1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
13 //! ## The threading model
15 //! An executing Rust program consists of a collection of native OS threads,
16 //! each with their own stack and local state.
18 //! Communication between threads can be done through
19 //! [channels](../../std/sync/mpsc/index.html), Rust's message-passing
20 //! types, along with [other forms of thread
21 //! synchronization](../../std/sync/index.html) and shared-memory data
22 //! structures. In particular, types that are guaranteed to be
23 //! threadsafe are easily shared between threads using the
24 //! atomically-reference-counted container,
25 //! [`Arc`](../../std/sync/struct.Arc.html).
27 //! Fatal logic errors in Rust cause *thread panic*, during which
28 //! a thread will unwind the stack, running destructors and freeing
29 //! owned resources. Thread panic is unrecoverable from within
30 //! the panicking thread (i.e. there is no 'try/catch' in Rust), but
31 //! the panic may optionally be detected from a different thread. If
32 //! the main thread panics, the application will exit with a non-zero
35 //! When the main thread of a Rust program terminates, the entire program shuts
36 //! down, even if other threads are still running. However, this module provides
37 //! convenient facilities for automatically waiting for the termination of a
38 //! child thread (i.e., join).
40 //! ## The `Thread` type
42 //! Threads are represented via the `Thread` type, which you can
43 //! get in one of two ways:
45 //! * By spawning a new thread, e.g. using the `thread::spawn` function.
46 //! * By requesting the current thread, using the `thread::current` function.
48 //! Threads can be named, and provide some built-in support for low-level
49 //! synchronization (described below).
51 //! The `thread::current()` function is available even for threads not spawned
52 //! by the APIs of this module.
54 //! ## Spawning a thread
56 //! A new thread can be spawned using the `thread::spawn` function:
61 //! thread::spawn(move || {
66 //! In this example, the spawned thread is "detached" from the current
67 //! thread. This means that it can outlive its parent (the thread that spawned
68 //! it), unless this parent is the main thread.
70 //! The parent thread can also wait on the completion of the child
71 //! thread; a call to `spawn` produces a `JoinHandle`, which provides
72 //! a `join` method for waiting:
77 //! let child = thread::spawn(move || {
81 //! let res = child.join();
84 //! The `join` method returns a `Result` containing `Ok` of the final
85 //! value produced by the child thread, or `Err` of the value given to
86 //! a call to `panic!` if the child panicked.
88 //! ## Configuring threads
90 //! A new thread can be configured before it is spawned via the `Builder` type,
91 //! which currently allows you to set the name and stack size for the child thread:
94 //! # #![allow(unused_must_use)]
97 //! thread::Builder::new().name("child1".to_string()).spawn(move || {
98 //! println!("Hello, world!");
102 //! ## Blocking support: park and unpark
104 //! Every thread is equipped with some basic low-level blocking support, via the
105 //! `park` and `unpark` functions.
107 //! Conceptually, each `Thread` handle has an associated token, which is
108 //! initially not present:
110 //! * The `thread::park()` function blocks the current thread unless or until
111 //! the token is available for its thread handle, at which point it atomically
112 //! consumes the token. It may also return *spuriously*, without consuming the
113 //! token. `thread::park_timeout()` does the same, but allows specifying a
114 //! maximum time to block the thread for.
116 //! * The `unpark()` method on a `Thread` atomically makes the token available
117 //! if it wasn't already.
119 //! In other words, each `Thread` acts a bit like a semaphore with initial count
120 //! 0, except that the semaphore is *saturating* (the count cannot go above 1),
121 //! and can return spuriously.
123 //! The API is typically used by acquiring a handle to the current thread,
124 //! placing that handle in a shared data structure so that other threads can
125 //! find it, and then `park`ing. When some desired condition is met, another
126 //! thread calls `unpark` on the handle.
128 //! The motivation for this design is twofold:
130 //! * It avoids the need to allocate mutexes and condvars when building new
131 //! synchronization primitives; the threads already provide basic blocking/signaling.
133 //! * It can be implemented very efficiently on many platforms.
135 //! ## Thread-local storage
137 //! This module also provides an implementation of thread local storage for Rust
138 //! programs. Thread local storage is a method of storing data into a global
139 //! variable which each thread in the program will have its own copy of.
