//! order exists in which all threads observe all modifications in the same
//! order (see Sequentially-consistent ordering below) "
//! So in the absence of weak memory effects a seq-cst load & a seq-cst store is identical
-//! to a acquire load and a release store given the global sequentially consistent order
+//! to an acquire load and a release store given the global sequentially consistent order
//! of the schedule.
//!
//! The timestamps used in the data-race detector assign each sequence of non-atomic operations
cell::{Cell, Ref, RefCell, RefMut},
fmt::Debug,
mem,
- rc::Rc,
};
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use rustc_target::abi::Size;
use crate::{
- ImmTy, Immediate, InterpResult, MPlaceTy, MemPlaceMeta, MemoryKind, MiriEvalContext,
- MiriEvalContextExt, MiriMemoryKind, OpTy, Pointer, RangeMap, Scalar, ScalarMaybeUninit, Tag,
- ThreadId, VClock, VTimestamp, VectorIdx,
+ AllocId, AllocRange, ImmTy, Immediate, InterpResult, MPlaceTy, MemPlaceMeta, MemoryKind,
+ MiriEvalContext, MiriEvalContextExt, MiriMemoryKind, OpTy, Pointer, RangeMap, Scalar,
+ ScalarMaybeUninit, Tag, ThreadId, VClock, VTimestamp, VectorIdx,
};
pub type AllocExtra = VClockAlloc;
-pub type MemoryExtra = Rc<GlobalState>;
+pub type MemoryExtra = GlobalState;
/// Valid atomic read-write operations, alias of atomic::Ordering (not non-exhaustive).
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
self.fence_release.clone_from(&self.clock);
}
- /// Apply the effects of a acquire fence to this
+ /// Apply the effects of an acquire fence to this
/// set of thread vector clocks.
#[inline]
fn apply_acquire_fence(&mut self) {
) -> InterpResult<'tcx, ScalarMaybeUninit<Tag>> {
let this = self.eval_context_ref();
let scalar = this.allow_data_races_ref(move |this| this.read_scalar(&place.into()))?;
- self.validate_atomic_load(place, atomic)?;
+ this.validate_atomic_load(place, atomic)?;
Ok(scalar)
}
) -> InterpResult<'tcx> {
let this = self.eval_context_mut();
this.allow_data_races_mut(move |this| this.write_scalar(val, &(*dest).into()))?;
- self.validate_atomic_store(dest, atomic)
+ this.validate_atomic_store(dest, atomic)
}
- /// Perform a atomic operation on a memory location.
+ /// Perform an atomic operation on a memory location.
fn atomic_op_immediate(
&mut self,
place: &MPlaceTy<'tcx, Tag>,
if lt { &rhs } else { &old }
};
- this.allow_data_races_mut(|this| this.write_immediate_to_mplace(**new_val, place))?;
+ this.allow_data_races_mut(|this| this.write_immediate(**new_val, &(*place).into()))?;
this.validate_atomic_rmw(&place, atomic)?;
// of the time, based on `rate`.
let rate = this.memory.extra.cmpxchg_weak_failure_rate;
let cmpxchg_success = eq.to_bool()?
- && (!can_fail_spuriously || this.memory.extra.rng.borrow_mut().gen::<f64>() < rate);
+ && (!can_fail_spuriously || this.memory.extra.rng.get_mut().gen::<f64>() < rate);
let res = Immediate::ScalarPair(
old.to_scalar_or_uninit(),
Scalar::from_bool(cmpxchg_success).into(),
place: &MPlaceTy<'tcx, Tag>,
atomic: AtomicWriteOp,
) -> InterpResult<'tcx> {
- let this = self.eval_context_ref();
+ let this = self.eval_context_mut();
this.validate_atomic_op(
place,
atomic,
use AtomicRwOp::*;
let acquire = matches!(atomic, Acquire | AcqRel | SeqCst);
let release = matches!(atomic, Release | AcqRel | SeqCst);
- let this = self.eval_context_ref();
+ let this = self.eval_context_mut();
this.validate_atomic_op(place, atomic, "Atomic RMW", move |memory, clocks, index, _| {
if acquire {
memory.load_acquire(clocks, index)?;
/// Update the data-race detector for an atomic fence on the current thread.
