rustc_data_structures/
marker.rs

1use std::alloc::Allocator;
2use std::marker::PointeeSized;
3
4#[diagnostic::on_unimplemented(message = "`{Self}` doesn't implement `DynSend`. \
5            Add it to `rustc_data_structures::marker` or use `IntoDynSyncSend` if it's already `Send`")]
6// This is an auto trait for types which can be sent across threads if `sync::is_dyn_thread_safe()`
7// is true. These types can be wrapped in a `FromDyn` to get a `Send` type. Wrapping a
8// `Send` type in `IntoDynSyncSend` will create a `DynSend` type.
9pub unsafe auto trait DynSend {}
10
11#[diagnostic::on_unimplemented(message = "`{Self}` doesn't implement `DynSync`. \
12            Add it to `rustc_data_structures::marker` or use `IntoDynSyncSend` if it's already `Sync`")]
13// This is an auto trait for types which can be shared across threads if `sync::is_dyn_thread_safe()`
14// is true. These types can be wrapped in a `FromDyn` to get a `Sync` type. Wrapping a
15// `Sync` type in `IntoDynSyncSend` will create a `DynSync` type.
16pub unsafe auto trait DynSync {}
17
18// Same with `Sync` and `Send`.
19unsafe impl<T: DynSync + ?Sized + PointeeSized> DynSend for &T {}
20
21macro_rules! impls_dyn_send_neg {
22    ($([$t1: ty $(where $($generics1: tt)*)?])*) => {
23        $(impl$(<$($generics1)*>)? !DynSend for $t1 {})*
24    };
25}
26
27// Consistent with `std`
28impls_dyn_send_neg!(
29    [std::env::Args]
30    [std::env::ArgsOs]
31    [*const T where T: ?Sized + PointeeSized]
32    [*mut T where T: ?Sized + PointeeSized]
33    [std::ptr::NonNull<T> where T: ?Sized + PointeeSized]
34    [std::rc::Rc<T, A> where T: ?Sized, A: Allocator]
35    [std::rc::Weak<T, A> where T: ?Sized, A: Allocator]
36    [std::sync::MutexGuard<'_, T> where T: ?Sized]
37    [std::sync::RwLockReadGuard<'_, T> where T: ?Sized]
38    [std::sync::RwLockWriteGuard<'_, T> where T: ?Sized]
39    [std::io::StdoutLock<'_>]
40    [std::io::StderrLock<'_>]
41);
42
43#[cfg(any(
44    unix,
45    target_os = "hermit",
46    all(target_vendor = "fortanix", target_env = "sgx"),
47    target_os = "solid_asp3",
48    target_os = "wasi",
49    target_os = "xous"
50))]
51// Consistent with `std`, `env_imp::Env` is `!Sync` in these platforms
52impl !DynSend for std::env::VarsOs {}
53
54macro_rules! already_send {
55    ($([$ty: ty])*) => {
56        $(unsafe impl DynSend for $ty where $ty: Send {})*
57    };
58}
59
60// These structures are already `Send`.
61already_send!(
62    [std::backtrace::Backtrace][std::io::Stdout][std::io::Stderr][std::io::Error][std::fs::File]
63        [rustc_arena::DroplessArena][jobserver_crate::Client][jobserver_crate::HelperThread]
64        [crate::memmap::Mmap][crate::profiling::SelfProfiler][crate::owned_slice::OwnedSlice]
65);
66
67macro_rules! impl_dyn_send {
68    ($($($attr: meta)* [$ty: ty where $($generics2: tt)*])*) => {
69        $(unsafe impl<$($generics2)*> DynSend for $ty {})*
70    };
71}
72
73impl_dyn_send!(
74    [std::sync::atomic::AtomicPtr<T> where T]
75    [std::sync::Mutex<T> where T: ?Sized+ DynSend]
76    [std::sync::mpsc::Sender<T> where T: DynSend]
77    [std::sync::Arc<T> where T: ?Sized + DynSync + DynSend]
78    [std::sync::LazyLock<T, F> where T: DynSend, F: DynSend]
79    [std::collections::HashSet<K, S> where K: DynSend, S: DynSend]
80    [std::collections::HashMap<K, V, S> where K: DynSend, V: DynSend, S: DynSend]
81    [std::collections::BTreeMap<K, V, A> where K: DynSend, V: DynSend, A: std::alloc::Allocator + Clone + DynSend]