140 //! Threads do not share this data, so accesses do not need to be synchronized.
142 //! At a high level, this module provides two variants of storage:
144 //! * Owned thread-local storage. This is a type of thread local key which
145 //! owns the value that it contains, and will destroy the value when the
146 //! thread exits. This variant is created with the `thread_local!` macro and
147 //! can contain any value which is `'static` (no borrowed pointers).
149 //! * Scoped thread-local storage. This type of key is used to store a reference
150 //! to a value into local storage temporarily for the scope of a function
151 //! call. There are no restrictions on what types of values can be placed
154 //! Both forms of thread local storage provide an accessor function, `with`,
155 //! which will yield a shared reference to the value to the specified
156 //! closure. Thread-local keys only allow shared access to values as there is no
157 //! way to guarantee uniqueness if a mutable borrow was allowed. Most values
158 //! will want to make use of some form of **interior mutability** through the
159 //! `Cell` or `RefCell` types.
161 #![stable(feature = "rust1", since = "1.0.0")]
166 use cell::UnsafeCell;
169 use sync::{Mutex, Condvar, Arc};
170 use sys::thread as imp;
171 use sys_common::thread_info;
172 use sys_common::unwind;
173 use sys_common::util;
174 use sys_common::{AsInner, IntoInner};
177 ////////////////////////////////////////////////////////////////////////////////
178 // Thread-local storage
179 ////////////////////////////////////////////////////////////////////////////////
181 #[macro_use] mod local;
182 #[macro_use] mod scoped_tls;
184 #[stable(feature = "rust1", since = "1.0.0")]
185 pub use self::local::{LocalKey, LocalKeyState};
187 #[unstable(feature = "scoped_tls",
188 reason = "scoped TLS has yet to have wide enough use to fully \
189 consider stabilizing its interface",
191 pub use self::scoped_tls::ScopedKey;
193 #[unstable(feature = "libstd_thread_internals", issue = "0")]
194 #[doc(hidden)] pub use self::local::__KeyInner as __LocalKeyInner;
195 #[unstable(feature = "libstd_thread_internals", issue = "0")]
196 #[doc(hidden)] pub use self::scoped_tls::__KeyInner as __ScopedKeyInner;
198 ////////////////////////////////////////////////////////////////////////////////
200 ////////////////////////////////////////////////////////////////////////////////
202 /// Thread configuration. Provides detailed control over the properties
203 /// and behavior of new threads.
204 #[stable(feature = "rust1", since = "1.0.0")]
206 // A name for the thread-to-be, for identification in panic messages
207 name: Option<String>,
208 // The size of the stack for the spawned thread
209 stack_size: Option<usize>,
213 /// Generates the base configuration for spawning a thread, from which
214 /// configuration methods can be chained.
215 #[stable(feature = "rust1", since = "1.0.0")]
216 pub fn new() -> Builder {
223 /// Names the thread-to-be. Currently the name is used for identification
224 /// only in panic messages.
225 #[stable(feature = "rust1", since = "1.0.0")]
226 pub fn name(mut self, name: String) -> Builder {
227 self.name = Some(name);
231 /// Sets the size of the stack for the new thread.
232 #[stable(feature = "rust1", since = "1.0.0")]
233 pub fn stack_size(mut self, size: usize) -> Builder {
234 self.stack_size = Some(size);
238 /// Spawns a new thread, and returns a join handle for it.
240 /// The child thread may outlive the parent (unless the parent thread
241 /// is the main thread; the whole process is terminated when the main
242 /// thread finishes). The join handle can be used to block on
243 /// termination of the child thread, including recovering its panics.
