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Auto merge of #2638 - DrMeepster:windows-condvars, r=RalfJung

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Implement condvars for Windows

Adds 3 shims for Windows: `SleepConditionVariableSRW`, `WakeConditionVariable`, `WakeAllConditionVariable` to add support for condvars (which fixes #2628).

Salvaged from what was removed from #2231
This commit is contained in:
bors 2022-11-06 09:57:45 +00:00
commit f60a2ae3e9
9 changed files with 504 additions and 30 deletions
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24
src/tools/miri/src/concurrency/sync.rs
View File

@ -116,13 +116,25 @@ struct RwLock {
declare_id!(CondvarId);
#[derive(Debug, Copy, Clone)]
pub enum RwLockMode {
Read,
Write,
}
#[derive(Debug)]
pub enum CondvarLock {
Mutex(MutexId),
RwLock { id: RwLockId, mode: RwLockMode },
}
/// A thread waiting on a conditional variable.
#[derive(Debug)]
struct CondvarWaiter {
/// The thread that is waiting on this variable.
thread: ThreadId,
/// The mutex on which the thread is waiting.
mutex: MutexId,
/// The mutex or rwlock on which the thread is waiting.
lock: CondvarLock,
}
/// The conditional variable state.
@ -569,16 +581,16 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
}
/// Mark that the thread is waiting on the conditional variable.
fn condvar_wait(&mut self, id: CondvarId, thread: ThreadId, mutex: MutexId) {
fn condvar_wait(&mut self, id: CondvarId, thread: ThreadId, lock: CondvarLock) {
let this = self.eval_context_mut();
let waiters = &mut this.machine.threads.sync.condvars[id].waiters;
assert!(waiters.iter().all(|waiter| waiter.thread != thread), "thread is already waiting");
waiters.push_back(CondvarWaiter { thread, mutex });
waiters.push_back(CondvarWaiter { thread, lock });
}
/// Wake up some thread (if there is any) sleeping on the conditional
/// variable.
fn condvar_signal(&mut self, id: CondvarId) -> Option<(ThreadId, MutexId)> {
fn condvar_signal(&mut self, id: CondvarId) -> Option<(ThreadId, CondvarLock)> {
let this = self.eval_context_mut();
let current_thread = this.get_active_thread();
let condvar = &mut this.machine.threads.sync.condvars[id];
@ -592,7 +604,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
if let Some(data_race) = data_race {
data_race.validate_lock_acquire(&condvar.data_race, waiter.thread);
}
(waiter.thread, waiter.mutex)
(waiter.thread, waiter.lock)
})
}

21
src/tools/miri/src/shims/unix/sync.rs
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@ -3,6 +3,7 @@ use std::time::SystemTime;
use rustc_hir::LangItem;
use rustc_middle::ty::{layout::TyAndLayout, query::TyCtxtAt, Ty};
use crate::concurrency::sync::CondvarLock;
use crate::concurrency::thread::{MachineCallback, Time};
use crate::*;
@ -696,8 +697,12 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
fn pthread_cond_signal(&mut self, cond_op: &OpTy<'tcx, Provenance>) -> InterpResult<'tcx, i32> {
let this = self.eval_context_mut();
let id = this.condvar_get_or_create_id(cond_op, CONDVAR_ID_OFFSET)?;
if let Some((thread, mutex)) = this.condvar_signal(id) {
post_cond_signal(this, thread, mutex)?;
if let Some((thread, lock)) = this.condvar_signal(id) {
if let CondvarLock::Mutex(mutex) = lock {
post_cond_signal(this, thread, mutex)?;
} else {
panic!("condvar should not have an rwlock on unix");
}
}
Ok(0)
@ -710,8 +715,12 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
let this = self.eval_context_mut();
let id = this.condvar_get_or_create_id(cond_op, CONDVAR_ID_OFFSET)?;
while let Some((thread, mutex)) = this.condvar_signal(id) {
post_cond_signal(this, thread, mutex)?;
while let Some((thread, lock)) = this.condvar_signal(id) {
if let CondvarLock::Mutex(mutex) = lock {
post_cond_signal(this, thread, mutex)?;
} else {
panic!("condvar should not have an rwlock on unix");
}
}
Ok(0)
@ -729,7 +738,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
let active_thread = this.get_active_thread();
release_cond_mutex_and_block(this, active_thread, mutex_id)?;
this.condvar_wait(id, active_thread, mutex_id);
this.condvar_wait(id, active_thread, CondvarLock::Mutex(mutex_id));
Ok(0)
}
@ -768,7 +777,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
};
release_cond_mutex_and_block(this, active_thread, mutex_id)?;
this.condvar_wait(id, active_thread, mutex_id);
this.condvar_wait(id, active_thread, CondvarLock::Mutex(mutex_id));
// We return success for now and override it in the timeout callback.
this.write_scalar(Scalar::from_i32(0), dest)?;

