rustc_data_structures/
marker.rs

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1use std::alloc::Allocator;
2
3#[rustc_on_unimplemented(message = "`{Self}` doesn't implement `DynSend`. \
4            Add it to `rustc_data_structures::marker` or use `IntoDynSyncSend` if it's already `Send`")]
5// This is an auto trait for types which can be sent across threads if `sync::is_dyn_thread_safe()`
6// is true. These types can be wrapped in a `FromDyn` to get a `Send` type. Wrapping a
7// `Send` type in `IntoDynSyncSend` will create a `DynSend` type.
8pub unsafe auto trait DynSend {}
9
10#[rustc_on_unimplemented(message = "`{Self}` doesn't implement `DynSync`. \
11            Add it to `rustc_data_structures::marker` or use `IntoDynSyncSend` if it's already `Sync`")]
12// This is an auto trait for types which can be shared across threads if `sync::is_dyn_thread_safe()`
13// is true. These types can be wrapped in a `FromDyn` to get a `Sync` type. Wrapping a
14// `Sync` type in `IntoDynSyncSend` will create a `DynSync` type.
15pub unsafe auto trait DynSync {}
16
17// Same with `Sync` and `Send`.
18unsafe impl<T: DynSync + ?Sized> DynSend for &T {}
19
20macro_rules! impls_dyn_send_neg {
21    ($([$t1: ty $(where $($generics1: tt)*)?])*) => {
22        $(impl$(<$($generics1)*>)? !DynSend for $t1 {})*
23    };
24}
25
26// Consistent with `std`
27impls_dyn_send_neg!(
28    [std::env::Args]
29    [std::env::ArgsOs]
30    [*const T where T: ?Sized]
31    [*mut T where T: ?Sized]
32    [std::ptr::NonNull<T> where T: ?Sized]
33    [std::rc::Rc<T, A> where T: ?Sized, A: Allocator]
34    [std::rc::Weak<T, A> where T: ?Sized, A: Allocator]
35    [std::sync::MutexGuard<'_, T> where T: ?Sized]
36    [std::sync::RwLockReadGuard<'_, T> where T: ?Sized]
37    [std::sync::RwLockWriteGuard<'_, T> where T: ?Sized]
38    [std::io::StdoutLock<'_>]
39    [std::io::StderrLock<'_>]
40);
41
42#[cfg(any(unix, target_os = "hermit", target_os = "wasi", target_os = "solid_asp3"))]
43// Consistent with `std`, `os_imp::Env` is `!Sync` in these platforms
44impl !DynSend for std::env::VarsOs {}
45
46macro_rules! already_send {
47    ($([$ty: ty])*) => {
48        $(unsafe impl DynSend for $ty where $ty: Send {})*
49    };
50}
51
52// These structures are already `Send`.
53already_send!(
54    [std::backtrace::Backtrace][std::io::Stdout][std::io::Stderr][std::io::Error][std::fs::File]
55        [rustc_arena::DroplessArena][crate::memmap::Mmap][crate::profiling::SelfProfiler]
56        [crate::owned_slice::OwnedSlice]
57);
58
59macro_rules! impl_dyn_send {
60    ($($($attr: meta)* [$ty: ty where $($generics2: tt)*])*) => {
61        $(unsafe impl<$($generics2)*> DynSend for $ty {})*
62    };
63}
64
65impl_dyn_send!(
66    [std::sync::atomic::AtomicPtr<T> where T]
67    [std::sync::Mutex<T> where T: ?Sized+ DynSend]
68    [std::sync::mpsc::Sender<T> where T: DynSend]
69    [std::sync::Arc<T> where T: ?Sized + DynSync + DynSend]
70    [std::sync::LazyLock<T, F> where T: DynSend, F: DynSend]
71    [std::collections::HashSet<K, S> where K: DynSend, S: DynSend]
72    [std::collections::HashMap<K, V, S> where K: DynSend, V: DynSend, S: DynSend]
