[libcamera-devel] [PATCH v3 2/2] android: Introduce PlatformFrameBufferAllocator

Hirokazu Honda hiroh at chromium.org
Fri Nov 26 10:35:43 CET 2021


Hi Jacopo,

On Fri, Nov 26, 2021 at 6:19 PM Jacopo Mondi <jacopo at jmondi.org> wrote:
>
> Hi Hiro
>
> On Fri, Nov 26, 2021 at 12:36:31PM +0900, Hirokazu Honda wrote:
> > Hi Jacopo, thank you for reviewing.
> >
> > On Thu, Nov 25, 2021 at 9:09 AM Jacopo Mondi <jacopo at jmondi.org> wrote:
> > >
> > > Hi Hiro,
> > >
> > > On Wed, Nov 24, 2021 at 03:39:47AM +0900, Hirokazu Honda wrote:
> > > > The existing FrameBufferAllocator is not allowed to allocate a
> > > > new buffer while Camera is running. This introduces
> > > > PlatformFrameBufferAllocator. It allocates FrameBuffer using
> > > > cros::CameraBufferManager on ChromeOS and gralloc on non ChromeOS
> > > > platform. The allocated FrameBuffer owns the underlying buffer
> > > > but must be destroyed before PlatformFrameBufferAllocator is
> > > > destroyed.
> > > >
> > > > Signed-off-by: Hirokazu Honda <hiroh at chromium.org>
> > > > Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> > > > ---
> > > >  src/android/frame_buffer_allocator.h          |  54 +++++++
> > > >  .../mm/cros_frame_buffer_allocator.cpp        |  88 +++++++++++
> > > >  .../mm/generic_frame_buffer_allocator.cpp     | 142 ++++++++++++++++++
> > > >  src/android/mm/meson.build                    |   6 +-
> > > >  4 files changed, 288 insertions(+), 2 deletions(-)
> > > >  create mode 100644 src/android/frame_buffer_allocator.h
> > > >  create mode 100644 src/android/mm/cros_frame_buffer_allocator.cpp
> > > >  create mode 100644 src/android/mm/generic_frame_buffer_allocator.cpp
> > > >
> > > > diff --git a/src/android/frame_buffer_allocator.h b/src/android/frame_buffer_allocator.h
> > > > new file mode 100644
> > > > index 00000000..41ed4ae1
> > > > --- /dev/null
> > > > +++ b/src/android/frame_buffer_allocator.h
> > > > @@ -0,0 +1,54 @@
> > > > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > > > +/*
> > > > + * Copyright (C) 2021, Google Inc.
> > > > + *
> > > > + * frame_buffer_allocator.h - Interface definition to allocate Frame buffer in
> > > > + * platform dependent way.
> > > > + */
> > > > +#ifndef __ANDROID_FRAME_BUFFER_ALLOCATOR_H__
> > > > +#define __ANDROID_FRAME_BUFFER_ALLOCATOR_H__
> > > > +
> > > > +#include <memory>
> > > > +
> > > > +#include <libcamera/base/class.h>
> > >
> > > checkstyle should have suggested you a separate group ?
> > > It didn't for me recently but I got told so :)
> > >
> >
> > I don't get any error.
> >
> > > > +#include <libcamera/camera.h>
> > > > +#include <libcamera/framebuffer.h>
> > > > +#include <libcamera/geometry.h>
> > > > +
> > > > +class CameraDevice;
> > > > +
> > > > +class PlatformFrameBufferAllocator : libcamera::Extensible
> > > > +{
> > > > +     LIBCAMERA_DECLARE_PRIVATE()
> > > > +
> > > > +public:
> > > > +     explicit PlatformFrameBufferAllocator(CameraDevice *const cameraDevice);
> > > > +     ~PlatformFrameBufferAllocator();
> > > > +
> > > > +     /*
> > > > +      * FrameBuffer owns the underlying buffer. Returns nullptr on failure.
> > > > +      * Note: The returned FrameBuffer needs to be destroyed before
> > > > +      * PlatformFrameBufferAllocator is destroyed.
