//! Implements threads.
use std::cell::RefCell;
+use std::collections::hash_map::Entry;
use std::convert::TryFrom;
-use std::num::{NonZeroU32, TryFromIntError};
+use std::num::TryFromIntError;
+use std::rc::Rc;
+use std::time::{Duration, Instant, SystemTime};
use log::trace;
use rustc_data_structures::fx::FxHashMap;
use rustc_hir::def_id::DefId;
use rustc_index::vec::{Idx, IndexVec};
-use rustc_middle::{
- middle::codegen_fn_attrs::CodegenFnAttrFlags,
- mir,
- ty::{self, Instance},
-};
+use crate::sync::SynchronizationState;
use crate::*;
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum SchedulingAction {
/// Execute step on the active thread.
ExecuteStep,
+ /// Execute a timeout callback.
+ ExecuteTimeoutCallback,
/// Execute destructors of the active thread.
ExecuteDtors,
/// Stop the program.
Stop,
}
+/// Timeout callbacks can be created by synchronization primitives to tell the
+/// scheduler that they should be called once some period of time passes.
+type TimeoutCallback<'mir, 'tcx> =
+ Box<dyn FnOnce(&mut InterpCx<'mir, 'tcx, Evaluator<'mir, 'tcx>>) -> InterpResult<'tcx> + 'tcx>;
+
/// A thread identifier.
#[derive(Clone, Copy, Debug, PartialOrd, Ord, PartialEq, Eq, Hash)]
pub struct ThreadId(u32);
}
}
-/// An identifier of a set of blocked threads. 0 is used to indicate the absence
-/// of a blockset identifier and, therefore, is not a valid identifier.
-#[derive(Clone, Copy, Debug, PartialOrd, Ord, PartialEq, Eq, Hash)]
-pub struct BlockSetId(NonZeroU32);
-
-impl BlockSetId {
- /// Panics if `id` is 0.
- pub fn new(id: u32) -> Self {
- Self(NonZeroU32::new(id).expect("0 is not a valid blockset id"))
- }
- pub fn to_u32_scalar<'tcx>(&self) -> Scalar<Tag> {
- Scalar::from_u32(self.0.get())
- }
-}
-
/// The state of a thread.
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
pub enum ThreadState {
/// The thread tried to join the specified thread and is blocked until that
/// thread terminates.
BlockedOnJoin(ThreadId),
- /// The thread is blocked and belongs to the given blockset.
- Blocked(BlockSetId),
- /// The thread has terminated its execution (we do not delete terminated
- /// threads).
+ /// The thread is blocked on some synchronization primitive. It is the
+ /// responsibility of the synchronization primitives to track threads that
+ /// are blocked by them.
+ BlockedOnSync,
+ /// The thread has terminated its execution. We do not delete terminated
+ /// threads (FIXME: why?).
Terminated,
}
/// A thread.
pub struct Thread<'mir, 'tcx> {
state: ThreadState,
+
/// Name of the thread.
thread_name: Option<Vec<u8>>,
+
/// The virtual call stack.
stack: Vec<Frame<'mir, 'tcx, Tag, FrameData<'tcx>>>,
+
/// The join status.
join_status: ThreadJoinStatus,
+
+ /// The temporary used for storing the argument of
+ /// the call to `miri_start_panic` (the panic payload) when unwinding.
+ /// This is pointer-sized, and matches the `Payload` type in `src/libpanic_unwind/miri.rs`.
+ pub(crate) panic_payload: Option<Scalar<Tag>>,
+
+ /// Last OS error location in memory. It is a 32-bit integer.
+ pub(crate) last_error: Option<MPlaceTy<'tcx, Tag>>,
}
impl<'mir, 'tcx> Thread<'mir, 'tcx> {
}
false
}
+
+ /// Get the name of the current thread, or `<unnamed>` if it was not set.
