Rename Share to Sync

This leaves the `Share` trait at `std::kinds` via a `#[deprecated]` `pub use`
statement, but the `NoShare` struct is no longer part of `std::kinds::marker`
due to #12660 (the build cannot bootstrap otherwise).

All code referencing the `Share` trait should now reference the `Sync` trait,
and all code referencing the `NoShare` type should now reference the `NoSync`
type. The functionality and meaning of this trait have not changed, only the
naming.

Closes #16281
[breaking-change]

Author: alexcrichton

src/doc/complement-design-faq.md

@@ -50,15 +50,15 @@ non-deterministic behavior. Rust provides the tools to make using a GC
 possible and even pleasant, but it should not be a requirement for
 implementing the language.
 
-## Non-`Share` `static mut` is unsafe
+## Non-`Sync` `static mut` is unsafe
 
-Types which are [`Share`][share] are thread-safe when multiple shared
-references to them are used concurrently. Types which are not `Share` are not
+Types which are [`Sync`][sync] are thread-safe when multiple shared
+references to them are used concurrently. Types which are not `Sync` are not
 thread-safe, and thus when used in a global require unsafe code to use.
 
-[share]: http://doc.rust-lang.org/core/kinds/trait.Share.html
+[sync]: http://doc.rust-lang.org/core/kinds/trait.Sync.html
 
-### If mutable static items that implement `Share` are safe, why is taking &mut SHARABLE unsafe?
+### If mutable static items that implement `Sync` are safe, why is taking &mut SHARABLE unsafe?
 
 Having multiple aliasing `&mut T`s is never allowed. Due to the nature of
 globals, the borrow checker cannot possibly ensure that a static obeys the

src/doc/guide-unsafe.md

@@ -699,10 +699,10 @@ Other features provided by lang items include:
 - stack unwinding and general failure; the `eh_personality`, `fail_`
   and `fail_bounds_checks` lang items.
 - the traits in `std::kinds` used to indicate types that satisfy
-  various kinds; lang items `send`, `share` and `copy`.
+  various kinds; lang items `send`, `sync` and `copy`.
 - the marker types and variance indicators found in
   `std::kinds::markers`; lang items `covariant_type`,
-  `contravariant_lifetime`, `no_share_bound`, etc.
+  `contravariant_lifetime`, `no_sync_bound`, etc.
 
 Lang items are loaded lazily by the compiler; e.g. if one never uses
 `Box` then there is no need to define functions for `exchange_malloc`

src/doc/rust.md

@@ -2111,7 +2111,7 @@ A complete list of the built-in language items follows:
   : Has a size known at compile time.
 * `copy`
   : Types that do not move ownership when used by-value.
-* `share`
+* `sync`
   : Able to be safely shared between tasks when aliased.
 * `drop`
   : Have destructors.
@@ -2191,8 +2191,8 @@ These types help drive the compiler's analysis
   : This type does not implement "send", even if eligible
 * `no_copy_bound`
   : This type does not implement "copy", even if eligible
-* `no_share_bound`
-  : This type does not implement "share", even if eligible
+* `no_sync_bound`
+  : This type does not implement "sync", even if eligible
 * `managed_bound`
   : This type implements "managed"
 

src/doc/tutorial.md

@@ -2196,7 +2196,7 @@ and may not be overridden:
 Types are sendable
 unless they contain references.
 
-* `Share` - Types that are *threadsafe*.
+* `Sync` - Types that are *threadsafe*.
 These are types that are safe to be used across several threads with access to
 a `&T` pointer. `Mutex<T>` is an example of a *sharable* type with internal mutable data.
 
@@ -2250,7 +2250,7 @@ We say that the `Printable` trait _provides_ a `print` method with the
 given signature.  This means that we can call `print` on an argument
 of any type that implements the `Printable` trait.
 
-Rust's built-in `Send` and `Share` types are examples of traits that
+Rust's built-in `Send` and `Sync` types are examples of traits that
 don't provide any methods.
 
 Traits may be implemented for specific types with [impls]. An impl for
@@ -2535,7 +2535,7 @@ select the method to call at runtime.
 
 This usage of traits is similar to Java interfaces.
 
-There are some built-in bounds, such as `Send` and `Share`, which are properties
+There are some built-in bounds, such as `Send` and `Sync`, which are properties
 of the components of types. By design, trait objects don't know the exact type
 of their contents and so the compiler cannot reason about those properties.
 
