[libcamera-devel] [PATCH v3 3/4] android: Stub GraphicBufferAllocator for build tests

[Laurent Pinchart]

Hi Mattijs,

Thank you for the patch.

On Sat, Sep 23, 2023 at 06:23:33PM +0200, Mattijs Korpershoek via libcamera-devel wrote:
> If we want to keep building libcamera on traditional Linux systems with:
>   -Dandroid=enabled -Dandroid_platform=generic
> 
> We should stub GraphicBufferAllocator, which is not available.
> It's only available when building with the VNDK or when building within the
> AOSP tree.
> 
> Also remove some deprecated methods and inclusions which are not needed for
> the stub class.
> 
> Note: the imported headers from Android generate the -Wextra-semi warning.
>       To avoid patching the files, a pragma has been added before inclusion.
> 
> Signed-off-by: Mattijs Korpershoek <mkorpershoek at baylibre.com>
> Reviewed-by: Jacopo Mondi <jacopo.mondi at ideasonboard.com>
> ---
>  .../libs/ui/include/ui/GraphicBufferAllocator.h    | 30 ------------
>  src/android/mm/graphic_buffer_allocator_stub.cpp   | 54 ++++++++++++++++++++++
>  src/android/mm/meson.build                         |  7 +++
>  3 files changed, 61 insertions(+), 30 deletions(-)
> 
> diff --git a/include/android/frameworks/native/libs/ui/include/ui/GraphicBufferAllocator.h b/include/android/frameworks/native/libs/ui/include/ui/GraphicBufferAllocator.h
> index e4674d746e37..9eac5bbe8324 100644
> --- a/include/android/frameworks/native/libs/ui/include/ui/GraphicBufferAllocator.h
> +++ b/include/android/frameworks/native/libs/ui/include/ui/GraphicBufferAllocator.h
> @@ -29,15 +29,10 @@
>  #include <ui/PixelFormat.h>
>  
>  #include <utils/Errors.h>
> -#include <utils/KeyedVector.h>
> -#include <utils/Mutex.h>
>  #include <utils/Singleton.h>
>  
>  namespace android {
>  
> -class GrallocAllocator;
> -class GraphicBufferMapper;
> -
>  class GraphicBufferAllocator : public Singleton<GraphicBufferAllocator>
>  {
>  public:
> @@ -52,25 +47,6 @@ public:
>                        uint64_t usage, buffer_handle_t* handle, uint32_t* stride,
>                        std::string requestorName);
>  
> -    /**
> -     * Allocates and does NOT import a gralloc buffer. Buffers cannot be used until they have
> -     * been imported. This function is for advanced use cases only.
> -     *
> -     * The raw native handle must be freed by calling native_handle_close() followed by
> -     * native_handle_delete().
> -     */
> -    status_t allocateRawHandle(uint32_t w, uint32_t h, PixelFormat format, uint32_t layerCount,
> -                               uint64_t usage, buffer_handle_t* handle, uint32_t* stride,
> -                               std::string requestorName);
> -
> -    /**
> -     * DEPRECATED: GraphicBufferAllocator does not use the graphicBufferId.
> -     */
> -    status_t allocate(uint32_t w, uint32_t h, PixelFormat format,
> -            uint32_t layerCount, uint64_t usage,
> -            buffer_handle_t* handle, uint32_t* stride, uint64_t graphicBufferId,
> -            std::string requestorName);
> -
>      status_t free(buffer_handle_t handle);
>  
>      uint64_t getTotalSize() const;
> @@ -94,15 +70,9 @@ protected:
>                              uint64_t usage, buffer_handle_t* handle, uint32_t* stride,
>                              std::string requestorName, bool importBuffer);
>  
> -    static Mutex sLock;
> -    static KeyedVector<buffer_handle_t, alloc_rec_t> sAllocList;
> -
>      friend class Singleton<GraphicBufferAllocator>;
>      GraphicBufferAllocator();
>      ~GraphicBufferAllocator();
> -
> -    GraphicBufferMapper& mMapper;
> -    std::unique_ptr<const GrallocAllocator> mAllocator;

This makes me very uncomfortable. You're changing the class size. It is
probably harmless here as the fields are at the end, but it's still
fairly bad practice, and could cause hard to debug issues later.

I think we're reaching a point where we may want to require a VNDK to
compile the Android HAL.

>  };
>  
>  // ---------------------------------------------------------------------------
> diff --git a/src/android/mm/graphic_buffer_allocator_stub.cpp b/src/android/mm/graphic_buffer_allocator_stub.cpp
> new file mode 100644
> index 000000000000..7e412c956887
> --- /dev/null
> +++ b/src/android/mm/graphic_buffer_allocator_stub.cpp
> @@ -0,0 +1,54 @@
> +/* SPDX-License-Identifier: Apache-2.0 */
> +/*
> + * Copyright (C) 2023, Ideas on Board
> + * Copyright (C) 2023, BayLibre
> + *
> + * graphic_buffer_allocator_stub.cpp - Android GraphicBufferAllocator
> + * stub for compile-testing
> + */
> +
> +#pragma GCC diagnostic push
> +#pragma GCC diagnostic ignored "-Wextra-semi"

Could you handle this in meson.build ? Adding pragmas around header
inclusion isn't nice, especially given that you need to do the same in
patch 4/4.

> +#include <ui/GraphicBufferAllocator.h>
> +#pragma GCC diagnostic pop
> +
> +namespace android {
> +
> +ANDROID_SINGLETON_STATIC_INSTANCE(GraphicBufferAllocator)
> +
> +GraphicBufferAllocator::GraphicBufferAllocator()
> +{
> +}
> +
> +GraphicBufferAllocator::~GraphicBufferAllocator()
> +{
> +}
> +
> +uint64_t GraphicBufferAllocator::getTotalSize() const
> +{
> +	return 0;
> +}
> +
> +#pragma GCC diagnostic push
> +#pragma GCC diagnostic ignored "-Wunused-parameter"

You can use [[maybe_unused]] instead.

> +status_t GraphicBufferAllocator::allocate(uint32_t width,
> +					  uint32_t height,
> +					  PixelFormat format,
> +					  uint32_t layerCount,
> +					  uint64_t usage,
> +					  buffer_handle_t *handle,
> +					  uint32_t *stride,
> +					  std::string requestorName)
> +{
> +	*handle = nullptr;
> +	*stride = 0;
> +	return INVALID_OPERATION;
> +}
> +
> +status_t GraphicBufferAllocator::free(buffer_handle_t handle)
> +{
> +	return INVALID_OPERATION;
> +}
> +#pragma GCC diagnostic pop
> +
> +} // namespace android
> diff --git a/src/android/mm/meson.build b/src/android/mm/meson.build
> index e3e0484c3720..4d1fb718e94e 100644
> --- a/src/android/mm/meson.build
> +++ b/src/android/mm/meson.build
> @@ -12,6 +12,13 @@ if platform == 'generic'
>      else
>          android_hal_sources += files(['libhardware_stub.c'])
>      endif
> +
> +    libui = dependency('libui', required : false)
> +    if libui.found()
> +        android_deps += [libui]
> +     else
> +        android_hal_sources += files(['graphic_buffer_allocator_stub.cpp'])
> +    endif
>  elif platform == 'cros'
>      android_hal_sources += files(['cros_camera_buffer.cpp',
>                                    'cros_frame_buffer_allocator.cpp'])
> 

-- 
Regards,

Laurent Pinchart