diff options
Diffstat (limited to 'library/std/src/sys/common/thread_local')
| -rw-r--r-- | library/std/src/sys/common/thread_local/fast_local.rs | 259 | ||||
| -rw-r--r-- | library/std/src/sys/common/thread_local/mod.rs | 36 | ||||
| -rw-r--r-- | library/std/src/sys/common/thread_local/os_local.rs | 215 | ||||
| -rw-r--r-- | library/std/src/sys/common/thread_local/static_local.rs | 80 |
4 files changed, 282 insertions, 308 deletions
diff --git a/library/std/src/sys/common/thread_local/fast_local.rs b/library/std/src/sys/common/thread_local/fast_local.rs index e229eb16a..447044a79 100644 --- a/library/std/src/sys/common/thread_local/fast_local.rs +++ b/library/std/src/sys/common/thread_local/fast_local.rs @@ -1,16 +1,17 @@ +use super::lazy::LazyKeyInner; +use crate::cell::Cell; +use crate::sys::thread_local_dtor::register_dtor; +use crate::{fmt, mem, panic}; + #[doc(hidden)] -#[macro_export] -#[allow_internal_unstable( - thread_local_internals, - cfg_target_thread_local, - thread_local, - libstd_thread_internals -)] +#[allow_internal_unstable(thread_local_internals, cfg_target_thread_local, thread_local)] #[allow_internal_unsafe] -macro_rules! __thread_local_inner { +#[unstable(feature = "thread_local_internals", issue = "none")] +#[rustc_macro_transparency = "semitransparent"] +pub macro thread_local_inner { // used to generate the `LocalKey` value for const-initialized thread locals (@key $t:ty, const $init:expr) => {{ - #[cfg_attr(not(bootstrap), inline)] + #[inline] #[deny(unsafe_op_in_unsafe_fn)] unsafe fn __getit( _init: $crate::option::Option<&mut $crate::option::Option<$t>>, @@ -49,7 +50,7 @@ macro_rules! __thread_local_inner { // 0 == we haven't registered a destructor, so do // so now. 0 => { - $crate::thread::__LocalKeyInner::<$t>::register_dtor( + $crate::thread::local_impl::Key::<$t>::register_dtor( $crate::ptr::addr_of_mut!(VAL) as *mut $crate::primitive::u8, destroy, ); @@ -69,7 +70,7 @@ macro_rules! __thread_local_inner { unsafe { $crate::thread::LocalKey::new(__getit) } - }}; + }}, // used to generate the `LocalKey` value for `thread_local!` (@key $t:ty, $init:expr) => { @@ -77,13 +78,13 @@ macro_rules! __thread_local_inner { #[inline] fn __init() -> $t { $init } - #[cfg_attr(not(bootstrap), inline)] + #[inline] unsafe fn __getit( init: $crate::option::Option<&mut $crate::option::Option<$t>>, ) -> $crate::option::Option<&'static $t> { #[thread_local] - static __KEY: $crate::thread::__LocalKeyInner<$t> = - $crate::thread::__LocalKeyInner::<$t>::new(); + static __KEY: $crate::thread::local_impl::Key<$t> = + $crate::thread::local_impl::Key::<$t>::new(); // FIXME: remove the #[allow(...)] marker when macros don't // raise warning for missing/extraneous unsafe blocks anymore. @@ -107,148 +108,140 @@ macro_rules! __thread_local_inner { $crate::thread::LocalKey::new(__getit) } } - }; + }, ($(#[$attr:meta])* $vis:vis $name:ident, $t:ty, $($init:tt)*) => { $(#[$attr])* $vis const $name: $crate::thread::LocalKey<$t> = - $crate::__thread_local_inner!(@key $t, $($init)*); - } + $crate::thread::local_impl::thread_local_inner!(@key $t, $($init)*); + }, } -#[doc(hidden)] -pub mod fast { - use super::super::lazy::LazyKeyInner; - use crate::cell::Cell; - use crate::sys::thread_local_dtor::register_dtor; - use crate::{fmt, mem, panic}; - - #[derive(Copy, Clone)] - enum DtorState { - Unregistered, - Registered, - RunningOrHasRun, - } +#[derive(Copy, Clone)] +enum DtorState { + Unregistered, + Registered, + RunningOrHasRun, +} - // This data structure has been carefully constructed so that the fast path - // only contains one branch on x86. That optimization is necessary to avoid - // duplicated tls lookups on OSX. +// This data structure has been carefully constructed so that the fast path +// only contains one branch on x86. That optimization is necessary to avoid +// duplicated tls lookups on OSX. +// +// LLVM issue: https://bugs.llvm.org/show_bug.cgi?id=41722 +pub struct Key<T> { + // If `LazyKeyInner::get` returns `None`, that indicates either: + // * The value has never been initialized + // * The value is being recursively initialized + // * The value has already been destroyed or is being destroyed + // To determine which kind of `None`, check `dtor_state`. // - // LLVM issue: https://bugs.llvm.org/show_bug.cgi?id=41722 - pub struct Key<T> { - // If `LazyKeyInner::get` returns `None`, that indicates either: - // * The value has never been initialized - // * The value is being recursively initialized - // * The value has already been destroyed or is being destroyed - // To determine which kind of `None`, check `dtor_state`. - // - // This is very optimizer friendly for the fast path - initialized but - // not yet dropped. - inner: LazyKeyInner<T>, + // This is very optimizer friendly for the fast path - initialized but + // not yet dropped. + inner: LazyKeyInner<T>, - // Metadata to keep track of the state of the destructor. Remember that - // this variable is thread-local, not global. - dtor_state: Cell<DtorState>, - } + // Metadata to keep track of the state of the destructor. Remember that + // this variable is thread-local, not global. + dtor_state: Cell<DtorState>, +} - impl<T> fmt::Debug for Key<T> { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - f.debug_struct("Key").finish_non_exhaustive() - } +impl<T> fmt::Debug for Key<T> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("Key").finish_non_exhaustive() } +} - impl<T> Key<T> { - pub const fn new() -> Key<T> { - Key { inner: LazyKeyInner::new(), dtor_state: Cell::new(DtorState::Unregistered) } - } +impl<T> Key<T> { + pub const fn new() -> Key<T> { + Key { inner: LazyKeyInner::new(), dtor_state: Cell::new(DtorState::Unregistered) } + } - // note that this is just a publicly-callable function only for the - // const-initialized form of thread locals, basically a way to call the - // free `register_dtor` function defined elsewhere in std. - pub unsafe fn register_dtor(a: *mut u8, dtor: unsafe extern "C" fn(*mut u8)) { - unsafe { - register_dtor(a, dtor); - } + // note that this is just a publicly-callable function only for the + // const-initialized form of thread locals, basically a way to call the + // free `register_dtor` function defined elsewhere in std. + pub unsafe fn register_dtor(a: *mut u8, dtor: unsafe extern "C" fn(*mut u8)) { + unsafe { + register_dtor(a, dtor); } + } - pub unsafe fn get<F: FnOnce() -> T>(&self, init: F) -> Option<&'static T> { - // SAFETY: See the definitions of `LazyKeyInner::get` and - // `try_initialize` for more information. - // - // The caller must ensure no mutable references are ever active to - // the inner cell or the inner T when this is called. - // The `try_initialize` is dependant on the passed `init` function - // for this. - unsafe { - match self.inner.get() { - Some(val) => Some(val), - None => self.try_initialize(init), - } + pub unsafe fn get<F: FnOnce() -> T>(&self, init: F) -> Option<&'static T> { + // SAFETY: See the definitions of `LazyKeyInner::get` and + // `try_initialize` for more information. + // + // The caller must ensure no mutable references are ever active to + // the inner cell or the inner T when this is called. + // The `try_initialize` is dependant on the passed `init` function + // for this. + unsafe { + match self.inner.get() { + Some(val) => Some(val), + None => self.try_initialize(init), } } + } - // `try_initialize` is only called once per fast thread local variable, - // except in corner cases where thread_local dtors reference other - // thread_local's, or it is being recursively initialized. - // - // Macos: Inlining this function can cause two `tlv_get_addr` calls to - // be performed for every call to `Key::get`. - // LLVM issue: https://bugs.llvm.org/show_bug.cgi?id=41722 - #[inline(never)] - unsafe fn try_initialize<F: FnOnce() -> T>(&self, init: F) -> Option<&'static T> { + // `try_initialize` is only called once per fast thread local variable, + // except in