//
// Note that the thunk is itself unsafe because the returned lifetime of the
// slot where data lives, `'static`, is not actually valid. The lifetime
- // here is actually `'thread`!
+ // here is actually slightly shorter than the currently running thread!
//
// Although this is an extra layer of indirection, it should in theory be
// trivially devirtualizable by LLVM because the value of `inner` never
// changes and the constant should be readonly within a crate. This mainly
// only runs into problems when TLS statics are exported across crates.
- inner: fn() -> Option<&'static UnsafeCell<Option<T>>>,
+ inner: unsafe fn() -> Option<&'static UnsafeCell<Option<T>>>,
// initialization routine to invoke to create a value
init: fn() -> T,
}
}
-#[cfg(not(stage0))]
/// Declare a new thread local storage key of type [`std::thread::LocalKey`].
///
/// # Syntax
);
}
-#[cfg(not(stage0))]
#[doc(hidden)]
#[unstable(feature = "thread_local_internals",
reason = "should not be necessary",
issue = "0")]
#[macro_export]
#[allow_internal_unstable]
+#[cfg_attr(not(stage0), allow_internal_unsafe)]
macro_rules! __thread_local_inner {
($(#[$attr:meta])* $vis:vis $name:ident, $t:ty, $init:expr) => {
$(#[$attr])* $vis static $name: $crate::thread::LocalKey<$t> = {
fn __init() -> $t { $init }
- fn __getit() -> $crate::option::Option<
+ unsafe fn __getit() -> $crate::option::Option<
&'static $crate::cell::UnsafeCell<
$crate::option::Option<$t>>>
{
__KEY.get()
}
- $crate::thread::LocalKey::new(__getit, __init)
+ unsafe {
+ $crate::thread::LocalKey::new(__getit, __init)
+ }
};
}
}
-#[cfg(stage0)]
-/// Declare a new thread local storage key of type `std::thread::LocalKey`.
-#[macro_export]
-#[stable(feature = "rust1", since = "1.0.0")]
-#[allow_internal_unstable]
-macro_rules! thread_local {
- // rule 0: empty (base case for the recursion)
- () => {};
-
- // rule 1: process multiple declarations where the first one is private
- ($(#[$attr:meta])* static $name:ident: $t:ty = $init:expr; $($rest:tt)*) => (
- thread_local!($(#[$attr])* static $name: $t = $init); // go to rule 2
- thread_local!($($rest)*);
- );
-
- // rule 2: handle a single private declaration
- ($(#[$attr:meta])* static $name:ident: $t:ty = $init:expr) => (
- $(#[$attr])* static $name: $crate::thread::LocalKey<$t> =
- __thread_local_inner!($t, $init);
- );
-
- // rule 3: handle multiple declarations where the first one is public
- ($(#[$attr:meta])* pub static $name:ident: $t:ty = $init:expr; $($rest:tt)*) => (
- thread_local!($(#[$attr])* pub static $name: $t = $init); // go to rule 4
- thread_local!($($rest)*);
- );
-
- // rule 4: handle a single public declaration
- ($(#[$attr:meta])* pub static $name:ident: $t:ty = $init:expr) => (
- $(#[$attr])* pub static $name: $crate::thread::LocalKey<$t> =
- __thread_local_inner!($t, $init);
- );
-}
-
-#[cfg(stage0)]
-#[doc(hidden)]
-#[unstable(feature = "thread_local_internals",
- reason = "should not be necessary",
- issue = "0")]
-#[macro_export]
-#[allow_internal_unstable]
-macro_rules! __thread_local_inner {
- ($t:ty, $init:expr) => {{
- fn __init() -> $t { $init }
-
- fn __getit() -> $crate::option::Option<
- &'static $crate::cell::UnsafeCell<
- $crate::option::Option<$t>>>
- {
- #[thread_local]
- #[cfg(target_thread_local)]
- static __KEY: $crate::thread::__FastLocalKeyInner<$t> =
- $crate::thread::__FastLocalKeyInner::new();
-
- #[cfg(not(target_thread_local))]
- static __KEY: $crate::thread::__OsLocalKeyInner<$t> =
- $crate::thread::__OsLocalKeyInner::new();
-
- __KEY.get()
- }
-
- $crate::thread::LocalKey::new(__getit, __init)
- }}
-}
-
/// Indicator of the state of a thread local storage key.
#[unstable(feature = "thread_local_state",
reason = "state querying was recently added",
#[unstable(feature = "thread_local_internals",
reason = "recently added to create a key",
issue = "0")]
- pub const fn new(inner: fn() -> Option<&'static UnsafeCell<Option<T>>>,
- init: fn() -> T) -> LocalKey<T> {
+ pub const unsafe fn new(inner: unsafe fn() -> Option<&'static UnsafeCell<Option<T>>>,
+ init: fn() -> T) -> LocalKey<T> {
LocalKey {
- inner: inner,
- init: init,
+ inner,
+ init,
}
}
}
}
+ #[cfg(stage0)]
unsafe impl<T> ::marker::Sync for Key<T> { }
impl<T> Key<T> {
}
}
- pub fn get(&'static self) -> Option<&'static UnsafeCell<Option<T>>> {
- unsafe {
- if mem::needs_drop::<T>() && self.dtor_running.get() {
- return None
- }
- self.register_dtor();
+ pub unsafe fn get(&self) -> Option<&'static UnsafeCell<Option<T>>> {
+ if mem::needs_drop::<T>() && self.dtor_running.get() {
+ return None
}
- Some(&self.inner)
+ self.register_dtor();
+ Some(&*(&self.inner as *const _))
}
unsafe fn register_dtor(&self) {
}
}
- pub fn get(&'static self) -> Option<&'static UnsafeCell<Option<T>>> {
- unsafe {
- let ptr = self.os.get() as *mut Value<T>;
- if !ptr.is_null() {
- if ptr as usize == 1 {
- return None
- }
- return Some(&(*ptr).value);
+ pub unsafe fn get(&'static self) -> Option<&'static UnsafeCell<Option<T>>> {
+ let ptr = self.os.get() as *mut Value<T>;
+ if !ptr.is_null() {
+ if ptr as usize == 1 {
+ return None
}
-
- // If the lookup returned null, we haven't initialized our own
- // local copy, so do that now.
- let ptr: Box<Value<T>> = box Value {
- key: self,
- value: UnsafeCell::new(None),
- };
- let ptr = Box::into_raw(ptr);
- self.os.set(ptr as *mut u8);
- Some(&(*ptr).value)
+ return Some(&(*ptr).value);
}
+
+ // If the lookup returned null, we haven't initialized our own
+ // local copy, so do that now.
+ let ptr: Box<Value<T>> = box Value {
+ key: self,
+ value: UnsafeCell::new(None),
+ };
+ let ptr = Box::into_raw(ptr);
+ self.os.set(ptr as *mut u8);
+ Some(&(*ptr).value)
}
}
projects / rust.git / blobdiff