+ fn thread_name(&self) -> &[u8] {
+ if let Some(ref thread_name) = self.thread_name { thread_name } else { b"<unnamed>" }
+ }
}
impl<'mir, 'tcx> std::fmt::Debug for Thread<'mir, 'tcx> {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
- if let Some(ref name) = self.thread_name {
- write!(f, "{}", String::from_utf8_lossy(name))?;
- } else {
- write!(f, "<unnamed>")?;
- }
- write!(f, "({:?}, {:?})", self.state, self.join_status)
+ write!(
+ f,
+ "{}({:?}, {:?})",
+ String::from_utf8_lossy(self.thread_name()),
+ self.state,
+ self.join_status
+ )
}
}
thread_name: None,
stack: Vec::new(),
join_status: ThreadJoinStatus::Joinable,
+ panic_payload: None,
+ last_error: None,
+ }
+ }
+}
+
+/// A specific moment in time.
+#[derive(Debug)]
+pub enum Time {
+ Monotonic(Instant),
+ RealTime(SystemTime),
+}
+
+impl Time {
+ /// How long do we have to wait from now until the specified time?
+ fn get_wait_time(&self) -> Duration {
+ match self {
+ Time::Monotonic(instant) => instant.saturating_duration_since(Instant::now()),
+ Time::RealTime(time) =>
+ time.duration_since(SystemTime::now()).unwrap_or(Duration::new(0, 0)),
}
}
}
+/// Callbacks are used to implement timeouts. For example, waiting on a
+/// conditional variable with a timeout creates a callback that is called after
+/// the specified time and unblocks the thread. If another thread signals on the
+/// conditional variable, the signal handler deletes the callback.
+struct TimeoutCallbackInfo<'mir, 'tcx> {
+ /// The callback should be called no earlier than this time.
+ call_time: Time,
+ /// The called function.
+ callback: TimeoutCallback<'mir, 'tcx>,
+}
+
+impl<'mir, 'tcx> std::fmt::Debug for TimeoutCallbackInfo<'mir, 'tcx> {
+ fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+ write!(f, "TimeoutCallback({:?})", self.call_time)
+ }
+}
+
/// A set of threads.
#[derive(Debug)]
pub struct ThreadManager<'mir, 'tcx> {
///
/// Note that this vector also contains terminated threads.
threads: IndexVec<ThreadId, Thread<'mir, 'tcx>>,
- /// A counter used to generate unique identifiers for blocksets.
- blockset_counter: u32,
+ /// This field is pub(crate) because the synchronization primitives
+ /// (`crate::sync`) need a way to access it.
+ pub(crate) sync: SynchronizationState,
/// A mapping from a thread-local static to an allocation id of a thread
/// specific allocation.
thread_local_alloc_ids: RefCell<FxHashMap<(DefId, ThreadId), AllocId>>,
/// A flag that indicates that we should change the active thread.
yield_active_thread: bool,
+ /// Callbacks that are called once the specified time passes.
+ timeout_callbacks: FxHashMap<ThreadId, TimeoutCallbackInfo<'mir, 'tcx>>,
}
impl<'mir, 'tcx> Default for ThreadManager<'mir, 'tcx> {
Self {
active_thread: ThreadId::new(0),
threads: threads,
- blockset_counter: 0,
+ sync: SynchronizationState::default(),
thread_local_alloc_ids: Default::default(),
yield_active_thread: false,
+ timeout_callbacks: FxHashMap::default(),
}
}
}
fn set_thread_local_alloc_id(&self, def_id: DefId, new_alloc_id: AllocId) {
self.thread_local_alloc_ids
.borrow_mut()
- .insert((def_id, self.active_thread), new_alloc_id)
- .unwrap_none();
+ .try_insert((def_id, self.active_thread), new_alloc_id)
+ .unwrap();
}
/// Borrow the stack of the active thread.
}
/// Mark that the active thread tries to join the thread with `joined_thread_id`.