corner cases where thread_local dtors reference other + // thread_local's, or it is being recursively initialized. + // + // Macos: Inlining this function can cause two `tlv_get_addr` calls to + // be performed for every call to `Key::get`. + // LLVM issue: https://bugs.llvm.org/show_bug.cgi?id=41722 + #[inline(never)] + unsafe fn try_initialize<F: FnOnce() -> T>(&self, init: F) -> Option<&'static T> { + // SAFETY: See comment above (this function doc). + if !mem::needs_drop::<T>() || unsafe { self.try_register_dtor() } { // SAFETY: See comment above (this function doc). - if !mem::needs_drop::<T>() || unsafe { self.try_register_dtor() } { - // SAFETY: See comment above (this function doc). - Some(unsafe { self.inner.initialize(init) }) - } else { - None - } + Some(unsafe { self.inner.initialize(init) }) + } else { + None } + } - // `try_register_dtor` is only called once per fast thread local - // variable, except in corner cases where thread_local dtors reference - // other thread_local's, or it is being recursively initialized. - unsafe fn try_register_dtor(&self) -> bool { - match self.dtor_state.get() { - DtorState::Unregistered => { - // SAFETY: dtor registration happens before initialization. - // Passing `self` as a pointer while using `destroy_value<T>` - // is safe because the function will build a pointer to a - // Key<T>, which is the type of self and so find the correct - // size. - unsafe { register_dtor(self as *const _ as *mut u8, destroy_value::<T>) }; - self.dtor_state.set(DtorState::Registered); - true - } - DtorState::Registered => { - // recursively initialized - true - } - DtorState::RunningOrHasRun => false, + // `try_register_dtor` is only called once per fast thread local + // variable, except in corner cases where thread_local dtors reference + // other thread_local's, or it is being recursively initialized. + unsafe fn try_register_dtor(&self) -> bool { + match self.dtor_state.get() { + DtorState::Unregistered => { + // SAFETY: dtor registration happens before initialization. + // Passing `self` as a pointer while using `destroy_value<T>` + // is safe because the function will build a pointer to a + // Key<T>, which is the type of self and so find the correct + // size. + unsafe { register_dtor(self as *const _ as *mut u8, destroy_value::<T>) }; + self.dtor_state.set(DtorState::Registered); + true } + DtorState::Registered => { + // recursively initialized + true + } + DtorState::RunningOrHasRun => false, } } +} - unsafe extern "C" fn destroy_value<T>(ptr: *mut u8) { - let ptr = ptr as *mut Key<T>; +unsafe extern "C" fn destroy_value<T>(ptr: *mut u8) { + let ptr = ptr as *mut Key<T>; - // SAFETY: - // - // The pointer `ptr` has been built just above and comes from - // `try_register_dtor` where it is originally a Key<T> coming from `self`, - // making it non-NUL and of the correct type. - // - // Right before we run the user destructor be sure to set the - // `Option<T>` to `None`, and `dtor_state` to `RunningOrHasRun`. This - // causes future calls to `get` to run `try_initialize_drop` again, - // which will now fail, and return `None`. - // - // Wrap the call in a catch to ensure unwinding is caught in the event - // a panic takes place in a destructor. - if let Err(_) = panic::catch_unwind(panic::AssertUnwindSafe(|| unsafe { - let value = (*ptr).inner.take(); - (*ptr).dtor_state.set(DtorState::RunningOrHasRun); - drop(value); - })) { - rtabort!("thread local panicked on drop"); - } + // SAFETY: + // + // The pointer `ptr` has been built just above and comes from + // `try_register_dtor` where it is originally a Key<T> coming from `self`, + // making it non-NUL and of the correct type. + // + // Right before we run the user destructor be sure to set the + // `Option<T>` to `None`, and `dtor_state` to `RunningOrHasRun`. This + // causes future calls to `get` to run `try_initialize_drop` again, + // which will now fail, and return `None`. + // + // Wrap the call in a catch to ensure unwinding is caught in the event + // a panic takes place in a destructor. + if let Err(_) = panic::catch_unwind(panic::AssertUnwindSafe(|| unsafe { + let value = (*ptr).inner.take(); + (*ptr).dtor_state.set(DtorState::RunningOrHasRun); + drop(value); + })) { + rtabort!