scePthreadRwlockUnlock called unlock_shared on the host mutex whenever the
caller was not the writer, which is undefined behaviour for an unlocked rwlock
or one write-locked by another thread. Track the reader count and return
EPERM like FreeBSD libthr when the caller does not own the write lock and no
read lock is held.
winpthreads initializes a PTHREAD_RWLOCK_INITIALIZER lock on its first
use and fails a concurrent first lock with EINVAL. std::shared_timed_mutex
ignores that result in release builds, so two guest threads could both
hold a fresh guest rwlock.
Lock and unlock the mutex once when the guest rwlock is created, before
another thread can reach it, and record the remaining host exposure.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The POSIX layer only exported init, destroy, rdlock, wrlock and unlock.
pthread_rwlock_tryrdlock, pthread_rwlock_trywrlock,
pthread_rwlock_timedrdlock and pthread_rwlock_timedwrlock now wrap the
existing scePthreadRwlock functions and accept the static initializer.
The timed variants take an absolute CLOCK_REALTIME deadline. Like
FreeBSD libthr they try the lock first and only validate abstime when
the lock is not free. A null abstime throws, as pthread_mutex_timedlock
does.
scePthreadRwlockTryrdlock and scePthreadRwlockTrywrlock return EBUSY
when the caller already holds the write lock instead of calling into
std::shared_timed_mutex, where that is undefined behaviour.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Dean
Claude
Hussein Kadhim
Zayd Zaari
Hannah Lyons
Andreas
DotDebian