1 //! Implements threads.
3 use std::cell::RefCell;
4 use std::collections::hash_map::Entry;
5 use std::convert::TryFrom;
6 use std::num::TryFromIntError;
8 use std::time::{Duration, Instant, SystemTime};
12 use rustc_data_structures::fx::FxHashMap;
13 use rustc_hir::def_id::DefId;
14 use rustc_index::vec::{Idx, IndexVec};
16 use crate::sync::SynchronizationState;
19 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
20 pub enum SchedulingAction {
21 /// Execute step on the active thread.
23 /// Execute a timeout callback.
24 ExecuteTimeoutCallback,
25 /// Execute destructors of the active thread.
31 /// Timeout callbacks can be created by synchronization primitives to tell the
32 /// scheduler that they should be called once some period of time passes.
33 type TimeoutCallback<'mir, 'tcx> =
34 Box<dyn FnOnce(&mut InterpCx<'mir, 'tcx, Evaluator<'mir, 'tcx>>) -> InterpResult<'tcx> + 'tcx>;
36 /// A thread identifier.
37 #[derive(Clone, Copy, Debug, PartialOrd, Ord, PartialEq, Eq, Hash)]
38 pub struct ThreadId(u32);
40 /// The main thread. When it terminates, the whole application terminates.
41 const MAIN_THREAD: ThreadId = ThreadId(0);
44 pub fn to_u32(self) -> u32 {
49 impl Idx for ThreadId {
50 fn new(idx: usize) -> Self {
51 ThreadId(u32::try_from(idx).unwrap())
54 fn index(self) -> usize {
55 usize::try_from(self.0).unwrap()
59 impl TryFrom<u64> for ThreadId {
60 type Error = TryFromIntError;
61 fn try_from(id: u64) -> Result<Self, Self::Error> {
62 u32::try_from(id).map(|id_u32| Self(id_u32))
66 impl From<u32> for ThreadId {
67 fn from(id: u32) -> Self {
73 pub fn to_u32_scalar<'tcx>(&self) -> Scalar<Tag> {
74 Scalar::from_u32(u32::try_from(self.0).unwrap())
78 /// The state of a thread.
79 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
80 pub enum ThreadState {
81 /// The thread is enabled and can be executed.
83 /// The thread tried to join the specified thread and is blocked until that
84 /// thread terminates.
85 BlockedOnJoin(ThreadId),
86 /// The thread is blocked on some synchronization primitive. It is the
87 /// responsibility of the synchronization primitives to track threads that
88 /// are blocked by them.
90 /// The thread has terminated its execution. We do not delete terminated
91 /// threads (FIXME: why?).
95 /// The join status of a thread.
96 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
97 enum ThreadJoinStatus {
98 /// The thread can be joined.
100 /// A thread is detached if its join handle was destroyed and no other
101 /// thread can join it.
103 /// The thread was already joined by some thread and cannot be joined again.
108 pub struct Thread<'mir, 'tcx> {
111 /// Name of the thread.
112 thread_name: Option<Vec<u8>>,
114 /// The virtual call stack.
115 stack: Vec<Frame<'mir, 'tcx, Tag, FrameData<'tcx>>>,
118 join_status: ThreadJoinStatus,
120 /// The temporary used for storing the argument of
121 /// the call to `miri_start_panic` (the panic payload) when unwinding.
122 /// This is pointer-sized, and matches the `Payload` type in `src/libpanic_unwind/miri.rs`.
123 pub(crate) panic_payload: Option<Scalar<Tag>>,
125 /// Last OS error location in memory. It is a 32-bit integer.
126 pub(crate) last_error: Option<MPlaceTy<'tcx, Tag>>,
129 impl<'mir, 'tcx> Thread<'mir, 'tcx> {
130 /// Check if the thread is done executing (no more stack frames). If yes,
131 /// change the state to terminated and return `true`.
132 fn check_terminated(&mut self) -> bool {
133 if self.state == ThreadState::Enabled {
134 if self.stack.is_empty() {
135 self.state = ThreadState::Terminated;
142 /// Get the name of the current thread, or `<unnamed>` if it was not set.
143 fn thread_name(&self) -> &[u8] {
144 if let Some(ref thread_name) = self.thread_name { thread_name } else { b"<unnamed>" }
148 impl<'mir, 'tcx> std::fmt::Debug for Thread<'mir, 'tcx> {
149 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
153 String::from_utf8_lossy(self.thread_name()),
160 impl<'mir, 'tcx> Default for Thread<'mir, 'tcx> {
161 fn default() -> Self {
163 state: ThreadState::Enabled,
166 join_status: ThreadJoinStatus::Joinable,
173 /// A specific moment in time.
