diff options
Diffstat (limited to 'library/std/src/sys/unsupported/locks/mutex.rs')
-rw-r--r-- | library/std/src/sys/unsupported/locks/mutex.rs | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/library/std/src/sys/unsupported/locks/mutex.rs b/library/std/src/sys/unsupported/locks/mutex.rs new file mode 100644 index 000000000..d7cb12e0c --- /dev/null +++ b/library/std/src/sys/unsupported/locks/mutex.rs @@ -0,0 +1,36 @@ +use crate::cell::Cell; + +pub struct Mutex { + // This platform has no threads, so we can use a Cell here. + locked: Cell<bool>, +} + +pub type MovableMutex = Mutex; + +unsafe impl Send for Mutex {} +unsafe impl Sync for Mutex {} // no threads on this platform + +impl Mutex { + #[inline] + pub const fn new() -> Mutex { + Mutex { locked: Cell::new(false) } + } + + #[inline] + pub unsafe fn init(&mut self) {} + + #[inline] + pub unsafe fn lock(&self) { + assert_eq!(self.locked.replace(true), false, "cannot recursively acquire mutex"); + } + + #[inline] + pub unsafe fn unlock(&self) { + self.locked.set(false); + } + + #[inline] + pub unsafe fn try_lock(&self) -> bool { + self.locked.replace(true) == false + } +} |