1 //! Implements threads.
3 use std::cell::RefCell;
4 use std::collections::hash_map::Entry;
5 use std::num::TryFromIntError;
6 use std::time::{Duration, Instant, SystemTime};
10 use rustc_data_structures::fx::FxHashMap;
11 use rustc_hir::def_id::DefId;
12 use rustc_index::vec::{Idx, IndexVec};
14 use crate::sync::SynchronizationState;
17 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
18 pub enum SchedulingAction {
19 /// Execute step on the active thread.
21 /// Execute a timeout callback.
22 ExecuteTimeoutCallback,
23 /// Execute destructors of the active thread.
29 /// Timeout callbacks can be created by synchronization primitives to tell the
30 /// scheduler that they should be called once some period of time passes.
31 type TimeoutCallback<'mir, 'tcx> =
32 Box<dyn FnOnce(&mut InterpCx<'mir, 'tcx, Evaluator<'mir, 'tcx>>) -> InterpResult<'tcx> + 'tcx>;
34 /// A thread identifier.
35 #[derive(Clone, Copy, Debug, PartialOrd, Ord, PartialEq, Eq, Hash)]
36 pub struct ThreadId(u32);
38 /// The main thread. When it terminates, the whole application terminates.
39 const MAIN_THREAD: ThreadId = ThreadId(0);
42 pub fn to_u32(self) -> u32 {
47 impl Idx for ThreadId {
48 fn new(idx: usize) -> Self {
49 ThreadId(u32::try_from(idx).unwrap())
52 fn index(self) -> usize {
53 usize::try_from(self.0).unwrap()
57 impl TryFrom<u64> for ThreadId {
58 type Error = TryFromIntError;
59 fn try_from(id: u64) -> Result<Self, Self::Error> {
60 u32::try_from(id).map(|id_u32| Self(id_u32))
64 impl From<u32> for ThreadId {
65 fn from(id: u32) -> Self {
71 pub fn to_u32_scalar<'tcx>(&self) -> Scalar<Tag> {
72 Scalar::from_u32(u32::try_from(self.0).unwrap())
76 /// The state of a thread.
77 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
78 pub enum ThreadState {
79 /// The thread is enabled and can be executed.
81 /// The thread tried to join the specified thread and is blocked until that
82 /// thread terminates.
83 BlockedOnJoin(ThreadId),
84 /// The thread is blocked on some synchronization primitive. It is the
85 /// responsibility of the synchronization primitives to track threads that
86 /// are blocked by them.
88 /// The thread has terminated its execution. We do not delete terminated
89 /// threads (FIXME: why?).
93 /// The join status of a thread.
94 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
95 enum ThreadJoinStatus {
96 /// The thread can be joined.
98 /// A thread is detached if its join handle was destroyed and no other
99 /// thread can join it.
101 /// The thread was already joined by some thread and cannot be joined again.
106 pub struct Thread<'mir, 'tcx> {
109 /// Name of the thread.
110 thread_name: Option<Vec<u8>>,
112 /// The virtual call stack.
113 stack: Vec<Frame<'mir, 'tcx, Tag, FrameData<'tcx>>>,
116 join_status: ThreadJoinStatus,
118 /// The temporary used for storing the argument of
119 /// the call to `miri_start_panic` (the panic payload) when unwinding.
120 /// This is pointer-sized, and matches the `Payload` type in `src/libpanic_unwind/miri.rs`.
121 pub(crate) panic_payload: Option<Scalar<Tag>>,
123 /// Last OS error location in memory. It is a 32-bit integer.
124 pub(crate) last_error: Option<MPlaceTy<'tcx, Tag>>,
127 impl<'mir, 'tcx> Thread<'mir, 'tcx> {
128 /// Check if the thread is done executing (no more stack frames). If yes,
129 /// change the state to terminated and return `true`.
130 fn check_terminated(&mut self) -> bool {
131 if self.state == ThreadState::Enabled {
132 if self.stack.is_empty() {
133 self.state = ThreadState::Terminated;
140 /// Get the name of the current thread, or `<unnamed>` if it was not set.