- fn join_thread(&mut self, joined_thread_id: ThreadId) -> InterpResult<'tcx> {
+ fn join_thread(
+ &mut self,
+ joined_thread_id: ThreadId,
+ data_race: &Option<Rc<data_race::GlobalState>>,
+ ) -> InterpResult<'tcx> {
if self.threads[joined_thread_id].join_status != ThreadJoinStatus::Joinable {
throw_ub_format!("trying to join a detached or already joined thread");
}
self.active_thread,
joined_thread_id
);
+ } else {
+ // The thread has already terminated - mark join happens-before
+ if let Some(data_race) = data_race {
+ data_race.thread_joined(self.active_thread, joined_thread_id);
+ }
}
Ok(())
}
/// Get the name of the active thread.
fn get_thread_name(&self) -> &[u8] {
- if let Some(ref thread_name) = self.active_thread_ref().thread_name {
- thread_name
- } else {
- b"<unnamed>"
- }
+ self.active_thread_ref().thread_name()
}
- /// Allocate a new blockset id.
- fn create_blockset(&mut self) -> BlockSetId {
- self.blockset_counter = self.blockset_counter.checked_add(1).unwrap();
- BlockSetId::new(self.blockset_counter)
+ /// Put the thread into the blocked state.
+ fn block_thread(&mut self, thread: ThreadId) {
+ let state = &mut self.threads[thread].state;
+ assert_eq!(*state, ThreadState::Enabled);
+ *state = ThreadState::BlockedOnSync;
}
- /// Block the currently active thread and put it into the given blockset.
- fn block_active_thread(&mut self, set: BlockSetId) {
- let state = &mut self.active_thread_mut().state;
- assert_eq!(*state, ThreadState::Enabled);
- *state = ThreadState::Blocked(set);
+ /// Put the blocked thread into the enabled state.
+ fn unblock_thread(&mut self, thread: ThreadId) {
+ let state = &mut self.threads[thread].state;
+ assert_eq!(*state, ThreadState::BlockedOnSync);
+ *state = ThreadState::Enabled;
}
- /// Unblock any one thread from the given blockset if it contains at least
- /// one. Return the id of the unblocked thread.
- fn unblock_some_thread(&mut self, set: BlockSetId) -> Option<ThreadId> {
- for (id, thread) in self.threads.iter_enumerated_mut() {
- if thread.state == ThreadState::Blocked(set) {
- trace!("unblocking {:?} in blockset {:?}", id, set);
- thread.state = ThreadState::Enabled;
- return Some(id);
+ /// Change the active thread to some enabled thread.
+ fn yield_active_thread(&mut self) {
+ // We do not yield immediately, as swapping out the current stack while executing a MIR statement
+ // could lead to all sorts of confusion.
+ // We should only switch stacks between steps.
+ self.yield_active_thread = true;
+ }
+
+ /// Register the given `callback` to be called once the `call_time` passes.
+ ///
+ /// The callback will be called with `thread` being the active thread, and
+ /// the callback may not change the active thread.
+ fn register_timeout_callback(
+ &mut self,
+ thread: ThreadId,
+ call_time: Time,
+ callback: TimeoutCallback<'mir, 'tcx>,
+ ) {
+ self.timeout_callbacks
+ .try_insert(thread, TimeoutCallbackInfo { call_time, callback })
+ .unwrap();
+ }
+
+ /// Unregister the callback for the `thread`.
+ fn unregister_timeout_callback_if_exists(&mut self, thread: ThreadId) {
+ self.timeout_callbacks.remove(&thread);
+ }
+
+ /// Get a callback that is ready to be called.
+ fn get_ready_callback(&mut self) -> Option<(ThreadId, TimeoutCallback<'mir, 'tcx>)> {
+ // We iterate over all threads in the order of their indices because
+ // this allows us to have a deterministic scheduler.
+ for thread in self.threads.indices() {
+ match self.timeout_callbacks.entry(thread) {
+ Entry::Occupied(entry) =>
+ if entry.get().call_time.get_wait_time() == Duration::new(0, 0) {
+ return Some((thread, entry.remove().callback));
+ },
+ Entry::Vacant(_) => {}
}
}
None
}
- /// Change the active thread to some enabled thread.
- fn yield_active_thread(&mut self) {
- self.yield_active_thread = true;
+ /// Wakes up threads joining on the active one and deallocates thread-local statics.
+ /// The `AllocId` that can now be freed is returned.
