Add Send/Sync to token, needed for LockGuard Send/Sync impl.

src/lock/api.rs

@@ -11,7 +11,7 @@ use core::ops::{Deref, DerefMut};
 // TODO: For weak memory, there needs to be a bit more stricter condition. unlock -hb→ lock.
 pub unsafe trait RawLock: Default + Send + Sync {
     /// Raw lock's token type.
-    type Token;
+    type Token: Send + Sync;
 
     /// Acquires the raw lock.
     fn lock(&self) -> Self::Token;

src/lock/clhlock.rs

@@ -12,6 +12,9 @@ struct Node {
 #[derive(Debug, Clone)]
 pub struct Token(*const CachePadded<Node>);
 
+unsafe impl Send for Token {}
+unsafe impl Sync for Token {}
+
 /// CLH lock.
 #[derive(Debug)]
 pub struct ClhLock {

src/lock/mcslock.rs

@@ -14,6 +14,9 @@ struct Node {
 #[derive(Debug, Clone)]
 pub struct Token(*mut CachePadded<Node>);
 
+unsafe impl Send for Token {}
+unsafe impl Sync for Token {}
+
 /// An MCS lock.
 #[derive(Debug)]
 pub struct McsLock {

src/lock/mcsparkinglock.rs

@@ -16,6 +16,9 @@ struct Node {
 #[derive(Debug, Clone)]
 pub struct Token(*mut CachePadded<Node>);
 
+unsafe impl Send for Token {}
+unsafe impl Sync for Token {}
+
 /// An MCS parking lock.
 #[derive(Debug)]
 pub struct McsParkingLock {