> > > > +      */
> > > > +     std::unique_ptr<libcamera::FrameBuffer> allocate(
> > > > +             int halPixelFormat, const libcamera::Size &size, uint32_t usage);
> > > > +};
> > > > +
> > > > +#define PUBLIC_FRAME_BUFFER_ALLOCATOR_IMPLEMENTATION                 \
> > > > +PlatformFrameBufferAllocator::PlatformFrameBufferAllocator(          \
> > > > +     CameraDevice *const cameraDevice)                               \
> > > > +     : Extensible(std::make_unique<Private>(this, cameraDevice))     \
> > > > +{                                                                    \
> > > > +}                                                                    \
> > > > +PlatformFrameBufferAllocator::~PlatformFrameBufferAllocator()                \
> > > > +{                                                                    \
> > > > +}                                                                    \
> > > > +std::unique_ptr<libcamera::FrameBuffer>                                      \
> > > > +PlatformFrameBufferAllocator::allocate(int halPixelFormat,           \
> > > > +                                    const libcamera::Size& size,     \
> > > > +                                    uint32_t usage)                  \
> > > > +{                                                                    \
> > > > +     return _d()->allocate(halPixelFormat, size, usage);             \
> > > > +}
> > > > +
> > > > +#endif /* __ANDROID_FRAME_BUFFER_ALLOCATOR_H__ */
> > > > diff --git a/src/android/mm/cros_frame_buffer_allocator.cpp b/src/android/mm/cros_frame_buffer_allocator.cpp
> > > > new file mode 100644
> > > > index 00000000..d6343e53
> > > > --- /dev/null
> > > > +++ b/src/android/mm/cros_frame_buffer_allocator.cpp
> > > > @@ -0,0 +1,88 @@
> > > > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > > > +/*
> > > > + * Copyright (C) 2021, Google Inc.
> > > > + *
> > > > + * cros_frame_buffer.cpp - Allocate FrameBuffer for Chromium OS using
> > > > + * CameraBufferManager
> > > > + */
> > > > +
> > > > +#include <memory>
> > > > +#include <vector>
> > > > +
> > > > +#include <libcamera/base/log.h>
> > > > +
> > > > +#include "libcamera/internal/framebuffer.h"
> > > > +
> > > > +#include "../camera_device.h"
> > > > +#include "../frame_buffer_allocator.h"
> > >
> > > Blank line ?
> > >
> > > > +#include "cros-camera/camera_buffer_manager.h"
> > > > +
> > > > +using namespace libcamera;
> > > > +
> > > > +LOG_DECLARE_CATEGORY(HAL)
> > > > +
> > > > +namespace {
> > >
> > > Blank line
> > >
> > > > +class CrosFrameBufferData : public FrameBuffer::Private
> > > > +{
> > > > +     LIBCAMERA_DECLARE_PUBLIC(FrameBuffer)
> > >
> > > Blank line
> > >
> > > > +public:
> > > > +     CrosFrameBufferData(cros::ScopedBufferHandle scopedHandle)
> > > > +             : FrameBuffer::Private(), scopedHandle_(std::move(scopedHandle))
> > > > +     {
> > > > +     }
> > > > +
> > > > +     ~CrosFrameBufferData() override = default;
> > >
> > > Does the compiler complains if you don't force the destructor to be
> > > generated ?
> > >
> >
> > No. Omitted.
> > > > +
> > > > +private:
> > > > +     cros::ScopedBufferHandle scopedHandle_;
> > > > +};
> > >
> > > Blank line
> > >
> > > > +} /* namespace */
> > > > +
> > > > +class PlatformFrameBufferAllocator::Private : public Extensible::Private
> > > > +{
> > > > +     LIBCAMERA_DECLARE_PUBLIC(PlatformFrameBufferAllocator)
> > > > +
> > > > +public:
> > > > +     Private([[maybe_unused]] PlatformFrameBufferAllocator *allocator,
> > >
> > > allocator is not used anymore in any of the two subclasses ? Can it be
> > > dropped ?
> > >
> >
> > I think having PlatformAllocator in argument is required for
> > PFBAllocator::Private class constructor.