+ fn thread_terminated(
+ &mut self,
+ data_race: &Option<Rc<data_race::GlobalState>>,
+ ) -> Vec<AllocId> {
+ let mut free_tls_statics = Vec::new();
+ {
+ let mut thread_local_statics = self.thread_local_alloc_ids.borrow_mut();
+ thread_local_statics.retain(|&(_def_id, thread), &mut alloc_id| {
+ if thread != self.active_thread {
+ // Keep this static around.
+ return true;
+ }
+ // Delete this static from the map and from memory.
+ // We cannot free directly here as we cannot use `?` in this context.
+ free_tls_statics.push(alloc_id);
+ return false;
+ });
+ }
+ // Set the thread into a terminated state in the data-race detector
+ if let Some(data_race) = data_race {
+ data_race.thread_terminated();
+ }
+ // Check if we need to unblock any threads.
+ for (i, thread) in self.threads.iter_enumerated_mut() {
+ if thread.state == ThreadState::BlockedOnJoin(self.active_thread) {
+ // The thread has terminated, mark happens-before edge to joining thread
+ if let Some(data_race) = data_race {
+ data_race.thread_joined(i, self.active_thread);
+ }
+ trace!("unblocking {:?} because {:?} terminated", i, self.active_thread);
+ thread.state = ThreadState::Enabled;
+ }
+ }
+ return free_tls_statics;
}
/// Decide which action to take next and on which thread.
/// used in stateless model checkers such as Loom: run the active thread as
/// long as we can and switch only when we have to (the active thread was
/// blocked, terminated, or has explicitly asked to be preempted).
- fn schedule(&mut self) -> InterpResult<'tcx, SchedulingAction> {
+ fn schedule(
+ &mut self,
+ data_race: &Option<Rc<data_race::GlobalState>>,
+ ) -> InterpResult<'tcx, SchedulingAction> {
// Check whether the thread has **just** terminated (`check_terminated`
// checks whether the thread has popped all its stack and if yes, sets
// the thread state to terminated).
if self.threads[self.active_thread].check_terminated() {
- // Check if we need to unblock any threads.
- for (i, thread) in self.threads.iter_enumerated_mut() {
- if thread.state == ThreadState::BlockedOnJoin(self.active_thread) {
- trace!("unblocking {:?} because {:?} terminated", i, self.active_thread);
- thread.state = ThreadState::Enabled;
- }
- }
return Ok(SchedulingAction::ExecuteDtors);
}
+ // If we get here again and the thread is *still* terminated, there are no more dtors to run.
if self.threads[MAIN_THREAD].state == ThreadState::Terminated {
// The main thread terminated; stop the program.
if self.threads.iter().any(|thread| thread.state != ThreadState::Terminated) {
}
return Ok(SchedulingAction::Stop);
}
+ // This thread and the program can keep going.
if self.threads[self.active_thread].state == ThreadState::Enabled
&& !self.yield_active_thread
{
// The currently active thread is still enabled, just continue with it.
return Ok(SchedulingAction::ExecuteStep);
}
+ // The active thread yielded. Let's see if there are any timeouts to take care of. We do
+ // this *before* running any other thread, to ensure that timeouts "in the past" fire before
+ // any other thread can take an action. This ensures that for `pthread_cond_timedwait`, "an
+ // error is returned if [...] the absolute time specified by abstime has already been passed
+ // at the time of the call".
+ // <https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_timedwait.html>
+ let potential_sleep_time =
+ self.timeout_callbacks.values().map(|info| info.call_time.get_wait_time()).min();
+ if potential_sleep_time == Some(Duration::new(0, 0)) {
+ return Ok(SchedulingAction::ExecuteTimeoutCallback);
+ }
+ // No callbacks scheduled, pick a regular thread to execute.
// We need to pick a new thread for execution.
for (id, thread) in self.threads.iter_enumerated() {
if thread.state == ThreadState::Enabled {
if !self.yield_active_thread || id != self.active_thread {
self.active_thread = id;
+ if let Some(data_race) = data_race {
+ data_race.thread_set_active(self.active_thread);
+ }
break;
}
}
}
// We have not found a thread to execute.
if self.threads.iter().all(|thread| thread.state == ThreadState::Terminated) {
- unreachable!();
+ unreachable!("all threads terminated without the main thread terminating?!");
+ } else if let Some(sleep_time) = potential_sleep_time {
+ // All threads are currently blocked, but we have unexecuted
+ // timeout_callbacks, which may unblock some of the threads. Hence,
+ // sleep until the first callback.
