From d9ae18088a62afc9cebcaa35809fa2457c37bac8 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Sun, 29 Aug 2021 21:03:23 +0300 Subject: libcamera: media_device: Move recursive lock handling to pipeline handler The MediaDevice lock is meant to prevent concurrent usage of multiple cameras from the same pipeline handlers. As media devices are acquired by pipeline handlers, we can't have multiple pipeline handlers trying to lock the same media device. The recursive locking detection can thus be moved to the pipeline handler. This simplifies the media device implementation that now implements true lock semantics, and prepares for support of concurrent camera usage. Signed-off-by: Laurent Pinchart --- src/libcamera/media_device.cpp | 14 +------------- src/libcamera/pipeline_handler.cpp | 13 ++++++++++++- 2 files changed, 13 insertions(+), 14 deletions(-) (limited to 'src') diff --git a/src/libcamera/media_device.cpp b/src/libcamera/media_device.cpp index aa93da75..ced19a10 100644 --- a/src/libcamera/media_device.cpp +++ b/src/libcamera/media_device.cpp @@ -63,8 +63,7 @@ LOG_DEFINE_CATEGORY(MediaDevice) * populate() before the media graph can be queried. */ MediaDevice::MediaDevice(const std::string &deviceNode) - : deviceNode_(deviceNode), fd_(-1), valid_(false), acquired_(false), - lockOwner_(false) + : deviceNode_(deviceNode), fd_(-1), valid_(false), acquired_(false) { } @@ -146,15 +145,9 @@ bool MediaDevice::lock() if (fd_ == -1) return false; - /* Do not allow nested locking in the same libcamera instance. */ - if (lockOwner_) - return false; - if (lockf(fd_, F_TLOCK, 0)) return false; - lockOwner_ = true; - return true; } @@ -172,11 +165,6 @@ void MediaDevice::unlock() if (fd_ == -1) return; - if (!lockOwner_) - return; - - lockOwner_ = false; - lockf(fd_, F_ULOCK, 0); } diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp index f69c4f03..3d61311c 100644 --- a/src/libcamera/pipeline_handler.cpp +++ b/src/libcamera/pipeline_handler.cpp @@ -62,7 +62,7 @@ LOG_DEFINE_CATEGORY(Pipeline) * respective factories. */ PipelineHandler::PipelineHandler(CameraManager *manager) - : manager_(manager) + : manager_(manager), lockOwner_(false) { } @@ -150,6 +150,10 @@ MediaDevice *PipelineHandler::acquireMediaDevice(DeviceEnumerator *enumerator, */ bool PipelineHandler::lock() { + /* Do not allow nested locking in the same libcamera instance. */ + if (lockOwner_) + return false; + for (std::shared_ptr &media : mediaDevices_) { if (!media->lock()) { unlock(); @@ -157,6 +161,8 @@ bool PipelineHandler::lock() } } + lockOwner_ = true; + return true; } @@ -172,8 +178,13 @@ bool PipelineHandler::lock() */ void PipelineHandler::unlock() { + if (lockOwner_) + return; + for (std::shared_ptr &media : mediaDevices_) media->unlock(); + + lockOwner_ = false; } /** -- cgit v1.2.1