{"id":127,"url":"https://patchwork.libcamera.org/api/1.1/patches/127/?format=json","web_url":"https://patchwork.libcamera.org/patch/127/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/1.1/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":"<20190102004903.24190-1-laurent.pinchart@ideasonboard.com>","date":"2019-01-02T00:49:01","name":"[libcamera-devel,1/3] libcamera: media_device: Add DeviceInfo features","commit_ref":null,"pull_url":null,"state":"accepted","archived":false,"hash":"840a4d7f5cfd0590464c8d75482d47c7c5ad6085","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/1.1/people/2/?format=json","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/127/mbox/","series":[{"id":47,"url":"https://patchwork.libcamera.org/api/1.1/series/47/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=47","date":"2019-01-02T00:49:01","name":"[libcamera-devel,1/3] libcamera: media_device: Add DeviceInfo features","version":1,"mbox":"https://patchwork.libcamera.org/series/47/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/127/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/127/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 3462160B30\n\tfor ;\n\tWed, 2 Jan 2019 01:48:08 +0100 (CET)","from avalon.bb.dnainternet.fi\n\t(dfj612ybrt5fhg77mgycy-3.rev.dnainternet.fi\n\t[IPv6:2001:14ba:21f5:5b00:2e86:4862:ef6a:2804])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id A9F7F505\n\tfor ;\n\tWed, 2 Jan 2019 01:48:07 +0100 (CET)"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1546390087;\n\tbh=Ht6R9xbDXuATQK4BdllJKlU5jcPbz9AZP0pXp0qK+JU=;\n\th=From:To:Subject:Date:From;\n\tb=jU3y16oafU4TPbKi+FA5MN5p1g9cPbqAVMnU2RKSGVkEfwjuDvx/pIkoLEWDDziwX\n\tGrpjh6tjDv/JaofOth6ijCFSgCNOTErmLL536wqbbHEvIaobZMewfDVwdkdJTuMEqU\n\tTsuRELrMtRJB22AioFik6s7yKBWO0X/YNkRfI+Oc=","From":"Laurent Pinchart ","To":"libcamera-devel@lists.libcamera.org","Date":"Wed, 2 Jan 2019 02:49:01 +0200","Message-Id":"<20190102004903.24190-1-laurent.pinchart@ideasonboard.com>","X-Mailer":"git-send-email 2.19.2","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","Subject":"[libcamera-devel] [PATCH 1/3] libcamera: media_device: Add\n\tDeviceInfo features","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":"Wed, 02 Jan 2019 00:48:08 -0000"},"content":"From: Jacopo Mondi \n\nAdd the features of the DeviceInfo class needed to replace it with\nMediaDevice.\n\nSigned-off-by: Jacopo Mondi \nSigned-off-by: Laurent Pinchart \n---\n src/libcamera/include/media_device.h | 5 +++\n src/libcamera/media_device.cpp | 52 ++++++++++++++++++++++++++--\n 2 files changed, 55 insertions(+), 2 deletions(-)","diff":"diff --git a/src/libcamera/include/media_device.h b/src/libcamera/include/media_device.h\nindex d787be391882..3fcdb4b4d5f8 100644\n--- a/src/libcamera/include/media_device.h\n+++ b/src/libcamera/include/media_device.h\n@@ -24,6 +24,10 @@ public:\n \tMediaDevice(const std::string &devnode);\n \t~MediaDevice();\n \n+\tbool acquire();\n+\tvoid release() { acquired_ = false; }\n+\tbool busy() const { return acquired_; }\n+\n \tint open();\n \tvoid close();\n \n@@ -41,6 +45,7 @@ private:\n \tstd::string devnode_;\n \tint fd_;\n \tbool valid_;\n+\tbool acquired_;\n \n \tstd::map objects_;\n \tMediaObject *object(unsigned int id);\ndiff --git a/src/libcamera/media_device.cpp b/src/libcamera/media_device.cpp\nindex 1bd4f43a0c79..605e504be124 100644\n--- a/src/libcamera/media_device.cpp\n+++ b/src/libcamera/media_device.cpp\n@@ -52,7 +52,11 @@ namespace libcamera {\n * controller device node. It can be closed at any time with a call to close().\n * This will not invalidate the media graph and all cached media objects remain\n * valid and can be accessed normally. The device can then be later reopened if\n- * needed to perform other operations that interact with the device node.\n+ * needed to perform other operations that interect with the device node.\n+ *\n+ * Media device can be claimed for exclusive use with acquire(), released with\n+ * release() and tested with busy(). This mechanism is aimed at pipeline\n+ * managers to claim media devices they support during enumeration.\n */\n \n /**\n@@ -63,7 +67,7 @@ namespace libcamera {\n * populated with open() and populate() before the media graph can be queried.\n */\n MediaDevice::MediaDevice(const std::string &devnode)\n-\t: devnode_(devnode), fd_(-1), valid_(false)\n+\t: devnode_(devnode), fd_(-1), valid_(false), acquired_(false)\n {\n }\n \n@@ -74,6 +78,50 @@ MediaDevice::~MediaDevice()\n \tclear();\n }\n \n+/**\n+ * \\brief Claim a device for exclusive use\n+ *\n+ * The device claiming mechanism offers simple media device access arbitration\n+ * between multiple users. When the media device is created, it is available to\n+ * all users. Users can query the media graph to determine whether they can\n+ * support the device and, if they do, claim the device for exclusive use. Other\n+ * users are then expected to skip over media devices in use as reported by the\n+ * busy() function.\n+ *\n+ * Once claimed the device shall be released by its user when not needed anymore\n+ * by calling the release() function.\n+ *\n+ * Exclusive access is only guaranteed if all users of the media device abide by\n+ * the device claiming mechanism, as it isn't enforced by the media device\n+ * itself.\n+ *\n+ * \\return true if the device was successfully claimed, or false if it was\n+ * already in use\n+ * \\sa release(), busy()\n+ */\n+bool MediaDevice::acquire()\n+{\n+\tif (acquired_)\n+\t\treturn false;\n+\n+\tacquired_ = true;\n+\treturn true;\n+}\n+\n+/**\n+ * \\fn MediaDevice::release()\n+ * \\brief Release a device previously claimed for exclusive use\n+ * \\sa acquire(), busy()\n+ */\n+\n+/**\n+ * \\fn MediaDevice::busy()\n+ * \\brief Check if a device is in use\n+ * \\return true if the device has been claimed for exclusive user, or false if\n+ * it is available\n+ * \\sa acquire(), release()\n+ */\n+\n /**\n * \\brief Open a media device and retrieve device information\n *\n","prefixes":["libcamera-devel","1/3"]}