("thread local panicked on drop"); } } diff --git a/library/std/src/sys/common/thread_local/mod.rs b/library/std/src/sys/common/thread_local/mod.rs index 1fee84a04..77f645883 100644 --- a/library/std/src/sys/common/thread_local/mod.rs +++ b/library/std/src/sys/common/thread_local/mod.rs @@ -1,35 +1,29 @@ -//! The following module declarations are outside cfg_if because the internal -//! `__thread_local_internal` macro does not seem to be exported properly when using cfg_if #![unstable(feature = "thread_local_internals", reason = "should not be necessary", issue = "none")] -#[cfg(all(target_thread_local, not(all(target_family = "wasm", not(target_feature = "atomics")))))] -mod fast_local; -#[cfg(all( - not(target_thread_local), - not(all(target_family = "wasm", not(target_feature = "atomics"))) -))] -mod os_local; -#[cfg(all(target_family = "wasm", not(target_feature = "atomics")))] -mod static_local; +// There are three thread-local implementations: "static", "fast", "OS". +// The "OS" thread local key type is accessed via platform-specific API calls and is slow, while the +// "fast" key type is accessed via code generated via LLVM, where TLS keys are set up by the linker. +// "static" is for single-threaded platforms where a global static is sufficient. -#[cfg(not(test))] cfg_if::cfg_if! { if #[cfg(all(target_family = "wasm", not(target_feature = "atomics")))] { #[doc(hidden)] - pub use static_local::statik::Key; - } else if #[cfg(all(target_thread_local, not(all(target_family = "wasm", not(target_feature = "atomics")))))] { + mod static_local; #[doc(hidden)] - pub use fast_local::fast::Key; - } else if #[cfg(all(not(target_thread_local), not(all(target_family = "wasm", not(target_feature = "atomics")))))] { + pub use static_local::{Key, thread_local_inner}; + } else if #[cfg(target_thread_local)] { #[doc(hidden)] - pub use os_local::os::Key; + mod fast_local; + #[doc(hidden)] + pub use fast_local::{Key, thread_local_inner}; + } else { + #[doc(hidden)] + mod os_local; + #[doc(hidden)] + pub use os_local::{Key, thread_local_inner}; } } -#[doc(hidden)] -#[cfg(test)] -pub use realstd::thread::__LocalKeyInner as Key; - mod lazy { use crate::cell::UnsafeCell; use crate::hint; diff --git a/library/std/src/sys/common/thread_local/os_local.rs b/library/std/src/sys/common/thread_local/os_local.rs index 1442a397e..5d48ce1e0 100644 --- a/library/std/src/sys/common/thread_local/os_local.rs +++ b/library/std/src/sys/common/thread_local/os_local.rs @@ -1,28 +1,29 @@ +use super::lazy::LazyKeyInner; +use crate::cell::Cell; +use crate::sys_common::thread_local_key::StaticKey as OsStaticKey; +use crate::{fmt, marker, panic, ptr}; + #[doc(hidden)] -#[macro_export] -#[allow_internal_unstable( - thread_local_internals, - cfg_target_thread_local, - thread_local, - libstd_thread_internals -)] +#[allow_internal_unstable(thread_local_internals)] #[allow_internal_unsafe] -macro_rules! __thread_local_inner { +#[unstable(feature = "thread_local_internals", issue = "none")] +#[rustc_macro_transparency = "semitransparent"] +pub macro thread_local_inner { // used to generate the `LocalKey` value for const-initialized thread locals (@key $t:ty, const $init:expr) => {{ - #[cfg_attr(not(bootstrap), inline)] + #[inline] #[deny(unsafe_op_in_unsafe_fn)] unsafe fn __getit( _init: $crate::option::Option<&mut $crate::option::Option<$t>>, ) -> $crate::option::Option<&'static $t> { const INIT_EXPR: $t = $init; - // On platforms without `#[thread_local]` we fall back to the + // On platforms without `#[thread_local]` we fall back to the // same implementation as below for os thread locals. #[inline] const fn __init() -> $t { INIT_EXPR } - static __KEY: $crate::thread::__LocalKeyInner<$t> = - $crate::thread::__LocalKeyInner::new(); + static __KEY: $crate::thread::local_impl::Key<$t> = + $crate::thread::local_impl::Key::new(); #[allow(unused_unsafe)] unsafe { __KEY.get(move || { @@ -41,7 +42,7 @@ macro_rules! __thread_local_inner { unsafe { $crate::thread::LocalKey::new(__getit) } - }}; + }}, // used to generate the `LocalKey` value for `thread_local!