141 fn thread_name(&self) -> &[u8] {
142 if let Some(ref thread_name) = self.thread_name { thread_name } else { b"<unnamed>" }
146 impl<'mir, 'tcx> std::fmt::Debug for Thread<'mir, 'tcx> {
147 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
151 String::from_utf8_lossy(self.thread_name()),
158 impl<'mir, 'tcx> Default for Thread<'mir, 'tcx> {
159 fn default() -> Self {
161 state: ThreadState::Enabled,
164 join_status: ThreadJoinStatus::Joinable,
171 /// A specific moment in time.
175 RealTime(SystemTime),
179 /// How long do we have to wait from now until the specified time?
180 fn get_wait_time(&self) -> Duration {
182 Time::Monotonic(instant) => instant.saturating_duration_since(Instant::now()),
183 Time::RealTime(time) =>
184 time.duration_since(SystemTime::now()).unwrap_or(Duration::new(0, 0)),
189 /// Callbacks are used to implement timeouts. For example, waiting on a
190 /// conditional variable with a timeout creates a callback that is called after
191 /// the specified time and unblocks the thread. If another thread signals on the
192 /// conditional variable, the signal handler deletes the callback.
193 struct TimeoutCallbackInfo<'mir, 'tcx> {
194 /// The callback should be called no earlier than this time.
196 /// The called function.
197 callback: TimeoutCallback<'mir, 'tcx>,
200 impl<'mir, 'tcx> std::fmt::Debug for TimeoutCallbackInfo<'mir, 'tcx> {
201 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
202 write!(f, "TimeoutCallback({:?})", self.call_time)
206 /// A set of threads.
208 pub struct ThreadManager<'mir, 'tcx> {
209 /// Identifier of the currently active thread.
210 active_thread: ThreadId,
211 /// Threads used in the program.
213 /// Note that this vector also contains terminated threads.
214 threads: IndexVec<ThreadId, Thread<'mir, 'tcx>>,
215 /// This field is pub(crate) because the synchronization primitives
216 /// (`crate::sync`) need a way to access it.
217 pub(crate) sync: SynchronizationState,
218 /// A mapping from a thread-local static to an allocation id of a thread
219 /// specific allocation.
220 thread_local_alloc_ids: RefCell<FxHashMap<(DefId, ThreadId), Pointer<Tag>>>,
221 /// A flag that indicates that we should change the active thread.
222 yield_active_thread: bool,
223 /// Callbacks that are called once the specified time passes.
224 timeout_callbacks: FxHashMap<ThreadId, TimeoutCallbackInfo<'mir, 'tcx>>,
227 impl<'mir, 'tcx> Default for ThreadManager<'mir, 'tcx> {
228 fn default() -> Self {
229 let mut threads = IndexVec::new();
230 // Create the main thread and add it to the list of threads.
231 let mut main_thread = Thread::default();
232 // The main thread can *not* be joined on.
233 main_thread.join_status = ThreadJoinStatus::Detached;
234 threads.push(main_thread);
236 active_thread: ThreadId::new(0),
238 sync: SynchronizationState::default(),
239 thread_local_alloc_ids: Default::default(),
240 yield_active_thread: false,
241 timeout_callbacks: FxHashMap::default(),
246 impl<'mir, 'tcx: 'mir> ThreadManager<'mir, 'tcx> {
247 /// Check if we have an allocation for the given thread local static for the
249 fn get_thread_local_alloc_id(&self, def_id: DefId) -> Option<Pointer<Tag>> {
250 self.thread_local_alloc_ids.borrow().get(&(def_id, self.active_thread)).cloned()
253 /// Set the pointer for the allocation of the given thread local
254 /// static for the active thread.
256 /// Panics if a thread local is initialized twice for the same thread.
257 fn set_thread_local_alloc(&self, def_id: DefId, ptr: Pointer<Tag>) {
258 self.thread_local_alloc_ids
260 .try_insert((def_id, self.active_thread), ptr)
264 /// Borrow the stack of the active thread.
265 fn active_thread_stack(&self) -> &[Frame<'mir, 'tcx, Tag, FrameData<'tcx>>] {
266 &self.threads[self.active_thread].stack
269 /// Mutably borrow the stack of the active thread.
270 fn active_thread_stack_mut(&mut self) -> &mut Vec<Frame<'mir, 'tcx, Tag, FrameData<'tcx>>> {
271 &mut self.threads[self.active_thread].stack
274 /// Create a new thread and returns its id.