> >
> > > > +             [[maybe_unused]] CameraDevice *const cameraDevice)
> > > > +     {
> > > > +     }
> > > > +
> > > > +     std::unique_ptr<libcamera::FrameBuffer> allocate(
> > > > +             int halPixelFormat, const libcamera::Size &size, uint32_t usage);
> > > > +};
> > > > +
> > > > +std::unique_ptr<libcamera::FrameBuffer>
> > > > +PlatformFrameBufferAllocator::Private::allocate(
> > > > +     int halPixelFormat, const libcamera::Size &size, uint32_t usage)
> > > > +{
> > > > +     cros::ScopedBufferHandle scopedHandle =
> > > > +             cros::CameraBufferManager::AllocateScopedBuffer(
> > > > +                     size.width, size.height, halPixelFormat, usage);
> > > > +     if (!scopedHandle) {
> > > > +             LOG(HAL, Error) << "Failed to allocate buffer handle";
> > > > +             return nullptr;
> > > > +     }
> > > > +
> > > > +     buffer_handle_t handle = *scopedHandle;
> > > > +     const size_t numPlanes = cros::CameraBufferManager::GetNumPlanes(handle);
> > > > +     std::vector<FrameBuffer::Plane> planes(numPlanes);
> > > > +     FileDescriptor fd{ handle->data[0] };
> > >
> > > afaict this duplicates the filedescriptor. If the
> > > cros:CameraBufferManager closes its copy on destruction, it's fine.
> > >
> >
> > Yes, correct.
> >
> > > > +     if (!fd.isValid()) {
> > > > +             LOG(HAL, Fatal) << "Invalid fd";
> > > > +             return nullptr;
> > > > +     }
> > > > +
> > > > +     /* This code assumes all the planes are located in the same buffer. */
> > > > +     for (auto [i, plane] : utils::enumerate(planes)) {
> > > > +             plane.fd = fd;
> > > > +             plane.offset = cros::CameraBufferManager::GetPlaneOffset(handle, i);
> > > > +             plane.length = cros::CameraBufferManager::GetPlaneSize(handle, i);
> > > > +     }
> > > > +
> > > > +     return std::make_unique<FrameBuffer>(
> > > > +             std::make_unique<CrosFrameBufferData>(std::move(scopedHandle)),
> > >
> > > DO you need to move scopedHandle ? You have a single constructor that
> > > will bind to && and & if I'm not mistaken.
> > >
> >
> > Yes, I have to.  cros::ScopedBufferHandle is move-only constructor.
> > Google c++ coding style restricts using && in move constructor only.
> > I think since CrosFrameBufferData is different from
> > cros::ScopedBufferHandle this is not move constructor.
>
> Ok but why constructing a new ScopedBufferHandle in the
> CrosFrameBufferData constructor ?
>
> You currently have
>
>         CrosFrameBufferData(cros::ScopedBufferHandle scopedHandle)
>                 : FrameBuffer::Private(), scopedHandle_(std::move(scopedHandle))
>         {
>         }
>
>        return std::make_unique<FrameBuffer>(
>               std::make_unique<CrosFrameBufferData>(std::move(scopedHandle)),
>               planes);
>
> While you could
>
>         CrosFrameBufferData(cros::ScopedBufferHandle &scopedHandle)
>                 : FrameBuffer::Private(), scopedHandle_(std::move(scopedHandle))
>         {
>         }
>
>        return std::make_unique<FrameBuffer>(
>               std::make_unique<CrosFrameBufferData>(scopedHandle), planes);
>

Hm, I think it is invalid or at least not recommended way to execute
std::move() against reference value.
If you would like to do that, I would do
CrosFrameBufferData(cros::ScopedBufferHandle &&scopedHandle).
Yes, it doesn't follow Google C++ style guide, but I am fine in this
tiny piece of code.

> With your ack I can apply these changes.
>
> Also, I wanted to have the allocator being used to replace
> FrameBufferAllocator in CameraStream before merging so it can be CTS
> tested. I'll do so and send a new version if you're not working on
> doing so.

I confirmed replacing it with this allocator works in a few CTS cases.
