJhZG8=?= ","To":"libcamera-devel@lists.libcamera.org","Date":"Mon, 3 May 2021 16:33:05 -0300","Message-Id":"<20210503193307.108607-2-nfraprado@collabora.com>","X-Mailer":"git-send-email 2.31.1","In-Reply-To":"<20210503193307.108607-1-nfraprado@collabora.com>","References":"<20210503193307.108607-1-nfraprado@collabora.com>","MIME-Version":"1.0","Subject":"[libcamera-devel] [RFC PATCH v2 1/3] libcamera: camera: Make stop()\n\tidempotent","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","Cc":"kernel@collabora.com, =?utf-8?q?Andr=C3=A9_Almeida?=\n\t","Content-Type":"text/plain; charset=\"utf-8\"","Content-Transfer-Encoding":"base64","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "},"content":"Make Camera::stop() idempotent so that it can be called in any state and\nconsecutive times. When called in any state other than CameraRunning, it\nis a no-op. This simplifies the cleanup path for applications.\n\nSigned-off-by: Nícolas F. R. A. Prado \n---\nChanges in v2:\n- Suggested by Kieran:\n - Add new isRunning() function instead of relying on isAccessAllowed()\n- Suggested by Laurent:\n - Make stop()'s description clearer\n\n src/libcamera/camera.cpp | 20 +++++++++++++++++---\n 1 file changed, 17 insertions(+), 3 deletions(-)","diff":"diff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp\nindex 1340c266cc5f..1c6c76c7c01e 100644\n--- a/src/libcamera/camera.cpp\n+++ b/src/libcamera/camera.cpp\n@@ -347,6 +347,7 @@ public:\n \t\tconst std::set &streams);\n \t~Private();\n \n+\tbool isRunning() const;\n \tint isAccessAllowed(State state, bool allowDisconnected = false,\n \t\t\t const char *from = __builtin_FUNCTION()) const;\n \tint isAccessAllowed(State low, State high,\n@@ -388,6 +389,15 @@ static const char *const camera_state_names[] = {\n \t\"Running\",\n };\n \n+bool Camera::Private::isRunning() const\n+{\n+\tState currentState = state_.load(std::memory_order_acquire);\n+\tif (currentState == CameraRunning)\n+\t\treturn true;\n+\n+\treturn false;\n+}\n+\n int Camera::Private::isAccessAllowed(State state, bool allowDisconnected,\n \t\t\t\t const char *from) const\n {\n@@ -1061,9 +1071,10 @@ int Camera::start(const ControlList *controls)\n * This method stops capturing and processing requests immediately. All pending\n * requests are cancelled and complete synchronously in an error state.\n *\n- * \\context This function may only be called when the camera is in the Running\n- * state as defined in \\ref camera_operation, and shall be synchronized by the\n- * caller with other functions that affect the camera state.\n+ * \\context This function may be called in any camera state as defined in \\ref\n+ * camera_operation, and shall be synchronized by the caller with other\n+ * functions that affect the camera state. If called when the camera isn't\n+ * running, it is a no-op.\n *\n * \\return 0 on success or a negative error code otherwise\n * \\retval -ENODEV The camera has been disconnected from the system\n@@ -1073,6 +1084,9 @@ int Camera::stop()\n {\n \tPrivate *const d = LIBCAMERA_D_PTR();\n \n+\tif (!d->isRunning())\n+\t\treturn 0;\n+\n \tint ret = d->isAccessAllowed(Private::CameraRunning);\n \tif (ret < 0)\n \t\treturn ret;\n","prefixes":["libcamera-devel","RFC","v2","1/3"]}