use rustc_index::vec::{Idx, IndexVec};
use rustc_middle::mir::Mutability;
+use crate::concurrency::data_race;
use crate::sync::SynchronizationState;
use crate::*;
}
impl ThreadId {
- pub fn to_u32_scalar(&self) -> Scalar<Tag> {
+ pub fn to_u32_scalar(&self) -> Scalar<Provenance> {
Scalar::from_u32(self.0)
}
}
thread_name: Option<Vec<u8>>,
/// The virtual call stack.
- stack: Vec<Frame<'mir, 'tcx, Tag, FrameData<'tcx>>>,
+ stack: Vec<Frame<'mir, 'tcx, Provenance, 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>>,
+ pub(crate) panic_payload: Option<Scalar<Provenance>>,
/// Last OS error location in memory. It is a 32-bit integer.
- pub(crate) last_error: Option<MPlaceTy<'tcx, Tag>>,
+ pub(crate) last_error: Option<MPlaceTy<'tcx, Provenance>>,
}
impl<'mir, 'tcx> Thread<'mir, 'tcx> {
}
}
+impl<'mir, 'tcx> Thread<'mir, 'tcx> {
+ fn new(name: &str) -> Self {
+ let mut thread = Thread::default();
+ thread.thread_name = Some(Vec::from(name.as_bytes()));
+ thread
+ }
+}
+
/// A specific moment in time.
#[derive(Debug)]
pub enum Time {
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), Pointer<Tag>>>,
+ thread_local_alloc_ids: RefCell<FxHashMap<(DefId, ThreadId), Pointer<Provenance>>>,
/// A flag that indicates that we should change the active thread.
yield_active_thread: bool,
/// Callbacks that are called once the specified time passes.
fn default() -> Self {
let mut threads = IndexVec::new();
// Create the main thread and add it to the list of threads.
- let mut main_thread = Thread::default();
+ let mut main_thread = Thread::new("main");
// The main thread can *not* be joined on.
main_thread.join_status = ThreadJoinStatus::Detached;
threads.push(main_thread);
impl<'mir, 'tcx: 'mir> ThreadManager<'mir, 'tcx> {
/// Check if we have an allocation for the given thread local static for the
/// active thread.
- fn get_thread_local_alloc_id(&self, def_id: DefId) -> Option<Pointer<Tag>> {
+ fn get_thread_local_alloc_id(&self, def_id: DefId) -> Option<Pointer<Provenance>> {
self.thread_local_alloc_ids.borrow().get(&(def_id, self.active_thread)).cloned()
}
/// static for the active thread.
///
/// Panics if a thread local is initialized twice for the same thread.
- fn set_thread_local_alloc(&self, def_id: DefId, ptr: Pointer<Tag>) {
+ fn set_thread_local_alloc(&self, def_id: DefId, ptr: Pointer<Provenance>) {
self.thread_local_alloc_ids
.borrow_mut()
.try_insert((def_id, self.active_thread), ptr)
}
/// 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, Provenance, FrameData<'tcx>>] {
&self.threads[self.active_thread].stack
}
/// Mutably borrow the stack of the active thread.
- fn active_thread_stack_mut(&mut self) -> &mut Vec<Frame<'mir, 'tcx, Tag, FrameData<'tcx>>> {
+ fn active_thread_stack_mut(
+ &mut self,
+ ) -> &mut Vec<Frame<'mir, 'tcx, Provenance, FrameData<'tcx>>> {
&mut self.threads[self.active_thread].stack
}
+ pub fn all_stacks(
+ &self,
+ ) -> impl Iterator<Item = &[Frame<'mir, 'tcx, Provenance, FrameData<'tcx>>]> {
+ self.threads.iter().map(|t| &t.stack[..])
+ }
+
/// Create a new thread and returns its id.
fn create_thread(&mut self) -> ThreadId {
let new_thread_id = ThreadId::new(self.threads.len());
}
/// Get the id of the currently active thread.
- fn get_active_thread_id(&self) -> ThreadId {
+ pub fn get_active_thread_id(&self) -> ThreadId {
self.active_thread
}
/// Get the total number of threads that were ever spawn by this program.
- fn get_total_thread_count(&self) -> usize {
+ pub fn get_total_thread_count(&self) -> usize {
self.threads.len()
}
+ /// Get the total of threads that are currently live, i.e., not yet terminated.
+ /// (They might be blocked.)