19
src/tools/miri/src/shims/windows/foreign_items.rs
View File

@ -273,6 +273,25 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
let result = this.InitOnceComplete(ptr, flags, context)?;
this.write_scalar(result, dest)?;
}
"SleepConditionVariableSRW" => {
let [condvar, lock, timeout, flags] =
this.check_shim(abi, Abi::System { unwind: false }, link_name, args)?;
let result = this.SleepConditionVariableSRW(condvar, lock, timeout, flags, dest)?;
this.write_scalar(result, dest)?;
}
"WakeConditionVariable" => {
let [condvar] =
this.check_shim(abi, Abi::System { unwind: false }, link_name, args)?;
this.WakeConditionVariable(condvar)?;
}
"WakeAllConditionVariable" => {
let [condvar] =
this.check_shim(abi, Abi::System { unwind: false }, link_name, args)?;
this.WakeAllConditionVariable(condvar)?;
}
// Dynamic symbol loading
"GetProcAddress" => {

161
src/tools/miri/src/shims/windows/sync.rs
View File

@ -3,11 +3,45 @@ use std::time::Duration;
use rustc_target::abi::Size;
use crate::concurrency::init_once::InitOnceStatus;
use crate::concurrency::sync::{CondvarLock, RwLockMode};
use crate::concurrency::thread::MachineCallback;
use crate::*;
const SRWLOCK_ID_OFFSET: u64 = 0;
const INIT_ONCE_ID_OFFSET: u64 = 0;
const CONDVAR_ID_OFFSET: u64 = 0;
impl<'mir, 'tcx> EvalContextExtPriv<'mir, 'tcx> for crate::MiriInterpCx<'mir, 'tcx> {}
trait EvalContextExtPriv<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
/// Try to reacquire the lock associated with the condition variable after we
/// were signaled.
fn reacquire_cond_lock(
&mut self,
thread: ThreadId,
lock: RwLockId,
mode: RwLockMode,
) -> InterpResult<'tcx> {
let this = self.eval_context_mut();
this.unblock_thread(thread);
match mode {
RwLockMode::Read =>
if this.rwlock_is_write_locked(lock) {
this.rwlock_enqueue_and_block_reader(lock, thread);
} else {
this.rwlock_reader_lock(lock, thread);
},
RwLockMode::Write =>
if this.rwlock_is_locked(lock) {
this.rwlock_enqueue_and_block_writer(lock, thread);
} else {
this.rwlock_writer_lock(lock, thread);
},
}
Ok(())
}
}
impl<'mir, 'tcx> EvalContextExt<'mir, 'tcx> for crate::MiriInterpCx<'mir, 'tcx> {}
#[allow(non_snake_case)]
@ -327,4 +361,131 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
Ok(())
}
fn SleepConditionVariableSRW(
&mut self,
condvar_op: &OpTy<'tcx, Provenance>,
lock_op: &OpTy<'tcx, Provenance>,
timeout_op: &OpTy<'tcx, Provenance>,
flags_op: &OpTy<'tcx, Provenance>,
dest: &PlaceTy<'tcx, Provenance>,
) -> InterpResult<'tcx, Scalar<Provenance>> {
let this = self.eval_context_mut();
let condvar_id = this.condvar_get_or_create_id(condvar_op, CONDVAR_ID_OFFSET)?;
let lock_id = this.rwlock_get_or_create_id(lock_op, SRWLOCK_ID_OFFSET)?;
let timeout_ms = this.read_scalar(timeout_op)?.to_u32()?;
let flags = this.read_scalar(flags_op)?.to_u32()?;
let timeout_time = if timeout_ms == this.eval_windows("c", "INFINITE")?.to_u32()? {
None
} else {
let duration = Duration::from_millis(timeout_ms.into());
Some(this.machine.clock.now().checked_add(duration).unwrap())
};
let shared_mode = 0x1; // CONDITION_VARIABLE_LOCKMODE_SHARED is not in std
let mode = if flags == 0 {
RwLockMode::Write
} else if flags == shared_mode {
RwLockMode::Read
} else {
throw_unsup_format!("unsupported `Flags` {flags} in `SleepConditionVariableSRW`");
