Make Send and Sync traits unsafe

src/liballoc/arc.rs

@@ -129,9 +129,9 @@ pub struct Weak<T> {
     _ptr: *mut ArcInner<T>,
 }
 
-impl<T: Sync + Send> Send for Arc<T> { }
+unsafe impl<T: Sync + Send> Send for Arc<T> { }
 
-impl<T: Sync + Send> Sync for Arc<T> { }
+unsafe impl<T: Sync + Send> Sync for Arc<T> { }
 
 struct ArcInner<T> {
     strong: atomic::AtomicUint,

src/libcore/cell.rs

@@ -577,6 +577,6 @@ impl<T> RacyCell<T> {
     }
 }
 
-impl<T:Send> Send for RacyCell<T> { }
+unsafe impl<T:Send> Send for RacyCell<T> { }
 
-impl<T> Sync for RacyCell<T> { } // Oh dear
+unsafe impl<T> Sync for RacyCell<T> { } // Oh dear

src/libcore/kinds.rs

@@ -19,7 +19,7 @@
 
 /// Types able to be transferred across task boundaries.
 #[lang="send"]
-pub trait Send for Sized? : 'static {
+pub unsafe trait Send for Sized? : 'static {
     // empty.
 }
 
@@ -81,7 +81,7 @@ pub trait Copy for Sized? {
 /// reference; not doing this is undefined behaviour (for example,
 /// `transmute`-ing from `&T` to `&mut T` is illegal).
 #[lang="sync"]
-pub trait Sync for Sized? {
+pub unsafe trait Sync for Sized? {
     // Empty
 }
 

src/libcore/ptr.rs

@@ -515,13 +515,13 @@ pub struct UniquePtr<T>(pub *mut T);
 /// reference is unaliased. Note that this aliasing invariant is
 /// unenforced by the type system; the abstraction using the
 /// `UniquePtr` must enforce it.
-impl<T:Send> Send for UniquePtr<T> { }
+unsafe impl<T:Send> Send for UniquePtr<T> { }
 
 /// `UniquePtr` pointers are `Sync` if `T` is `Sync` because the data they
 /// reference is unaliased. Note that this aliasing invariant is
 /// unenforced by the type system; the abstraction using the
 /// `UniquePtr` must enforce it.
-impl<T:Sync> Sync for UniquePtr<T> { }
+unsafe impl<T:Sync> Sync for UniquePtr<T> { }
 
 impl<T> UniquePtr<T> {
     /// Returns a null UniquePtr.

src/librustc_trans/back/write.rs

@@ -281,7 +281,7 @@ struct ModuleConfig {
     time_passes: bool,
 }
 
-impl Send for ModuleConfig { }
+unsafe impl Send for ModuleConfig { }
 
 impl ModuleConfig {
     fn new(tm: TargetMachineRef, passes: Vec<String>) -> ModuleConfig {

src/librustc_trans/trans/mod.rs

@@ -60,8 +60,8 @@ pub struct ModuleTranslation {
     pub llmod: ModuleRef,
 }
 
-impl Send for ModuleTranslation { }
+unsafe impl Send for ModuleTranslation { }
-impl Sync for ModuleTranslation { }
+unsafe impl Sync for ModuleTranslation { }
 
 pub struct CrateTranslation {
     pub modules: Vec<ModuleTranslation>,

src/libstd/c_str.rs

@@ -89,8 +89,8 @@ pub struct CString {
     owns_buffer_: bool,
 }
 
-impl Send for CString { }
+unsafe impl Send for CString { }
-impl Sync for CString { }
+unsafe impl Sync for CString { }
 
 impl Clone for CString {
     /// Clone this CString into a new, uniquely owned CString. For safety

src/libstd/comm/blocking.rs

@@ -13,16 +13,19 @@
 use thread::Thread;
 use sync::atomic::{AtomicBool, INIT_ATOMIC_BOOL, Ordering};
 use sync::Arc;
+use kinds::{Sync, Send};
 use kinds::marker::{NoSend, NoSync};
 use mem;
 use clone::Clone;
 
-#[deriving(Send, Sync)]
 struct Inner {
     thread: Thread,
     woken: AtomicBool,
 }
 
+unsafe impl Send for Inner {}
+unsafe impl Sync for Inner {}
+
 #[deriving(Clone)]
 pub struct SignalToken {
     inner: Arc<Inner>,

src/libstd/comm/mod.rs

@@ -363,7 +363,7 @@ pub struct Receiver<T> {
 
 // The receiver port can be sent from place to place, so long as it
 // is not used to receive non-sendable things.
-impl<T:Send> Send for Receiver<T> { }
+unsafe impl<T:Send> Send for Receiver<T> { }
 