+ std::thread::sleep(sleep_time);
+ Ok(SchedulingAction::ExecuteTimeoutCallback)
} else {
throw_machine_stop!(TerminationInfo::Deadlock);
}
// Public interface to thread management.
impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
- /// A workaround for thread-local statics until
- /// https://github.com/rust-lang/rust/issues/70685 is fixed: change the
- /// thread-local allocation id with a freshly generated allocation id for
- /// the currently active thread.
- fn remap_thread_local_alloc_ids(
- &self,
- val: &mut mir::interpret::ConstValue<'tcx>,
- ) -> InterpResult<'tcx> {
- let this = self.eval_context_ref();
- match *val {
- mir::interpret::ConstValue::Scalar(Scalar::Ptr(ref mut ptr)) => {
- let alloc_id = ptr.alloc_id;
- let alloc = this.tcx.alloc_map.lock().get(alloc_id);
- let tcx = this.tcx;
- let is_thread_local = |def_id| {
- tcx.codegen_fn_attrs(def_id).flags.contains(CodegenFnAttrFlags::THREAD_LOCAL)
- };
- match alloc {
- Some(GlobalAlloc::Static(def_id)) if is_thread_local(def_id) => {
- ptr.alloc_id = this.get_or_create_thread_local_alloc_id(def_id)?;
- }
- _ => {}
- }
- }
- _ => {
- // FIXME: Handling only `Scalar` seems to work for now, but at
- // least in principle thread-locals could be in any constant, so
- // we should also consider other cases. However, once
- // https://github.com/rust-lang/rust/issues/70685 gets fixed,
- // this code will have to be rewritten anyway.
- }
- }
- Ok(())
- }
-
/// Get a thread-specific allocation id for the given thread-local static.
/// If needed, allocate a new one.
- ///
- /// FIXME: This method should be replaced as soon as
- /// https://github.com/rust-lang/rust/issues/70685 gets fixed.
- fn get_or_create_thread_local_alloc_id(&self, def_id: DefId) -> InterpResult<'tcx, AllocId> {
- let this = self.eval_context_ref();
+ fn get_or_create_thread_local_alloc_id(
+ &mut self,
+ def_id: DefId,
+ ) -> InterpResult<'tcx, AllocId> {
+ let this = self.eval_context_mut();
let tcx = this.tcx;
if let Some(new_alloc_id) = this.machine.threads.get_thread_local_alloc_id(def_id) {
// We already have a thread-specific allocation id for this
} else {
// We need to allocate a thread-specific allocation id for this
// thread-local static.
- //
- // At first, we invoke the `const_eval_raw` query and extract the
- // allocation from it. Unfortunately, we have to duplicate the code
- // from `Memory::get_global_alloc` that does this.
- //
- // Then we store the retrieved allocation back into the `alloc_map`
- // to get a fresh allocation id, which we can use as a
- // thread-specific allocation id for the thread-local static.
+ // First, we compute the initial value for this static.
if tcx.is_foreign_item(def_id) {
throw_unsup_format!("foreign thread-local statics are not supported");
}
- // Invoke the `const_eval_raw` query.
- let instance = Instance::mono(tcx.tcx, def_id);
- let gid = GlobalId { instance, promoted: None };
- let raw_const =
- tcx.const_eval_raw(ty::ParamEnv::reveal_all().and(gid)).map_err(|err| {
- // no need to report anything, the const_eval call takes care of that
- // for statics
- assert!(tcx.is_static(def_id));
- err
- })?;
- let id = raw_const.alloc_id;
- // Extract the allocation from the query result.
- let mut alloc_map = tcx.alloc_map.lock();
- let allocation = alloc_map.unwrap_memory(id);
- // Create a new allocation id for the same allocation in this hacky
- // way. Internally, `alloc_map` deduplicates allocations, but this
- // is fine because Miri will make a copy before a first mutable
- // access.
