{"id":4196,"url":"https://patchwork.libcamera.org/api/1.1/patches/4196/?format=json","web_url":"https://patchwork.libcamera.org/patch/4196/","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":"<20200623190836.53446-23-paul.elder@ideasonboard.com>","date":"2020-06-23T19:08:36","name":"[libcamera-devel,v3,22/22] v4l2: v4l2_camera_proxy: Serialize accesses to the proxy","commit_ref":null,"pull_url":null,"state":"superseded","archived":false,"hash":"a78ea1d93936572be0fbfca8264906869ef814a5","submitter":{"id":17,"url":"https://patchwork.libcamera.org/api/1.1/people/17/?format=json","name":"Paul Elder","email":"paul.elder@ideasonboard.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/4196/mbox/","series":[{"id":1034,"url":"https://patchwork.libcamera.org/api/1.1/series/1034/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=1034","date":"2020-06-23T19:08:14","name":"Support v4l2-compliance","version":3,"mbox":"https://patchwork.libcamera.org/series/1034/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/4196/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/4196/checks/","tags":{},"headers":{"Return-Path":"","Received":["from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 9DD28609A5\n\tfor ;\n\tTue, 23 Jun 2020 21:09:54 +0200 (CEST)","from jade.rasen.tech (unknown\n\t[IPv6:2400:4051:61:600:8147:f2a2:a8c6:9087])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id D82D62A9;\n\tTue, 23 Jun 2020 21:09:52 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key; \n\tunprotected) header.d=ideasonboard.com\n\theader.i=@ideasonboard.com\n\theader.b=\"aYFYKMfd\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1592939394;\n\tbh=k8o6WuWrzmBNrvXuH4vQNDxdWsdjieEbXQZDGJ4Tib8=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=aYFYKMfdizUdEB3LEj/WS9j4AU9LmiDaW2fM2FHpDHKnazmUj9Oj7xXEFIzQOgtQg\n\tdvILgj1TUHqiFDFUQCgU9XJmWfMf4BuKKaLeQuY8Eb+XPgCmM7enG/4E+kfuDRxadS\n\t/NQZXFDC49F8Z8z767+/CZKj8PtD4c85jipjs+ss=","From":"Paul Elder ","To":"libcamera-devel@lists.libcamera.org","Date":"Wed, 24 Jun 2020 04:08:36 +0900","Message-Id":"<20200623190836.53446-23-paul.elder@ideasonboard.com>","X-Mailer":"git-send-email 2.27.0","In-Reply-To":"<20200623190836.53446-1-paul.elder@ideasonboard.com>","References":"<20200623190836.53446-1-paul.elder@ideasonboard.com>","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","Subject":"[libcamera-devel] [PATCH v3 22/22] v4l2: v4l2_camera_proxy:\n\tSerialize accesses to the proxy","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":"Tue, 23 Jun 2020 19:09:54 -0000"},"content":"Make the V4L2 compatibility layer thread-safe by serializing accesses to\nthe V4L2CameraProxy with a lock. Release the lock when blocking for\ndqbuf.\n\nSigned-off-by: Paul Elder \n\n---\nNew in v3\n---\n src/v4l2/v4l2_camera_proxy.cpp | 21 +++++++++++++++++----\n src/v4l2/v4l2_camera_proxy.h | 5 ++++-\n 2 files changed, 21 insertions(+), 5 deletions(-)","diff":"diff --git a/src/v4l2/v4l2_camera_proxy.cpp b/src/v4l2/v4l2_camera_proxy.cpp\nindex ed3bcbc..fb3a1fc 100644\n--- a/src/v4l2/v4l2_camera_proxy.cpp\n+++ b/src/v4l2/v4l2_camera_proxy.cpp\n@@ -43,6 +43,8 @@ V4L2CameraProxy::V4L2CameraProxy(unsigned int index,\n \n int V4L2CameraProxy::open(V4L2CameraFile *file)\n {\n+\tMutexLocker locker(proxyMutex_);\n+\n \tLOG(V4L2Compat, Debug) << \"Servicing open fd = \" << file->efd();\n \n \tfiles_.insert(file);\n@@ -75,6 +77,8 @@ int V4L2CameraProxy::open(V4L2CameraFile *file)\n \n void V4L2CameraProxy::close(V4L2CameraFile *file)\n {\n+\tMutexLocker locker(proxyMutex_);\n+\n \tLOG(V4L2Compat, Debug) << \"Servicing close fd = \" << file->efd();\n \n \tfiles_.erase(file);\n@@ -90,6 +94,8 @@ void V4L2CameraProxy::close(V4L2CameraFile *file)\n void *V4L2CameraProxy::mmap(void *addr, size_t length, int prot, int flags,\n \t\t\t off64_t offset)\n {\n+\tMutexLocker locker(proxyMutex_);\n+\n \tLOG(V4L2Compat, Debug) << \"Servicing mmap\";\n \n \t/* \\todo Validate prot and flags properly. */\n@@ -124,6 +130,8 @@ void *V4L2CameraProxy::mmap(void *addr, size_t length, int prot, int flags,\n \n int V4L2CameraProxy::munmap(void *addr, size_t length)\n {\n+\tMutexLocker locker(proxyMutex_);\n+\n \tLOG(V4L2Compat, Debug) << \"Servicing munmap\";\n \n \tauto iter = mmaps_.find(addr);\n@@ -592,7 +600,8 @@ int V4L2CameraProxy::vidioc_qbuf(V4L2CameraFile *file, struct v4l2_buffer *arg)\n \treturn ret;\n }\n \n-int V4L2CameraProxy::vidioc_dqbuf(V4L2CameraFile *file, struct v4l2_buffer *arg)\n+int V4L2CameraProxy::vidioc_dqbuf(V4L2CameraFile *file,\n+\t\t\t\t struct v4l2_buffer *arg, MutexLocker &locker)\n {\n \tLOG(V4L2Compat, Debug) << \"Servicing vidioc_dqbuf fd = \" << file->efd();\n \n@@ -609,9 +618,11 @@ int V4L2CameraProxy::vidioc_dqbuf(V4L2CameraFile *file, struct v4l2_buffer *arg)\n \t !validateMemoryType(arg->memory))\n \t\treturn -EINVAL;\n \n-\tif (!(file->nonBlocking()))\n+\tif (!(file->nonBlocking())) {\n+\t\tlocker.unlock();\n \t\tvcam_->waitForBufferAvailable();\n-\telse if (!vcam_->isBufferAvailable())\n+\t\tlocker.lock();\n+\t} else if (!vcam_->isBufferAvailable())\n \t\treturn -EAGAIN;\n \n \t/*\n@@ -706,6 +717,8 @@ const std::set V4L2CameraProxy::supportedIoctls_ = {\n \n int V4L2CameraProxy::ioctl(V4L2CameraFile *file, unsigned long request, void *arg)\n {\n+\tMutexLocker locker(proxyMutex_);\n+\n \tif (!arg && (_IOC_DIR(request) & _IOC_WRITE)) {\n \t\terrno = EFAULT;\n \t\treturn -1;\n@@ -766,7 +779,7 @@ int V4L2CameraProxy::ioctl(V4L2CameraFile *file, unsigned long request, void *ar\n \t\tret = vidioc_qbuf(file, static_cast(arg));\n \t\tbreak;\n \tcase VIDIOC_DQBUF:\n-\t\tret = vidioc_dqbuf(file, static_cast(arg));\n+\t\tret = vidioc_dqbuf(file, static_cast(arg), locker);\n \t\tbreak;\n \tcase VIDIOC_STREAMON:\n \t\tret = vidioc_streamon(file, static_cast(arg));\ndiff --git a/src/v4l2/v4l2_camera_proxy.h b/src/v4l2/v4l2_camera_proxy.h\nindex 041f536..b6d2c2c 100644\n--- a/src/v4l2/v4l2_camera_proxy.h\n+++ b/src/v4l2/v4l2_camera_proxy.h\n@@ -61,7 +61,7 @@ private:\n \tint vidioc_reqbufs(V4L2CameraFile *file, struct v4l2_requestbuffers *arg);\n \tint vidioc_querybuf(V4L2CameraFile *file, struct v4l2_buffer *arg);\n \tint vidioc_qbuf(V4L2CameraFile *file, struct v4l2_buffer *arg);\n-\tint vidioc_dqbuf(V4L2CameraFile *file, struct v4l2_buffer *arg);\n+\tint vidioc_dqbuf(V4L2CameraFile *file, struct v4l2_buffer *arg, MutexLocker &locker);\n \tint vidioc_streamon(V4L2CameraFile *file, int *arg);\n \tint vidioc_streamoff(V4L2CameraFile *file, int *arg);\n \n@@ -105,6 +105,9 @@ private:\n \t * g/s_priority, enum/g/s_input\n \t */\n \tV4L2CameraFile *owner_;\n+\n+\t/* This mutex is to serialize access to the proxy. */\n+\tMutex proxyMutex_;\n };\n \n #endif /* __V4L2_CAMERA_PROXY_H__ */\n","prefixes":["libcamera-devel","v3","22/22"]}