@@ -2548,7 +2548,7 @@ trait Foo {}
 trait Bar<T> {}
 
 fn sendable_foo(f: Box<Foo + Send>) { /* ... */ }
-fn shareable_bar<T: Share>(b: &Bar<T> + Share) { /* ... */ }
+fn sync_bar<T: Sync>(b: &Bar<T> + Sync) { /* ... */ }
 ~~~
 
 When no colon is specified (such as the type `Box<Foo>`), it is inferred that the

src/etc/vim/syntax/rust.vim

@@ -76,7 +76,7 @@ syn keyword   rustType        f64 i8 i16 i32 i64 str Self
 " to make it easy to update.
 
 " Core operators {{{3
-syn keyword   rustTrait       Copy Send Sized Share
+syn keyword   rustTrait       Copy Send Sized Sync
 syn keyword   rustTrait       Add Sub Mul Div Rem Neg Not
 syn keyword   rustTrait       BitAnd BitOr BitXor
 syn keyword   rustTrait       Drop Deref DerefMut

src/liballoc/arc.rs

@@ -15,7 +15,7 @@
 
 use core::atomic;
 use core::clone::Clone;
-use core::kinds::{Share, Send};
+use core::kinds::{Sync, Send};
 use core::mem::{min_align_of, size_of, drop};
 use core::mem;
 use core::ops::{Drop, Deref};
@@ -76,7 +76,7 @@ struct ArcInner<T> {
     data: T,
 }
 
-impl<T: Share + Send> Arc<T> {
+impl<T: Sync + Send> Arc<T> {
     /// Create an atomically reference counted wrapper.
     #[inline]
     #[stable]
@@ -95,8 +95,8 @@ impl<T: Share + Send> Arc<T> {
     fn inner(&self) -> &ArcInner<T> {
         // This unsafety is ok because while this arc is alive we're guaranteed
         // that the inner pointer is valid. Furthermore, we know that the
-        // `ArcInner` structure itself is `Share` because the inner data is
-        // `Share` as well, so we're ok loaning out an immutable pointer to
+        // `ArcInner` structure itself is `Sync` because the inner data is
+        // `Sync` as well, so we're ok loaning out an immutable pointer to
         // these contents.
         unsafe { &*self._ptr }
     }
@@ -115,7 +115,7 @@ impl<T: Share + Send> Arc<T> {
 }
 
 #[unstable = "waiting on stability of Clone"]
-impl<T: Share + Send> Clone for Arc<T> {
+impl<T: Sync + Send> Clone for Arc<T> {
     /// Duplicate an atomically reference counted wrapper.
     ///
     /// The resulting two `Arc` objects will point to the same underlying data
@@ -140,14 +140,14 @@ impl<T: Share + Send> Clone for Arc<T> {
 }
 
 #[experimental = "Deref is experimental."]
-impl<T: Send + Share> Deref<T> for Arc<T> {
+impl<T: Send + Sync> Deref<T> for Arc<T> {
     #[inline]
     fn deref(&self) -> &T {
         &self.inner().data
     }
 }
 
-impl<T: Send + Share + Clone> Arc<T> {
+impl<T: Send + Sync + Clone> Arc<T> {
     /// Acquires a mutable pointer to the inner contents by guaranteeing that
     /// the reference count is one (no sharing is possible).
     ///
@@ -175,7 +175,7 @@ impl<T: Send + Share + Clone> Arc<T> {
 
 #[unsafe_destructor]
 #[experimental = "waiting on stability of Drop"]
-impl<T: Share + Send> Drop for Arc<T> {
+impl<T: Sync + Send> Drop for Arc<T> {
     fn drop(&mut self) {
         // This structure has #[unsafe_no_drop_flag], so this drop glue may run
         // more than once (but it is guaranteed to be zeroed after the first if
@@ -219,7 +219,7 @@ impl<T: Share + Send> Drop for Arc<T> {
 }
 
 #[experimental = "Weak pointers may not belong in this module."]
-impl<T: Share + Send> Weak<T> {
+impl<T: Sync + Send> Weak<T> {
     /// Attempts to upgrade this weak reference to a strong reference.
     ///
     /// This method will fail to upgrade this reference if the strong reference
@@ -245,7 +245,7 @@ impl<T: Share + Send> Weak<T> {
 }
 
 #[experimental = "Weak pointers may not belong in this module."]
-impl<T: Share + Send> Clone for Weak<T> {
+impl<T: Sync + Send> Clone for Weak<T> {