275 fn create_thread(&mut self) -> ThreadId {
276 let new_thread_id = ThreadId::new(self.threads.len());
277 self.threads.push(Default::default());
281 /// Set an active thread and return the id of the thread that was active before.
282 fn set_active_thread_id(&mut self, id: ThreadId) -> ThreadId {
283 let active_thread_id = self.active_thread;
284 self.active_thread = id;
285 assert!(self.active_thread.index() < self.threads.len());
289 /// Get the id of the currently active thread.
290 fn get_active_thread_id(&self) -> ThreadId {
294 /// Get the total number of threads that were ever spawn by this program.
295 fn get_total_thread_count(&self) -> usize {
299 /// Has the given thread terminated?
300 fn has_terminated(&self, thread_id: ThreadId) -> bool {
301 self.threads[thread_id].state == ThreadState::Terminated
304 /// Have all threads terminated?
305 fn have_all_terminated(&self) -> bool {
306 self.threads.iter().all(|thread| thread.state == ThreadState::Terminated)
309 /// Enable the thread for execution. The thread must be terminated.
310 fn enable_thread(&mut self, thread_id: ThreadId) {
311 assert!(self.has_terminated(thread_id));
312 self.threads[thread_id].state = ThreadState::Enabled;
315 /// Get a mutable borrow of the currently active thread.
316 fn active_thread_mut(&mut self) -> &mut Thread<'mir, 'tcx> {
317 &mut self.threads[self.active_thread]
320 /// Get a shared borrow of the currently active thread.
321 fn active_thread_ref(&self) -> &Thread<'mir, 'tcx> {
322 &self.threads[self.active_thread]
325 /// Mark the thread as detached, which means that no other thread will try
326 /// to join it and the thread is responsible for cleaning up.
327 fn detach_thread(&mut self, id: ThreadId) -> InterpResult<'tcx> {
328 if self.threads[id].join_status != ThreadJoinStatus::Joinable {
329 throw_ub_format!("trying to detach thread that was already detached or joined");
331 self.threads[id].join_status = ThreadJoinStatus::Detached;
335 /// Mark that the active thread tries to join the thread with `joined_thread_id`.
338 joined_thread_id: ThreadId,
339 data_race: Option<&mut data_race::GlobalState>,
340 ) -> InterpResult<'tcx> {
341 if self.threads[joined_thread_id].join_status != ThreadJoinStatus::Joinable {
342 throw_ub_format!("trying to join a detached or already joined thread");
344 if joined_thread_id == self.active_thread {
345 throw_ub_format!("trying to join itself");
350 .all(|thread| thread.state != ThreadState::BlockedOnJoin(joined_thread_id)),
351 "a joinable thread already has threads waiting for its termination"
353 // Mark the joined thread as being joined so that we detect if other
354 // threads try to join it.
355 self.threads[joined_thread_id].join_status = ThreadJoinStatus::Joined;
356 if self.threads[joined_thread_id].state != ThreadState::Terminated {
357 // The joined thread is still running, we need to wait for it.
358 self.active_thread_mut().state = ThreadState::BlockedOnJoin(joined_thread_id);
360 "{:?} blocked on {:?} when trying to join",
365 // The thread has already terminated - mark join happens-before
366 if let Some(data_race) = data_race {
367 data_race.thread_joined(self.active_thread, joined_thread_id);
373 /// Set the name of the active thread.
374 fn set_thread_name(&mut self, new_thread_name: Vec<u8>) {
375 self.active_thread_mut().thread_name = Some(new_thread_name);
378 /// Get the name of the active thread.
379 fn get_thread_name(&self) -> &[u8] {
380 self.active_thread_ref().thread_name()
383 /// Put the thread into the blocked state.
384 fn block_thread(&mut self, thread: ThreadId) {
385 let state = &mut self.threads[thread].state;
386 assert_eq!(*state, ThreadState::Enabled);
387 *state = ThreadState::BlockedOnSync;
390 /// Put the blocked thread into the enabled state.
391 fn unblock_thread(&mut self, thread: ThreadId) {
392 let state = &mut self.threads[thread].state;
393 assert_eq!(*state, ThreadState::BlockedOnSync);
394 *state = ThreadState::Enabled;
397 /// Change the active thread to some enabled thread.