82    [Vec<T, A> where T: DynSend, A: std::alloc::Allocator + DynSend]
83    [Box<T, A> where T: ?Sized + DynSend, A: std::alloc::Allocator + DynSend]
84    [crate::sync::RwLock<T> where T: DynSend]
85    [crate::tagged_ptr::TaggedRef<'a, P, T> where 'a, P: Sync, T: Send + crate::tagged_ptr::Tag]
86    [rustc_arena::TypedArena<T> where T: DynSend]
87    [hashbrown::HashTable<T> where T: DynSend]
88    [indexmap::IndexSet<V, S> where V: DynSend, S: DynSend]
89    [indexmap::IndexMap<K, V, S> where K: DynSend, V: DynSend, S: DynSend]
90    [thin_vec::ThinVec<T> where T: DynSend]
91    [smallvec::SmallVec<A> where A: smallvec::Array + DynSend]
92);
93
94macro_rules! impls_dyn_sync_neg {
95    ($([$t1: ty $(where $($generics1: tt)*)?])*) => {
96        $(impl$(<$($generics1)*>)? !DynSync for $t1 {})*
97    };
98}
99
100// Consistent with `std`
101impls_dyn_sync_neg!(
102    [std::env::Args]
103    [std::env::ArgsOs]
104    [*const T where T: ?Sized + PointeeSized]
105    [*mut T where T: ?Sized + PointeeSized]
106    [std::cell::Cell<T> where T: ?Sized]
107    [std::cell::RefCell<T> where T: ?Sized]
108    [std::cell::UnsafeCell<T> where T: ?Sized]
109    [std::ptr::NonNull<T> where T: ?Sized + PointeeSized]
110    [std::rc::Rc<T, A> where T: ?Sized, A: Allocator]
111    [std::rc::Weak<T, A> where T: ?Sized, A: Allocator]
112    [std::cell::OnceCell<T> where T]
113    [std::sync::mpsc::Receiver<T> where T]
114    [std::sync::mpsc::Sender<T> where T]
115);
116
117#[cfg(any(
118    unix,
119    target_os = "hermit",
120    all(target_vendor = "fortanix", target_env = "sgx"),
121    target_os = "solid_asp3",
122    target_os = "wasi",
123    target_os = "xous"
124))]
125// Consistent with `std`, `env_imp::Env` is `!Sync` in these platforms
126impl !DynSync for std::env::VarsOs {}
127
128macro_rules! already_sync {
129    ($([$ty: ty])*) => {
130        $(unsafe impl DynSync for $ty where $ty: Sync {})*
131    };
132}
133
134// These structures are already `Sync`.
135already_sync!(
136    [std::sync::atomic::AtomicBool][std::sync::atomic::AtomicUsize][std::sync::atomic::AtomicU8]
137        [std::sync::atomic::AtomicU32][std::backtrace::Backtrace][std::io::Error][std::fs::File]
138        [jobserver_crate::Client][jobserver_crate::HelperThread][crate::memmap::Mmap]
139        [crate::profiling::SelfProfiler][crate::owned_slice::OwnedSlice]
140);
141
142// Use portable AtomicU64 for targets without native 64-bit atomics
143#[cfg(target_has_atomic = "64")]
144already_sync!([std::sync::atomic::AtomicU64]);
145
146#[cfg(not(target_has_atomic = "64"))]
147already_sync!([portable_atomic::AtomicU64]);
148
149macro_rules! impl_dyn_sync {
150    ($($($attr: meta)* [$ty: ty where $($generics2: tt)*])*) => {
151        $(unsafe impl<$($generics2)*> DynSync for $ty {})*
152    };
153}
154
155impl_dyn_sync!(
156    [std::sync::atomic::AtomicPtr<T> where T]
157    [std::sync::OnceLock<T> where T: DynSend + DynSync]
158    [std::sync::Mutex<T> where T: ?Sized + DynSend]
159    [std::sync::Arc<T> where T: ?Sized + DynSync + DynSend]
160    [std::sync::LazyLock<T, F> where T: DynSend + DynSync, F: DynSend]
161    [std::collections::HashSet<K, S> where K: DynSync, S: DynSync]
162    [std::collections::HashMap<K, V, S> where K: DynSync, V: DynSync, S: DynSync]
163    [std::collections::BTreeMap<K, V, A> where K: DynSync, V: DynSync, A: std::alloc::Allocator + Clone + DynSync]
164    [Vec<T, A> where T: DynSync, A: std::alloc::Allocator + DynSync]
