Make Send and Sync traits unsafe

2 files changed, 5 insertions, 3 deletions

diff --git a/src/libstd/sys/common/helper_thread.rs b/src/libstd/sys/common/helper_thread.rs
index 9df69d8e0d6..b0137bdad06 100644
--- a/src/libstd/sys/common/helper_thread.rs
+++ b/src/libstd/sys/common/helper_thread.rs
@@ -59,9 +59,9 @@ pub struct Helper<M> {
     pub shutdown: UnsafeCell<bool>,
 }
 
-impl<M:Send> Send for Helper<M> { }
+unsafe impl<M:Send> Send for Helper<M> { }
 
-impl<M:Send> Sync for Helper<M> { }
+unsafe impl<M:Send> Sync for Helper<M> { }
 
 impl<M: Send> Helper<M> {
     /// Lazily boots a helper thread, becoming a no-op if the helper has already
diff --git a/src/libstd/sys/common/mutex.rs b/src/libstd/sys/common/mutex.rs
index 5869c280517..567c26956ef 100644
--- a/src/libstd/sys/common/mutex.rs
+++ b/src/libstd/sys/common/mutex.rs
@@ -8,6 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use kinds::Sync;
 use sys::mutex as imp;
 
 /// An OS-based mutual exclusion lock.
@@ -15,9 +16,10 @@ use sys::mutex as imp;
 /// This is the thinnest cross-platform wrapper around OS mutexes. All usage of
 /// this mutex is unsafe and it is recommended to instead use the safe wrapper
 /// at the top level of the crate instead of this type.
-#[deriving(Sync)]
 pub struct Mutex(imp::Mutex);
 
+unsafe impl Sync for Mutex {}
+
 /// Constant initializer for statically allocated mutexes.
 pub const MUTEX_INIT: Mutex = Mutex(imp::MUTEX_INIT);