Wrap AHardwareBuffer_LockPlanes too.
Bug: 371874777
Test: atest libnativewindow_rs-internal_test
Change-Id: I1a765c4b0a9455a3d5ed19582a8cfd5593f812fe
diff --git a/libs/nativewindow/rust/src/lib.rs b/libs/nativewindow/rust/src/lib.rs
index 9876362..d760285 100644
--- a/libs/nativewindow/rust/src/lib.rs
+++ b/libs/nativewindow/rust/src/lib.rs
@@ -30,8 +30,8 @@
StatusCode,
};
use ffi::{
- AHardwareBuffer, AHardwareBuffer_Desc, AHardwareBuffer_readFromParcel,
- AHardwareBuffer_writeToParcel, ARect,
+ AHardwareBuffer, AHardwareBuffer_Desc, AHardwareBuffer_Plane, AHardwareBuffer_Planes,
+ AHardwareBuffer_readFromParcel, AHardwareBuffer_writeToParcel, ARect,
};
use std::ffi::c_void;
use std::fmt::{self, Debug, Formatter};
@@ -313,6 +313,57 @@
})
}
+ /// Lock a potentially multi-planar hardware buffer for direct CPU access.
+ ///
+ /// # Safety
+ ///
+ /// - If `fence` is `None`, the caller must ensure that all writes to the buffer have completed
+ /// before calling this function.
+ /// - If the buffer has `AHARDWAREBUFFER_FORMAT_BLOB`, multiple threads or process may lock the
+ /// buffer simultaneously, but the caller must ensure that they don't access it simultaneously
+ /// and break Rust's aliasing rules, like any other shared memory.
+ /// - Otherwise if `usage` includes `AHARDWAREBUFFER_USAGE_CPU_WRITE_RARELY` or
+ /// `AHARDWAREBUFFER_USAGE_CPU_WRITE_OFTEN`, the caller must ensure that no other threads or
+ /// processes lock the buffer simultaneously for any usage.
+ /// - Otherwise, the caller must ensure that no other threads lock the buffer for writing
+ /// simultaneously.
+ /// - If `rect` is not `None`, the caller must not modify the buffer outside of that rectangle.
+ pub unsafe fn lock_planes<'a>(
+ &'a self,
+ usage: AHardwareBuffer_UsageFlags,
+ fence: Option<BorrowedFd>,
+ rect: Option<&ARect>,
+ ) -> Result<Vec<PlaneGuard<'a>>, StatusCode> {
+ let fence = if let Some(fence) = fence { fence.as_raw_fd() } else { -1 };
+ let rect = rect.map(ptr::from_ref).unwrap_or(null());
+ let mut planes = AHardwareBuffer_Planes {
+ planeCount: 0,
+ planes: [const { AHardwareBuffer_Plane { data: null_mut(), pixelStride: 0, rowStride: 0 } };
+ 4],
+ };
+
+ // SAFETY: The `AHardwareBuffer` pointer we wrap is always valid, and the various out
+ // pointers are valid because they come from references. Our caller promises that writes have
+ // completed and there will be no simultaneous read/write locks.
+ let status = unsafe {
+ ffi::AHardwareBuffer_lockPlanes(self.0.as_ptr(), usage.0, fence, rect, &mut planes)
+ };
+ status_result(status)?;
+ let plane_count = planes.planeCount.try_into().unwrap();
+ Ok(planes.planes[..plane_count]
+ .iter()
+ .map(|plane| PlaneGuard {
+ guard: HardwareBufferGuard {
+ buffer: self,
+ address: NonNull::new(plane.data)
+ .expect("AHardwareBuffer_lockAndGetInfo set a null outVirtualAddress"),
+ },
+ pixel_stride: plane.pixelStride,
+ row_stride: plane.rowStride,
+ })
+ .collect())
+ }
+
/// Locks the hardware buffer for direct CPU access, returning information about the bytes per
/// pixel and stride as well.
///
@@ -510,6 +561,18 @@
pub stride: u32,
}
+/// A guard for a single plane of a locked `HardwareBuffer`, with additional information about the
+/// stride.
+#[derive(Debug)]
+pub struct PlaneGuard<'a> {
+ /// The locked buffer guard.
+ pub guard: HardwareBufferGuard<'a>,
+ /// The stride in bytes between the color channel for one pixel to the next pixel.
+ pub pixel_stride: u32,
+ /// The stride in bytes between rows in the buffer.
+ pub row_stride: u32,
+}
+
#[cfg(test)]
mod test {
use super::*;