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.
72 //! Often a parent thread uses a child thread to perform some particular task,
73 //! and at some point must wait for the child to complete before continuing.
74 //! For this scenario, use the `thread::scoped` function:
79 //! let guard = thread::scoped(move || {
83 //! // do some other work in the meantime
84 //! let output = guard.join();
87 //! The `scoped` function doesn't return a `Thread` directly; instead,
88 //! it returns a *join guard*. The join guard is an RAII-style guard
89 //! that will automatically join the child thread (block until it
90 //! terminates) when it is dropped. You can join the child thread in
91 //! advance by calling the `join` method on the guard, which will also
92 //! return the result produced by the thread. A handle to the thread
93 //! itself is available via the `thread` method of the join guard.
95 //! ## Configuring threads
97 //! A new thread can be configured before it is spawned via the `Builder` type,
98 //! which currently allows you to set the name, stack size, and writers for
99 //! `println!` and `panic!` for the child thread:
104 //! thread::Builder::new().name("child1".to_string()).spawn(move || {
105 //! println!("Hello, world!");
109 //! ## Blocking support: park and unpark
111 //! Every thread is equipped with some basic low-level blocking support, via the
112 //! `park` and `unpark` functions.
114 //! Conceptually, each `Thread` handle has an associated token, which is
115 //! initially not present:
117 //! * The `thread::park()` function blocks the current thread unless or until
118 //! the token is available for its thread handle, at which point it atomically
119 //! consumes the token. It may also return *spuriously*, without consuming the
120 //! token. `thread::park_timeout()` does the same, but allows specifying a
121 //! maximum time to block the thread for.
123 //! * The `unpark()` method on a `Thread` atomically makes the token available
124 //! if it wasn't already.
126 //! In other words, each `Thread` acts a bit like a semaphore with initial count
127 //! 0, except that the semaphore is *saturating* (the count cannot go above 1),
128 //! and can return spuriously.
130 //! The API is typically used by acquiring a handle to the current thread,
131 //! placing that handle in a shared data structure so that other threads can
132 //! find it, and then `park`ing. When some desired condition is met, another
133 //! thread calls `unpark` on the handle.
135 //! The motivation for this design is twofold:
137 //! * It avoids the need to allocate mutexes and condvars when building new
138 //! synchronization primitives; the threads already provide basic blocking/signaling.
140 //! * It can be implemented very efficiently on many platforms.
142 #![stable(feature = "rust1", since = "1.0.0")]
147 use cell::UnsafeCell;
150 use marker::PhantomData;
152 use rt::{self, unwind};
153 use sync::{Mutex, Condvar, Arc};
157 use sys::thread as imp;
158 use sys_common::{stack, thread_info};
160 /// Thread configuration. Provides detailed control over the properties
161 /// and behavior of new threads.
162 #[stable(feature = "rust1", since = "1.0.0")]
164 // A name for the thread-to-be, for identification in panic messages
165 name: Option<String>,
166 // The size of the stack for the spawned thread
167 stack_size: Option<usize>,
168 // Thread-local stdout
169 stdout: Option<Box<Writer + Send + 'static>>,
170 // Thread-local stderr
171 stderr: Option<Box<Writer + Send + 'static>>,
175 /// Generate the base configuration for spawning a thread, from which
176 /// configuration methods can be chained.
177 #[stable(feature = "rust1", since = "1.0.0")]
178 pub fn new() -> Builder {
187 /// Name the thread-to-be. Currently the name is used for identification
188 /// only in panic messages.
189 #[stable(feature = "rust1", since = "1.0.0")]
190 pub fn name(mut self, name: String) -> Builder {
191 self.name = Some(name);
195 /// Set the size of the stack for the new thread.
196 #[stable(feature = "rust1", since = "1.0.0")]
197 pub fn stack_size(mut self, size: usize) -> Builder {
198 self.stack_size = Some(size);
202 /// Redirect thread-local stdout.
203 #[unstable(feature = "std_misc",
204 reason = "Will likely go away after proc removal")]
205 pub fn stdout(mut self, stdout: Box<Writer + Send + 'static>) -> Builder {
206 self.stdout = Some(stdout);
210 /// Redirect thread-local stderr.
211 #[unstable(feature = "std_misc",
212 reason = "Will likely go away after proc removal")]
213 pub fn stderr(mut self, stderr: Box<Writer + Send + 'static>) -> Builder {
214 self.stderr = Some(stderr);
218 /// Spawn a new thread, and return a join handle for it.
