{"id":978,"url":"https://patchwork.libcamera.org/api/patches/978/?format=json","web_url":"https://patchwork.libcamera.org/patch/978/","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":"<20190414013506.10515-10-niklas.soderlund@ragnatech.se>","date":"2019-04-14T01:35:04","name":"[libcamera-devel,RFC,09/11] libcamera: media_device: Add functions to lock device for other processes","commit_ref":null,"pull_url":null,"state":"superseded","archived":false,"hash":"f4a68a421271af5d7cb65e7fa0092c72164d2945","submitter":{"id":5,"url":"https://patchwork.libcamera.org/api/people/5/?format=json","name":"Niklas Söderlund","email":"niklas.soderlund@ragnatech.se"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/978/mbox/","series":[{"id":249,"url":"https://patchwork.libcamera.org/api/series/249/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=249","date":"2019-04-14T01:34:55","name":"libcamerea: Add support for exclusive access to cameras between processes","version":1,"mbox":"https://patchwork.libcamera.org/series/249/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/978/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/978/checks/","tags":{},"headers":{"Return-Path":"","Received":["from bin-mail-out-05.binero.net (bin-mail-out-05.binero.net\n\t[195.74.38.228])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 1474E60DD8\n\tfor ;\n\tSun, 14 Apr 2019 03:35:20 +0200 (CEST)","from bismarck.berto.se (unknown [89.233.230.99])\n\tby bin-vsp-out-02.atm.binero.net (Halon) with ESMTPA\n\tid 8ff64ebe-5e55-11e9-8e2c-005056917f90;\n\tSun, 14 Apr 2019 03:35:19 +0200 (CEST)"],"X-Halon-ID":"8ff64ebe-5e55-11e9-8e2c-005056917f90","Authorized-sender":"niklas@soderlund.pp.se","From":"=?utf-8?q?Niklas_S=C3=B6derlund?= ","To":"libcamera-devel@lists.libcamera.org","Date":"Sun, 14 Apr 2019 03:35:04 +0200","Message-Id":"<20190414013506.10515-10-niklas.soderlund@ragnatech.se>","X-Mailer":"git-send-email 2.21.0","In-Reply-To":"<20190414013506.10515-1-niklas.soderlund@ragnatech.se>","References":"<20190414013506.10515-1-niklas.soderlund@ragnatech.se>","MIME-Version":"1.0","Content-Type":"text/plain; charset=UTF-8","Content-Transfer-Encoding":"8bit","Subject":"[libcamera-devel] [RFC 09/11] libcamera: media_device: Add\n\tfunctions to lock device for other processes","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.23","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","X-List-Received-Date":"Sun, 14 Apr 2019 01:35:21 -0000"},"content":"Add lock() and unlock() which backed by lockf() allows an instance of\nlibcamera to claim exclusive access to a media device. These functions\nis the base to allow multiple users of libcamera to coexist in the\nsystem without stepping on each others toes.\n\nSigned-off-by: Niklas Söderlund \n---\n src/libcamera/include/media_device.h | 4 ++++\n src/libcamera/media_device.cpp | 29 +++++++++++++++++++++++++++-\n 2 files changed, 32 insertions(+), 1 deletion(-)","diff":"diff --git a/src/libcamera/include/media_device.h b/src/libcamera/include/media_device.h\nindex 5d28a7bb8214ef4a..e2956549fa201ea3 100644\n--- a/src/libcamera/include/media_device.h\n+++ b/src/libcamera/include/media_device.h\n@@ -64,6 +64,10 @@ private:\n \tbool acquire();\n \tvoid release();\n \n+\tbool lockOwner_;\n+\tbool lock();\n+\tvoid unlock();\n+\n \tstd::map objects_;\n \tMediaObject *object(unsigned int id);\n \tbool addObject(MediaObject *object);\ndiff --git a/src/libcamera/media_device.cpp b/src/libcamera/media_device.cpp\nindex 46931f52688f6c82..5cea4e63715125c8 100644\n--- a/src/libcamera/media_device.cpp\n+++ b/src/libcamera/media_device.cpp\n@@ -62,7 +62,8 @@ LOG_DEFINE_CATEGORY(MediaDevice)\n * populate() before the media graph can be queried.\n */\n MediaDevice::MediaDevice(const std::string &deviceNode)\n-\t: deviceNode_(deviceNode), fd_(-1), valid_(false), acquired_(false)\n+\t: deviceNode_(deviceNode), fd_(-1), valid_(false), acquired_(false),\n+\t lockOwner_(false)\n {\n }\n \n@@ -421,6 +422,32 @@ void MediaDevice::release()\n \tacquired_ = false;\n }\n \n+bool MediaDevice::lock()\n+{\n+\tif (fd_ == -1)\n+\t\treturn false;\n+\n+\tif (lockOwner_)\n+\t\treturn true;\n+\n+\tif (lockf(fd_, F_TLOCK, 0))\n+\t\treturn false;\n+\n+\tlockOwner_ = true;\n+\n+\treturn true;\n+}\n+\n+void MediaDevice::unlock()\n+{\n+\tif (fd_ == -1)\n+\t\treturn;\n+\n+\tlockOwner_ = false;\n+\n+\tlockf(fd_, F_ULOCK, 0);\n+}\n+\n /**\n * \\var MediaDevice::objects_\n * \\brief Global map of media objects (entities, pads, links) keyed by their\n","prefixes":["libcamera-devel","RFC","09/11"]}