fn validate_atomic_fence(&mut self, atomic: AtomicFenceOp) -> InterpResult<'tcx> {
let this = self.eval_context_mut();
- if let Some(data_race) = &this.memory.extra.data_race {
+ if let Some(data_race) = &mut this.memory.extra.data_race {
data_race.maybe_perform_sync_operation(move |index, mut clocks| {
log::trace!("Atomic fence on {:?} with ordering {:?}", index, atomic);
// Apply data-race detection for the current fences
- // this treats AcqRel and SeqCst as the same as a acquire
+ // this treats AcqRel and SeqCst as the same as an acquire
// and release fence applied in the same timestamp.
if atomic != AtomicFenceOp::Release {
// Either Acquire | AcqRel | SeqCst
Ok(())
}
}
-
- fn reset_vector_clocks(&mut self, ptr: Pointer<Tag>, size: Size) -> InterpResult<'tcx> {
- let this = self.eval_context_mut();
- if let Some(data_race) = &mut this.memory.extra.data_race {
- if data_race.multi_threaded.get() {
- let alloc_meta =
- this.memory.get_raw_mut(ptr.alloc_id)?.extra.data_race.as_mut().unwrap();
- alloc_meta.reset_clocks(ptr.offset, size);
- }
- }
- Ok(())
- }
}
/// Vector clock metadata for a logical memory allocation.
pub struct VClockAlloc {
/// Assigning each byte a MemoryCellClocks.
alloc_ranges: RefCell<RangeMap<MemoryCellClocks>>,
-
- /// Pointer to global state.
- global: MemoryExtra,
}
impl VClockAlloc {
| MiriMemoryKind::ExternStatic
| MiriMemoryKind::Tls,
)
- | MemoryKind::CallerLocation
- | MemoryKind::Vtable => (0, VectorIdx::MAX_INDEX),
+ | MemoryKind::CallerLocation => (0, VectorIdx::MAX_INDEX),
};
VClockAlloc {
- global: Rc::clone(global),
alloc_ranges: RefCell::new(RangeMap::new(
len,
MemoryCellClocks::new(alloc_timestamp, alloc_index),
}
}
- fn reset_clocks(&mut self, offset: Size, len: Size) {
- let mut alloc_ranges = self.alloc_ranges.borrow_mut();
- for (_, range) in alloc_ranges.iter_mut(offset, len) {
- // Reset the portion of the range
- *range = MemoryCellClocks::new(0, VectorIdx::MAX_INDEX);
- }
- }
-
// Find an index, if one exists where the value
// in `l` is greater than the value in `r`.
fn find_gt_index(l: &VClock, r: &VClock) -> Option<VectorIdx> {
range: &MemoryCellClocks,
action: &str,
is_atomic: bool,
- pointer: Pointer<Tag>,
- len: Size,
+ ptr_dbg: Pointer<AllocId>,
) -> InterpResult<'tcx> {
let (current_index, current_clocks) = global.current_thread_state();
let write_clock;
// Throw the data-race detection.
throw_ub_format!(
- "Data race detected between {} on {} and {} on {}, memory({:?},offset={},size={})\
- \n(current vector clock = {:?}, conflicting timestamp = {:?})",
+ "Data race detected between {} on {} and {} on {} at {:?} (current vector clock = {:?}, conflicting timestamp = {:?})",
action,
current_thread_info,
other_action,
other_thread_info,
- pointer.alloc_id,
- pointer.offset.bytes(),
- len.bytes(),
+ ptr_dbg,
current_clocks.clock,
other_clock
)
/// being created or if it is temporarily disabled during a racy read or write
/// operation for which data-race detection is handled separately, for example
/// atomic read operations.