     #[inline]
     fn clone(&self) -> Weak<T> {
         // See comments in Arc::clone() for why this is relaxed
@@ -256,7 +256,7 @@ impl<T: Share + Send> Clone for Weak<T> {
 
 #[unsafe_destructor]
 #[experimental = "Weak pointers may not belong in this module."]
-impl<T: Share + Send> Drop for Weak<T> {
+impl<T: Sync + Send> Drop for Weak<T> {
     fn drop(&mut self) {
         // see comments above for why this check is here
         if self._ptr.is_null() { return }

src/liballoc/rc.rs

@@ -179,7 +179,7 @@ pub struct Rc<T> {
     // field accesses of the contained type via Deref
     _ptr: *mut RcBox<T>,
     _nosend: marker::NoSend,
-    _noshare: marker::NoShare
+    _noshare: marker::NoSync
 }
 
 #[stable]
@@ -199,7 +199,7 @@ impl<T> Rc<T> {
                     weak: Cell::new(1)
                 }),
                 _nosend: marker::NoSend,
-                _noshare: marker::NoShare
+                _noshare: marker::NoSync
             }
         }
     }
@@ -213,7 +213,7 @@ impl<T> Rc<T> {
         Weak {
             _ptr: self._ptr,
             _nosend: marker::NoSend,
-            _noshare: marker::NoShare
+            _noshare: marker::NoSync
         }
     }
 }
@@ -348,7 +348,7 @@ impl<T> Clone for Rc<T> {
     #[inline]
     fn clone(&self) -> Rc<T> {
         self.inc_strong();
-        Rc { _ptr: self._ptr, _nosend: marker::NoSend, _noshare: marker::NoShare }
+        Rc { _ptr: self._ptr, _nosend: marker::NoSend, _noshare: marker::NoSync }
     }
 }
 
@@ -412,7 +412,7 @@ pub struct Weak<T> {
     // field accesses of the contained type via Deref
     _ptr: *mut RcBox<T>,
     _nosend: marker::NoSend,
-    _noshare: marker::NoShare
+    _noshare: marker::NoSync
 }
 
 #[experimental = "Weak pointers may not belong in this module."]
@@ -423,7 +423,7 @@ impl<T> Weak<T> {
             None
         } else {
             self.inc_strong();
-            Some(Rc { _ptr: self._ptr, _nosend: marker::NoSend, _noshare: marker::NoShare })
+            Some(Rc { _ptr: self._ptr, _nosend: marker::NoSend, _noshare: marker::NoSync })
         }
     }
 }
@@ -451,7 +451,7 @@ impl<T> Clone for Weak<T> {
     #[inline]
     fn clone(&self) -> Weak<T> {
         self.inc_weak();
-        Weak { _ptr: self._ptr, _nosend: marker::NoSend, _noshare: marker::NoShare }
+        Weak { _ptr: self._ptr, _nosend: marker::NoSend, _noshare: marker::NoSync }
     }
 }
 

src/libcore/cell.rs

@@ -165,7 +165,7 @@ use option::{None, Option, Some};
 #[unstable = "likely to be renamed; otherwise stable"]
 pub struct Cell<T> {
     value: UnsafeCell<T>,
-    noshare: marker::NoShare,
+    noshare: marker::NoSync,
 }
 
 #[stable]
@@ -174,7 +174,7 @@ impl<T:Copy> Cell<T> {
     pub fn new(value: T) -> Cell<T> {
         Cell {
             value: UnsafeCell::new(value),
-            noshare: marker::NoShare,
+            noshare: marker::NoSync,
         }
     }
 
@@ -213,7 +213,7 @@ pub struct RefCell<T> {
     value: UnsafeCell<T>,
     borrow: Cell<BorrowFlag>,
     nocopy: marker::NoCopy,
-    noshare: marker::NoShare,
+    noshare: marker::NoSync,
 }
 
 // Values [1, MAX-1] represent the number of `Ref` active
@@ -230,7 +230,7 @@ impl<T> RefCell<T> {
             value: UnsafeCell::new(value),
             borrow: Cell::new(UNUSED),
             nocopy: marker::NoCopy,
-            noshare: marker::NoShare,
+            noshare: marker::NoSync,
         }
     }
 
@@ -430,7 +430,7 @@ impl<'b, T> DerefMut<T> for RefMut<'b, T> {
 ///
 /// struct NotThreadSafe<T> {
 ///     value: UnsafeCell<T>,
-///     marker: marker::NoShare
+///     marker: marker::NoSync
 /// }
 /// ```
 ///