177 RealTime(SystemTime),
181 /// How long do we have to wait from now until the specified time?
182 fn get_wait_time(&self) -> Duration {
184 Time::Monotonic(instant) => instant.saturating_duration_since(Instant::now()),
185 Time::RealTime(time) =>
186 time.duration_since(SystemTime::now()).unwrap_or(Duration::new(0, 0)),
191 /// Callbacks are used to implement timeouts. For example, waiting on a
192 /// conditional variable with a timeout creates a callback that is called after
193 /// the specified time and unblocks the thread. If another thread signals on the
194 /// conditional variable, the signal handler deletes the callback.
195 struct TimeoutCallbackInfo<'mir, 'tcx> {
196 /// The callback should be called no earlier than this time.
198 /// The called function.
199 callback: TimeoutCallback<'mir, 'tcx>,
202 impl<'mir, 'tcx> std::fmt::Debug for TimeoutCallbackInfo<'mir, 'tcx> {
203 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
204 write!(f, "TimeoutCallback({:?})", self.call_time)
208 /// A set of threads.
210 pub struct ThreadManager<'mir, 'tcx> {
211 /// Identifier of the currently active thread.
212 active_thread: ThreadId,
213 /// Threads used in the program.
215 /// Note that this vector also contains terminated threads.
216 threads: IndexVec<ThreadId, Thread<'mir, 'tcx>>,
217 /// This field is pub(crate) because the synchronization primitives
218 /// (`crate::sync`) need a way to access it.
219 pub(crate) sync: SynchronizationState,
220 /// A mapping from a thread-local static to an allocation id of a thread
221 /// specific allocation.
222 thread_local_alloc_ids: RefCell<FxHashMap<(DefId, ThreadId), AllocId>>,
223 /// A flag that indicates that we should change the active thread.
224 yield_active_thread: bool,
225 /// Callbacks that are called once the specified time passes.
226 timeout_callbacks: FxHashMap<ThreadId, TimeoutCallbackInfo<'mir, 'tcx>>,
229 impl<'mir, 'tcx> Default for ThreadManager<'mir, 'tcx> {
230 fn default() -> Self {
231 let mut threads = IndexVec::new();
232 // Create the main thread and add it to the list of threads.
233 let mut main_thread = Thread::default();
234 // The main thread can *not* be joined on.
235 main_thread.join_status = ThreadJoinStatus::Detached;
236 threads.push(main_thread);
238 active_thread: ThreadId::new(0),
240 sync: SynchronizationState::default(),
241 thread_local_alloc_ids: Default::default(),
242 yield_active_thread: false,
243 timeout_callbacks: FxHashMap::default(),
248 impl<'mir, 'tcx: 'mir> ThreadManager<'mir, 'tcx> {
249 /// Check if we have an allocation for the given thread local static for the
251 fn get_thread_local_alloc_id(&self, def_id: DefId) -> Option<AllocId> {
252 self.thread_local_alloc_ids.borrow().get(&(def_id, self.active_thread)).cloned()
255 /// Set the allocation id as the allocation id of the given thread local
256 /// static for the active thread.
258 /// Panics if a thread local is initialized twice for the same thread.
259 fn set_thread_local_alloc_id(&self, def_id: DefId, new_alloc_id: AllocId) {
260 self.thread_local_alloc_ids
262 .try_insert((def_id, self.active_thread), new_alloc_id)
266 /// Borrow the stack of the active thread.
267 fn active_thread_stack(&self) -> &[Frame<'mir, 'tcx, Tag, FrameData<'tcx>>] {
268 &self.threads[self.active_thread].stack
271 /// Mutably borrow the stack of the active thread.
272 fn active_thread_stack_mut(&mut self) -> &mut Vec<Frame<'mir, 'tcx, Tag, FrameData<'tcx>>> {
273 &mut self.threads[self.active_thread].stack
276 /// Create a new thread and returns its id.
277 fn create_thread(&mut self) -> ThreadId {
278 let new_thread_id = ThreadId::new(self.threads.len());
279 self.threads.push(Default::default());
283 /// Set an active thread and return the id of the thread that was active before.
