[libcamera-devel] [PATCH v5 03/12] v4l2: Consolidate mutex classes to Mutex and MutexLocker

[Umang Jain]

Hi Hiro,

Thank you for the patch.

On 12/1/21 1:23 PM, Hirokazu Honda wrote:
> std::mutex and std::unique_lock are used in v4l2 directory,
> mixing Mutex and MutexLocker. This consolidates them to Mutex
> and MutexLocker.
>
> This also fixes vidioc_dqbuf argument to take Mutex instead of
> MutexLocker.
>
> Signed-off-by: Hirokazu Honda <hiroh at chromium.org>
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>


Reviewed-by: Umang Jain <umang.jain at ideasonboard.com>

> ---
>   src/v4l2/v4l2_camera.h         | 4 ++--
>   src/v4l2/v4l2_camera_proxy.cpp | 8 ++++----
>   src/v4l2/v4l2_camera_proxy.h   | 4 +++-
>   3 files changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/src/v4l2/v4l2_camera.h b/src/v4l2/v4l2_camera.h
> index 4afbb331..bf1b6de4 100644
> --- a/src/v4l2/v4l2_camera.h
> +++ b/src/v4l2/v4l2_camera.h
> @@ -8,10 +8,10 @@
>   #pragma once
>   
>   #include <deque>
> -#include <mutex>
>   #include <utility>
>   
>   #include <libcamera/base/semaphore.h>
> +#include <libcamera/base/thread.h>
>   
>   #include <libcamera/camera.h>
>   #include <libcamera/file_descriptor.h>
> @@ -71,7 +71,7 @@ private:
>   
>   	bool isRunning_;
>   
> -	std::mutex bufferLock_;
> +	libcamera::Mutex bufferLock_;
>   	libcamera::FrameBufferAllocator *bufferAllocator_;
>   
>   	std::vector<std::unique_ptr<libcamera::Request>> requestPool_;
> diff --git a/src/v4l2/v4l2_camera_proxy.cpp b/src/v4l2/v4l2_camera_proxy.cpp
> index 3610e63c..79bc880d 100644
> --- a/src/v4l2/v4l2_camera_proxy.cpp
> +++ b/src/v4l2/v4l2_camera_proxy.cpp
> @@ -575,7 +575,7 @@ int V4L2CameraProxy::vidioc_qbuf(V4L2CameraFile *file, struct v4l2_buffer *arg)
>   }
>   
>   int V4L2CameraProxy::vidioc_dqbuf(V4L2CameraFile *file, struct v4l2_buffer *arg,
> -				  MutexLocker *locker)
> +				  Mutex *lock)
>   {
>   	LOG(V4L2Compat, Debug) << "Servicing vidioc_dqbuf fd = " << file->efd();
>   
> @@ -593,9 +593,9 @@ int V4L2CameraProxy::vidioc_dqbuf(V4L2CameraFile *file, struct v4l2_buffer *arg,
>   		return -EINVAL;
>   
>   	if (!file->nonBlocking()) {
> -		locker->unlock();
> +		lock->unlock();
>   		vcam_->waitForBufferAvailable();
> -		locker->lock();
> +		lock->lock();
>   	} else if (!vcam_->isBufferAvailable())
>   		return -EAGAIN;
>   
> @@ -753,7 +753,7 @@ int V4L2CameraProxy::ioctl(V4L2CameraFile *file, unsigned long request, void *ar
>   		ret = vidioc_qbuf(file, static_cast<struct v4l2_buffer *>(arg));
>   		break;
>   	case VIDIOC_DQBUF:
> -		ret = vidioc_dqbuf(file, static_cast<struct v4l2_buffer *>(arg), &locker);
> +		ret = vidioc_dqbuf(file, static_cast<struct v4l2_buffer *>(arg), &proxyMutex_);
>   		break;
>   	case VIDIOC_STREAMON:
>   		ret = vidioc_streamon(file, static_cast<int *>(arg));
> diff --git a/src/v4l2/v4l2_camera_proxy.h b/src/v4l2/v4l2_camera_proxy.h
> index fccec241..040954dd 100644
> --- a/src/v4l2/v4l2_camera_proxy.h
> +++ b/src/v4l2/v4l2_camera_proxy.h
> @@ -14,6 +14,8 @@
>   #include <sys/types.h>
>   #include <vector>
>   
> +#include <libcamera/base/thread.h>
> +
>   #include <libcamera/camera.h>
>   
>   #include "v4l2_camera.h"
> @@ -57,7 +59,7 @@ private:
>   	int vidioc_querybuf(V4L2CameraFile *file, struct v4l2_buffer *arg);
>   	int vidioc_qbuf(V4L2CameraFile *file, struct v4l2_buffer *arg);
>   	int vidioc_dqbuf(V4L2CameraFile *file, struct v4l2_buffer *arg,
> -			 libcamera::MutexLocker *locker);
> +			 libcamera::Mutex *lock);
>   	int vidioc_streamon(V4L2CameraFile *file, int *arg);
>   	int vidioc_streamoff(V4L2CameraFile *file, int *arg);
>