220 /// The child thread may outlive the parent (unless the parent thread
221 /// is the main thread; the whole process is terminated when the main
222 /// thread finishes.) The join handle can be used to block on
223 /// termination of the child thread, including recovering its panics.
227 /// Unlike the `spawn` free function, this method yields an
228 /// `io::Result` to capture any failure to create the thread at
230 #[stable(feature = "rust1", since = "1.0.0")]
231 pub fn spawn<F>(self, f: F) -> io::Result<JoinHandle> where
232 F: FnOnce(), F: Send + 'static
234 self.spawn_inner(Thunk::new(f)).map(|i| JoinHandle(i))
237 /// Spawn a new child thread that must be joined within a given
238 /// scope, and return a `JoinGuard`.
240 /// The join guard can be used to explicitly join the child thread (via
241 /// `join`), returning `Result<T>`, or it will implicitly join the child
242 /// upon being dropped. Because the child thread may refer to data on the
243 /// current thread's stack (hence the "scoped" name), it cannot be detached;
244 /// it *must* be joined before the relevant stack frame is popped. See the
245 /// module documentation for additional details.
249 /// Unlike the `scoped` free function, this method yields an
250 /// `io::Result` to capture any failure to create the thread at
252 #[stable(feature = "rust1", since = "1.0.0")]
253 pub fn scoped<'a, T, F>(self, f: F) -> io::Result<JoinGuard<'a, T>> where
254 T: Send + 'a, F: FnOnce() -> T, F: Send + 'a
256 self.spawn_inner(Thunk::new(f)).map(|inner| {
257 JoinGuard { inner: inner, _marker: PhantomData }
261 fn spawn_inner<T: Send>(self, f: Thunk<(), T>) -> io::Result<JoinInner<T>> {
262 let Builder { name, stack_size, stdout, stderr } = self;
264 let stack_size = stack_size.unwrap_or(rt::min_stack());
266 let my_thread = Thread::new(name);
267 let their_thread = my_thread.clone();
269 let my_packet = Packet(Arc::new(UnsafeCell::new(None)));
270 let their_packet = Packet(my_packet.0.clone());
272 // Spawning a new OS thread guarantees that __morestack will never get
273 // triggered, but we must manually set up the actual stack bounds once
274 // this function starts executing. This raises the lower limit by a bit
275 // because by the time that this function is executing we've already
276 // consumed at least a little bit of stack (we don't know the exact byte
277 // address at which our stack started).
279 let something_around_the_top_of_the_stack = 1;
280 let addr = &something_around_the_top_of_the_stack as *const i32;
281 let my_stack_top = addr as usize;
282 let my_stack_bottom = my_stack_top - stack_size + 1024;
284 if let Some(name) = their_thread.name() {
287 stack::record_os_managed_stack_bounds(my_stack_bottom,
289 thread_info::set(imp::guard::current(), their_thread);
292 let mut output = None;
293 let f: Thunk<(), T> = if stdout.is_some() || stderr.is_some() {
295 let _ = stdout.map(stdio::set_stdout);
296 let _ = stderr.map(stdio::set_stderr);
304 let ptr = &mut output;
306 // There are two primary reasons that general try/catch is
307 // unsafe. The first is that we do not support nested
308 // try/catch. The fact that this is happening in a newly-spawned
309 // thread suffices. The second is that unwinding while unwinding
310 // is not defined. We take care of that by having an
311 // 'unwinding' flag in the thread itself. For these reasons,
312 // this unsafety should be ok.
314 unwind::try(move || *ptr = Some(f.invoke(())))
318 *their_packet.0.get() = Some(match (output, try_result) {
319 (Some(data), Ok(_)) => Ok(data),
320 (None, Err(cause)) => Err(cause),
327 native: try!(unsafe { imp::create(stack_size, Thunk::new(main)) }),
335 /// Spawn a new thread, returning a `JoinHandle` for it.
337 /// The join handle will implicitly *detach* the child thread upon being
338 /// dropped. In this case, the child thread may outlive the parent (unless
339 /// the parent thread is the main thread; the whole process is terminated when
340 /// the main thread finishes.) Additionally, the join handle provides a `join`
341 /// method that can be used to join the child thread. If the child thread
342 /// panics, `join` will return an `Err` containing the argument given to
347 /// Panicks if the OS fails to create a thread; use `Builder::spawn`
348 /// to recover from such errors.
349 #[stable(feature = "rust1", since = "1.0.0")]
350 pub fn spawn<F>(f: F) -> JoinHandle where F: FnOnce(), F: Send + 'static {
351 Builder::new().spawn(f).unwrap()
354 /// Spawn a new *scoped* thread, returning a `JoinGuard` for it.
