nativewindow: Misc. improvements for AHardwareBuffer Rust wrapper (4ab0fdc9) · Commits · e / os / platform_frameworks_native

libs/bufferstreams/rust/src/lib.rs

+1 −1

Original line number	Diff line number	Diff line
		@@ -159,7 +159,7 @@ pub type BufferError = anyhow::Error;
		/// Struct used to contain the buffer.
		pub struct Frame {
		/// A handle to the C buffer interface.
		pub buffer: AHardwareBuffer,
		pub buffer: HardwareBuffer,
		/// The time at which the buffer was dispatched.
		pub present_time: Instant,
		/// A fence used for reading/writing safely.

libs/bufferstreams/rust/src/stream_config.rs

+3 −3

Original line number	Diff line number	Diff line
		@@ -33,9 +33,9 @@ pub struct StreamConfig {
		}

		impl StreamConfig {
		/// Tries to create a new AHardwareBuffer from settings in a [StreamConfig].
		pub fn create_hardware_buffer(&self) -> Option<AHardwareBuffer> {
		AHardwareBuffer::new(self.width, self.height, self.layers, self.format, self.usage)
		/// Tries to create a new HardwareBuffer from settings in a [StreamConfig].
		pub fn create_hardware_buffer(&self) -> Option<HardwareBuffer> {
		HardwareBuffer::new(self.width, self.height, self.layers, self.format, self.usage)
		}
		}

libs/nativewindow/rust/src/lib.rs

+92 −29

Original line number	Diff line number	Diff line
		@@ -16,15 +16,17 @@

		extern crate nativewindow_bindgen as ffi;

		pub use ffi::{AHardwareBuffer_Format, AHardwareBuffer_UsageFlags};
		pub use ffi::{AHardwareBuffer, AHardwareBuffer_Format, AHardwareBuffer_UsageFlags};

		use std::os::raw::c_void;
		use std::ptr;
		use std::fmt::{self, Debug, Formatter};
		use std::mem::ManuallyDrop;
		use std::ptr::{self, NonNull};

		/// Wrapper around an opaque C AHardwareBuffer.
		pub struct AHardwareBuffer(*mut ffi::AHardwareBuffer);
		#[derive(PartialEq, Eq)]
		pub struct HardwareBuffer(NonNull<AHardwareBuffer>);

		impl AHardwareBuffer {
		impl HardwareBuffer {
		/// Test whether the given format and usage flag combination is allocatable. If this function
		/// returns true, it means that a buffer with the given description can be allocated on this
		/// implementation, unless resource exhaustion occurs. If this function returns false, it means
		@@ -79,13 +81,13 @@ impl AHardwareBuffer {
		rfu0: 0,
		rfu1: 0,
		};
		let mut buffer = ptr::null_mut();
		let mut ptr = ptr::null_mut();
		// SAFETY: The returned pointer is valid until we drop/deallocate it. The function may fail
		// and return a status, but we check it later.
		let status = unsafe { ffi::AHardwareBuffer_allocate(&buffer_desc, &mut buffer) };
		let status = unsafe { ffi::AHardwareBuffer_allocate(&buffer_desc, &mut ptr) };

		if status == 0 {
		Some(Self(buffer))
		Some(Self(NonNull::new(ptr).expect("Allocated AHardwareBuffer was null")))
		} else {
		None
		}
		@@ -101,9 +103,15 @@ impl AHardwareBuffer {
		///
		/// This function adopts the pointer but does NOT increment the refcount on the buffer. If the
		/// caller uses the pointer after the created object is dropped it will cause a memory leak.
		pub unsafe fn take_from_raw(buffer_ptr: *mut c_void) -> Self {
		assert!(!buffer_ptr.is_null());
		Self(buffer_ptr as *mut ffi::AHardwareBuffer)
		pub unsafe fn from_raw(buffer_ptr: NonNull<AHardwareBuffer>) -> Self {
		Self(buffer_ptr)
		}

		/// Get the internal \|AHardwareBuffer\| pointer without decrementing the refcount. This can
		/// be used to provide a pointer to the AHB for a C/C++ API over the FFI.
		pub fn into_raw(self) -> NonNull<AHardwareBuffer> {
		let buffer = ManuallyDrop::new(self);
		buffer.0
		}

		/// Get the system wide unique id for an AHardwareBuffer. This function may panic in extreme
		@@ -113,7 +121,7 @@ impl AHardwareBuffer {
		pub fn id(&self) -> u64 {
		let mut out_id = 0;
		// SAFETY: Neither pointers can be null.
		let status = unsafe { ffi::AHardwareBuffer_getId(self.0, &mut out_id) };
		let status = unsafe { ffi::AHardwareBuffer_getId(self.0.as_ref(), &mut out_id) };
		assert_eq!(status, 0, "id() failed for AHardwareBuffer with error code: {status}");

		out_id
		@@ -161,27 +169,55 @@ impl AHardwareBuffer {
		rfu1: 0,
		};
		// SAFETY: neither the buffer nor AHardwareBuffer_Desc pointers will be null.
		unsafe { ffi::AHardwareBuffer_describe(self.0, &mut buffer_desc) };
		unsafe { ffi::AHardwareBuffer_describe(self.0.as_ref(), &mut buffer_desc) };
		buffer_desc
		}
		}

