1.0.0[−][src]Trait flatdata::marker::Sync
Types for which it is safe to share references between threads.
This trait is automatically implemented when the compiler determines it's appropriate.
The precise definition is: a type T
is Sync
if and only if &T
is
Send
. In other words, if there is no possibility of
undefined behavior (including data races) when passing
&T
references between threads.
As one would expect, primitive types like u8
and f64
are all Sync
, and so are simple aggregate types containing them,
like tuples, structs and enums. More examples of basic Sync
types include "immutable" types like &T
, and those with simple
inherited mutability, such as Box<T>
, Vec<T>
and
most other collection types. (Generic parameters need to be Sync
for their container to be Sync
.)
A somewhat surprising consequence of the definition is that &mut T
is Sync
(if T
is Sync
) even though it seems like that might
provide unsynchronized mutation. The trick is that a mutable
reference behind a shared reference (that is, & &mut T
)
becomes read-only, as if it were a & &T
. Hence there is no risk
of a data race.
Types that are not Sync
are those that have "interior
mutability" in a non-thread-safe form, such as cell::Cell
and cell::RefCell
. These types allow for mutation of
their contents even through an immutable, shared reference. For
example the set
method on Cell<T>
takes &self
, so it requires
only a shared reference &Cell<T>
. The method performs no
synchronization, thus Cell
cannot be Sync
.
Another example of a non-Sync
type is the reference-counting
pointer rc::Rc
. Given any reference &Rc<T>
, you can clone
a new Rc<T>
, modifying the reference counts in a non-atomic way.
For cases when one does need thread-safe interior mutability,
Rust provides atomic data types, as well as explicit locking via
sync::Mutex
and sync::RwLock
. These types
ensure that any mutation cannot cause data races, hence the types
are Sync
. Likewise, sync::Arc
provides a thread-safe
analogue of Rc
.
Any types with interior mutability must also use the
cell::UnsafeCell
wrapper around the value(s) which
can be mutated through a shared reference. Failing to doing this is
undefined behavior. For example, transmute
-ing
from &T
to &mut T
is invalid.
See the Nomicon for more
details about Sync
.
Implementations on Foreign Types
impl<T> !Sync for Sender<T>
[src]
impl<T> !Sync for Sender<T>
impl<T> Sync for RwLock<T> where
T: Send + Sync + ?Sized,
[src]
impl<T> Sync for RwLock<T> where
T: Send + Sync + ?Sized,
impl !Sync for Args
[src]
impl !Sync for Args
impl<T> Sync for Key<T>
[src]
impl<T> Sync for Key<T>
impl<T> Sync for Mutex<T> where
T: Send + ?Sized,
[src]
impl<T> Sync for Mutex<T> where
T: Send + ?Sized,
impl Sync for Once
[src]
impl Sync for Once
impl<'a, T> Sync for RwLockWriteGuard<'a, T> where
T: Sync + ?Sized,
[src]
impl<'a, T> Sync for RwLockWriteGuard<'a, T> where
T: Sync + ?Sized,
impl !Sync for ArgsOs
[src]
impl !Sync for ArgsOs
impl<'a, T> Sync for RwLockReadGuard<'a, T> where
T: Sync + ?Sized,
[src]
impl<'a, T> Sync for RwLockReadGuard<'a, T> where
T: Sync + ?Sized,
impl<'a, T> Sync for MutexGuard<'a, T> where
T: Sync + ?Sized,
[src]
impl<'a, T> Sync for MutexGuard<'a, T> where
T: Sync + ?Sized,
impl<T> !Sync for Receiver<T>
[src]
impl<T> !Sync for Receiver<T>
impl<T> Sync for JoinHandle<T>
[src]
impl<T> Sync for JoinHandle<T>
impl Sync for Waker
[src]
impl Sync for Waker
impl<T> Sync for AtomicPtr<T>
[src]
impl<T> Sync for AtomicPtr<T>
impl<T> !Sync for NonNull<T> where
T: ?Sized,
[src]
impl<T> !Sync for NonNull<T> where
T: ?Sized,
NonNull
pointers are not Sync
because the data they reference may be aliased.