` (@key $t:ty, $init:expr) => { @@ -55,8 +56,8 @@ macro_rules! __thread_local_inner { unsafe fn __getit( init: $crate::option::Option<&mut $crate::option::Option<$t>>, ) -> $crate::option::Option<&'static $t> { - static __KEY: $crate::thread::__LocalKeyInner<$t> = - $crate::thread::__LocalKeyInner::new(); + static __KEY: $crate::thread::local_impl::Key<$t> = + $crate::thread::local_impl::Key::new(); // FIXME: remove the #[allow(...)] marker when macros don't // raise warning for missing/extraneous unsafe blocks anymore. @@ -80,118 +81,110 @@ macro_rules! __thread_local_inner { $crate::thread::LocalKey::new(__getit) } } - }; + }, ($(#[$attr:meta])* $vis:vis $name:ident, $t:ty, $($init:tt)*) => { $(#[$attr])* $vis const $name: $crate::thread::LocalKey<$t> = - $crate::__thread_local_inner!(@key $t, $($init)*); - } + $crate::thread::local_impl::thread_local_inner!(@key $t, $($init)*); + }, } -#[doc(hidden)] -pub mod os { - use super::super::lazy::LazyKeyInner; - use crate::cell::Cell; - use crate::sys_common::thread_local_key::StaticKey as OsStaticKey; - use crate::{fmt, marker, panic, ptr}; - - /// Use a regular global static to store this key; the state provided will then be - /// thread-local. - pub struct Key<T> { - // OS-TLS key that we'll use to key off. - os: OsStaticKey, - marker: marker::PhantomData<Cell<T>>, - } +/// Use a regular global static to store this key; the state provided will then be +/// thread-local. +pub struct Key<T> { + // OS-TLS key that we'll use to key off. + os: OsStaticKey, + marker: marker::PhantomData<Cell<T>>, +} - impl<T> fmt::Debug for Key<T> { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - f.debug_struct("Key").finish_non_exhaustive() - } +impl<T> fmt::Debug for Key<T> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("Key").finish_non_exhaustive() } +} - unsafe impl<T> Sync for Key<T> {} +unsafe impl<T> Sync for Key<T> {} - struct Value<T: 'static> { - inner: LazyKeyInner<T>, - key: &'static Key<T>, +struct Value<T: 'static> { + inner: LazyKeyInner<T>, + key: &'static Key<T>, +} + +impl<T: 'static> Key<T> { + #[rustc_const_unstable(feature = "thread_local_internals", issue = "none")] + pub const fn new() -> Key<T> { + Key { os: OsStaticKey::new(Some(destroy_value::<T>)), marker: marker::PhantomData } } - impl<T: 'static> Key<T> { - #[rustc_const_unstable(feature = "thread_local_internals", issue = "none")] - pub const fn new() -> Key<T> { - Key { os: OsStaticKey::new(Some(destroy_value::<T>)), marker: marker::PhantomData } + /// It is a requirement for the caller to ensure that no mutable + /// reference is active when this method is called. + pub unsafe fn get(&'static self, init: impl FnOnce() -> T) -> Option<&'static T> { + // SAFETY: See the documentation for this method. + let ptr = unsafe { self.os.get() as *mut Value<T> }; + if ptr.addr() > 1 { + // SAFETY: the check ensured the pointer is safe (its destructor + // is not running) + it is coming from a trusted source (self). + if let Some(ref value) = unsafe { (*ptr).inner.get() } { + return Some(value); + } } + // SAFETY: At this point we are sure we have no value and so + // initializing (or trying to) is safe. + unsafe { self.try_initialize(init) } + } - /// It is a requirement for the caller to ensure that no mutable - /// reference is active when this method is called. - pub unsafe fn get(&'static self, init: impl FnOnce() -> T) -> Option<&'static T> { - // SAFETY: See the documentation for this method. - let ptr = unsafe { self.os.get() as *mut Value<T> }; - if ptr.addr() > 1 { - // SAFETY: the check ensured the pointer is safe (its