 /// An iterator over messages on a receiver, this iterator will block
 /// whenever `next` is called, waiting for a new message, and `None` will be
@@ -382,7 +382,7 @@ pub struct Sender<T> {
 
 // The send port can be sent from place to place, so long as it
 // is not used to send non-sendable things.
-impl<T:Send> Send for Sender<T> { }
+unsafe impl<T:Send> Send for Sender<T> { }
 
 /// The sending-half of Rust's synchronous channel type. This half can only be
 /// owned by one task, but it can be cloned to send to other tasks.

src/libstd/comm/mpsc_queue.rs

@@ -76,8 +76,8 @@ pub struct Queue<T> {
     tail: UnsafeCell<*mut Node<T>>,
 }
 
-impl<T:Send> Send for Queue<T> { }
+unsafe impl<T:Send> Send for Queue<T> { }
-impl<T:Send> Sync for Queue<T> { }
+unsafe impl<T:Send> Sync for Queue<T> { }
 
 impl<T> Node<T> {
     unsafe fn new(v: Option<T>) -> *mut Node<T> {

src/libstd/comm/spsc_queue.rs

@@ -73,9 +73,9 @@ pub struct Queue<T> {
     cache_subtractions: AtomicUint,
 }
 
-impl<T: Send> Send for Queue<T> { }
+unsafe impl<T: Send> Send for Queue<T> { }
 
-impl<T: Send> Sync for Queue<T> { }
+unsafe impl<T: Send> Sync for Queue<T> { }
 
 impl<T: Send> Node<T> {
     fn new() -> *mut Node<T> {

src/libstd/comm/sync.rs

@@ -53,11 +53,10 @@ pub struct Packet<T> {
     lock: Mutex<State<T>>,
 }
 
-impl<T:Send> Send for Packet<T> { }
+unsafe impl<T:Send> Send for Packet<T> { }
 
-impl<T:Send> Sync for Packet<T> { }
+unsafe impl<T:Send> Sync for Packet<T> { }
 
-#[deriving(Send)]
 struct State<T> {
     disconnected: bool, // Is the channel disconnected yet?
     queue: Queue,       // queue of senders waiting to send data
@@ -74,6 +73,8 @@ struct State<T> {
     canceled: Option<&'static mut bool>,
 }
 
+unsafe impl<T: Send> Send for State<T> {}
+
 /// Possible flavors of threads who can be blocked on this channel.
 enum Blocker {
     BlockedSender(SignalToken),
@@ -93,7 +94,7 @@ struct Node {
     next: *mut Node,
 }
 
-impl Send for Node {}
+unsafe impl Send for Node {}
 
 /// A simple ring-buffer
 struct Buffer<T> {

src/libstd/rt/exclusive.rs

@@ -26,9 +26,9 @@ pub struct Exclusive<T> {
     data: UnsafeCell<T>,
 }
 
-impl<T:Send> Send for Exclusive<T> { }
+unsafe impl<T:Send> Send for Exclusive<T> { }
 
-impl<T:Send> Sync for Exclusive<T> { }
+unsafe impl<T:Send> Sync for Exclusive<T> { }
 
 /// An RAII guard returned via `lock`
 pub struct ExclusiveGuard<'a, T:'a> {

src/libstd/sync/mutex.rs

@@ -11,7 +11,7 @@
 use prelude::*;
 
 use cell::{UnsafeCell, RacyCell};
-use kinds::marker;
+use kinds::{marker, Sync};
 use sync::{poison, AsMutexGuard};
 use sys_common::mutex as sys;
 
@@ -73,9 +73,9 @@ pub struct Mutex<T> {
     data: RacyCell<T>,
 }
 
-impl<T:Send> Send for Mutex<T> { }
+unsafe impl<T:Send> Send for Mutex<T> { }
 
-impl<T:Send> Sync for Mutex<T> { }
+unsafe impl<T:Send> Sync for Mutex<T> { }
 
 /// The static mutex type is provided to allow for static allocation of mutexes.
 ///
@@ -98,12 +98,13 @@ impl<T:Send> Sync for Mutex<T> { }
 /// }
 /// // lock is unlocked here.
 /// ```
-#[deriving(Sync)]
 pub struct StaticMutex {
     lock: sys::Mutex,
     poison: RacyCell<poison::Flag>,
 }
 
+unsafe impl Sync for StaticMutex {}
+
 /// An RAII implementation of a "scoped lock" of a mutex. When this structure is
 /// dropped (falls out of scope), the lock will be unlocked.
 ///

src/libstd/sync/once.rs

@@ -14,6 +14,7 @@
 //! example use case would be for initializing an FFI library.
 