356 /// The join guard can be used to explicitly join the child thread (via
357 /// `join`), returning `Result<T>`, or it will implicitly join the child
358 /// upon being dropped. Because the child thread may refer to data on the
359 /// current thread's stack (hence the "scoped" name), it cannot be detached;
360 /// it *must* be joined before the relevant stack frame is popped. See the
361 /// module documentation for additional details.
365 /// Panicks if the OS fails to create a thread; use `Builder::scoped`
366 /// to recover from such errors.
367 #[stable(feature = "rust1", since = "1.0.0")]
368 pub fn scoped<'a, T, F>(f: F) -> JoinGuard<'a, T> where
369 T: Send + 'a, F: FnOnce() -> T, F: Send + 'a
371 Builder::new().scoped(f).unwrap()
374 /// Gets a handle to the thread that invokes it.
375 #[stable(feature = "rust1", since = "1.0.0")]
376 pub fn current() -> Thread {
377 thread_info::current_thread()
380 /// Cooperatively give up a timeslice to the OS scheduler.
381 #[stable(feature = "rust1", since = "1.0.0")]
383 unsafe { imp::yield_now() }
386 /// Determines whether the current thread is unwinding because of panic.
388 #[stable(feature = "rust1", since = "1.0.0")]
389 pub fn panicking() -> bool {
393 /// Block unless or until the current thread's token is made available (may wake spuriously).
395 /// See the module doc for more detail.
397 // The implementation currently uses the trivial strategy of a Mutex+Condvar
398 // with wakeup flag, which does not actually allow spurious wakeups. In the
399 // future, this will be implemented in a more efficient way, perhaps along the lines of
400 // http://cr.openjdk.java.net/~stefank/6989984.1/raw_files/new/src/os/linux/vm/os_linux.cpp
401 // or futuxes, and in either case may allow spurious wakeups.
402 #[stable(feature = "rust1", since = "1.0.0")]
404 let thread = current();
405 let mut guard = thread.inner.lock.lock().unwrap();
407 guard = thread.inner.cvar.wait(guard).unwrap();
412 /// Block unless or until the current thread's token is made available or
413 /// the specified duration has been reached (may wake spuriously).
415 /// The semantics of this function are equivalent to `park()` except that the
416 /// thread will be blocked for roughly no longer than dur. This method
417 /// should not be used for precise timing due to anomalies such as
418 /// preemption or platform differences that may not cause the maximum
419 /// amount of time waited to be precisely dur
421 /// See the module doc for more detail.
422 #[unstable(feature = "std_misc", reason = "recently introduced, depends on Duration")]
423 pub fn park_timeout(dur: Duration) {
424 let thread = current();
425 let mut guard = thread.inner.lock.lock().unwrap();
427 let (g, _) = thread.inner.cvar.wait_timeout(guard, dur).unwrap();
433 /// The internal representation of a `Thread` handle
435 name: Option<String>,
436 lock: Mutex<bool>, // true when there is a buffered unpark
440 unsafe impl Sync for Inner {}
443 #[stable(feature = "rust1", since = "1.0.0")]
444 /// A handle to a thread.
450 // Used only internally to construct a thread object without spawning
451 fn new(name: Option<String>) -> Thread {
453 inner: Arc::new(Inner {
455 lock: Mutex::new(false),
456 cvar: Condvar::new(),
461 /// Deprecated: use module-level free function.
462 #[deprecated(since = "1.0.0", reason = "use module-level free function")]
463 #[unstable(feature = "std_misc",
464 reason = "may change with specifics of new Send semantics")]
465 pub fn spawn<F>(f: F) -> Thread where F: FnOnce(), F: Send + 'static {
466 Builder::new().spawn(f).unwrap().thread().clone()
469 /// Deprecated: use module-level free function.
470 #[deprecated(since = "1.0.0", reason = "use module-level free function")]
471 #[unstable(feature = "std_misc",
472 reason = "may change with specifics of new Send semantics")]
473 pub fn scoped<'a, T, F>(f: F) -> JoinGuard<'a, T> where
474 T: Send + 'a, F: FnOnce() -> T, F: Send + 'a
476 Builder::new().scoped(f).unwrap()
479 /// Deprecated: use module-level free function.
480 #[deprecated(since = "1.0.0", reason = "use module-level free function")]
481 #[stable(feature = "rust1", since = "1.0.0")]
482 pub fn current() -> Thread {
483 thread_info::current_thread()
486 /// Deprecated: use module-level free function.