- pub fn read<'tcx>(&self, pointer: Pointer<Tag>, len: Size) -> InterpResult<'tcx> {
- if self.global.multi_threaded.get() {
- let (index, clocks) = self.global.current_thread_state();
+ pub fn read<'tcx>(
+ &self,
+ alloc_id: AllocId,
+ range: AllocRange,
+ global: &GlobalState,
+ ) -> InterpResult<'tcx> {
+ if global.multi_threaded.get() {
+ let (index, clocks) = global.current_thread_state();
let mut alloc_ranges = self.alloc_ranges.borrow_mut();
- for (_, range) in alloc_ranges.iter_mut(pointer.offset, len) {
+ for (offset, range) in alloc_ranges.iter_mut(range.start, range.size) {
if let Err(DataRace) = range.read_race_detect(&*clocks, index) {
// Report data-race.
return Self::report_data_race(
- &self.global,
+ global,
range,
"Read",
false,
- pointer,
- len,
+ Pointer::new(alloc_id, offset),
);
}
}
// Shared code for detecting data-races on unique access to a section of memory
fn unique_access<'tcx>(
&mut self,
- pointer: Pointer<Tag>,
- len: Size,
+ alloc_id: AllocId,
+ range: AllocRange,
write_type: WriteType,
+ global: &mut GlobalState,
) -> InterpResult<'tcx> {
- if self.global.multi_threaded.get() {
- let (index, clocks) = self.global.current_thread_state();
- for (_, range) in self.alloc_ranges.get_mut().iter_mut(pointer.offset, len) {
+ if global.multi_threaded.get() {
+ let (index, clocks) = global.current_thread_state();
+ for (offset, range) in self.alloc_ranges.get_mut().iter_mut(range.start, range.size) {
if let Err(DataRace) = range.write_race_detect(&*clocks, index, write_type) {
// Report data-race
return Self::report_data_race(
- &self.global,
+ global,
range,
write_type.get_descriptor(),
false,
- pointer,
- len,
+ Pointer::new(alloc_id, offset),
);
}
}
/// data-race threads if `multi-threaded` is false, either due to no threads
/// being created or if it is temporarily disabled during a racy read or write
/// operation
- pub fn write<'tcx>(&mut self, pointer: Pointer<Tag>, len: Size) -> InterpResult<'tcx> {
- self.unique_access(pointer, len, WriteType::Write)
+ pub fn write<'tcx>(
+ &mut self,
+ alloc_id: AllocId,
+ range: AllocRange,
+ global: &mut GlobalState,
+ ) -> InterpResult<'tcx> {
+ self.unique_access(alloc_id, range, WriteType::Write, global)
}
/// Detect data-races for an unsynchronized deallocate operation, will not perform
/// data-race threads if `multi-threaded` is false, either due to no threads
/// being created or if it is temporarily disabled during a racy read or write
/// operation
- pub fn deallocate<'tcx>(&mut self, pointer: Pointer<Tag>, len: Size) -> InterpResult<'tcx> {
- self.unique_access(pointer, len, WriteType::Deallocate)
+ pub fn deallocate<'tcx>(
+ &mut self,
+ alloc_id: AllocId,
+ range: AllocRange,
+ global: &mut GlobalState,
+ ) -> InterpResult<'tcx> {
+ self.unique_access(alloc_id, range, WriteType::Deallocate, global)
}
}
result
}
- /// Generic atomic operation implementation,
- /// this accesses memory via get_raw instead of
- /// get_raw_mut, due to issues calling get_raw_mut
- /// for atomic loads from read-only memory.
- /// FIXME: is this valid, or should get_raw_mut be used for
- /// atomic-stores/atomic-rmw?
+ /// Generic atomic operation implementation
fn validate_atomic_op<A: Debug + Copy>(
&self,
place: &MPlaceTy<'tcx, Tag>,
let this = self.eval_context_ref();
if let Some(data_race) = &this.memory.extra.data_race {
if data_race.multi_threaded.get() {
- // Load and log the atomic operation.
