use std::cell::RefCell;
use std::collections::hash_map::Entry;
-use std::convert::TryFrom;
use std::num::TryFromIntError;
use std::time::{Duration, Instant, SystemTime};
use rustc_data_structures::fx::FxHashMap;
use rustc_hir::def_id::DefId;
use rustc_index::vec::{Idx, IndexVec};
+use rustc_middle::mir::Mutability;
+use crate::concurrency::data_race;
use crate::sync::SynchronizationState;
use crate::*;
impl TryFrom<u64> for ThreadId {
type Error = TryFromIntError;
fn try_from(id: u64) -> Result<Self, Self::Error> {
- u32::try_from(id).map(|id_u32| Self(id_u32))
+ u32::try_from(id).map(Self)
}
}
}
impl ThreadId {
- pub fn to_u32_scalar<'tcx>(&self) -> Scalar<Tag> {
- Scalar::from_u32(u32::try_from(self.0).unwrap())
+ pub fn to_u32_scalar(&self) -> Scalar<Tag> {
+ Scalar::from_u32(self.0)
}
}
threads.push(main_thread);
Self {
active_thread: ThreadId::new(0),
- threads: threads,
+ threads,
sync: SynchronizationState::default(),
thread_local_alloc_ids: Default::default(),
yield_active_thread: false,
}
/// Borrow the stack of the active thread.
- fn active_thread_stack(&self) -> &[Frame<'mir, 'tcx, Tag, FrameData<'tcx>>] {
+ pub fn active_thread_stack(&self) -> &[Frame<'mir, 'tcx, Tag, FrameData<'tcx>>] {
&self.threads[self.active_thread].stack
}
// 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;
+ false
});
}
// Set the thread into a terminated state in the data-race detector
thread.state = ThreadState::Enabled;
}
}
- return free_tls_statics;
+ free_tls_statics
}
/// Decide which action to take next and on which thread.
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() {
+ // The active thread blocked or yielded. So we go search for another enabled thread.
+ // Curcially, we start searching at the current active thread ID, rather than at 0, since we
+ // want to avoid always scheduling threads 0 and 1 without ever making progress in thread 2.
+ //
+ // `skip(N)` means we start iterating at thread N, so we skip 1 more to start just *after*
+ // the active thread. Then after that we look at `take(N)`, i.e., the threads *before* the
+ // active thread.
+ let threads = self
+ .threads
+ .iter_enumerated()
+ .skip(self.active_thread.index() + 1)
+ .chain(self.threads.iter_enumerated().take(self.active_thread.index()));
+ for (id, thread) in threads {
+ debug_assert_ne!(self.active_thread, id);
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;
+ self.active_thread = id;
+ if let Some(data_race) = data_race {
+ data_race.thread_set_active(self.active_thread);
}
+ break;
}
}
self.yield_active_thread = false;
throw_unsup_format!("foreign thread-local statics are not supported");
}
let allocation = tcx.eval_static_initializer(def_id)?;
+ let mut allocation = allocation.inner().clone();
+ // This allocation will be deallocated when the thread dies, so it is not in read-only memory.
+ allocation.mutability = Mutability::Mut;
// Create a fresh allocation with this content.
- let new_alloc =
- this.memory.allocate_with(allocation.inner().clone(), MiriMemoryKind::Tls.into());
+ let new_alloc = this.allocate_raw_ptr(allocation, MiriMemoryKind::Tls.into())?;
this.machine.threads.set_thread_local_alloc(def_id, new_alloc);
Ok(new_alloc)
}
fn create_thread(&mut self) -> ThreadId {
let this = self.eval_context_mut();
let id = this.machine.threads.create_thread();
- if let Some(data_race) = &mut this.memory.extra.data_race {
+ if let Some(data_race) = &mut this.machine.data_race {
data_race.thread_created(id);
}
id
#[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, this.memory.extra.data_race.as_mut())?;
+ this.machine.threads.join_thread(joined_thread_id, this.machine.data_race.as_mut())?;
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 {
+ if let Some(data_race) = &this.machine.data_race {
data_race.thread_set_active(thread_id);
}
this.machine.threads.set_active_thread_id(thread_id)
#[inline]
fn set_active_thread_name(&mut self, new_thread_name: Vec<u8>) {
let this = self.eval_context_mut();
- if let Some(data_race) = &mut this.memory.extra.data_race {
+ if let Some(data_race) = &mut this.machine.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.yield_active_thread();
}
+ #[inline]
+ fn maybe_preempt_active_thread(&mut self) {
+ use rand::Rng as _;
+
+ let this = self.eval_context_mut();
+ if this.machine.rng.get_mut().gen_bool(this.machine.preemption_rate) {
+ this.yield_active_thread();
+ }
+ }
+
#[inline]
fn register_timeout_callback(
&mut self,
#[inline]
fn schedule(&mut self) -> InterpResult<'tcx, SchedulingAction> {
let this = self.eval_context_mut();
- let data_race = &this.memory.extra.data_race;
+ let data_race = &this.machine.data_race;
this.machine.threads.schedule(data_race)
}
#[inline]
fn thread_terminated(&mut self) -> InterpResult<'tcx> {
let this = self.eval_context_mut();
- for ptr in this.machine.threads.thread_terminated(this.memory.extra.data_race.as_mut()) {
- this.memory.deallocate(ptr.into(), None, MiriMemoryKind::Tls.into())?;
+ for ptr in this.machine.threads.thread_terminated(this.machine.data_race.as_mut()) {
+ this.deallocate_ptr(ptr.into(), None, MiriMemoryKind::Tls.into())?;
}
Ok(())
}
projects / rust.git / blobdiff