};
let active_thread = this.get_active_thread();
let was_locked = match mode {
RwLockMode::Read => this.rwlock_reader_unlock(lock_id, active_thread),
RwLockMode::Write => this.rwlock_writer_unlock(lock_id, active_thread),
};
if !was_locked {
throw_ub_format!(
"calling SleepConditionVariableSRW with an SRWLock that is not locked by the current thread"
);
}
this.block_thread(active_thread);
this.condvar_wait(condvar_id, active_thread, CondvarLock::RwLock { id: lock_id, mode });
if let Some(timeout_time) = timeout_time {
struct Callback<'tcx> {
thread: ThreadId,
condvar_id: CondvarId,
lock_id: RwLockId,
mode: RwLockMode,
dest: PlaceTy<'tcx, Provenance>,
}
impl<'tcx> VisitTags for Callback<'tcx> {
fn visit_tags(&self, visit: &mut dyn FnMut(SbTag)) {
let Callback { thread: _, condvar_id: _, lock_id: _, mode: _, dest } = self;
dest.visit_tags(visit);
}
}
impl<'mir, 'tcx: 'mir> MachineCallback<'mir, 'tcx> for Callback<'tcx> {
fn call(&self, this: &mut MiriInterpCx<'mir, 'tcx>) -> InterpResult<'tcx> {
this.reacquire_cond_lock(self.thread, self.lock_id, self.mode)?;
this.condvar_remove_waiter(self.condvar_id, self.thread);
let error_timeout = this.eval_windows("c", "ERROR_TIMEOUT")?;
this.set_last_error(error_timeout)?;
this.write_scalar(this.eval_windows("c", "FALSE")?, &self.dest)?;
Ok(())
}
}
this.register_timeout_callback(
active_thread,
Time::Monotonic(timeout_time),
Box::new(Callback {
thread: active_thread,
condvar_id,
lock_id,
mode,
dest: dest.clone(),
}),
);
}
this.eval_windows("c", "TRUE")
}
fn WakeConditionVariable(&mut self, condvar_op: &OpTy<'tcx, Provenance>) -> InterpResult<'tcx> {
let this = self.eval_context_mut();
let condvar_id = this.condvar_get_or_create_id(condvar_op, CONDVAR_ID_OFFSET)?;
if let Some((thread, lock)) = this.condvar_signal(condvar_id) {
if let CondvarLock::RwLock { id, mode } = lock {
this.reacquire_cond_lock(thread, id, mode)?;
this.unregister_timeout_callback_if_exists(thread);
} else {
panic!("mutexes should not exist on windows");
}
}
Ok(())
}
fn WakeAllConditionVariable(
&mut self,
condvar_op: &OpTy<'tcx, Provenance>,
) -> InterpResult<'tcx> {
let this = self.eval_context_mut();
let condvar_id = this.condvar_get_or_create_id(condvar_op, CONDVAR_ID_OFFSET)?;
while let Some((thread, lock)) = this.condvar_signal(condvar_id) {
if let CondvarLock::RwLock { id, mode } = lock {
this.reacquire_cond_lock(thread, id, mode)?;
this.unregister_timeout_callback_if_exists(thread);
} else {
panic!("mutexes should not exist on windows");
}
}
Ok(())
}
}

20
src/tools/miri/tests/pass/concurrency/sync.rs
View File

@ -230,20 +230,8 @@ fn main() {
check_once();
park_timeout();
park_unpark();
if !cfg!(windows) {
// ignore-target-windows: Condvars on Windows are not supported yet
check_barriers();
check_conditional_variables_notify_one();
check_conditional_variables_timed_wait_timeout();
check_conditional_variables_timed_wait_notimeout();
} else {
// We need to fake the same output...
for _ in 0..10 {
println!("before wait");
}
for _ in 0..10 {
println!("after wait");
}
}
check_barriers();
check_conditional_variables_notify_one();
check_conditional_variables_timed_wait_timeout();
check_conditional_variables_timed_wait_notimeout();
}

