On Thursday 23 October 2025 11:02:28 LIU Hao wrote:
> 在 2025-10-23 02:40, Pali Rohár 写道:
> > Thank you very much for information. So from this information it looks
> > like that the volatile keyword is not required on more places in
> > mingw-w64-libraries/winpthreads/src/spinlock.c file.
> >
> > Would you have a time to revisit that file?
>
> There are 6 occurrences of `volatile` in spinlock.c, and they are all parts
> of pointee types, so I believe all of them are unnecessary.
Ok, what about this change?
winpthreads: Remove unnecessary volatile from spinlock.c
diff --git a/mingw-w64-libraries/winpthreads/src/spinlock.c
b/mingw-w64-libraries/winpthreads/src/spinlock.c
index 0590e0f4f982..452c36528a6b 100644
--- a/mingw-w64-libraries/winpthreads/src/spinlock.c
+++ b/mingw-w64-libraries/winpthreads/src/spinlock.c
@@ -57,8 +57,8 @@ pthread_spin_destroy (pthread_spinlock_t *lock)
int
pthread_spin_lock (pthread_spinlock_t *lock)
{
- volatile spinlock_word_t *lk = (volatile spinlock_word_t *)lock;
- while (unlikely(InterlockedExchangePointer((PVOID volatile *)lk, 0) == 0))
+ spinlock_word_t *lk = (spinlock_word_t *)lock;
+ while (unlikely(InterlockedExchangePointer((PVOID*)lk, 0) == 0))
YieldProcessor();
return 0;
}
@@ -67,18 +67,18 @@ int
pthread_spin_trylock (pthread_spinlock_t *lock)
{
spinlock_word_t *lk = (spinlock_word_t *)lock;
- return InterlockedExchangePointer((PVOID volatile *)lk, 0) == 0 ? EBUSY : 0;
+ return InterlockedExchangePointer((PVOID*)lk, 0) == 0 ? EBUSY : 0;
}
int
pthread_spin_unlock (pthread_spinlock_t *lock)
{
- volatile spinlock_word_t *lk = (volatile spinlock_word_t *)lock;
+ spinlock_word_t *lk = (spinlock_word_t *)lock;
#if defined(__GNUC__) || defined(__clang__)
__atomic_store_n(lk, -1, __ATOMIC_RELEASE);
#else
- InterlockedExchangePointer((PVOID volatile *)lk, (void*)-1);
+ InterlockedExchangePointer((PVOID*)lk, (void*)-1);
#endif
return 0;
}
> There are some uses in other files, as parts of definitions of fields or
> variables, like in mutex.c and in thread.c. Those fields should be read with
> atomic operations, but at the moment they aren't, so `volatile` isn't safe
> to remove there for now. (I don't know how to do `__atomic_load_n` in MSVC.)
>
>
> --
> Best regards,
> LIU Hao
_______________________________________________
Mingw-w64-public mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