165    [Box<T, A> where T: ?Sized + DynSync, A: std::alloc::Allocator + DynSync]
166    [crate::sync::RwLock<T> where T: DynSend + DynSync]
167    [crate::sync::WorkerLocal<T> where T: DynSend]
168    [crate::intern::Interned<'a, T> where 'a, T: DynSync]
169    [crate::tagged_ptr::TaggedRef<'a, P, T> where 'a, P: Sync, T: Sync + crate::tagged_ptr::Tag]
170    [parking_lot::lock_api::Mutex<R, T> where R: DynSync, T: ?Sized + DynSend]
171    [parking_lot::lock_api::RwLock<R, T> where R: DynSync, T: ?Sized + DynSend + DynSync]
172    [hashbrown::HashTable<T> where T: DynSync]
173    [indexmap::IndexSet<V, S> where V: DynSync, S: DynSync]
174    [indexmap::IndexMap<K, V, S> where K: DynSync, V: DynSync, S: DynSync]
175    [smallvec::SmallVec<A> where A: smallvec::Array + DynSync]
176    [thin_vec::ThinVec<T> where T: DynSync]
177);
178
179pub fn assert_dyn_sync<T: ?Sized + PointeeSized + DynSync>() {}
180pub fn assert_dyn_send<T: ?Sized + PointeeSized + DynSend>() {}
181pub fn assert_dyn_send_val<T: ?Sized + PointeeSized + DynSend>(_t: &T) {}
182pub fn assert_dyn_send_sync_val<T: ?Sized + PointeeSized + DynSync + DynSend>(_t: &T) {}
183
184#[derive(Copy, Clone)]
185pub struct FromDyn<T>(T);
186
187impl<T> FromDyn<T> {
188    #[inline(always)]
189    pub fn from(val: T) -> Self {
190        // Check that `sync::is_dyn_thread_safe()` is true on creation so we can
191        // implement `Send` and `Sync` for this structure when `T`
192        // implements `DynSend` and `DynSync` respectively.
193        assert!(crate::sync::is_dyn_thread_safe());
194        FromDyn(val)
195    }
196
197    #[inline(always)]
198    pub fn derive<O>(&self, val: O) -> FromDyn<O> {
199        // We already did the check for `sync::is_dyn_thread_safe()` when creating `Self`
200        FromDyn(val)
201    }
202
203    #[inline(always)]
204    pub fn into_inner(self) -> T {
205        self.0
206    }
207}
208
209// `FromDyn` is `Send` if `T` is `DynSend`, since it ensures that sync::is_dyn_thread_safe() is true.
210unsafe impl<T: DynSend> Send for FromDyn<T> {}
211
212// `FromDyn` is `Sync` if `T` is `DynSync`, since it ensures that sync::is_dyn_thread_safe() is true.
213unsafe impl<T: DynSync> Sync for FromDyn<T> {}
214
215impl<T> std::ops::Deref for FromDyn<T> {
216    type Target = T;
217
218    #[inline(always)]
219    fn deref(&self) -> &Self::Target {
220        &self.0
221    }
222}
223
224impl<T> std::ops::DerefMut for FromDyn<T> {
225    #[inline(always)]
226    fn deref_mut(&mut self) -> &mut Self::Target {
227        &mut self.0
228    }
229}
230
231// A wrapper to convert a struct that is already a `Send` or `Sync` into
232// an instance of `DynSend` and `DynSync`, since the compiler cannot infer
233// it automatically in some cases. (e.g. Box<dyn Send / Sync>)
234#[derive(Copy, Clone)]
235pub struct IntoDynSyncSend<T: ?Sized + PointeeSized>(pub T);
236
237unsafe impl<T: ?Sized + PointeeSized + Send> DynSend for IntoDynSyncSend<T> {}
238unsafe impl<T: ?Sized + PointeeSized + Sync> DynSync for IntoDynSyncSend<T> {}
239
240impl<T> std::ops::Deref for IntoDynSyncSend<T> {
241    type Target = T;
242
243    #[inline(always)]
244    fn deref(&self) -> &T {
245        &self.0
246    }
247}
248
249impl<T> std::ops::DerefMut for IntoDynSyncSend<T> {
250    #[inline(always)]
251    fn deref_mut(&mut self) -> &mut T {
252        &mut self.0
253    }
254}
rustc_data_structures/marker.rs

rustc_data_structures/
marker.rs