284 fn set_active_thread_id(&mut self, id: ThreadId) -> ThreadId {
285 let active_thread_id = self.active_thread;
286 self.active_thread = id;
287 assert!(self.active_thread.index() < self.threads.len());
291 /// Get the id of the currently active thread.
292 fn get_active_thread_id(&self) -> ThreadId {
296 /// Get the total number of threads that were ever spawn by this program.
297 fn get_total_thread_count(&self) -> usize {
301 /// Has the given thread terminated?
302 fn has_terminated(&self, thread_id: ThreadId) -> bool {
303 self.threads[thread_id].state == ThreadState::Terminated
306 /// Enable the thread for execution. The thread must be terminated.
307 fn enable_thread(&mut self, thread_id: ThreadId) {
308 assert!(self.has_terminated(thread_id));
309 self.threads[thread_id].state = ThreadState::Enabled;
312 /// Get a mutable borrow of the currently active thread.
313 fn active_thread_mut(&mut self) -> &mut Thread<'mir, 'tcx> {
314 &mut self.threads[self.active_thread]
317 /// Get a shared borrow of the currently active thread.
318 fn active_thread_ref(&self) -> &Thread<'mir, 'tcx> {
319 &self.threads[self.active_thread]
322 /// Mark the thread as detached, which means that no other thread will try
323 /// to join it and the thread is responsible for cleaning up.
324 fn detach_thread(&mut self, id: ThreadId) -> InterpResult<'tcx> {
325 if self.threads[id].join_status != ThreadJoinStatus::Joinable {
326 throw_ub_format!("trying to detach thread that was already detached or joined");
328 self.threads[id].join_status = ThreadJoinStatus::Detached;
332 /// Mark that the active thread tries to join the thread with `joined_thread_id`.
335 joined_thread_id: ThreadId,
336 data_race: &Option<Rc<data_race::GlobalState>>,
337 ) -> InterpResult<'tcx> {
338 if self.threads[joined_thread_id].join_status != ThreadJoinStatus::Joinable {
339 throw_ub_format!("trying to join a detached or already joined thread");
341 if joined_thread_id == self.active_thread {
342 throw_ub_format!("trying to join itself");
347 .all(|thread| thread.state != ThreadState::BlockedOnJoin(joined_thread_id)),
348 "a joinable thread already has threads waiting for its termination"
350 // Mark the joined thread as being joined so that we detect if other
351 // threads try to join it.
352 self.threads[joined_thread_id].join_status = ThreadJoinStatus::Joined;
353 if self.threads[joined_thread_id].state != ThreadState::Terminated {
354 // The joined thread is still running, we need to wait for it.
355 self.active_thread_mut().state = ThreadState::BlockedOnJoin(joined_thread_id);
357 "{:?} blocked on {:?} when trying to join",
362 // The thread has already terminated - mark join happens-before
363 if let Some(data_race) = data_race {
364 data_race.thread_joined(self.active_thread, joined_thread_id);
370 /// Set the name of the active thread.
371 fn set_thread_name(&mut self, new_thread_name: Vec<u8>) {
372 self.active_thread_mut().thread_name = Some(new_thread_name);
375 /// Get the name of the active thread.
376 fn get_thread_name(&self) -> &[u8] {
377 self.active_thread_ref().thread_name()
380 /// Put the thread into the blocked state.
381 fn block_thread(&mut self, thread: ThreadId) {
382 let state = &mut self.threads[thread].state;
383 assert_eq!(*state, ThreadState::Enabled);
384 *state = ThreadState::BlockedOnSync;
387 /// Put the blocked thread into the enabled state.
388 fn unblock_thread(&mut self, thread: ThreadId) {
389 let state = &mut self.threads[thread].state;
390 assert_eq!(*state, ThreadState::BlockedOnSync);
391 *state = ThreadState::Enabled;
394 /// Change the active thread to some enabled thread.
395 fn yield_active_thread(&mut self) {
396 // We do not yield immediately, as swapping out the current stack while executing a MIR statement
397 // could lead to all sorts of confusion.
398 // We should only switch stacks between steps.
399 self.yield_active_thread = true;
402 /// Register the given `callback` to be called once the `call_time` passes.
404 /// The callback will be called with `thread` being the active thread, and
405 /// the callback may not change the active thread.
406 fn register_timeout_callback(
410 callback: TimeoutCallback<'mir, 'tcx>,
412 self.timeout_callbacks
413 .try_insert(thread, TimeoutCallbackInfo { call_time, callback })
417 /// Unregister the callback for the `thread`.