destructor - // is not running) + it is coming from a trusted source (self). - if let Some(ref value) = unsafe { (*ptr).inner.get() } { - return Some(value); - } - } - // SAFETY: At this point we are sure we have no value and so - // initializing (or trying to) is safe. - unsafe { self.try_initialize(init) } + // `try_initialize` is only called once per os thread local variable, + // except in corner cases where thread_local dtors reference other + // thread_local's, or it is being recursively initialized. + unsafe fn try_initialize(&'static self, init: impl FnOnce() -> T) -> Option<&'static T> { + // SAFETY: No mutable references are ever handed out meaning getting + // the value is ok. + let ptr = unsafe { self.os.get() as *mut Value<T> }; + if ptr.addr() == 1 { + // destructor is running + return None; } - // `try_initialize` is only called once per os thread local variable, - // except in corner cases where thread_local dtors reference other - // thread_local's, or it is being recursively initialized. - unsafe fn try_initialize(&'static self, init: impl FnOnce() -> T) -> Option<&'static T> { - // SAFETY: No mutable references are ever handed out meaning getting - // the value is ok. - let ptr = unsafe { self.os.get() as *mut Value<T> }; - if ptr.addr() == 1 { - // destructor is running - return None; + let ptr = if ptr.is_null() { + // If the lookup returned null, we haven't initialized our own + // local copy, so do that now. + let ptr = Box::into_raw(Box::new(Value { inner: LazyKeyInner::new(), key: self })); + // SAFETY: At this point we are sure there is no value inside + // ptr so setting it will not affect anyone else. + unsafe { + self.os.set(ptr as *mut u8); } - - let ptr = if ptr.is_null() { - // If the lookup returned null, we haven't initialized our own - // local copy, so do that now. - let ptr = Box::into_raw(Box::new(Value { inner: LazyKeyInner::new(), key: self })); - // SAFETY: At this point we are sure there is no value inside - // ptr so setting it will not affect anyone else. - unsafe { - self.os.set(ptr as *mut u8); - } - ptr - } else { - // recursive initialization - ptr - }; - - // SAFETY: ptr has been ensured as non-NUL just above an so can be - // dereferenced safely. - unsafe { Some((*ptr).inner.initialize(init)) } - } + ptr + } else { + // recursive initialization + ptr + }; + + // SAFETY: ptr has been ensured as non-NUL just above an so can be + // dereferenced safely. + unsafe { Some((*ptr).inner.initialize(init)) } } +} - unsafe extern "C" fn destroy_value<T: 'static>(ptr: *mut u8) { - // SAFETY: - // - // The OS TLS ensures that this key contains a null value when this - // destructor starts to run. We set it back to a sentinel value of 1 to - // ensure that any future calls to `get` for this thread will return - // `None`. - // - // Note that to prevent an infinite loop we reset it back to null right - // before we return from the destructor ourselves. - // - // Wrap the call in a catch to ensure unwinding is caught in the event - // a panic takes place in a destructor. - if let Err(_) = panic::catch_unwind(|| unsafe { - let ptr = Box::from_raw(ptr as *mut Value<T>); - let key = ptr.key; - key.os.set(ptr::invalid_mut(1)); - drop(ptr); - key.os.set(ptr::null_mut()); - }) { - rtabort!("thread local panicked on drop"); - } +unsafe extern "C" fn destroy_value<T: 'static>(ptr: *mut u8) { + // SAFETY: + // + // The OS TLS ensures that this key contains a null value when this + // destructor starts to run. We set it back to a sentinel value of 1 to + // ensure that any future calls to `get` for this thread will return + // `None`. + // + // Note that to prevent an infinite loop we reset it back to null right + // before we return from the destructor ourselves. + // + // Wrap the call in a catch to ensure unwinding is caught in the event + // a panic takes place in a destructor. + if let Err(_) = panic::catch_unwind(|| unsafe { + let ptr = Box::from_raw(ptr as *mut Value<T>); + let key = ptr.key; + key.os.set(ptr::invalid_mut(1)); + drop(ptr); + key.os.set(ptr::null_mut()); + }) { + rtabort!