		impl Drop for AHardwareBuffer {
		impl Drop for HardwareBuffer {
		fn drop(&mut self) {
		// SAFETY: self.0 will never be null. AHardwareBuffers allocated from within Rust will have
		// a refcount of one, and there is a safety warning on taking an AHardwareBuffer from a raw
		// pointer requiring callers to ensure the refcount is managed appropriately.
		unsafe { ffi::AHardwareBuffer_release(self.0) }
		unsafe { ffi::AHardwareBuffer_release(self.0.as_ptr()) }
		}
		}

		impl Debug for HardwareBuffer {
		fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
		f.debug_struct("HardwareBuffer").field("id", &self.id()).finish()
		}
		}

		impl Clone for HardwareBuffer {
		fn clone(&self) -> Self {
		// SAFETY: ptr is guaranteed to be non-null and the acquire can not fail.
		unsafe { ffi::AHardwareBuffer_acquire(self.0.as_ptr()) };
		Self(self.0)
		}
		}

		// SAFETY: The underlying *AHardwareBuffers can be moved between threads.
		unsafe impl Send for HardwareBuffer {}

		// SAFETY: The underlying *AHardwareBuffers can be used from multiple threads.
		//
		// AHardwareBuffers are backed by C++ GraphicBuffers, which are mostly immutable. The only cases
		// where they are not immutable are:
		//
		// - reallocation (which is never actually done across the codebase and requires special
		// privileges/platform code access to do)
		// - "locking" for reading/writing (which is explicitly allowed to be done across multiple threads
		// according to the docs on the underlying gralloc calls)
		unsafe impl Sync for HardwareBuffer {}

		#[cfg(test)]
		mod ahardwarebuffer_tests {
		mod test {
		use super::*;

		#[test]
		fn create_valid_buffer_returns_ok() {
		let buffer = AHardwareBuffer::new(
		let buffer = HardwareBuffer::new(
		512,
		512,
		1,
		@@ -193,19 +229,12 @@ mod ahardwarebuffer_tests {

		#[test]
		fn create_invalid_buffer_returns_err() {
		let buffer = AHardwareBuffer::new(512, 512, 1, 0, AHardwareBuffer_UsageFlags(0));
		let buffer = HardwareBuffer::new(512, 512, 1, 0, AHardwareBuffer_UsageFlags(0));
		assert!(buffer.is_none());
		}

		#[test]
		#[should_panic]
		fn take_from_raw_panics_on_null() {
		// SAFETY: Passing a null pointer is safe, it should just panic.
		unsafe { AHardwareBuffer::take_from_raw(ptr::null_mut()) };
		}

		#[test]
		fn take_from_raw_allows_getters() {
		fn from_raw_allows_getters() {
		let buffer_desc = ffi::AHardwareBuffer_Desc {
		width: 1024,
		height: 512,
		@@ -225,13 +254,13 @@ mod ahardwarebuffer_tests {

		// SAFETY: The pointer must be valid because it was just allocated successfully, and we
		// don't use it after calling this.
		let buffer = unsafe { AHardwareBuffer::take_from_raw(raw_buffer_ptr as *mut c_void) };
		let buffer = unsafe { HardwareBuffer::from_raw(NonNull::new(raw_buffer_ptr).unwrap()) };
		assert_eq!(buffer.width(), 1024);
		}

		#[test]
		fn basic_getters() {
		let buffer = AHardwareBuffer::new(
		let buffer = HardwareBuffer::new(
		1024,
		512,
		1,
		@@ -252,7 +281,7 @@ mod ahardwarebuffer_tests {

		#[test]
		fn id_getter() {
		let buffer = AHardwareBuffer::new(
		let buffer = HardwareBuffer::new(
		1024,
		512,
		1,
		@@ -263,4 +292,38 @@ mod ahardwarebuffer_tests {

		assert_ne!(0, buffer.id());
		}

		#[test]
		fn clone() {
		let buffer = HardwareBuffer::new(
		1024,
		512,
		1,
		AHardwareBuffer_Format::AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM,
		AHardwareBuffer_UsageFlags::AHARDWAREBUFFER_USAGE_CPU_READ_OFTEN,
		)
		.expect("Buffer with some basic parameters was not created successfully");
		let buffer2 = buffer.clone();

		assert_eq!(buffer, buffer2);
		}

		#[test]
		fn into_raw() {
		let buffer = HardwareBuffer::new(
		1024,
		512,
		1,
		AHardwareBuffer_Format::AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM,
		AHardwareBuffer_UsageFlags::AHARDWAREBUFFER_USAGE_CPU_READ_OFTEN,
		)
		.expect("Buffer with some basic parameters was not created successfully");
		let buffer2 = buffer.clone();

		let raw_buffer = buffer.into_raw();
		// SAFETY: This is the same pointer we had before.
		let remade_buffer = unsafe { HardwareBuffer::from_raw(raw_buffer) };

		assert_eq!(remade_buffer, buffer2);
		}
		}

libs/nativewindow/tests/benchmark/buffer_benchmarks.rs

+2 −2

Original line number	Diff line number	Diff line
		@@ -21,8 +21,8 @@ use criterion::*;
		use nativewindow::*;

		#[inline]
		fn create_720p_buffer() -> AHardwareBuffer {
		AHardwareBuffer::new(
		fn create_720p_buffer() -> HardwareBuffer {
		HardwareBuffer::new(
		1280,
		720,
		1,