398 fn yield_active_thread(&mut self) {
399 // We do not yield immediately, as swapping out the current stack while executing a MIR statement
400 // could lead to all sorts of confusion.
401 // We should only switch stacks between steps.
402 self.yield_active_thread = true;
405 /// Register the given `callback` to be called once the `call_time` passes.
407 /// The callback will be called with `thread` being the active thread, and
408 /// the callback may not change the active thread.
409 fn register_timeout_callback(
413 callback: TimeoutCallback<'mir, 'tcx>,
415 self.timeout_callbacks
416 .try_insert(thread, TimeoutCallbackInfo { call_time, callback })
420 /// Unregister the callback for the `thread`.
421 fn unregister_timeout_callback_if_exists(&mut self, thread: ThreadId) {
422 self.timeout_callbacks.remove(&thread);
425 /// Get a callback that is ready to be called.
426 fn get_ready_callback(&mut self) -> Option<(ThreadId, TimeoutCallback<'mir, 'tcx>)> {
427 // We iterate over all threads in the order of their indices because
428 // this allows us to have a deterministic scheduler.
429 for thread in self.threads.indices() {
430 match self.timeout_callbacks.entry(thread) {
431 Entry::Occupied(entry) =>
432 if entry.get().call_time.get_wait_time() == Duration::new(0, 0) {
433 return Some((thread, entry.remove().callback));
435 Entry::Vacant(_) => {}
441 /// Wakes up threads joining on the active one and deallocates thread-local statics.
442 /// The `AllocId` that can now be freed are returned.
443 fn thread_terminated(
445 mut data_race: Option<&mut data_race::GlobalState>,
446 ) -> Vec<Pointer<Tag>> {
447 let mut free_tls_statics = Vec::new();
449 let mut thread_local_statics = self.thread_local_alloc_ids.borrow_mut();
450 thread_local_statics.retain(|&(_def_id, thread), &mut alloc_id| {
451 if thread != self.active_thread {
452 // Keep this static around.
455 // Delete this static from the map and from memory.
456 // We cannot free directly here as we cannot use `?` in this context.
457 free_tls_statics.push(alloc_id);
461 // Set the thread into a terminated state in the data-race detector
462 if let Some(ref mut data_race) = data_race {
463 data_race.thread_terminated();
465 // Check if we need to unblock any threads.
466 for (i, thread) in self.threads.iter_enumerated_mut() {
467 if thread.state == ThreadState::BlockedOnJoin(self.active_thread) {
468 // The thread has terminated, mark happens-before edge to joining thread
469 if let Some(ref mut data_race) = data_race {
470 data_race.thread_joined(i, self.active_thread);
472 trace!("unblocking {:?} because {:?} terminated", i, self.active_thread);
473 thread.state = ThreadState::Enabled;
476 return free_tls_statics;
479 /// Decide which action to take next and on which thread.
481 /// The currently implemented scheduling policy is the one that is commonly
482 /// used in stateless model checkers such as Loom: run the active thread as
483 /// long as we can and switch only when we have to (the active thread was
484 /// blocked, terminated, or has explicitly asked to be preempted).
487 data_race: &Option<data_race::GlobalState>,
488 ) -> InterpResult<'tcx, SchedulingAction> {
489 // Check whether the thread has **just** terminated (`check_terminated`
490 // checks whether the thread has popped all its stack and if yes, sets
491 // the thread state to terminated).
492 if self.threads[self.active_thread].check_terminated() {
493 return Ok(SchedulingAction::ExecuteDtors);
495 // If we get here again and the thread is *still* terminated, there are no more dtors to run.
496 if self.threads[MAIN_THREAD].state == ThreadState::Terminated {
497 // The main thread terminated; stop the program.
498 // We do *not* run TLS dtors of remaining threads, which seems to match rustc behavior.
499 return Ok(SchedulingAction::Stop);
501 // This thread and the program can keep going.
502 if self.threads[self.active_thread].state == ThreadState::Enabled
503 && !self.yield_active_thread
505 // The currently active thread is still enabled, just continue with it.
