sync: add Semaphore (#1973)

Provide an asynchronous Semaphore implementation. This is useful for
synchronizing concurrent access to a shared resource.

1 files changed, 3 insertions, 3 deletions

diff --git a/tokio/src/sync/mutex.rs b/tokio/src/sync/mutex.rs
index bee00df4..ec59d695 100644
--- a/tokio/src/sync/mutex.rs
+++ b/tokio/src/sync/mutex.rs
@@ -35,7 +35,7 @@
 //! [`MutexGuard`]: struct.MutexGuard.html
 
 use crate::future::poll_fn;
-use crate::sync::semaphore;
+use crate::sync::semaphore_ll as semaphore;
 
 use std::cell::UnsafeCell;
 use std::error::Error;
@@ -74,7 +74,7 @@ unsafe impl<T> Sync for Mutex<T> where T: Send {}
 unsafe impl<'a, T> Sync for MutexGuard<'a, T> where T: Send + Sync {}
 
 /// An enumeration of possible errors associated with a `TryLockResult`
-/// which can occur while trying to aquire a lock from the `try_lock`
+/// which can occur while trying to acquire a lock from the `try_lock`
 /// method on a `Mutex`.
 #[derive(Debug)]
 pub enum TryLockError {
@@ -129,7 +129,7 @@ impl<T> Mutex<T> {
         guard
     }
 
-    /// Try to aquire the lock
+    /// Try to acquire the lock
     pub fn try_lock(&self) -> Result<MutexGuard<'_, T>, TryLockError> {
         let mut permit = semaphore::Permit::new();
         match permit.try_acquire(&self.s) {