diff options
| -rw-r--r-- | library/std/src/sys/unsupported/rwlock.rs | 34 |
1 files changed, 16 insertions, 18 deletions
diff --git a/library/std/src/sys/unsupported/rwlock.rs b/library/std/src/sys/unsupported/rwlock.rs index d37f34ac935..4e4f0f00f69 100644 --- a/library/std/src/sys/unsupported/rwlock.rs +++ b/library/std/src/sys/unsupported/rwlock.rs @@ -1,7 +1,9 @@ -use crate::cell::UnsafeCell; +#![deny(unsafe_op_in_unsafe_fn)] + +use crate::cell::Cell; pub struct RWLock { - mode: UnsafeCell<isize>, + mode: Cell<isize>, } unsafe impl Send for RWLock {} @@ -9,14 +11,14 @@ unsafe impl Sync for RWLock {} // no threads on this platform impl RWLock { pub const fn new() -> RWLock { - RWLock { mode: UnsafeCell::new(0) } + RWLock { mode: Cell::new(0) } } #[inline] pub unsafe fn read(&self) { - let mode = self.mode.get(); - if *mode >= 0 { - *mode += 1; + let m = self.mode.get(); + if m >= 0 { + self.mode.set(m + 1); } else { rtabort!("rwlock locked for writing"); } @@ -24,9 +26,9 @@ impl RWLock { #[inline] pub unsafe fn try_read(&self) -> bool { - let mode = self.mode.get(); - if *mode >= 0 { - *mode += 1; + let m = self.mode.get(); + if m >= 0 { + self.mode.set(m + 1); true } else { false @@ -35,19 +37,15 @@ impl RWLock { #[inline] pub unsafe fn write(&self) { - let mode = self.mode.get(); - if *mode == 0 { - *mode = -1; - } else { + if self.mode.replace(-1) != 0 { rtabort!("rwlock locked for reading") } } #[inline] pub unsafe fn try_write(&self) -> bool { - let mode = self.mode.get(); - if *mode == 0 { - *mode = -1; + if self.mode.get() == 0 { + self.mode.set(-1); true } else { false @@ -56,12 +54,12 @@ impl RWLock { #[inline] pub unsafe fn read_unlock(&self) { - *self.mode.get() -= 1; + self.mode.set(self.mode.get() - 1); } #[inline] pub unsafe fn write_unlock(&self) { - *self.mode.get() += 1; + self.mode.set(0); } #[inline] |