+ pub fn get_live_thread_count(&self) -> usize {
+ self.threads.iter().filter(|t| !matches!(t.state, ThreadState::Terminated)).count()
+ }
+
/// Has the given thread terminated?
fn has_terminated(&self, thread_id: ThreadId) -> bool {
self.threads[thread_id].state == ThreadState::Terminated
} 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);
+ data_race.thread_joined(self, self.active_thread, joined_thread_id);
}
}
Ok(())
}
/// Set the name of the active thread.
- fn set_thread_name(&mut self, new_thread_name: Vec<u8>) {
+ fn set_active_thread_name(&mut self, new_thread_name: Vec<u8>) {
self.active_thread_mut().thread_name = Some(new_thread_name);
}
/// Get the name of the active thread.
- fn get_thread_name(&self) -> &[u8] {
+ pub fn get_active_thread_name(&self) -> &[u8] {
self.active_thread_ref().thread_name()
}
+ /// Get the name of the given thread.
+ pub fn get_thread_name(&self, thread: ThreadId) -> &[u8] {
+ self.threads[thread].thread_name()
+ }
+
/// Put the thread into the blocked state.
fn block_thread(&mut self, thread: ThreadId) {
let state = &mut self.threads[thread].state;
fn thread_terminated(
&mut self,
mut data_race: Option<&mut data_race::GlobalState>,
- ) -> Vec<Pointer<Tag>> {
+ ) -> Vec<Pointer<Provenance>> {
let mut free_tls_statics = Vec::new();
{
let mut thread_local_statics = self.thread_local_alloc_ids.borrow_mut();
false
});
}
- // Set the thread into a terminated state in the data-race detector
+ // Set the thread into a terminated state in the data-race detector.
if let Some(ref mut data_race) = data_race {
- data_race.thread_terminated();
+ data_race.thread_terminated(self);
}
// Check if we need to unblock any threads.
+ let mut joined_threads = vec![]; // store which threads joined, we'll need it
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(ref mut data_race) = data_race {
- data_race.thread_joined(i, self.active_thread);
+ if data_race.is_some() {
+ joined_threads.push(i);
}
trace!("unblocking {:?} because {:?} terminated", i, self.active_thread);
thread.state = ThreadState::Enabled;
}
}
+ for &i in &joined_threads {
+ data_race.as_mut().unwrap().thread_joined(self, i, self.active_thread);
+ }
free_tls_statics
}
/// 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,
- data_race: &Option<data_race::GlobalState>,
- ) -> InterpResult<'tcx, SchedulingAction> {
+ fn schedule(&mut self) -> 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).
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;
+ break;
}
}
self.yield_active_thread = false;
fn get_or_create_thread_local_alloc(
&mut self,
def_id: DefId,
- ) -> InterpResult<'tcx, Pointer<Tag>> {
+ ) -> InterpResult<'tcx, Pointer<Provenance>> {
let this = self.eval_context_mut();
let tcx = this.tcx;
if let Some(old_alloc) = this.machine.threads.get_thread_local_alloc_id(def_id) {
// 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.allocate_raw_ptr(allocation, 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)
}
let this = self.eval_context_mut();
let id = this.machine.threads.create_thread();
if let Some(data_race) = &mut this.machine.data_race {
- data_race.thread_created(id);
+ data_race.thread_created(&this.machine.threads, id);
}
id
}
#[inline]
fn set_active_thread(&mut self, thread_id: ThreadId) -> ThreadId {
let this = self.eval_context_mut();
- 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 active_thread_stack(&self) -> &[Frame<'mir, 'tcx, Tag, FrameData<'tcx>>] {
+ fn active_thread_stack(&self) -> &[Frame<'mir, 'tcx, Provenance, FrameData<'tcx>>] {
let this = self.eval_context_ref();
this.machine.threads.active_thread_stack()
}
#[inline]
- fn active_thread_stack_mut(&mut self) -> &mut Vec<Frame<'mir, 'tcx, Tag, FrameData<'tcx>>> {
+ fn active_thread_stack_mut(
+ &mut self,
+ ) -> &mut Vec<Frame<'mir, 'tcx, Provenance, FrameData<'tcx>>> {
let this = self.eval_context_mut();
this.machine.threads.active_thread_stack_mut()
}
#[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.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.set_thread_name(new_thread_name);
+ this.machine.threads.set_active_thread_name(new_thread_name);
}
#[inline]
'mir: 'c,
{
let this = self.eval_context_ref();
- this.machine.threads.get_thread_name()
+ this.machine.threads.get_active_thread_name()
}
#[inline]
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.machine.data_race;
- this.machine.threads.schedule(data_race)
+ this.machine.threads.schedule()
}
/// Handles thread termination of the active thread: wakes up threads joining on this one,
projects / rust.git / blobdiff