 use int;
+use kinds::Sync;
 use mem::drop;
 use ops::FnOnce;
 use sync::atomic;
@@ -35,13 +36,14 @@ use sync::{StaticMutex, MUTEX_INIT};
 ///     // run initialization here
 /// });
 /// ```
-#[deriving(Sync)]
 pub struct Once {
     mutex: StaticMutex,
     cnt: atomic::AtomicInt,
     lock_cnt: atomic::AtomicInt,
 }
 
+unsafe impl Sync for Once {}
+
 /// Initialization value for static `Once` values.
 pub const ONCE_INIT: Once = Once {
     mutex: MUTEX_INIT,

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

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);
 

src/libstd/sys/unix/c.rs

@@ -162,8 +162,8 @@ mod signal {
         sa_restorer: *mut libc::c_void,
     }
 
-    impl ::kinds::Send for sigaction { }
+    unsafe impl ::kinds::Send for sigaction { }
-    impl ::kinds::Sync for sigaction { }
+    unsafe impl ::kinds::Sync for sigaction { }
 
     #[repr(C)]
     #[cfg(target_word_size = "32")]

src/libstd/sys/unix/mutex.rs

@@ -8,11 +8,11 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use kinds::Sync;
 use cell::{UnsafeCell, RacyCell};
 use sys::sync as ffi;
 use sys_common::mutex;
 
-#[deriving(Sync)]
 pub struct Mutex { inner: RacyCell<ffi::pthread_mutex_t> }
 
 #[inline]
@@ -24,6 +24,8 @@ pub const MUTEX_INIT: Mutex = Mutex {
     inner: RacyCell(UnsafeCell { value: ffi::PTHREAD_MUTEX_INITIALIZER }),
 };
 
+unsafe impl Sync for Mutex {}
+
 impl Mutex {
     #[inline]
     pub unsafe fn new() -> Mutex {

src/libstd/sys/unix/pipe.rs

@@ -210,12 +210,13 @@ impl Clone for UnixStream {
 // Unix Listener
 ////////////////////////////////////////////////////////////////////////////////
 
-#[deriving(Sync)]
 pub struct UnixListener {
     inner: Inner,
     path: CString,
 }
 
+unsafe impl Sync for UnixListener {}
+
 impl UnixListener {
     pub fn bind(addr: &CString) -> IoResult<UnixListener> {
         bind(addr, libc::SOCK_STREAM).map(|fd| {
@@ -253,7 +254,6 @@ pub struct UnixAcceptor {
     deadline: u64,
 }
 
-#[deriving(Sync)]
 struct AcceptorInner {
     listener: UnixListener,
     reader: FileDesc,
@@ -261,6 +261,8 @@ struct AcceptorInner {
     closed: atomic::AtomicBool,
 }
 
+unsafe impl Sync for AcceptorInner {}
+
 impl UnixAcceptor {
     pub fn fd(&self) -> fd_t { self.inner.listener.fd() }
 

src/libstd/sys/unix/tcp.rs

@@ -29,11 +29,12 @@ pub use sys_common::net::TcpStream;
 // TCP listeners
 ////////////////////////////////////////////////////////////////////////////////
 
-#[deriving(Sync)]
 pub struct TcpListener {
     pub inner: FileDesc,
 }
 
+unsafe impl Sync for TcpListener {}
+
 impl TcpListener {
     pub fn bind(addr: ip::SocketAddr) -> IoResult<TcpListener> {
         let fd = try!(net::socket(addr, libc::SOCK_STREAM));
@@ -90,7 +91,6 @@ pub struct TcpAcceptor {
     deadline: u64,
 }
 
-#[deriving(Sync)]
 struct AcceptorInner {
     listener: TcpListener,
     reader: FileDesc,
@@ -98,6 +98,8 @@ struct AcceptorInner {
     closed: atomic::AtomicBool,
 }
 
+unsafe impl Sync for AcceptorInner {}
+
 impl TcpAcceptor {
     pub fn fd(&self) -> sock_t { self.inner.listener.fd() }
 

src/libstd/thread.rs

@@ -283,19 +283,22 @@ impl Builder {
     }
 }
 
-#[deriving(Sync)]
 struct Inner {
     name: Option<String>,
     lock: Mutex<bool>,          // true when there is a buffered unpark
     cvar: Condvar,
 }
 
-#[deriving(Clone, Sync)]
+unsafe impl Sync for Inner {}
+
+#[deriving(Clone)]
 /// A handle to a thread.
 pub struct Thread {
     inner: Arc<Inner>,
 }
 
