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LibC: Use BAN::atomic_* functions in pthread spinlock 

This allows us not to reinterpret_cast pthread_spin_t to
BAN::Atomic<pthread_spin_t> which is much better :)
This commit is contained in:
Bananymous 2025-04-19 23:41:20 +03:00
parent 98e05fd179
commit 3642eabac0
1 changed files with 12 additions and 25 deletions
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37
userspace/libraries/LibC/pthread.cpp
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@ -307,58 +307,45 @@ pthread_t pthread_self(void)
#endif #endif
} }
static inline BAN::Atomic<pthread_t>& pthread_spin_get_atomic(pthread_spinlock_t* lock)
{
static_assert(sizeof(pthread_spinlock_t) <= sizeof(BAN::Atomic<pthread_t>));
static_assert(alignof(pthread_spinlock_t) <= alignof(BAN::Atomic<pthread_t>));
return *reinterpret_cast<BAN::Atomic<pthread_t>*>(lock);
}
int pthread_spin_destroy(pthread_spinlock_t* lock) int pthread_spin_destroy(pthread_spinlock_t* lock)
{ {
pthread_spin_get_atomic(lock).~Atomic<pthread_t>(); (void)lock;
return 0; return 0;
} }
int pthread_spin_init(pthread_spinlock_t* lock, int pshared) int pthread_spin_init(pthread_spinlock_t* lock, int pshared)
{ {
(void)pshared; (void)pshared;
new (lock) BAN::Atomic<pthread_t>(0); *lock = 0;
return 0; return 0;
} }
int pthread_spin_lock(pthread_spinlock_t* lock) int pthread_spin_lock(pthread_spinlock_t* lock)
{ {
auto& atomic = pthread_spin_get_atomic(lock); const auto tid = pthread_self();
ASSERT(BAN::atomic_load(*lock, BAN::MemoryOrder::memory_order_relaxed) != tid);
const pthread_t tid = pthread_self();
ASSERT(atomic.load(BAN::MemoryOrder::memory_order_relaxed) != tid);
pthread_t expected = 0; pthread_t expected = 0;
while (!atomic.compare_exchange(expected, tid, BAN::MemoryOrder::memory_order_acquire)) while (!BAN::atomic_compare_exchange(*lock, expected, tid, BAN::MemoryOrder::memory_order_acquire))
expected = 0; expected = 0;
return 0; return 0;
} }
int pthread_spin_trylock(pthread_spinlock_t* lock) int pthread_spin_trylock(pthread_spinlock_t* lock)
{ {
auto& atomic = pthread_spin_get_atomic(lock); const auto tid = pthread_self();
ASSERT(BAN::atomic_load(*lock, BAN::MemoryOrder::memory_order_relaxed) != tid);
const pthread_t tid = pthread_self();
ASSERT(atomic.load(BAN::MemoryOrder::memory_order_relaxed) != tid);
pthread_t expected = 0; pthread_t expected = 0;
if (atomic.compare_exchange(expected, tid, BAN::MemoryOrder::memory_order_acquire)) if (!BAN::atomic_compare_exchange(*lock, expected, tid, BAN::MemoryOrder::memory_order_acquire))
return 0; return EBUSY;
return EBUSY; return 0;
} }
int pthread_spin_unlock(pthread_spinlock_t* lock) int pthread_spin_unlock(pthread_spinlock_t* lock)
{ {
auto& atomic = pthread_spin_get_atomic(lock); ASSERT(BAN::atomic_load(*lock, BAN::MemoryOrder::memory_order_relaxed) == pthread_self());
ASSERT(atomic.load(BAN::MemoryOrder::memory_order_relaxed) == pthread_self()); BAN::atomic_store(*lock, 0, BAN::MemoryOrder::memory_order_release);
atomic.store(0, BAN::MemoryOrder::memory_order_release);
return 0; return 0;
} }