418 fn unregister_timeout_callback_if_exists(&mut self, thread: ThreadId) {
419 self.timeout_callbacks.remove(&thread);
422 /// Get a callback that is ready to be called.
423 fn get_ready_callback(&mut self) -> Option<(ThreadId, TimeoutCallback<'mir, 'tcx>)> {
424 // We iterate over all threads in the order of their indices because
425 // this allows us to have a deterministic scheduler.
426 for thread in self.threads.indices() {
427 match self.timeout_callbacks.entry(thread) {
428 Entry::Occupied(entry) =>
429 if entry.get().call_time.get_wait_time() == Duration::new(0, 0) {
430 return Some((thread, entry.remove().callback));
432 Entry::Vacant(_) => {}
438 /// Wakes up threads joining on the active one and deallocates thread-local statics.
439 /// The `AllocId` that can now be freed is returned.
440 fn thread_terminated(
442 data_race: &Option<Rc<data_race::GlobalState>>,
444 let mut free_tls_statics = Vec::new();
446 let mut thread_local_statics = self.thread_local_alloc_ids.borrow_mut();
447 thread_local_statics.retain(|&(_def_id, thread), &mut alloc_id| {
448 if thread != self.active_thread {
449 // Keep this static around.
452 // Delete this static from the map and from memory.
453 // We cannot free directly here as we cannot use `?` in this context.
454 free_tls_statics.push(alloc_id);
458 // Set the thread into a terminated state in the data-race detector
459 if let Some(data_race) = data_race {
460 data_race.thread_terminated();
462 // Check if we need to unblock any threads.
463 for (i, thread) in self.threads.iter_enumerated_mut() {
464 if thread.state == ThreadState::BlockedOnJoin(self.active_thread) {
465 // The thread has terminated, mark happens-before edge to joining thread
466 if let Some(data_race) = data_race {
467 data_race.thread_joined(i, self.active_thread);
469 trace!("unblocking {:?} because {:?} terminated", i, self.active_thread);
470 thread.state = ThreadState::Enabled;
473 return free_tls_statics;
476 /// Decide which action to take next and on which thread.
478 /// The currently implemented scheduling policy is the one that is commonly
479 /// used in stateless model checkers such as Loom: run the active thread as
480 /// long as we can and switch only when we have to (the active thread was
481 /// blocked, terminated, or has explicitly asked to be preempted).
484 data_race: &Option<Rc<data_race::GlobalState>>,
485 ) -> InterpResult<'tcx, SchedulingAction> {
486 // Check whether the thread has **just** terminated (`check_terminated`
487 // checks whether the thread has popped all its stack and if yes, sets
488 // the thread state to terminated).
489 if self.threads[self.active_thread].check_terminated() {
490 return Ok(SchedulingAction::ExecuteDtors);
492 // If we get here again and the thread is *still* terminated, there are no more dtors to run.
493 if self.threads[MAIN_THREAD].state == ThreadState::Terminated {
494 // The main thread terminated; stop the program.
495 if self.threads.iter().any(|thread| thread.state != ThreadState::Terminated) {
496 // FIXME: This check should be either configurable or just emit
497 // a warning. For example, it seems normal for a program to
498 // terminate without waiting for its detached threads to
499 // terminate. However, this case is not trivial to support
500 // because we also probably do not want to consider the memory
501 // owned by these threads as leaked.
502 throw_unsup_format!("the main thread terminated without waiting for other threads");
504 return Ok(SchedulingAction::Stop);
506 // This thread and the program can keep going.
507 if self.threads[self.active_thread].state == ThreadState::Enabled
508 && !self.yield_active_thread
510 // The currently active thread is still enabled, just continue with it.
511 return Ok(SchedulingAction::ExecuteStep);
513 // The active thread yielded. Let's see if there are any timeouts to take care of. We do
514 // this *before* running any other thread, to ensure that timeouts "in the past" fire before
515 // any other thread can take an action. This ensures that for `pthread_cond_timedwait`, "an
516 // error is returned if [...] the absolute time specified by abstime has already been passed
517 // at the time of the call".
518 // <https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_timedwait.html>
519 let potential_sleep_time =
520 self.timeout_callbacks.values().map(|info| info.call_time.get_wait_time()).min();
521 if potential_sleep_time == Some(Duration::new(0, 0)) {
522 return Ok(SchedulingAction::ExecuteTimeoutCallback);
524 // No callbacks scheduled, pick a regular thread to execute.
