overview

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Overview

Example: sync package overview

The ndk/sync package provides Go bindings for Android's native sync framework (sync fences / sync file descriptors).

Android sync fences are kernel-level synchronization primitives used to coordinate GPU and display operations. A sync fence represents a point in time on a GPU command stream — it signals when all commands submitted before it have completed.

Typical usage in the graphics pipeline:

1. GPU driver creates a fence when submitting work
2. Fence fd is passed to SurfaceFlinger / HWC
3. Consumer waits on the fence before reading the buffer
4. This enables pipelined rendering without CPU stalls

The sync fence API operates on file descriptors:

• sync_merge(name, fd1, fd2) — merge two fences into one
• sync_wait(fd, timeout_ms) — block until fence signals
• sync_file_info(fd) — query fence metadata

Sync fences are typically obtained from EGL (eglDupNativeFenceFD), Vulkan (vkGetFenceFdKHR), or AHardwareBuffer operations.

This program must run on an Android device.