506 return Ok(SchedulingAction::ExecuteStep);
508 // The active thread yielded. Let's see if there are any timeouts to take care of. We do
509 // this *before* running any other thread, to ensure that timeouts "in the past" fire before
510 // any other thread can take an action. This ensures that for `pthread_cond_timedwait`, "an
511 // error is returned if [...] the absolute time specified by abstime has already been passed
512 // at the time of the call".
513 // <https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_timedwait.html>
514 let potential_sleep_time =
515 self.timeout_callbacks.values().map(|info| info.call_time.get_wait_time()).min();
516 if potential_sleep_time == Some(Duration::new(0, 0)) {
517 return Ok(SchedulingAction::ExecuteTimeoutCallback);
519 // No callbacks scheduled, pick a regular thread to execute.
520 // We need to pick a new thread for execution.
521 for (id, thread) in self.threads.iter_enumerated() {
522 if thread.state == ThreadState::Enabled {
523 if !self.yield_active_thread || id != self.active_thread {
524 self.active_thread = id;
525 if let Some(data_race) = data_race {
526 data_race.thread_set_active(self.active_thread);
532 self.yield_active_thread = false;
533 if self.threads[self.active_thread].state == ThreadState::Enabled {
534 return Ok(SchedulingAction::ExecuteStep);
536 // We have not found a thread to execute.
537 if self.threads.iter().all(|thread| thread.state == ThreadState::Terminated) {
538 unreachable!("all threads terminated without the main thread terminating?!");
539 } else if let Some(sleep_time) = potential_sleep_time {
540 // All threads are currently blocked, but we have unexecuted
541 // timeout_callbacks, which may unblock some of the threads. Hence,
542 // sleep until the first callback.
543 std::thread::sleep(sleep_time);
544 Ok(SchedulingAction::ExecuteTimeoutCallback)
546 throw_machine_stop!(TerminationInfo::Deadlock);
551 // Public interface to thread management.
552 impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
553 pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
554 /// Get a thread-specific allocation id for the given thread-local static.
555 /// If needed, allocate a new one.
556 fn get_or_create_thread_local_alloc(
559 ) -> InterpResult<'tcx, Pointer<Tag>> {
560 let this = self.eval_context_mut();
562 if let Some(old_alloc) = this.machine.threads.get_thread_local_alloc_id(def_id) {
563 // We already have a thread-specific allocation id for this
564 // thread-local static.
567 // We need to allocate a thread-specific allocation id for this
568 // thread-local static.
569 // First, we compute the initial value for this static.
570 if tcx.is_foreign_item(def_id) {
571 throw_unsup_format!("foreign thread-local statics are not supported");
573 let allocation = tcx.eval_static_initializer(def_id)?;
574 // Create a fresh allocation with this content.
576 this.allocate_raw_ptr(allocation.inner().clone(), MiriMemoryKind::Tls.into());
577 this.machine.threads.set_thread_local_alloc(def_id, new_alloc);
583 fn create_thread(&mut self) -> ThreadId {
584 let this = self.eval_context_mut();
585 let id = this.machine.threads.create_thread();
586 if let Some(data_race) = &mut this.machine.data_race {
587 data_race.thread_created(id);
593 fn detach_thread(&mut self, thread_id: ThreadId) -> InterpResult<'tcx> {
594 let this = self.eval_context_mut();
595 this.machine.threads.detach_thread(thread_id)
599 fn join_thread(&mut self, joined_thread_id: ThreadId) -> InterpResult<'tcx> {
600 let this = self.eval_context_mut();
601 this.machine.threads.join_thread(joined_thread_id, this.machine.data_race.as_mut())?;
606 fn set_active_thread(&mut self, thread_id: ThreadId) -> ThreadId {
607 let this = self.eval_context_mut();
608 if let Some(data_race) = &this.machine.data_race {
609 data_race.thread_set_active(thread_id);
611 this.machine.threads.set_active_thread_id(thread_id)
615 fn get_active_thread(&self) -> ThreadId {
616 let this = self.eval_context_ref();
617 this.machine.threads.get_active_thread_id()
621 fn active_thread_mut(&mut self) -> &mut Thread<'mir, 'tcx> {
