Merge pull request rust-lang#4672 from RalfJung/sync-objs

Make pthread and other "native" synchronization objects more resilient

Author: RalfJung

src/tools/miri/src/borrow_tracker/mod.rs

@@ -11,6 +11,22 @@ use crate::*;
 pub mod stacked_borrows;
 pub mod tree_borrows;
 
+/// Indicates which kind of access is being performed.
+#[derive(Copy, Clone, Hash, PartialEq, Eq, Debug)]
+pub enum AccessKind {
+    Read,
+    Write,
+}
+
+impl fmt::Display for AccessKind {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            AccessKind::Read => write!(f, "read access"),
+            AccessKind::Write => write!(f, "write access"),
+        }
+    }
+}
+
 /// Tracking pointer provenance
 #[derive(Copy, Clone, Hash, PartialEq, Eq, PartialOrd, Ord)]
 pub struct BorTag(NonZero<u64>);
@@ -115,15 +131,6 @@ impl VisitProvenance for GlobalStateInner {
 /// We need interior mutable access to the global state.
 pub type GlobalState = RefCell<GlobalStateInner>;
 
-impl fmt::Display for AccessKind {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            AccessKind::Read => write!(f, "read access"),
-            AccessKind::Write => write!(f, "write access"),
-        }
-    }
-}
-
 /// Policy on whether to recurse into fields to retag
 #[derive(Copy, Clone, Debug)]
 pub enum RetagFields {

src/tools/miri/src/borrow_tracker/stacked_borrows/diagnostics.rs

@@ -5,7 +5,7 @@ use rustc_data_structures::fx::FxHashSet;
 use rustc_span::{Span, SpanData};
 use smallvec::SmallVec;
 
-use crate::borrow_tracker::{GlobalStateInner, ProtectorKind};
+use crate::borrow_tracker::{AccessKind, GlobalStateInner, ProtectorKind};
 use crate::*;
 
 /// Error reporting

src/tools/miri/src/borrow_tracker/stacked_borrows/mod.rs

@@ -21,7 +21,7 @@ pub use self::stack::Stack;
 use crate::borrow_tracker::stacked_borrows::diagnostics::{
     AllocHistory, DiagnosticCx, DiagnosticCxBuilder,
 };
-use crate::borrow_tracker::{GlobalStateInner, ProtectorKind};
+use crate::borrow_tracker::{AccessKind, GlobalStateInner, ProtectorKind};
 use crate::concurrency::data_race::{NaReadType, NaWriteType};
 use crate::*;
 

src/tools/miri/src/borrow_tracker/tree_borrows/diagnostics.rs

@@ -4,10 +4,10 @@ use std::ops::Range;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_span::{Span, SpanData};
 
-use crate::borrow_tracker::ProtectorKind;
 use crate::borrow_tracker::tree_borrows::perms::{PermTransition, Permission};
 use crate::borrow_tracker::tree_borrows::tree::LocationState;
 use crate::borrow_tracker::tree_borrows::unimap::UniIndex;
+use crate::borrow_tracker::{AccessKind, ProtectorKind};
 use crate::*;
 
 /// Cause of an access: either a real access or one

src/tools/miri/src/borrow_tracker/tree_borrows/mod.rs

@@ -5,7 +5,7 @@ use rustc_middle::ty::{self, Ty};
 
 use self::foreign_access_skipping::IdempotentForeignAccess;
 use self::tree::LocationState;
-use crate::borrow_tracker::{GlobalState, GlobalStateInner, ProtectorKind};
+use crate::borrow_tracker::{AccessKind, GlobalState, GlobalStateInner, ProtectorKind};
 use crate::concurrency::data_race::NaReadType;
 use crate::*;
 

src/tools/miri/src/borrow_tracker/tree_borrows/perms.rs

@@ -1,7 +1,7 @@
 use std::cmp::{Ordering, PartialOrd};
 use std::fmt;
 
-use crate::AccessKind;
+use crate::borrow_tracker::AccessKind;
 use crate::borrow_tracker::tree_borrows::diagnostics::TransitionError;
 use crate::borrow_tracker::tree_borrows::tree::AccessRelatedness;
 

src/tools/miri/src/borrow_tracker/tree_borrows/tree.rs

@@ -25,7 +25,7 @@ use crate::borrow_tracker::tree_borrows::diagnostics::{
 use crate::borrow_tracker::tree_borrows::foreign_access_skipping::IdempotentForeignAccess;
 use crate::borrow_tracker::tree_borrows::perms::PermTransition;
 use crate::borrow_tracker::tree_borrows::unimap::{UniIndex, UniKeyMap, UniValMap};
-use crate::borrow_tracker::{GlobalState, ProtectorKind};
+use crate::borrow_tracker::{AccessKind, GlobalState, ProtectorKind};
 use crate::*;
 
 mod tests;

src/tools/miri/src/concurrency/init_once.rs

@@ -57,6 +57,10 @@ impl InitOnceRef {
     pub fn begin(&self) {
         self.0.borrow_mut().begin();
     }
+
+    pub fn queue_is_empty(&self) -> bool {
+        self.0.borrow().waiters.is_empty()
+    }
 }
 
 impl VisitProvenance for InitOnceRef {