247 /// Unlike the `spawn` free function, this method yields an
248 /// `io::Result` to capture any failure to create the thread at
250 #[stable(feature = "rust1", since = "1.0.0")]
251 pub fn spawn<F, T>(self, f: F) -> io::Result<JoinHandle<T>> where
252 F: FnOnce() -> T, F: Send + 'static, T: Send + 'static
254 let Builder { name, stack_size } = self;
256 let stack_size = stack_size.unwrap_or(util::min_stack());
258 let my_thread = Thread::new(name);
259 let their_thread = my_thread.clone();
261 let my_packet : Arc<UnsafeCell<Option<Result<T>>>>
262 = Arc::new(UnsafeCell::new(None));
263 let their_packet = my_packet.clone();
266 if let Some(name) = their_thread.name() {
267 imp::Thread::set_name(name);
270 thread_info::set(imp::guard::current(), their_thread);
271 let mut output = None;
273 let ptr = &mut output;
274 unwind::try(move || *ptr = Some(f()))
276 *their_packet.get() = Some(try_result.map(|()| {
282 Ok(JoinHandle(JoinInner {
284 Some(try!(imp::Thread::new(stack_size, Box::new(main))))
287 packet: Packet(my_packet),
292 ////////////////////////////////////////////////////////////////////////////////
294 ////////////////////////////////////////////////////////////////////////////////
296 /// Spawns a new thread, returning a `JoinHandle` for it.
298 /// The join handle will implicitly *detach* the child thread upon being
299 /// dropped. In this case, the child thread may outlive the parent (unless
300 /// the parent thread is the main thread; the whole process is terminated when
301 /// the main thread finishes.) Additionally, the join handle provides a `join`
302 /// method that can be used to join the child thread. If the child thread
303 /// panics, `join` will return an `Err` containing the argument given to
308 /// Panics if the OS fails to create a thread; use `Builder::spawn`
309 /// to recover from such errors.
310 #[stable(feature = "rust1", since = "1.0.0")]
311 pub fn spawn<F, T>(f: F) -> JoinHandle<T> where
312 F: FnOnce() -> T, F: Send + 'static, T: Send + 'static
314 Builder::new().spawn(f).unwrap()
317 /// Gets a handle to the thread that invokes it.
318 #[stable(feature = "rust1", since = "1.0.0")]
319 pub fn current() -> Thread {
320 thread_info::current_thread().expect("use of std::thread::current() is not \
321 possible after the thread's local \
322 data has been destroyed")
325 /// Cooperatively gives up a timeslice to the OS scheduler.
326 #[stable(feature = "rust1", since = "1.0.0")]
328 imp::Thread::yield_now()
331 /// Determines whether the current thread is unwinding because of panic.
333 #[stable(feature = "rust1", since = "1.0.0")]
334 pub fn panicking() -> bool {
338 /// Invokes a closure, capturing the cause of panic if one occurs.
340 /// This function will return `Ok` with the closure's result if the closure
341 /// does not panic, and will return `Err(cause)` if the closure panics. The
342 /// `cause` returned is the object with which panic was originally invoked.
344 /// It is currently undefined behavior to unwind from Rust code into foreign
345 /// code, so this function is particularly useful when Rust is called from
346 /// another language (normally C). This can run arbitrary Rust code, capturing a
347 /// panic and allowing a graceful handling of the error.
349 /// It is **not** recommended to use this function for a general try/catch
350 /// mechanism. The `Result` type is more appropriate to use for functions that
351 /// can fail on a regular basis.
353 /// The closure provided is required to adhere to the `'static` bound to ensure
354 /// that it cannot reference data in the parent stack frame, mitigating problems
355 /// with exception safety. Furthermore, a `Send` bound is also required,
356 /// providing the same safety guarantees as `thread::spawn` (ensuring the
357 /// closure is properly isolated from the parent).
358 #[unstable(feature = "catch_panic", reason = "recent API addition",
360 #[rustc_deprecated(since = "1.6.0", reason = "renamed to std::panic::recover")]
361 pub fn catch_panic<F, R>(f: F) -> Result<R>
362 where F: FnOnce() -> R + Send + 'static
364 let mut result = None;
366 let result = &mut result;
367 try!(unwind::try(move || *result = Some(f())))
372 /// Puts the current thread to sleep for the specified amount of time.
374 /// The thread may sleep longer than the duration specified due to scheduling
375 /// specifics or platform-dependent functionality. Note that on unix platforms
376 /// this function will not return early due to a signal being received or a
378 #[stable(feature = "rust1", since = "1.0.0")]
379 #[rustc_deprecated(since = "1.6.0", reason = "replaced by `std::thread::sleep`")]
380 pub fn sleep_ms(ms: u32) {
381 sleep(Duration::from_millis(ms as u64))
384 /// Puts the current thread to sleep for the specified amount of time.
386 /// The thread may sleep longer than the duration specified due to scheduling
387 /// specifics or platform-dependent functionality.
