[libcamera-devel] [PATCH] gstreamer: Drop libcamera_private dependency

[Nicolas Dufresne]

Hi,

Le mardi 27 juin 2023 à 13:52 +0200, Umang Jain a écrit :
> Drop libcamera_private dependency entirely as to avoid libcamerasrc
> getting more dependent on it. In order to achieve that, one of the
> mutex locks in GstLibcameraSrcState needs to be replaced with GMutex.
> 
> However doing so, this won't let us to use the clang's thread annotation
> macros in libcamera (which should be fine as libcamerasrc would move
> out of libcamera repo once matured).
> 
> Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
> Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

Reviewed-by: Nicolas Dufresne <nicolas.dufresne at collabora.com>

> ---
>  src/gstreamer/gstlibcamerasrc.cpp | 23 +++++++++++------------
>  src/gstreamer/meson.build         |  2 +-
>  2 files changed, 12 insertions(+), 13 deletions(-)
> 
> diff --git a/src/gstreamer/gstlibcamerasrc.cpp b/src/gstreamer/gstlibcamerasrc.cpp
> index 11f15068..b5c6e9ab 100644
> --- a/src/gstreamer/gstlibcamerasrc.cpp
> +++ b/src/gstreamer/gstlibcamerasrc.cpp
> @@ -32,8 +32,6 @@
>  #include <queue>
>  #include <vector>
>  
> -#include <libcamera/base/mutex.h>
> -
>  #include <libcamera/camera.h>
>  #include <libcamera/camera_manager.h>
>  #include <libcamera/control_ids.h>
> @@ -125,11 +123,9 @@ struct GstLibcameraSrcState {
>  	 * be held while calling into other graph elements (e.g. when calling
>  	 * gst_pad_query()).
>  	 */
> -	Mutex lock_;
> -	std::queue<std::unique_ptr<RequestWrap>> queuedRequests_
> -		LIBCAMERA_TSA_GUARDED_BY(lock_);
> -	std::queue<std::unique_ptr<RequestWrap>> completedRequests_
> -		LIBCAMERA_TSA_GUARDED_BY(lock_);
> +	GMutex lock_;
> +	std::queue<std::unique_ptr<RequestWrap>> queuedRequests_;
> +	std::queue<std::unique_ptr<RequestWrap>> completedRequests_;
>  
>  	ControlList initControls_;
>  	guint group_id_;
> @@ -208,7 +204,7 @@ int GstLibcameraSrcState::queueRequest()
>  	cam_->queueRequest(wrap->request_.get());
>  
>  	{
> -		MutexLocker locker(lock_);
> +		GLibLocker locker(&lock_);
>  		queuedRequests_.push(std::move(wrap));
>  	}
>  
> @@ -224,7 +220,7 @@ GstLibcameraSrcState::requestCompleted(Request *request)
>  	std::unique_ptr<RequestWrap> wrap;
>  
>  	{
> -		MutexLocker locker(lock_);
> +		GLibLocker locker(&lock_);
>  		wrap = std::move(queuedRequests_.front());
>  		queuedRequests_.pop();
>  	}
> @@ -251,7 +247,7 @@ GstLibcameraSrcState::requestCompleted(Request *request)
>  	}
>  
>  	{
> -		MutexLocker locker(lock_);
> +		GLibLocker locker(&lock_);
>  		completedRequests_.push(std::move(wrap));
>  	}
>  
> @@ -265,7 +261,7 @@ int GstLibcameraSrcState::processRequest()
>  	int err = 0;
>  
>  	{
> -		MutexLocker locker(lock_);
> +		GLibLocker locker(&lock_);
>  
>  		if (!completedRequests_.empty()) {
>  			wrap = std::move(completedRequests_.front());
> @@ -639,7 +635,7 @@ gst_libcamera_src_task_leave([[maybe_unused]] GstTask *task,
>  	state->cam_->stop();
>  
>  	{
> -		MutexLocker locker(state->lock_);
> +		GLibLocker locker(&state->lock_);
>  		state->completedRequests_ = {};
>  	}
>  
> @@ -776,6 +772,7 @@ gst_libcamera_src_finalize(GObject *object)
>  
>  	g_rec_mutex_clear(&self->stream_lock);
>  	g_clear_object(&self->task);
> +	g_mutex_clear(&self->state->lock_);
>  	g_free(self->camera_name);
>  	delete self->controls;
>  	delete self->state;
> @@ -795,6 +792,8 @@ gst_libcamera_src_init(GstLibcameraSrc *self)
>  	gst_task_set_leave_callback(self->task, gst_libcamera_src_task_leave, self, nullptr);
>  	gst_task_set_lock(self->task, &self->stream_lock);
>  
> +	g_mutex_init(&state->lock_);
> +
>  	state->srcpads_.push_back(gst_pad_new_from_template(templ, "src"));
>  	gst_element_add_pad(GST_ELEMENT(self), state->srcpads_.back());
>  
> diff --git a/src/gstreamer/meson.build b/src/gstreamer/meson.build
> index eda246d7..77c79140 100644
> --- a/src/gstreamer/meson.build
> +++ b/src/gstreamer/meson.build
> @@ -42,7 +42,7 @@ endif
>  libcamera_gst = shared_library('gstlibcamera',
>      libcamera_gst_sources,
>      cpp_args : libcamera_gst_cpp_args,
> -    dependencies : [libcamera_private, gstvideo_dep, gstallocator_dep],
> +    dependencies : [libcamera_public, gstvideo_dep, gstallocator_dep],
>      install: true,
>      install_dir : '@0@/gstreamer-1.0'.format(get_option('libdir')),
>  )