73    [std::collections::BTreeMap<K, V, A> where K: DynSend, V: DynSend, A: std::alloc::Allocator + Clone + DynSend]
74    [Vec<T, A> where T: DynSend, A: std::alloc::Allocator + DynSend]
75    [Box<T, A> where T: ?Sized + DynSend, A: std::alloc::Allocator + DynSend]
76    [crate::sync::RwLock<T> where T: DynSend]
77    [crate::tagged_ptr::TaggedRef<'a, P, T> where 'a, P: Sync, T: Send + crate::tagged_ptr::Tag]
78    [rustc_arena::TypedArena<T> where T: DynSend]
79    [hashbrown::HashTable<T> where T: DynSend]
80    [indexmap::IndexSet<V, S> where V: DynSend, S: DynSend]
81    [indexmap::IndexMap<K, V, S> where K: DynSend, V: DynSend, S: DynSend]
82    [thin_vec::ThinVec<T> where T: DynSend]
83    [smallvec::SmallVec<A> where A: smallvec::Array + DynSend]
84);
85
86macro_rules! impls_dyn_sync_neg {
87    ($([$t1: ty $(where $($generics1: tt)*)?])*) => {
88        $(impl$(<$($generics1)*>)? !DynSync for $t1 {})*
89    };
90}
91
92// Consistent with `std`
93impls_dyn_sync_neg!(
94    [std::env::Args]
95    [std::env::ArgsOs]
96    [*const T where T: ?Sized]
97    [*mut T where T: ?Sized]
98    [std::cell::Cell<T> where T: ?Sized]
99    [std::cell::RefCell<T> where T: ?Sized]
100    [std::cell::UnsafeCell<T> where T: ?Sized]
101    [std::ptr::NonNull<T> where T: ?Sized]
102    [std::rc::Rc<T, A> where T: ?Sized, A: Allocator]
103    [std::rc::Weak<T, A> where T: ?Sized, A: Allocator]
104    [std::cell::OnceCell<T> where T]
105    [std::sync::mpsc::Receiver<T> where T]
106    [std::sync::mpsc::Sender<T> where T]
107);
108
109#[cfg(any(unix, target_os = "hermit", target_os = "wasi", target_os = "solid_asp3"))]
110// Consistent with `std`, `os_imp::Env` is `!Sync` in these platforms
111impl !DynSync for std::env::VarsOs {}
112
113macro_rules! already_sync {
114    ($([$ty: ty])*) => {
115        $(unsafe impl DynSync for $ty where $ty: Sync {})*
116    };
117}
118
119// These structures are already `Sync`.
120already_sync!(
121    [std::sync::atomic::AtomicBool][std::sync::atomic::AtomicUsize][std::sync::atomic::AtomicU8]
122        [std::sync::atomic::AtomicU32][std::backtrace::Backtrace][std::io::Error][std::fs::File]
123        [jobserver_crate::Client][crate::memmap::Mmap][crate::profiling::SelfProfiler]
124        [crate::owned_slice::OwnedSlice]
125);
126
127// Use portable AtomicU64 for targets without native 64-bit atomics
128#[cfg(target_has_atomic = "64")]
129already_sync!([std::sync::atomic::AtomicU64]);
130
131#[cfg(not(target_has_atomic = "64"))]
132already_sync!([portable_atomic::AtomicU64]);
133
134macro_rules! impl_dyn_sync {
135    ($($($attr: meta)* [$ty: ty where $($generics2: tt)*])*) => {
136        $(unsafe impl<$($generics2)*> DynSync for $ty {})*
137    };
138}
139
140impl_dyn_sync!(
141    [std::sync::atomic::AtomicPtr<T> where T]
142    [std::sync::OnceLock<T> where T: DynSend + DynSync]
143    [std::sync::Mutex<T> where T: ?Sized + DynSend]
144    [std::sync::Arc<T> where T: ?Sized + DynSync + DynSend]
145    [std::sync::LazyLock<T, F> where T: DynSend + DynSync, F: DynSend]
146    [std::collections::HashSet<K, S> where K: DynSync, S: DynSync]
147    [std::collections::HashMap<K, V, S> where K: DynSync, V: DynSync, S: DynSync]