- let new_alloc_id = alloc_map.create_memory_alloc(allocation);
+ let allocation = tcx.eval_static_initializer(def_id)?;
+ // Create a fresh allocation with this content.
+ let new_alloc_id =
+ this.memory.allocate_with(allocation.clone(), MiriMemoryKind::Tls.into()).alloc_id;
this.machine.threads.set_thread_local_alloc_id(def_id, new_alloc_id);
Ok(new_alloc_id)
}
}
#[inline]
- fn create_thread(&mut self) -> InterpResult<'tcx, ThreadId> {
+ fn create_thread(&mut self) -> ThreadId {
let this = self.eval_context_mut();
- Ok(this.machine.threads.create_thread())
+ let id = this.machine.threads.create_thread();
+ if let Some(data_race) = &this.memory.extra.data_race {
+ data_race.thread_created(id);
+ }
+ id
}
#[inline]
#[inline]
fn join_thread(&mut self, joined_thread_id: ThreadId) -> InterpResult<'tcx> {
let this = self.eval_context_mut();
- this.machine.threads.join_thread(joined_thread_id)
+ let data_race = &this.memory.extra.data_race;
+ this.machine.threads.join_thread(joined_thread_id, data_race)?;
+ Ok(())
+ }
+
+ #[inline]
+ fn set_active_thread(&mut self, thread_id: ThreadId) -> ThreadId {
+ let this = self.eval_context_mut();
+ if let Some(data_race) = &this.memory.extra.data_race {
+ data_race.thread_set_active(thread_id);
+ }
+ this.machine.threads.set_active_thread_id(thread_id)
+ }
+
+ #[inline]
+ fn get_active_thread(&self) -> ThreadId {
+ let this = self.eval_context_ref();
+ this.machine.threads.get_active_thread_id()
}
#[inline]
- fn set_active_thread(&mut self, thread_id: ThreadId) -> InterpResult<'tcx, ThreadId> {
+ fn active_thread_mut(&mut self) -> &mut Thread<'mir, 'tcx> {
let this = self.eval_context_mut();
- Ok(this.machine.threads.set_active_thread_id(thread_id))
+ this.machine.threads.active_thread_mut()
}
#[inline]
- fn get_active_thread(&self) -> InterpResult<'tcx, ThreadId> {
+ fn active_thread_ref(&self) -> &Thread<'mir, 'tcx> {
let this = self.eval_context_ref();
- Ok(this.machine.threads.get_active_thread_id())
+ this.machine.threads.active_thread_ref()
}
#[inline]
- fn get_total_thread_count(&self) -> InterpResult<'tcx, usize> {
+ fn get_total_thread_count(&self) -> usize {
let this = self.eval_context_ref();
- Ok(this.machine.threads.get_total_thread_count())
+ this.machine.threads.get_total_thread_count()
}
#[inline]
- fn has_terminated(&self, thread_id: ThreadId) -> InterpResult<'tcx, bool> {
+ fn has_terminated(&self, thread_id: ThreadId) -> bool {
let this = self.eval_context_ref();
- Ok(this.machine.threads.has_terminated(thread_id))
+ this.machine.threads.has_terminated(thread_id)
}
#[inline]
- fn enable_thread(&mut self, thread_id: ThreadId) -> InterpResult<'tcx> {
+ fn enable_thread(&mut self, thread_id: ThreadId) {
let this = self.eval_context_mut();
this.machine.threads.enable_thread(thread_id);
- Ok(())
}
#[inline]
}
#[inline]
- fn set_active_thread_name(&mut self, new_thread_name: Vec<u8>) -> InterpResult<'tcx, ()> {
+ fn set_active_thread_name(&mut self, new_thread_name: Vec<u8>) {
let this = self.eval_context_mut();
- Ok(this.machine.threads.set_thread_name(new_thread_name))
+ if let Some(data_race) = &this.memory.extra.data_race {
+ if let Ok(string) = String::from_utf8(new_thread_name.clone()) {
+ data_race.thread_set_name(this.machine.threads.active_thread, string);
+ }
+ }
+ this.machine.threads.set_thread_name(new_thread_name);
}
#[inline]
- fn get_active_thread_name<'c>(&'c self) -> InterpResult<'tcx, &'c [u8]>