1
src/tools/miri/tests/pass/concurrency/sync_nopreempt.rs
View File

@ -1,4 +1,3 @@
//@ignore-target-windows: Condvars on Windows are not supported yet.
// We are making scheduler assumptions here.
//@compile-flags: -Zmiri-strict-provenance -Zmiri-preemption-rate=0

227
src/tools/miri/tests/pass/concurrency/windows_condvar_shared.rs Normal file
View File

@ -0,0 +1,227 @@
//@only-target-windows: Uses win32 api functions
// We are making scheduler assumptions here.
//@compile-flags: -Zmiri-preemption-rate=0
use std::ffi::c_void;
use std::ptr::null_mut;
use std::thread;
#[derive(Copy, Clone)]
struct SendPtr<T>(*mut T);
unsafe impl<T> Send for SendPtr<T> {}
extern "system" {
fn SleepConditionVariableSRW(
condvar: *mut *mut c_void,
lock: *mut *mut c_void,
timeout: u32,
flags: u32,
) -> i32;
fn WakeAllConditionVariable(condvar: *mut *mut c_void);
fn AcquireSRWLockExclusive(lock: *mut *mut c_void);
fn AcquireSRWLockShared(lock: *mut *mut c_void);
fn ReleaseSRWLockExclusive(lock: *mut *mut c_void);
fn ReleaseSRWLockShared(lock: *mut *mut c_void);
}
const CONDITION_VARIABLE_LOCKMODE_SHARED: u32 = 1;
const INFINITE: u32 = u32::MAX;
/// threads should be able to reacquire the lock while it is locked by multiple other threads in shared mode
fn all_shared() {
println!("all_shared");
let mut lock = null_mut();
let mut condvar = null_mut();
let lock_ptr = SendPtr(&mut lock);
let condvar_ptr = SendPtr(&mut condvar);
let mut handles = Vec::with_capacity(10);
// waiters
for i in 0..5 {
handles.push(thread::spawn(move || {
unsafe {
AcquireSRWLockShared(lock_ptr.0);
}
println!("exclusive waiter {i} locked");
let r = unsafe {
SleepConditionVariableSRW(
condvar_ptr.0,
lock_ptr.0,
INFINITE,
CONDITION_VARIABLE_LOCKMODE_SHARED,
)
};
assert_ne!(r, 0);
println!("exclusive waiter {i} reacquired lock");
// unlocking is unnecessary because the lock is never used again
}));
}
// ensures each waiter is waiting by this point
thread::yield_now();
// readers
for i in 0..5 {
handles.push(thread::spawn(move || {
unsafe {
AcquireSRWLockShared(lock_ptr.0);
}
println!("reader {i} locked");
// switch to next reader or main thread
thread::yield_now();
unsafe {
ReleaseSRWLockShared(lock_ptr.0);
}
println!("reader {i} unlocked");
}));
}
// ensures each reader has acquired the lock
thread::yield_now();
unsafe {
WakeAllConditionVariable(condvar_ptr.0);
}
for handle in handles {
handle.join().unwrap();
}
}
// reacquiring a lock should wait until the lock is not exclusively locked
fn shared_sleep_and_exclusive_lock() {
println!("shared_sleep_and_exclusive_lock");
let mut lock = null_mut();
let mut condvar = null_mut();
let lock_ptr = SendPtr(&mut lock);
let condvar_ptr = SendPtr(&mut condvar);
let mut waiters = Vec::with_capacity(5);
for i in 0..5 {
waiters.push(thread::spawn(move || {
unsafe {
AcquireSRWLockShared(lock_ptr.0);
}
println!("shared waiter {i} locked");
let r = unsafe {
SleepConditionVariableSRW(
condvar_ptr.0,
lock_ptr.0,
INFINITE,
CONDITION_VARIABLE_LOCKMODE_SHARED,
)
};
assert_ne!(r, 0);
println!("shared waiter {i} reacquired lock");
// unlocking is unnecessary because the lock is never used again
}));
}
// ensures each waiter is waiting by this point
thread::yield_now();
unsafe {
AcquireSRWLockExclusive(lock_ptr.0);
}
println!("main locked");
unsafe {
WakeAllConditionVariable(condvar_ptr.0);
}
// waiters are now waiting for the lock to be unlocked
thread::yield_now();
unsafe {
ReleaseSRWLockExclusive(lock_ptr.0);
}
println!("main unlocked");
for handle in waiters {
handle.join().unwrap();
}
}
// threads reacquiring locks should wait for all locks to be released first
fn exclusive_sleep_and_shared_lock() {
println!("exclusive_sleep_and_shared_lock");
let mut lock = null_mut();
let mut condvar = null_mut();
let lock_ptr = SendPtr(&mut lock);
let condvar_ptr = SendPtr(&mut condvar);
let mut handles = Vec::with_capacity(10);
for i in 0..5 {
handles.push(thread::spawn(move || {
unsafe {
AcquireSRWLockExclusive(lock_ptr.0);
}
println!("exclusive waiter {i} locked");
let r = unsafe { SleepConditionVariableSRW(condvar_ptr.0, lock_ptr.0, INFINITE, 0) };
assert_ne!(r, 0);
println!("exclusive waiter {i} reacquired lock");
// switch to next waiter or main thread
thread::yield_now();
unsafe {
ReleaseSRWLockExclusive(lock_ptr.0);
}
println!("exclusive waiter {i} unlocked");
}));
}
for i in 0..5 {
handles.push(thread::spawn(move || {
unsafe {
AcquireSRWLockShared(lock_ptr.0);
}
println!("reader {i} locked");
// switch to next reader or main thread
thread::yield_now();
unsafe {
ReleaseSRWLockShared(lock_ptr.0);
}
println!("reader {i} unlocked");
}));
}
// ensures each reader has acquired the lock
thread::yield_now();
unsafe {
WakeAllConditionVariable(condvar_ptr.0);
}
for handle in handles {
handle.join().unwrap();
}
}
fn main() {
all_shared();
shared_sleep_and_exclusive_lock();
exclusive_sleep_and_shared_lock();
}