However, there is one small issue. I will send you my local patch.

-Hiro
>
> Thanks
>    j
>
> >
> > -Hiro
> >
> > > With minors and the file descriptor duplication clarified
> > > Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>
> > >
> > > Thanks
> > >   j
> > >
> > > > +             planes);
> > > > +}
> > > > +
> > > > +PUBLIC_FRAME_BUFFER_ALLOCATOR_IMPLEMENTATION
> > > > diff --git a/src/android/mm/generic_frame_buffer_allocator.cpp b/src/android/mm/generic_frame_buffer_allocator.cpp
> > > > new file mode 100644
> > > > index 00000000..f00fd704
> > > > --- /dev/null
> > > > +++ b/src/android/mm/generic_frame_buffer_allocator.cpp
> > > > @@ -0,0 +1,142 @@
> > > > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > > > +/*
> > > > + * Copyright (C) 2021, Google Inc.
> > > > + *
> > > > + * generic_camera_buffer.cpp - Allocate FrameBuffer using gralloc API
> > > > + */
> > > > +
> > > > +#include <memory>
> > > > +#include <vector>
> > > > +
> > > > +#include <libcamera/base/log.h>
> > > > +
> > > > +#include "libcamera/internal/formats.h"
> > > > +#include "libcamera/internal/framebuffer.h"
> > > > +
> > > > +#include <hardware/camera3.h>
> > > > +#include <hardware/gralloc.h>
> > > > +#include <hardware/hardware.h>
> > > > +
> > > > +#include "../camera_device.h"
> > > > +#include "../frame_buffer_allocator.h"
> > > > +
> > > > +using namespace libcamera;
> > > > +
> > > > +LOG_DECLARE_CATEGORY(HAL)
> > > > +
> > > > +namespace {
> > > > +class GenericFrameBufferData : public FrameBuffer::Private
> > > > +{
> > > > +     LIBCAMERA_DECLARE_PUBLIC(FrameBuffer)
> > > > +
> > > > +public:
> > > > +     GenericFrameBufferData(struct alloc_device_t *allocDevice,
> > > > +                            buffer_handle_t handle)
> > > > +             : allocDevice_(allocDevice), handle_(handle)
> > > > +     {
> > > > +             ASSERT(allocDevice_);
> > > > +             ASSERT(handle_);
> > > > +     }
> > > > +
> > > > +     ~GenericFrameBufferData() override
> > > > +     {
> > > > +             /*
> > > > +              * allocDevice_ is used to destroy handle_. allocDevice_ is
> > > > +              * owned by PlatformFrameBufferAllocator::Private.
> > > > +              * GenericFrameBufferData must be destroyed before it is
> > > > +              * destroyed.
> > > > +              *
> > > > +              * \todo Consider managing alloc_device_t with std::shared_ptr
> > > > +              * if this is difficult to maintain.
> > > > +              *
> > > > +              * \todo Thread safety against alloc_device_t is not documented.
> > > > +              * Is it no problem to call alloc/free in parallel?