389 /// # Platform behavior
391 /// On Unix platforms this function will not return early due to a
392 /// signal being received or a spurious wakeup. Platforms which do not support
393 /// nanosecond precision for sleeping will have `dur` rounded up to the nearest
394 /// granularity of time they can sleep for.
395 #[stable(feature = "thread_sleep", since = "1.4.0")]
396 pub fn sleep(dur: Duration) {
397 imp::Thread::sleep(dur)
400 /// Blocks unless or until the current thread's token is made available.
402 /// Every thread is equipped with some basic low-level blocking support, via
403 /// the `park()` function and the [`unpark()`][unpark] method. These can be
404 /// used as a more CPU-efficient implementation of a spinlock.
406 /// [unpark]: struct.Thread.html#method.unpark
408 /// The API is typically used by acquiring a handle to the current thread,
409 /// placing that handle in a shared data structure so that other threads can
410 /// find it, and then parking (in a loop with a check for the token actually
413 /// A call to `park` does not guarantee that the thread will remain parked
414 /// forever, and callers should be prepared for this possibility.
416 /// See the [module documentation][thread] for more detail.
418 /// [thread]: index.html
420 // The implementation currently uses the trivial strategy of a Mutex+Condvar
421 // with wakeup flag, which does not actually allow spurious wakeups. In the
422 // future, this will be implemented in a more efficient way, perhaps along the lines of
423 // http://cr.openjdk.java.net/~stefank/6989984.1/raw_files/new/src/os/linux/vm/os_linux.cpp
424 // or futuxes, and in either case may allow spurious wakeups.
425 #[stable(feature = "rust1", since = "1.0.0")]
427 let thread = current();
428 let mut guard = thread.inner.lock.lock().unwrap();
430 guard = thread.inner.cvar.wait(guard).unwrap();
435 /// Blocks unless or until the current thread's token is made available or
436 /// the specified duration has been reached (may wake spuriously).
438 /// The semantics of this function are equivalent to `park()` except that the
439 /// thread will be blocked for roughly no longer than *ms*. This method
440 /// should not be used for precise timing due to anomalies such as
441 /// preemption or platform differences that may not cause the maximum
442 /// amount of time waited to be precisely *ms* long.
444 /// See the module doc for more detail.
445 #[stable(feature = "rust1", since = "1.0.0")]
446 #[rustc_deprecated(since = "1.6.0", reason = "replaced by `std::thread::park_timeout`")]
447 pub fn park_timeout_ms(ms: u32) {
448 park_timeout(Duration::from_millis(ms as u64))
451 /// Blocks unless or until the current thread's token is made available or
452 /// the specified duration has been reached (may wake spuriously).
454 /// The semantics of this function are equivalent to `park()` except that the
455 /// thread will be blocked for roughly no longer than *dur*. This method
456 /// should not be used for precise timing due to anomalies such as
457 /// preemption or platform differences that may not cause the maximum
458 /// amount of time waited to be precisely *dur* long.
460 /// See the module doc for more detail.
462 /// # Platform behavior
464 /// Platforms which do not support nanosecond precision for sleeping will have
465 /// `dur` rounded up to the nearest granularity of time they can sleep for.
466 #[stable(feature = "park_timeout", since = "1.4.0")]
467 pub fn park_timeout(dur: Duration) {
468 let thread = current();
469 let mut guard = thread.inner.lock.lock().unwrap();
471 let (g, _) = thread.inner.cvar.wait_timeout(guard, dur).unwrap();
477 ////////////////////////////////////////////////////////////////////////////////
479 ////////////////////////////////////////////////////////////////////////////////
481 /// The internal representation of a `Thread` handle
483 name: Option<String>,
484 lock: Mutex<bool>, // true when there is a buffered unpark
489 #[stable(feature = "rust1", since = "1.0.0")]
490 /// A handle to a thread.
496 // Used only internally to construct a thread object without spawning
497 fn new(name: Option<String>) -> Thread {
499 inner: Arc::new(Inner {
501 lock: Mutex::new(false),
502 cvar: Condvar::new(),
507 /// Atomically makes the handle's token available if it is not already.
509 /// See the module doc for more detail.
