use std::cell::RefCell;
use std::collections::hash_map::Entry;
use std::convert::TryFrom;
-use std::rc::Rc;
use std::num::TryFromIntError;
+use std::rc::Rc;
use std::time::{Duration, Instant, SystemTime};
use log::trace;
/// 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>"
- }
+ 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 {
- write!(f, "{}({:?}, {:?})", String::from_utf8_lossy(self.thread_name()), self.state, self.join_status)
+ write!(
+ f,
+ "{}({:?}, {:?})",
+ String::from_utf8_lossy(self.thread_name()),
+ self.state,
+ self.join_status
+ )
}
}
}
/// Mark that the active thread tries to join the thread with `joined_thread_id`.
- fn join_thread(&mut self, joined_thread_id: ThreadId, data_race: &Option<Rc<data_race::GlobalState>>) -> 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");
}
/// 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> {
+ 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();
/// 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<Rc<data_race::GlobalState>>) -> 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() {
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);
}
- // At least for `pthread_cond_timedwait` we need to report timeout when
- // the function is called already after the specified time even if a
- // signal is received before the thread gets scheduled. Therefore, we
- // need to schedule all timeout callbacks before we continue regular
- // execution.
- //
- // Documentation:
- // 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.
+ // 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 {
pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
/// Get a thread-specific allocation id for the given thread-local static.
/// If needed, allocate a new one.
- fn get_or_create_thread_local_alloc_id(&mut self, def_id: DefId) -> InterpResult<'tcx, AllocId> {
+ 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) {
}
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;
+ 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)
}
let this = self.eval_context_mut();
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
- );
+ data_race.thread_set_name(this.machine.threads.active_thread, string);
}
}
this.machine.threads.set_thread_name(new_thread_name);
fn run_timeout_callback(&mut self) -> InterpResult<'tcx> {
let this = self.eval_context_mut();
let (thread, callback) =
- this.machine.threads.get_ready_callback().expect("no callback found");
+ 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
projects / rust.git / blobdiff