gralloc

Documentation

Overview

Package gralloc provides gralloc buffer allocation via the Android IAllocator HAL service.

Index

• type Buffer
  • func Allocate(ctx context.Context, sm *servicemanager.ServiceManager, width int32, ...) (*Buffer, error)
  • func (b *Buffer) Mmap() error
  • func (b *Buffer) Munmap()

Types

type Buffer

type Buffer struct {
	Handle common.NativeHandle
	Stride int32
	Width  uint32
	Height uint32
	Format int32
	Usage  uint64

	// MmapData holds a persistent mmap of the dmabuf, set by Mmap().
	// Keeping it mapped avoids mmap/munmap syscalls per frame read.
	MmapData []byte
}

Buffer holds a gralloc-allocated buffer with its NativeHandle.

func Allocate

func Allocate(
	ctx context.Context,
	sm *servicemanager.ServiceManager,
	width int32,
	height int32,
	format gfxCommon.PixelFormat,
	usage gfxCommon.BufferUsage,
) (*Buffer, error)

Allocate allocates a gralloc buffer using the IAllocator HAL service. The returned Buffer contains a dmabuf FD that can be mmap'd for CPU read access.

func (*Buffer) Mmap

func (b *Buffer) Mmap() error

Mmap creates a persistent read-only mmap of this buffer's dmabuf FD. The MmapData field can then be read directly. Call Munmap to release.

func (*Buffer) Munmap

func (b *Buffer) Munmap()

Munmap releases the persistent mmap created by Mmap.