("thread local panicked on drop"); } } diff --git a/library/std/src/sys/common/thread_local/static_local.rs b/library/std/src/sys/common/thread_local/static_local.rs index ec4f2a12b..80322a978 100644 --- a/library/std/src/sys/common/thread_local/static_local.rs +++ b/library/std/src/sys/common/thread_local/static_local.rs @@ -1,13 +1,12 @@ +use super::lazy::LazyKeyInner; +use crate::fmt; + #[doc(hidden)] -#[macro_export] -#[allow_internal_unstable( - thread_local_internals, - cfg_target_thread_local, - thread_local, - libstd_thread_internals -)] +#[allow_internal_unstable(thread_local_internals)] #[allow_internal_unsafe] -macro_rules! __thread_local_inner { +#[unstable(feature = "thread_local_internals", issue = "none")] +#[rustc_macro_transparency = "semitransparent"] +pub macro thread_local_inner { // used to generate the `LocalKey` value for const-initialized thread locals (@key $t:ty, const $init:expr) => {{ #[inline] // see comments below @@ -30,7 +29,7 @@ macro_rules! __thread_local_inner { unsafe { $crate::thread::LocalKey::new(__getit) } - }}; + }}, // used to generate the `LocalKey` value for `thread_local!` (@key $t:ty, $init:expr) => { @@ -41,8 +40,8 @@ macro_rules! __thread_local_inner { unsafe fn __getit( init: $crate::option::Option<&mut $crate::option::Option<$t>>, ) -> $crate::option::Option<&'static $t> { - static __KEY: $crate::thread::__LocalKeyInner<$t> = - $crate::thread::__LocalKeyInner::new(); + static __KEY: $crate::thread::local_impl::Key<$t> = + $crate::thread::local_impl::Key::new(); // FIXME: remove the #[allow(...)] marker when macros don't // raise warning for missing/extraneous unsafe blocks anymore. @@ -66,50 +65,45 @@ macro_rules! __thread_local_inner { $crate::thread::LocalKey::new(__getit) } } - }; + }, ($(#[$attr:meta])* $vis:vis $name:ident, $t:ty, $($init:tt)*) => { $(#[$attr])* $vis const $name: $crate::thread::LocalKey<$t> = - $crate::__thread_local_inner!(@key $t, $($init)*); - } + $crate::thread::local_impl::thread_local_inner!(@key $t, $($init)*); + }, } /// On some targets like wasm there's no threads, so no need to generate /// thread locals and we can instead just use plain statics! -#[doc(hidden)] -pub mod statik { - use super::super::lazy::LazyKeyInner; - use crate::fmt; - pub struct Key<T> { - inner: LazyKeyInner<T>, - } +pub struct Key<T> { + inner: LazyKeyInner<T>, +} - unsafe impl<T> Sync for Key<T> {} +unsafe impl<T> Sync for Key<T> {} - impl<T> fmt::Debug for Key<T> { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - f.debug_struct("Key").finish_non_exhaustive() - } +impl<T> fmt::Debug for Key<T> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("Key").finish_non_exhaustive() } +} - impl<T> Key<T> { - pub const fn new() -> Key<T> { - Key { inner: LazyKeyInner::new() } - } +impl<T> Key<T> { + pub const fn new() -> Key<T> { + Key { inner: LazyKeyInner::new() } + } - pub unsafe fn get(&self, init: impl FnOnce() -> T) -> Option<&'static T> { - // SAFETY: The caller must ensure no reference is ever handed out to - // the inner cell nor mutable reference to the Option<T> inside said - // cell. This make it safe to hand a reference, though the lifetime - // of 'static is itself unsafe, making the get method unsafe. - let value = unsafe { - match self.inner.get() { - Some(ref value) => value, - None => self.inner.initialize(init), - } - }; + pub unsafe fn get(&self, init: impl FnOnce() -> T) -> Option<&'static T> { + // SAFETY: The caller must ensure no reference is ever handed out to + // the inner cell nor mutable reference to the Option<T> inside said + // cell. This make it safe to hand a reference, though the lifetime + // of 'static is itself unsafe, making the get method unsafe. + let value = unsafe { + match self.inner.get() { + Some(ref value) => value, + None => self.inner.initialize(init), + } + }; - Some(value) - } + Some(value) } } |