510 #[stable(feature = "rust1", since = "1.0.0")]
511 pub fn unpark(&self) {
512 let mut guard = self.inner.lock.lock().unwrap();
515 self.inner.cvar.notify_one();
519 /// Gets the thread's name.
520 #[stable(feature = "rust1", since = "1.0.0")]
521 pub fn name(&self) -> Option<&str> {
522 self.inner.name.as_ref().map(|s| &**s)
526 #[stable(feature = "rust1", since = "1.0.0")]
527 impl fmt::Debug for Thread {
528 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
529 fmt::Debug::fmt(&self.name(), f)
533 // a hack to get around privacy restrictions
534 impl thread_info::NewThread for Thread {
535 fn new(name: Option<String>) -> Thread { Thread::new(name) }
538 ////////////////////////////////////////////////////////////////////////////////
540 ////////////////////////////////////////////////////////////////////////////////
542 /// Indicates the manner in which a thread exited.
544 /// A thread that completes without panicking is considered to exit successfully.
545 #[stable(feature = "rust1", since = "1.0.0")]
546 pub type Result<T> = ::result::Result<T, Box<Any + Send + 'static>>;
548 // This packet is used to communicate the return value between the child thread
549 // and the parent thread. Memory is shared through the `Arc` within and there's
550 // no need for a mutex here because synchronization happens with `join()` (the
551 // parent thread never reads this packet until the child has exited).
553 // This packet itself is then stored into a `JoinInner` which in turns is placed
554 // in `JoinHandle` and `JoinGuard`. Due to the usage of `UnsafeCell` we need to
555 // manually worry about impls like Send and Sync. The type `T` should
556 // already always be Send (otherwise the thread could not have been created) and
557 // this type is inherently Sync because no methods take &self. Regardless,
558 // however, we add inheriting impls for Send/Sync to this type to ensure it's
559 // Send/Sync and that future modifications will still appropriately classify it.
560 struct Packet<T>(Arc<UnsafeCell<Option<Result<T>>>>);
562 unsafe impl<T: Send> Send for Packet<T> {}
563 unsafe impl<T: Sync> Sync for Packet<T> {}
565 /// Inner representation for JoinHandle
566 struct JoinInner<T> {
567 native: Option<imp::Thread>,
572 impl<T> JoinInner<T> {
573 fn join(&mut self) -> Result<T> {
574 self.native.take().unwrap().join();
576 (*self.packet.0.get()).take().unwrap()
581 /// An owned permission to join on a thread (block on its termination).
583 /// A `JoinHandle` *detaches* the child thread when it is dropped.
585 /// Due to platform restrictions, it is not possible to `Clone` this
586 /// handle: the ability to join a child thread is a uniquely-owned
588 #[stable(feature = "rust1", since = "1.0.0")]
589 pub struct JoinHandle<T>(JoinInner<T>);
591 impl<T> JoinHandle<T> {
592 /// Extracts a handle to the underlying thread
593 #[stable(feature = "rust1", since = "1.0.0")]
594 pub fn thread(&self) -> &Thread {
598 /// Waits for the associated thread to finish.
600 /// If the child thread panics, `Err` is returned with the parameter given
602 #[stable(feature = "rust1", since = "1.0.0")]
603 pub fn join(mut self) -> Result<T> {
608 impl<T> AsInner<imp::Thread> for JoinHandle<T> {
609 fn as_inner(&self) -> &imp::Thread { self.0.native.as_ref().unwrap() }
612 impl<T> IntoInner<imp::Thread> for JoinHandle<T> {
613 fn into_inner(self) -> imp::Thread { self.0.native.unwrap() }
616 fn _assert_sync_and_send() {
617 fn _assert_both<T: Send + Sync>() {}
618 _assert_both::<JoinHandle<()>>();
619 _assert_both::<Thread>();
622 ////////////////////////////////////////////////////////////////////////////////
624 ////////////////////////////////////////////////////////////////////////////////
631 use sync::mpsc::{channel, Sender};
633 use super::{Builder};
638 // !!! These tests are dangerous. If something is buggy, they will hang, !!!
639 // !!! instead of exiting cleanly. This might wedge the buildbots. !!!