> > > > +              */
> > > > +             allocDevice_->free(allocDevice_, handle_);
> > > > +     }
> > > > +
> > > > +private:
> > > > +     struct alloc_device_t *allocDevice_;
> > > > +     const buffer_handle_t handle_;
> > > > +};
> > > > +} /* namespace */
> > > > +
> > > > +class PlatformFrameBufferAllocator::Private : public Extensible::Private
> > > > +{
> > > > +     LIBCAMERA_DECLARE_PUBLIC(PlatformFrameBufferAllocator)
> > > > +
> > > > +public:
> > > > +     Private([[maybe_unused]] PlatformFrameBufferAllocator *allocator,
> > > > +             CameraDevice *const cameraDevice)
> > > > +             : cameraDevice_(cameraDevice),
> > > > +               hardwareModule_(cameraDevice->camera3Device()->common.module),
> > > > +               allocDevice_(nullptr)
> > > > +     {
> > > > +             ASSERT(hardwareModule_);
> > > > +     }
> > > > +
> > > > +     ~Private() override;
> > > > +
> > > > +     std::unique_ptr<libcamera::FrameBuffer> allocate(
> > > > +             int halPixelFormat, const libcamera::Size &size, uint32_t usage);
> > > > +
> > > > +private:
> > > > +     const CameraDevice *const cameraDevice_;
> > > > +     struct hw_module_t *const hardwareModule_;
> > > > +     struct alloc_device_t *allocDevice_;
> > > > +};
> > > > +
> > > > +PlatformFrameBufferAllocator::Private::~Private()
> > > > +{
> > > > +     if (allocDevice_)
> > > > +             gralloc_close(allocDevice_);
> > > > +}
> > > > +
> > > > +std::unique_ptr<libcamera::FrameBuffer>
> > > > +PlatformFrameBufferAllocator::Private::allocate(
> > > > +     int halPixelFormat, const libcamera::Size &size, uint32_t usage)
> > > > +{
> > > > +     if (!allocDevice_) {
> > > > +             int ret = gralloc_open(hardwareModule_, &allocDevice_);
> > > > +             if (ret) {
> > > > +                     LOG(HAL, Fatal) << "gralloc_open() failed: " << ret;
> > > > +                     return nullptr;
> > > > +             }
> > > > +     }
> > > > +
> > > > +     int stride = 0;
> > > > +     buffer_handle_t handle = nullptr;
> > > > +     int ret = allocDevice_->alloc(allocDevice_, size.width, size.height,
> > > > +                                   halPixelFormat, usage, &handle, &stride);
> > > > +     if (ret) {
> > > > +             LOG(HAL, Error) << "failed buffer allocating: " << ret;
> > > > +             return nullptr;
> > > > +     }
> > > > +     if (!handle) {
> > > > +             LOG(HAL, Fatal) << "buffer_handle_t is empty on success";
> > > > +             return nullptr;
> > > > +     }
> > > > +
> > > > +     const libcamera::PixelFormat pixelFormat =
> > > > +             cameraDevice_->capabilities()->toPixelFormat(halPixelFormat);
> > > > +     const auto &info = PixelFormatInfo::info(pixelFormat);
> > > > +     std::vector<FrameBuffer::Plane> planes(info.numPlanes());
> > > > +
> > > > +     /* This code assumes the planes are mapped consecutively. */
> > > > +     FileDescriptor fd{ handle->data[0] };
> > > > +     size_t offset = 0;
> > > > +     for (auto [i, plane] : utils::enumerate(planes)) {
> > > > +             const size_t planeSize = info.planeSize(size.height, i, stride);
> > > > +
> > > > +             planes[i].fd = fd;
> > > > +             planes[i].offset = offset;
> > > > +             planes[i].length = planeSize;
> > > > +             offset += planeSize;
> > > > +     }
> > > > +
> > > > +     return std::make_unique<FrameBuffer>(
> > > > +             std::make_unique<GenericFrameBufferData>(allocDevice_, handle),
> > > > +             planes);
> > > > +}
> > > > +
> > > > +PUBLIC_FRAME_BUFFER_ALLOCATOR_IMPLEMENTATION
> > > > diff --git a/src/android/mm/meson.build b/src/android/mm/meson.build
> > > > index eeb5cc2e..d40a3b0b 100644
> > > > --- a/src/android/mm/meson.build
> > > > +++ b/src/android/mm/meson.build
> > > > @@ -2,8 +2,10 @@
> > > >
> > > >  platform = get_option('android_platform')
> > > >  if platform == 'generic'
> > > > -    android_hal_sources += files(['generic_camera_buffer.cpp'])
> > > > +    android_hal_sources += files(['generic_camera_buffer.cpp',
> > > > +                                  'generic_frame_buffer_allocator.cpp'])
> > > >  elif platform == 'cros'
> > > > -    android_hal_sources += files(['cros_camera_buffer.cpp'])
> > > > +    android_hal_sources += files(['cros_camera_buffer.cpp',
> > > > +                                  'cros_frame_buffer_allocator.cpp'])
> > > >      android_deps += [dependency('libcros_camera')]
> > > >  endif
> > > > --
> > > > 2.34.0.rc2.393.gf8c9666880-goog
> > > >


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