- let place_ptr = place.ptr.assert_ptr();
let size = place.layout.size;
+ let (alloc_id, base_offset, ptr) = this.memory.ptr_get_alloc(place.ptr)?;
+ // Load and log the atomic operation.
+ // Note that atomic loads are possible even from read-only allocations, so `get_alloc_extra_mut` is not an option.
let alloc_meta =
- &this.memory.get_raw(place_ptr.alloc_id)?.extra.data_race.as_ref().unwrap();
+ &this.memory.get_alloc_extra(alloc_id)?.data_race.as_ref().unwrap();
log::trace!(
- "Atomic op({}) with ordering {:?} on memory({:?}, offset={}, size={})",
+ "Atomic op({}) with ordering {:?} on {:?} (size={})",
description,
&atomic,
- place_ptr.alloc_id,
- place_ptr.offset.bytes(),
+ ptr,
size.bytes()
);
// Perform the atomic operation.
- let data_race = &alloc_meta.global;
data_race.maybe_perform_sync_operation(|index, mut clocks| {
- for (_, range) in
- alloc_meta.alloc_ranges.borrow_mut().iter_mut(place_ptr.offset, size)
+ for (offset, range) in
+ alloc_meta.alloc_ranges.borrow_mut().iter_mut(base_offset, size)
{
if let Err(DataRace) = op(range, &mut *clocks, index, atomic) {
mem::drop(clocks);
return VClockAlloc::report_data_race(
- &alloc_meta.global,
+ data_race,
range,
description,
true,
- place_ptr,
- size,
+ Pointer::new(alloc_id, offset),
)
.map(|_| true);
}
// Log changes to atomic memory.
if log::log_enabled!(log::Level::Trace) {
- for (_, range) in alloc_meta.alloc_ranges.borrow().iter(place_ptr.offset, size)
+ for (_offset, range) in alloc_meta.alloc_ranges.borrow().iter(base_offset, size)
{
log::trace!(
- "Updated atomic memory({:?}, offset={}, size={}) to {:#?}",
- place.ptr.assert_ptr().alloc_id,
- place_ptr.offset.bytes(),
+ "Updated atomic memory({:?}, size={}) to {:#?}",
+ ptr,
size.bytes(),
range.atomic_ops
);
/// Global data-race detection state, contains the currently
/// executing thread as well as the vector-clocks associated
/// with each of the threads.
+// FIXME: it is probably better to have one large RefCell, than to have so many small ones.
#[derive(Debug, Clone)]
pub struct GlobalState {
/// Set to true once the first additional
/// Create a new global state, setup with just thread-id=0
/// advanced to timestamp = 1.
pub fn new() -> Self {
- let global_state = GlobalState {
+ let mut global_state = GlobalState {
multi_threaded: Cell::new(false),
vector_clocks: RefCell::new(IndexVec::new()),
vector_info: RefCell::new(IndexVec::new()),
// Setup the main-thread since it is not explicitly created:
// uses vector index and thread-id 0, also the rust runtime gives
// the main-thread a name of "main".
- let index = global_state.vector_clocks.borrow_mut().push(ThreadClockSet::default());
- global_state.vector_info.borrow_mut().push(ThreadId::new(0));
- global_state.thread_info.borrow_mut().push(ThreadExtraState {
+ let index = global_state.vector_clocks.get_mut().push(ThreadClockSet::default());
+ global_state.vector_info.get_mut().push(ThreadId::new(0));
+ global_state.thread_info.get_mut().push(ThreadExtraState {
vector_index: Some(index),
thread_name: Some("main".to_string().into_boxed_str()),
termination_vector_clock: None,
// Hook for thread creation, enabled multi-threaded execution and marks
// the current thread timestamp as happening-before the current thread.