642 fn test_unnamed_thread() {
643 thread::spawn(move|| {
644 assert!(thread::current().name().is_none());
645 }).join().ok().unwrap();
649 fn test_named_thread() {
650 Builder::new().name("ada lovelace".to_string()).spawn(move|| {
651 assert!(thread::current().name().unwrap() == "ada lovelace".to_string());
652 }).unwrap().join().unwrap();
656 fn test_run_basic() {
657 let (tx, rx) = channel();
658 thread::spawn(move|| {
659 tx.send(()).unwrap();
665 fn test_join_panic() {
666 match thread::spawn(move|| {
669 result::Result::Err(_) => (),
670 result::Result::Ok(()) => panic!()
675 fn test_spawn_sched() {
678 let (tx, rx) = channel();
680 fn f(i: i32, tx: Sender<()>) {
682 thread::spawn(move|| {
684 tx.send(()).unwrap();
696 fn test_spawn_sched_childs_on_default_sched() {
697 let (tx, rx) = channel();
699 thread::spawn(move|| {
700 thread::spawn(move|| {
701 tx.send(()).unwrap();
708 fn avoid_copying_the_body<F>(spawnfn: F) where F: FnOnce(Box<Fn() + Send>) {
709 let (tx, rx) = channel();
711 let x: Box<_> = box 1;
712 let x_in_parent = (&*x) as *const i32 as usize;
714 spawnfn(Box::new(move|| {
715 let x_in_child = (&*x) as *const i32 as usize;
716 tx.send(x_in_child).unwrap();
719 let x_in_child = rx.recv().unwrap();
720 assert_eq!(x_in_parent, x_in_child);
724 fn test_avoid_copying_the_body_spawn() {
725 avoid_copying_the_body(|v| {
726 thread::spawn(move || v());
731 fn test_avoid_copying_the_body_thread_spawn() {
732 avoid_copying_the_body(|f| {
733 thread::spawn(move|| {
740 fn test_avoid_copying_the_body_join() {
741 avoid_copying_the_body(|f| {
742 let _ = thread::spawn(move|| {
749 fn test_child_doesnt_ref_parent() {
750 // If the child refcounts the parent thread, this will stack overflow when
751 // climbing the thread tree to dereference each ancestor. (See #1789)
752 // (well, it would if the constant were 8000+ - I lowered it to be more
753 // valgrind-friendly. try this at home, instead..!)
754 const GENERATIONS: u32 = 16;
755 fn child_no(x: u32) -> Box<Fn() + Send> {
756 return Box::new(move|| {
758 thread::spawn(move|| child_no(x+1)());
762 thread::spawn(|| child_no(0)());
766 fn test_simple_newsched_spawn() {
767 thread::spawn(move || {});
771 fn test_try_panic_message_static_str() {
772 match thread::spawn(move|| {
773 panic!("static string");
776 type T = &'static str;
777 assert!(e.is::<T>());
778 assert_eq!(*e.downcast::<T>().unwrap(), "static string");
785 fn test_try_panic_message_owned_str() {
786 match thread::spawn(move|| {
787 panic!("owned string".to_string());
791 assert!(e.is::<T>());
792 assert_eq!(*e.downcast::<T>().unwrap(), "owned string".to_string());
799 fn test_try_panic_message_any() {
800 match thread::spawn(move|| {
801 panic!(box 413u16 as Box<Any + Send>);
804 type T = Box<Any + Send>;
805 assert!(e.is::<T>());
806 let any = e.downcast::<T>().unwrap();
807 assert!(any.is::<u16>());
808 assert_eq!(*any.downcast::<u16>().unwrap(), 413);
815 fn test_try_panic_message_unit_struct() {
818 match thread::spawn(move|| {
821 Err(ref e) if e.is::<Juju>() => {}
822 Err(_) | Ok(()) => panic!()
827 fn test_park_timeout_unpark_before() {
829 thread::current().unpark();
830 thread::park_timeout_ms(u32::MAX);
835 fn test_park_timeout_unpark_not_called() {
837 thread::park_timeout_ms(10);
842 fn test_park_timeout_unpark_called_other_thread() {
844 let th = thread::current();
846 let _guard = thread::spawn(move || {
851 thread::park_timeout_ms(u32::MAX);
856 fn sleep_ms_smoke() {
860 // NOTE: the corresponding test for stderr is in run-pass/thread-stderr, due
861 // to the test harness apparently interfering with stderr configuration.