+unsafe impl Sync for Thread {}
+
 impl Thread {
     // Used only internally to construct a thread object without spawning
     fn new(name: Option<String>) -> Thread {

src/libstd/thread_local/mod.rs

@@ -280,7 +280,7 @@ mod imp {
         pub dtor_running: UnsafeCell<bool>, // should be Cell
     }
 
-    impl<T> ::kinds::Sync for Key<T> { }
+    unsafe impl<T> ::kinds::Sync for Key<T> { }
 
     #[doc(hidden)]
     impl<T> Key<T> {
@@ -412,7 +412,7 @@ mod imp {
         pub os: OsStaticKey,
     }
 
-    impl<T> ::kinds::Sync for Key<T> { }
+    unsafe impl<T> ::kinds::Sync for Key<T> { }
 
     struct Value<T: 'static> {
         key: &'static Key<T>,

src/libstd/thread_local/scoped.rs

@@ -202,7 +202,7 @@ mod imp {
     #[doc(hidden)]
     pub struct KeyInner<T> { pub inner: UnsafeCell<*mut T> }
 
-    #[cfg(not(stage0))] impl<T> ::kinds::Sync for KeyInner<T> { }
+    unsafe impl<T> ::kinds::Sync for KeyInner<T> { }
 
     #[doc(hidden)]
     impl<T> KeyInner<T> {
@@ -224,7 +224,7 @@ mod imp {
         pub marker: marker::InvariantType<T>,
     }
 
-    #[cfg(not(stage0))] impl<T> ::kinds::Sync for KeyInner<T> { }
+    unsafe impl<T> ::kinds::Sync for KeyInner<T> { }
 
     #[doc(hidden)]
     impl<T> KeyInner<T> {

src/libtest/lib.rs

@@ -976,7 +976,7 @@ enum TestEvent {
 
 pub type MonitorMsg = (TestDesc, TestResult, Vec<u8> );
 
-impl Send for MonitorMsg {}
+unsafe impl Send for MonitorMsg {}
 
 fn run_tests<F>(opts: &TestOpts,
                 tests: Vec<TestDescAndFn> ,

src/test/run-pass/const-block.rs

@@ -18,7 +18,7 @@ struct Foo {
     b: *const ()
 }
 
-impl Sync for Foo {}
+unsafe impl Sync for Foo {}
 
 fn foo<T>(a: T) -> T {
     a

src/test/run-pass/const-cast-ptr-int.rs

@@ -14,7 +14,7 @@ struct TestStruct {
     x: *const u8
 }
 
-impl Sync for TestStruct {}
+unsafe impl Sync for TestStruct {}
 
 static a: TestStruct = TestStruct{x: 0 as *const u8};
 

src/test/run-pass/const-cast.rs

@@ -14,7 +14,7 @@ struct TestStruct {
     x: *const libc::c_void
 }
 
-impl Sync for TestStruct {}
+unsafe impl Sync for TestStruct {}
 
 extern fn foo() {}
 const x: extern "C" fn() = foo;

src/test/run-pass/issue-13837.rs

@@ -12,7 +12,7 @@ struct TestStruct {
     x: *const [int; 2]
 }
 
-impl Sync for TestStruct {}
+unsafe impl Sync for TestStruct {}
 
 static TEST_VALUE : TestStruct = TestStruct{x: 0x1234 as *const [int; 2]};
 

src/test/run-pass/issue-17718-static-unsafe-interior.rs

@@ -36,7 +36,7 @@ struct Wrap<T> {
     value: T
 }
 
-impl<T: Send> Sync for Wrap<T> {}
+unsafe impl<T: Send> Sync for Wrap<T> {}
 
 static UNSAFE: RacyCell<int> = RacyCell(UnsafeCell{value: 1});
 static WRAPPED_UNSAFE: Wrap<&'static RacyCell<int>> = Wrap { value: &UNSAFE };

src/test/run-pass/issue-2718.rs

@@ -46,7 +46,7 @@ pub mod pipes {
         payload: Option<T>
     }
 
-    impl<T:Send> Send for packet<T> {}
+    unsafe impl<T:Send> Send for packet<T> {}
 
     pub fn packet<T:Send>() -> *const packet<T> {
         unsafe {

src/test/run-pass/typeck_type_placeholder_1.rs

@@ -15,7 +15,7 @@ struct TestStruct {
     x: *const int
 }
 
-impl Sync for TestStruct {}
+unsafe impl Sync for TestStruct {}
 
 static CONSTEXPR: TestStruct = TestStruct{x: &413 as *const _};