60
src/tools/miri/tests/pass/concurrency/windows_condvar_shared.stdout Normal file
View File

@ -0,0 +1,60 @@
all_shared
exclusive waiter 0 locked
exclusive waiter 1 locked
exclusive waiter 2 locked
exclusive waiter 3 locked
exclusive waiter 4 locked
reader 0 locked
reader 1 locked
reader 2 locked
reader 3 locked
reader 4 locked
exclusive waiter 0 reacquired lock
exclusive waiter 1 reacquired lock
exclusive waiter 2 reacquired lock
exclusive waiter 3 reacquired lock
exclusive waiter 4 reacquired lock
reader 0 unlocked
reader 1 unlocked
reader 2 unlocked
reader 3 unlocked
reader 4 unlocked
shared_sleep_and_exclusive_lock
shared waiter 0 locked
shared waiter 1 locked
shared waiter 2 locked
shared waiter 3 locked
shared waiter 4 locked
main locked
main unlocked
shared waiter 0 reacquired lock
shared waiter 1 reacquired lock
shared waiter 2 reacquired lock
shared waiter 3 reacquired lock
shared waiter 4 reacquired lock
exclusive_sleep_and_shared_lock
exclusive waiter 0 locked
exclusive waiter 1 locked
exclusive waiter 2 locked
exclusive waiter 3 locked
exclusive waiter 4 locked
reader 0 locked
reader 1 locked
reader 2 locked
reader 3 locked
reader 4 locked
reader 0 unlocked
reader 1 unlocked
reader 2 unlocked
reader 3 unlocked
reader 4 unlocked
exclusive waiter 0 reacquired lock
exclusive waiter 0 unlocked
exclusive waiter 1 reacquired lock
exclusive waiter 1 unlocked
exclusive waiter 2 reacquired lock
exclusive waiter 2 unlocked
exclusive waiter 3 reacquired lock
exclusive waiter 3 unlocked
exclusive waiter 4 reacquired lock
exclusive waiter 4 unlocked

1
src/tools/miri/tests/pass/panic/concurrent-panic.rs
View File

@ -1,4 +1,3 @@
//@ignore-target-windows: Condvars on Windows are not supported yet.
// We are making scheduler assumptions here.
//@compile-flags: -Zmiri-preemption-rate=0