622 let this = self.eval_context_mut();
623 this.machine.threads.active_thread_mut()
627 fn active_thread_ref(&self) -> &Thread<'mir, 'tcx> {
628 let this = self.eval_context_ref();
629 this.machine.threads.active_thread_ref()
633 fn get_total_thread_count(&self) -> usize {
634 let this = self.eval_context_ref();
635 this.machine.threads.get_total_thread_count()
639 fn has_terminated(&self, thread_id: ThreadId) -> bool {
640 let this = self.eval_context_ref();
641 this.machine.threads.has_terminated(thread_id)
645 fn have_all_terminated(&self) -> bool {
646 let this = self.eval_context_ref();
647 this.machine.threads.have_all_terminated()
651 fn enable_thread(&mut self, thread_id: ThreadId) {
652 let this = self.eval_context_mut();
653 this.machine.threads.enable_thread(thread_id);
657 fn active_thread_stack(&self) -> &[Frame<'mir, 'tcx, Tag, FrameData<'tcx>>] {
658 let this = self.eval_context_ref();
659 this.machine.threads.active_thread_stack()
663 fn active_thread_stack_mut(&mut self) -> &mut Vec<Frame<'mir, 'tcx, Tag, FrameData<'tcx>>> {
664 let this = self.eval_context_mut();
665 this.machine.threads.active_thread_stack_mut()
669 fn set_active_thread_name(&mut self, new_thread_name: Vec<u8>) {
670 let this = self.eval_context_mut();
671 if let Some(data_race) = &mut this.machine.data_race {
672 if let Ok(string) = String::from_utf8(new_thread_name.clone()) {
673 data_race.thread_set_name(this.machine.threads.active_thread, string);
676 this.machine.threads.set_thread_name(new_thread_name);
680 fn get_active_thread_name<'c>(&'c self) -> &'c [u8]
684 let this = self.eval_context_ref();
685 this.machine.threads.get_thread_name()
689 fn block_thread(&mut self, thread: ThreadId) {
690 let this = self.eval_context_mut();
691 this.machine.threads.block_thread(thread);
695 fn unblock_thread(&mut self, thread: ThreadId) {
696 let this = self.eval_context_mut();
697 this.machine.threads.unblock_thread(thread);
701 fn yield_active_thread(&mut self) {
702 let this = self.eval_context_mut();
703 this.machine.threads.yield_active_thread();
707 fn register_timeout_callback(
711 callback: TimeoutCallback<'mir, 'tcx>,
713 let this = self.eval_context_mut();
714 this.machine.threads.register_timeout_callback(thread, call_time, callback);
718 fn unregister_timeout_callback_if_exists(&mut self, thread: ThreadId) {
719 let this = self.eval_context_mut();
720 this.machine.threads.unregister_timeout_callback_if_exists(thread);
723 /// Execute a timeout callback on the callback's thread.
725 fn run_timeout_callback(&mut self) -> InterpResult<'tcx> {
726 let this = self.eval_context_mut();
727 let (thread, callback) =
728 if let Some((thread, callback)) = this.machine.threads.get_ready_callback() {
731 // get_ready_callback can return None if the computer's clock
732 // was shifted after calling the scheduler and before the call
733 // to get_ready_callback (see issue
734 // https://github.com/rust-lang/miri/issues/1763). In this case,
735 // just do nothing, which effectively just returns to the
739 // This back-and-forth with `set_active_thread` is here because of two
741 // 1. Make the caller and not the callback responsible for changing
743 // 2. Make the scheduler the only place that can change the active
745 let old_thread = this.set_active_thread(thread);
747 this.set_active_thread(old_thread);
751 /// Decide which action to take next and on which thread.
753 fn schedule(&mut self) -> InterpResult<'tcx, SchedulingAction> {
754 let this = self.eval_context_mut();
755 let data_race = &this.machine.data_race;
756 this.machine.threads.schedule(data_race)
759 /// Handles thread termination of the active thread: wakes up threads joining on this one,
760 /// and deallocated thread-local statics.
762 /// This is called from `tls.rs` after handling the TLS dtors.
764 fn thread_terminated(&mut self) -> InterpResult<'tcx> {
765 let this = self.eval_context_mut();
766 for ptr in this.machine.threads.thread_terminated(this.machine.data_race.as_mut()) {
767 this.deallocate_ptr(ptr.into(), None, MiriMemoryKind::Tls.into())?;