diff --git a/library/std/src/sys/vxworks/mod.rs b/library/std/src/sys/vxworks/mod.rs index 1763ed50547..def23c70456 100644 --- a/library/std/src/sys/vxworks/mod.rs +++ b/library/std/src/sys/vxworks/mod.rs @@ -26,6 +26,7 @@ pub mod pipe; pub mod process; pub mod rand; +#[path = "../unix/rwlock.rs"] pub mod rwlock; pub mod stack_overflow; pub mod stdio; diff --git a/library/std/src/sys/vxworks/rwlock.rs b/library/std/src/sys/vxworks/rwlock.rs deleted file mode 100644 index c90304c2b4a..00000000000 --- a/library/std/src/sys/vxworks/rwlock.rs +++ /dev/null @@ -1,114 +0,0 @@ -use crate::cell::UnsafeCell; -use crate::sync::atomic::{AtomicUsize, Ordering}; - -pub struct RWLock { - inner: UnsafeCell, - write_locked: UnsafeCell, - num_readers: AtomicUsize, -} - -unsafe impl Send for RWLock {} -unsafe impl Sync for RWLock {} - -impl RWLock { - pub const fn new() -> RWLock { - RWLock { - inner: UnsafeCell::new(libc::PTHREAD_RWLOCK_INITIALIZER), - write_locked: UnsafeCell::new(false), - num_readers: AtomicUsize::new(0), - } - } - - #[inline] - pub unsafe fn read(&self) { - let r = libc::pthread_rwlock_rdlock(self.inner.get()); - if r == libc::EAGAIN { - panic!("rwlock maximum reader count exceeded"); - } else if r == libc::EDEADLK || (r == 0 && *self.write_locked.get()) { - if r == 0 { - self.raw_unlock(); - } - panic!("rwlock read lock would result in deadlock"); - } else { - debug_assert_eq!(r, 0); - self.num_readers.fetch_add(1, Ordering::Relaxed); - } - } - - #[inline] - pub unsafe fn try_read(&self) -> bool { - let r = libc::pthread_rwlock_tryrdlock(self.inner.get()); - if r == 0 { - if *self.write_locked.get() { - self.raw_unlock(); - false - } else { - self.num_readers.fetch_add(1, Ordering::Relaxed); - true - } - } else { - false - } - } - - #[inline] - pub unsafe fn write(&self) { - let r = libc::pthread_rwlock_wrlock(self.inner.get()); - // See comments above for why we check for EDEADLK and write_locked. We - // also need to check that num_readers is 0. - if r == libc::EDEADLK - || *self.write_locked.get() - || self.num_readers.load(Ordering::Relaxed) != 0 - { - if r == 0 { - self.raw_unlock(); - } - panic!("rwlock write lock would result in deadlock"); - } else { - debug_assert_eq!(r, 0); - } - *self.write_locked.get() = true; - } - - #[inline] - pub unsafe fn try_write(&self) -> bool { - let r = libc::pthread_rwlock_trywrlock(self.inner.get()); - if r == 0 { - if *self.write_locked.get() || self.num_readers.load(Ordering::Relaxed) != 0 { - self.raw_unlock(); - false - } else { - *self.write_locked.get() = true; - true - } - } else { - false - } - } - - #[inline] - unsafe fn raw_unlock(&self) { - let r = libc::pthread_rwlock_unlock(self.inner.get()); - debug_assert_eq!(r, 0); - } - - #[inline] - pub unsafe fn read_unlock(&self) { - debug_assert!(!*self.write_locked.get()); - self.num_readers.fetch_sub(1, Ordering::Relaxed); - self.raw_unlock(); - } - - #[inline] - pub unsafe fn write_unlock(&self) { - debug_assert_eq!(self.num_readers.load(Ordering::Relaxed), 0); - debug_assert!(*self.write_locked.get()); - *self.write_locked.get() = false; - self.raw_unlock(); - } - #[inline] - pub unsafe fn destroy(&self) { - let r = libc::pthread_rwlock_destroy(self.inner.get()); - debug_assert_eq!(r, 0); - } -}