#[inline]
- pub fn thread_created(&self, thread: ThreadId) {
+ pub fn thread_created(&mut self, thread: ThreadId) {
let current_index = self.current_index();
// Increment the number of active threads.
let created_index = if let Some(reuse_index) = self.find_vector_index_reuse_candidate() {
// Now re-configure the re-use candidate, increment the clock
// for the new sync use of the vector.
- let mut vector_clocks = self.vector_clocks.borrow_mut();
+ let vector_clocks = self.vector_clocks.get_mut();
vector_clocks[reuse_index].increment_clock(reuse_index);
// Locate the old thread the vector was associated with and update
// it to represent the new thread instead.
- let mut vector_info = self.vector_info.borrow_mut();
+ let vector_info = self.vector_info.get_mut();
let old_thread = vector_info[reuse_index];
vector_info[reuse_index] = thread;
} else {
// No vector re-use candidates available, instead create
// a new vector index.
- let mut vector_info = self.vector_info.borrow_mut();
+ let vector_info = self.vector_info.get_mut();
vector_info.push(thread)
};
thread_info[thread].vector_index = Some(created_index);
// Create a thread clock set if applicable.
- let mut vector_clocks = self.vector_clocks.borrow_mut();
+ let vector_clocks = self.vector_clocks.get_mut();
if created_index == vector_clocks.next_index() {
vector_clocks.push(ThreadClockSet::default());
}
/// Hook on a thread join to update the implicit happens-before relation
/// between the joined thread and the current thread.
#[inline]
- pub fn thread_joined(&self, current_thread: ThreadId, join_thread: ThreadId) {
- let mut clocks_vec = self.vector_clocks.borrow_mut();
- let thread_info = self.thread_info.borrow();
+ pub fn thread_joined(&mut self, current_thread: ThreadId, join_thread: ThreadId) {
+ let clocks_vec = self.vector_clocks.get_mut();
+ let thread_info = self.thread_info.get_mut();
// Load the vector clock of the current thread.
let current_index = thread_info[current_thread]
// If the thread is marked as terminated but not joined
// then move the thread to the re-use set.
- let mut termination = self.terminated_threads.borrow_mut();
+ let termination = self.terminated_threads.get_mut();
if let Some(index) = termination.remove(&join_thread) {
- let mut reuse = self.reuse_candidates.borrow_mut();
+ let reuse = self.reuse_candidates.get_mut();
reuse.insert(index);
}
}
/// This should be called strictly before any calls to
/// `thread_joined`.
#[inline]
- pub fn thread_terminated(&self) {
+ pub fn thread_terminated(&mut self) {
let current_index = self.current_index();
// Increment the clock to a unique termination timestamp.
- let mut vector_clocks = self.vector_clocks.borrow_mut();
+ let vector_clocks = self.vector_clocks.get_mut();
let current_clocks = &mut vector_clocks[current_index];
current_clocks.increment_clock(current_index);
// Load the current thread id for the executing vector.
- let vector_info = self.vector_info.borrow();
+ let vector_info = self.vector_info.get_mut();
let current_thread = vector_info[current_index];
// Load the current thread metadata, and move to a terminated
// vector state. Setting up the vector clock all join operations
// will use.
- let mut thread_info = self.thread_info.borrow_mut();
+ let thread_info = self.thread_info.get_mut();
let current = &mut thread_info[current_thread];
current.termination_vector_clock = Some(current_clocks.clock.clone());
// Add this thread as a candidate for re-use after a thread join
// occurs.
- let mut termination = self.terminated_threads.borrow_mut();
+ let termination = self.terminated_threads.get_mut();
termination.insert(current_thread, current_index);
// Reduce the number of active threads, now that a thread has
/// the thread name is used for improved diagnostics
/// during a data-race.
#[inline]
- pub fn thread_set_name(&self, thread: ThreadId, name: String) {
+ pub fn thread_set_name(&mut self, thread: ThreadId, name: String) {
let name = name.into_boxed_str();
- let mut thread_info = self.thread_info.borrow_mut();
+ let thread_info = self.thread_info.get_mut();
thread_info[thread].thread_name = Some(name);
}