148    [std::collections::BTreeMap<K, V, A> where K: DynSync, V: DynSync, A: std::alloc::Allocator + Clone + DynSync]
149    [Vec<T, A> where T: DynSync, A: std::alloc::Allocator + DynSync]
150    [Box<T, A> where T: ?Sized + DynSync, A: std::alloc::Allocator + DynSync]
151    [crate::sync::RwLock<T> where T: DynSend + DynSync]
152    [crate::sync::WorkerLocal<T> where T: DynSend]
153    [crate::intern::Interned<'a, T> where 'a, T: DynSync]
154    [crate::tagged_ptr::TaggedRef<'a, P, T> where 'a, P: Sync, T: Sync + crate::tagged_ptr::Tag]
155    [parking_lot::lock_api::Mutex<R, T> where R: DynSync, T: ?Sized + DynSend]
156    [parking_lot::lock_api::RwLock<R, T> where R: DynSync, T: ?Sized + DynSend + DynSync]
157    [hashbrown::HashTable<T> where T: DynSync]
158    [indexmap::IndexSet<V, S> where V: DynSync, S: DynSync]
159    [indexmap::IndexMap<K, V, S> where K: DynSync, V: DynSync, S: DynSync]
160    [smallvec::SmallVec<A> where A: smallvec::Array + DynSync]
161    [thin_vec::ThinVec<T> where T: DynSync]
162);
163
164pub fn assert_dyn_sync<T: ?Sized + DynSync>() {}
165pub fn assert_dyn_send<T: ?Sized + DynSend>() {}
166pub fn assert_dyn_send_val<T: ?Sized + DynSend>(_t: &T) {}
167pub fn assert_dyn_send_sync_val<T: ?Sized + DynSync + DynSend>(_t: &T) {}
168
169#[derive(Copy, Clone)]
170pub struct FromDyn<T>(T);
171
172impl<T> FromDyn<T> {
173    #[inline(always)]
174    pub fn from(val: T) -> Self {
175        // Check that `sync::is_dyn_thread_safe()` is true on creation so we can
176        // implement `Send` and `Sync` for this structure when `T`
177        // implements `DynSend` and `DynSync` respectively.
178        assert!(crate::sync::is_dyn_thread_safe());
179        FromDyn(val)
180    }
181
182    #[inline(always)]
183    pub fn into_inner(self) -> T {
184        self.0
185    }
186}
187
188// `FromDyn` is `Send` if `T` is `DynSend`, since it ensures that sync::is_dyn_thread_safe() is true.
189unsafe impl<T: DynSend> Send for FromDyn<T> {}
190
191// `FromDyn` is `Sync` if `T` is `DynSync`, since it ensures that sync::is_dyn_thread_safe() is true.
192unsafe impl<T: DynSync> Sync for FromDyn<T> {}
193
194impl<T> std::ops::Deref for FromDyn<T> {
195    type Target = T;
196
197    #[inline(always)]
198    fn deref(&self) -> &Self::Target {
199        &self.0
200    }
201}
202
203// A wrapper to convert a struct that is already a `Send` or `Sync` into
204// an instance of `DynSend` and `DynSync`, since the compiler cannot infer
205// it automatically in some cases. (e.g. Box<dyn Send / Sync>)
206#[derive(Copy, Clone)]
207pub struct IntoDynSyncSend<T: ?Sized>(pub T);
208
209unsafe impl<T: ?Sized + Send> DynSend for IntoDynSyncSend<T> {}
210unsafe impl<T: ?Sized + Sync> DynSync for IntoDynSyncSend<T> {}
211
212impl<T> std::ops::Deref for IntoDynSyncSend<T> {
213    type Target = T;
214
215    #[inline(always)]
216    fn deref(&self) -> &T {
217        &self.0
218    }
219}
220
221impl<T> std::ops::DerefMut for IntoDynSyncSend<T> {
222    #[inline(always)]
223    fn deref_mut(&mut self) -> &mut T {
224        &mut self.0
225    }
226}
rustc_data_structures/marker.rs

rustc_data_structures/
marker.rs