impl<T> !Sync for *mut T where
T: ?Sized,
[src]
impl<T> !Sync for *mut T where
T: ?Sized,
impl Sync for AtomicI64
[src]
impl Sync for AtomicI64
impl Sync for AtomicI8
[src]
impl Sync for AtomicI8
impl Sync for AtomicUsize
[src]
impl Sync for AtomicUsize
impl Sync for AtomicI32
[src]
impl Sync for AtomicI32
impl Sync for AtomicBool
[src]
impl Sync for AtomicBool
impl Sync for AtomicU32
[src]
impl Sync for AtomicU32
impl<'_, T> Sync for IterMut<'_, T> where
T: Sync,
[src]
impl<'_, T> Sync for IterMut<'_, T> where
T: Sync,
impl Sync for AtomicIsize
[src]
impl Sync for AtomicIsize
impl<T> !Sync for UnsafeCell<T> where
T: ?Sized,
[src]
impl<T> !Sync for UnsafeCell<T> where
T: ?Sized,
impl Sync for AtomicU16
[src]
impl Sync for AtomicU16
impl<T> !Sync for Cell<T> where
T: ?Sized,
[src]
impl<T> !Sync for Cell<T> where
T: ?Sized,
impl Sync for AtomicU8
[src]
impl Sync for AtomicU8
impl<'_, T> Sync for Iter<'_, T> where
T: Sync,
[src]
impl<'_, T> Sync for Iter<'_, T> where
T: Sync,
impl Sync for AtomicI16
[src]
impl Sync for AtomicI16
impl !Sync for LocalWaker
[src]
impl !Sync for LocalWaker
impl<T> !Sync for RefCell<T> where
T: ?Sized,
[src]
impl<T> !Sync for RefCell<T> where
T: ?Sized,
impl Sync for AtomicU64
[src]
impl Sync for AtomicU64
impl<T> !Sync for *const T where
T: ?Sized,
[src]
impl<T> !Sync for *const T where
T: ?Sized,
impl<T> !Sync for Rc<T> where
T: ?Sized,
[src]
impl<T> !Sync for Rc<T> where
T: ?Sized,
impl<'a> Sync for Drain<'a>
[src]
impl<'a> Sync for Drain<'a>
impl<T> Sync for IntoIter<T> where
T: Sync,
[src]
impl<T> Sync for IntoIter<T> where
T: Sync,
impl<'a, T> Sync for Drain<'a, T> where
T: Sync,
[src]
impl<'a, T> Sync for Drain<'a, T> where
T: Sync,
impl<'a, T> Sync for Iter<'a, T> where
T: Sync,
[src]
impl<'a, T> Sync for Iter<'a, T> where
T: Sync,
impl<T> !Sync for Weak<T> where
T: ?Sized,
[src]
impl<T> !Sync for Weak<T> where
T: ?Sized,
impl<T> Sync for LinkedList<T> where
T: Sync,
[src]
impl<T> Sync for LinkedList<T> where
T: Sync,
impl<'a, T> Sync for IterMut<'a, T> where
T: Sync,
[src]
impl<'a, T> Sync for IterMut<'a, T> where
T: Sync,
impl<T> Sync for Weak<T> where
T: Send + Sync + ?Sized,
[src]
impl<T> Sync for Weak<T> where
T: Send + Sync + ?Sized,
impl<T> Sync for Arc<T> where
T: Send + Sync + ?Sized,
[src]
impl<T> Sync for Arc<T> where
T: Send + Sync + ?Sized,
impl<'a, T> Sync for Drain<'a, T> where
T: Sync,
[src]
impl<'a, T> Sync for Drain<'a, T> where
T: Sync,
impl Sync for isize
impl Sync for isize
impl Sync for i8
impl Sync for i8
impl Sync for i16
impl Sync for i16
impl Sync for i32
impl Sync for i32
impl Sync for i64
impl Sync for i64
impl Sync for i128
impl Sync for i128
impl Sync for usize
impl Sync for usize
impl Sync for u8
impl Sync for u8
impl Sync for u16
impl Sync for u16
impl Sync for u32
impl Sync for u32
impl Sync for u64
impl Sync for u64
impl Sync for u128
impl Sync for u128
impl Sync for f32
impl Sync for f32
impl Sync for f64
impl Sync for f64
impl Sync for f32
impl Sync for f32
impl Sync for f64
impl Sync for f64
impl Sync for char
impl Sync for char
impl Sync for str
impl Sync for str
impl Sync for str
Loading content...
impl Sync for str
Implementors
Loading content...Auto implementors
impl !Sync for FileResourceStorage
impl !Sync for FileResourceStorage
impl !Sync for MemoryDescriptor
impl !Sync for MemoryDescriptor
impl !Sync for MemoryResourceStorage
impl !Sync for MemoryResourceStorage
impl Sync for ResourceStorageError
impl Sync for ResourceStorageError
impl Sync for PhantomPinned
impl Sync for PhantomPinned
impl<'a, Idx, Ts> !Sync for MultiVector<'a, Idx, Ts>
impl<'a, Idx, Ts> !Sync for MultiVector<'a, Idx, Ts>
impl<'a, Idx, Ts> Sync for MultiArrayView<'a, Idx, Ts> where
Idx: Sync,
Ts: Sync,
impl<'a, Idx, Ts> Sync for MultiArrayView<'a, Idx, Ts> where
Idx: Sync,
Ts: Sync,
impl<'a, T> !Sync for ExternalVector<'a, T>
impl<'a, T> !Sync for ExternalVector<'a, T>
impl<'a, T> Sync for ArrayView<'a, T> where
T: Sync,
impl<'a, T> Sync for ArrayView<'a, T> where
T: Sync,
impl<T> Sync for StructBuf<T> where
T: Sync,
impl<T> Sync for StructBuf<T> where
T: Sync,
impl<T> Sync for Vector<T> where
T: Sync,
impl<T> Sync for Vector<T> where
T: Sync,
impl<T: ?Sized> Sync for PhantomData<T> where
T: Sync,
impl<T: ?Sized> Sync for PhantomData<T> where
T: Sync,