+ fn get_active_thread_name<'c>(&'c self) -> &'c [u8]
where
'mir: 'c,
{
let this = self.eval_context_ref();
- Ok(this.machine.threads.get_thread_name())
+ this.machine.threads.get_thread_name()
}
#[inline]
- fn create_blockset(&mut self) -> InterpResult<'tcx, BlockSetId> {
+ fn block_thread(&mut self, thread: ThreadId) {
let this = self.eval_context_mut();
- Ok(this.machine.threads.create_blockset())
+ this.machine.threads.block_thread(thread);
}
#[inline]
- fn block_active_thread(&mut self, set: BlockSetId) -> InterpResult<'tcx> {
+ fn unblock_thread(&mut self, thread: ThreadId) {
let this = self.eval_context_mut();
- Ok(this.machine.threads.block_active_thread(set))
+ this.machine.threads.unblock_thread(thread);
}
#[inline]
- fn unblock_some_thread(&mut self, set: BlockSetId) -> InterpResult<'tcx, Option<ThreadId>> {
+ fn yield_active_thread(&mut self) {
let this = self.eval_context_mut();
- Ok(this.machine.threads.unblock_some_thread(set))
+ this.machine.threads.yield_active_thread();
}
#[inline]
- fn yield_active_thread(&mut self) -> InterpResult<'tcx> {
+ fn register_timeout_callback(
+ &mut self,
+ thread: ThreadId,
+ call_time: Time,
+ callback: TimeoutCallback<'mir, 'tcx>,
+ ) {
let this = self.eval_context_mut();
- this.machine.threads.yield_active_thread();
+ this.machine.threads.register_timeout_callback(thread, call_time, callback);
+ }
+
+ #[inline]
+ fn unregister_timeout_callback_if_exists(&mut self, thread: ThreadId) {
+ let this = self.eval_context_mut();
+ this.machine.threads.unregister_timeout_callback_if_exists(thread);
+ }
+
+ /// Execute a timeout callback on the callback's thread.
+ #[inline]
+ fn run_timeout_callback(&mut self) -> InterpResult<'tcx> {
+ let this = self.eval_context_mut();
+ let (thread, callback) =
+ if let Some((thread, callback)) = this.machine.threads.get_ready_callback() {
+ (thread, callback)
+ } else {
+ // get_ready_callback can return None if the computer's clock
+ // was shifted after calling the scheduler and before the call
+ // to get_ready_callback (see issue
+ // https://github.com/rust-lang/miri/issues/1763). In this case,
+ // just do nothing, which effectively just returns to the
+ // scheduler.
+ return Ok(());
+ };
+ // This back-and-forth with `set_active_thread` is here because of two
+ // design decisions:
+ // 1. Make the caller and not the callback responsible for changing
+ // thread.
+ // 2. Make the scheduler the only place that can change the active
+ // thread.
+ let old_thread = this.set_active_thread(thread);
+ callback(this)?;
+ this.set_active_thread(old_thread);
Ok(())
}
#[inline]
fn schedule(&mut self) -> InterpResult<'tcx, SchedulingAction> {
let this = self.eval_context_mut();
- this.machine.threads.schedule()
+ let data_race = &this.memory.extra.data_race;
+ this.machine.threads.schedule(data_race)
+ }
+
+ /// Handles thread termination of the active thread: wakes up threads joining on this one,
+ /// and deallocated thread-local statics.
+ ///
+ /// This is called from `tls.rs` after handling the TLS dtors.
+ #[inline]
+ fn thread_terminated(&mut self) -> InterpResult<'tcx> {
+ let this = self.eval_context_mut();
+ let data_race = &this.memory.extra.data_race;
+ for alloc_id in this.machine.threads.thread_terminated(data_race) {
+ let ptr = this.memory.global_base_pointer(alloc_id.into())?;
+ this.memory.deallocate(ptr, None, MiriMemoryKind::Tls.into())?;
+ }
+ Ok(())
}
}
projects / rust.git / blobdiff