525 // We need to pick a new thread for execution.
526 for (id, thread) in self.threads.iter_enumerated() {
527 if thread.state == ThreadState::Enabled {
528 if !self.yield_active_thread || id != self.active_thread {
529 self.active_thread = id;
530 if let Some(data_race) = data_race {
531 data_race.thread_set_active(self.active_thread);
537 self.yield_active_thread = false;
538 if self.threads[self.active_thread].state == ThreadState::Enabled {
539 return Ok(SchedulingAction::ExecuteStep);
541 // We have not found a thread to execute.
542 if self.threads.iter().all(|thread| thread.state == ThreadState::Terminated) {
543 unreachable!("all threads terminated without the main thread terminating?!");
544 } else if let Some(sleep_time) = potential_sleep_time {
545 // All threads are currently blocked, but we have unexecuted
546 // timeout_callbacks, which may unblock some of the threads. Hence,
547 // sleep until the first callback.
548 std::thread::sleep(sleep_time);
549 Ok(SchedulingAction::ExecuteTimeoutCallback)
551 throw_machine_stop!(TerminationInfo::Deadlock);
556 // Public interface to thread management.
557 impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
558 pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
559 /// Get a thread-specific allocation id for the given thread-local static.
560 /// If needed, allocate a new one.
561 fn get_or_create_thread_local_alloc_id(
564 ) -> InterpResult<'tcx, AllocId> {
565 let this = self.eval_context_mut();
567 if let Some(new_alloc_id) = this.machine.threads.get_thread_local_alloc_id(def_id) {
568 // We already have a thread-specific allocation id for this
569 // thread-local static.
572 // We need to allocate a thread-specific allocation id for this
573 // thread-local static.
574 // First, we compute the initial value for this static.
575 if tcx.is_foreign_item(def_id) {
576 throw_unsup_format!("foreign thread-local statics are not supported");
578 let allocation = tcx.eval_static_initializer(def_id)?;
579 // Create a fresh allocation with this content.
581 this.memory.allocate_with(allocation.clone(), MiriMemoryKind::Tls.into()).alloc_id;
582 this.machine.threads.set_thread_local_alloc_id(def_id, new_alloc_id);
588 fn create_thread(&mut self) -> ThreadId {
589 let this = self.eval_context_mut();
590 let id = this.machine.threads.create_thread();
591 if let Some(data_race) = &this.memory.extra.data_race {
592 data_race.thread_created(id);
598 fn detach_thread(&mut self, thread_id: ThreadId) -> InterpResult<'tcx> {
599 let this = self.eval_context_mut();
600 this.machine.threads.detach_thread(thread_id)
604 fn join_thread(&mut self, joined_thread_id: ThreadId) -> InterpResult<'tcx> {
605 let this = self.eval_context_mut();
606 let data_race = &this.memory.extra.data_race;
607 this.machine.threads.join_thread(joined_thread_id, data_race)?;
612 fn set_active_thread(&mut self, thread_id: ThreadId) -> ThreadId {
613 let this = self.eval_context_mut();
614 if let Some(data_race) = &this.memory.extra.data_race {
615 data_race.thread_set_active(thread_id);
617 this.machine.threads.set_active_thread_id(thread_id)
621 fn get_active_thread(&self) -> ThreadId {
622 let this = self.eval_context_ref();
623 this.machine.threads.get_active_thread_id()
627 fn active_thread_mut(&mut self) -> &mut Thread<'mir, 'tcx> {
628 let this = self.eval_context_mut();
629 this.machine.threads.active_thread_mut()
633 fn active_thread_ref(&self) -> &Thread<'mir, 'tcx> {
634 let this = self.eval_context_ref();
635 this.machine.threads.active_thread_ref()
639 fn get_total_thread_count(&self) -> usize {
640 let this = self.eval_context_ref();
641 this.machine.threads.get_total_thread_count()
645 fn has_terminated(&self, thread_id: ThreadId) -> bool {
646 let this = self.eval_context_ref();
647 this.machine.threads.has_terminated(thread_id)
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) = &this.memory.extra.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.memory.extra.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 let data_race = &this.memory.extra.data_race;
767 for alloc_id in this.machine.threads.thread_terminated(data_race) {
768 let ptr = this.memory.global_base_pointer(alloc_id.into())?;
769 this.memory.deallocate(ptr, None, MiriMemoryKind::Tls.into())?;