The APC delivery was allocated after SuspendThread, so a target holding
the allocator lock deadlocked the raising thread; it is now allocated
before the suspend. The wait count a raise checks lived in the target's
thread_local storage and dangled once the thread exited; it is now a
member of PthreadPrivate, which TimedWait counts into through a
thread-local pointer bound when the thread starts, and a raise on a
thread that already finished returns ESRCH. TechnicalDebt gets one line
per unverified choice: Windows only, the FreeBSD ucontext layout, the
signal mask, the YMM upper halves, and delivery to threads outside
TimedWait.
AI-assisted: yes
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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