[x264-devel] [PATCH v2 0/2] Fix input-frame recycling and threadpool shutdown races

[xiujunwang.dev at gmail.com]

Hi,

Following up on this two-patch series from September 25. Both races
were reproduced with ThreadSanitizer on macOS arm64, with validation
results included in the cover letter.

Could someone take a look, or suggest an appropriate reviewer? Happy
to provide additional reproducer details or tests if helpful.

Thanks,
Xiujun


On Fri, 25 Sep 2026 23:41:27 +0800, 汪秀军 <xiujunwang.dev at gmail.com> wrote:
> Hello,
>
> The v1 patch message bodies were damaged by Gmail's flowed-text
> formatting, which collapsed some indentation. Please use this v2
> series. The patch content is unchanged; the two raw patch files are
> attached to their respective messages.
>
> This series fixes two races reproduced on x264 master 0480cb05.
>
> Patch 1 serializes input-frame release and unused-list push/pop with a
> shared mutex. The lookahead thread can release last_nonb concurrently
> with the caller releasing fenc or obtaining another input frame.
>
> Patch 2 moves the threadpool exit check under its existing run mutex.
> This independent race was exposed by closing without flushing.
>
> Validation on macOS arm64, Apple clang 21.0.0:
> - Unmodified master reproduces both races under ThreadSanitizer.
> - Six 1,200-frame TSan runs pass without suppressions.
> - A 128x288, four-slice-thread TSan run passes for 240 frames.
> - Closing without flushing after each input count 0..40 passes under TSan.
> - Native-assembly checkasm8 and checkasm10 pass.
> - Six release-mode comparisons have identical non-SEI NAL data and
>   decoded frame MD5s.
> - A --disable-thread build and a 200-frame encode pass.
>
> These tests cover the configurations above; OpenCL and other platforms
> were not tested.
>
> Best regards,
> Xiujun Wang