487 #[deprecated(since = "1.0.0", reason = "use module-level free function")]
488 #[unstable(feature = "std_misc", reason = "name may change")]
490 unsafe { imp::yield_now() }
493 /// Deprecated: use module-level free function.
494 #[deprecated(since = "1.0.0", reason = "use module-level free function")]
496 #[stable(feature = "rust1", since = "1.0.0")]
497 pub fn panicking() -> bool {
501 /// Deprecated: use module-level free function.
502 #[deprecated(since = "1.0.0", reason = "use module-level free function")]
503 #[unstable(feature = "std_misc", reason = "recently introduced")]
505 let thread = current();
506 let mut guard = thread.inner.lock.lock().unwrap();
508 guard = thread.inner.cvar.wait(guard).unwrap();
513 /// Deprecated: use module-level free function.
514 #[deprecated(since = "1.0.0", reason = "use module-level free function")]
515 #[unstable(feature = "std_misc", reason = "recently introduced")]
516 pub fn park_timeout(dur: Duration) {
517 let thread = current();
518 let mut guard = thread.inner.lock.lock().unwrap();
520 let (g, _) = thread.inner.cvar.wait_timeout(guard, dur).unwrap();
526 /// Atomically makes the handle's token available if it is not already.
528 /// See the module doc for more detail.
529 #[stable(feature = "rust1", since = "1.0.0")]
530 pub fn unpark(&self) {
531 let mut guard = self.inner.lock.lock().unwrap();
534 self.inner.cvar.notify_one();
538 /// Get the thread's name.
539 #[stable(feature = "rust1", since = "1.0.0")]
540 pub fn name(&self) -> Option<&str> {
541 self.inner.name.as_ref().map(|s| &**s)
545 #[stable(feature = "rust1", since = "1.0.0")]
546 impl fmt::Debug for Thread {
547 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
548 fmt::Debug::fmt(&self.name(), f)
552 // a hack to get around privacy restrictions
553 impl thread_info::NewThread for Thread {
554 fn new(name: Option<String>) -> Thread { Thread::new(name) }
557 /// Indicates the manner in which a thread exited.
559 /// A thread that completes without panicking is considered to exit successfully.
560 #[stable(feature = "rust1", since = "1.0.0")]
561 pub type Result<T> = ::result::Result<T, Box<Any + Send + 'static>>;
563 struct Packet<T>(Arc<UnsafeCell<Option<Result<T>>>>);
565 unsafe impl<T:Send> Send for Packet<T> {}
566 unsafe impl<T> Sync for Packet<T> {}
568 /// Inner representation for JoinHandle and JoinGuard
569 struct JoinInner<T> {
570 native: imp::rust_thread,
576 impl<T> JoinInner<T> {
577 fn join(&mut self) -> Result<T> {
578 assert!(!self.joined);
579 unsafe { imp::join(self.native) };
582 (*self.packet.0.get()).take().unwrap()
587 /// An owned permission to join on a thread (block on its termination).
589 /// Unlike a `JoinGuard`, a `JoinHandle` *detaches* the child thread
590 /// when it is dropped, rather than automatically joining on drop.
592 /// Due to platform restrictions, it is not possible to `Clone` this
593 /// handle: the ability to join a child thread is a uniquely-owned
595 #[stable(feature = "rust1", since = "1.0.0")]
596 pub struct JoinHandle(JoinInner<()>);
599 /// Extract a handle to the underlying thread
600 #[stable(feature = "rust1", since = "1.0.0")]
601 pub fn thread(&self) -> &Thread {
605 /// Wait for the associated thread to finish.
607 /// If the child thread panics, `Err` is returned with the parameter given
609 #[stable(feature = "rust1", since = "1.0.0")]
610 pub fn join(mut self) -> Result<()> {
615 #[stable(feature = "rust1", since = "1.0.0")]
616 impl Drop for JoinHandle {
619 unsafe { imp::detach(self.0.native) }
624 /// An RAII-style guard that will block until thread termination when dropped.
626 /// The type `T` is the return type for the thread's main function.
628 /// Joining on drop is necessary to ensure memory safety when stack
629 /// data is shared between a parent and child thread.
631 /// Due to platform restrictions, it is not possible to `Clone` this
632 /// handle: the ability to join a child thread is a uniquely-owned
634 #[must_use = "thread will be immediately joined if `JoinGuard` is not used"]
635 #[stable(feature = "rust1", since = "1.0.0")]
636 pub struct JoinGuard<'a, T: 'a> {
638 _marker: PhantomData<&'a T>,
641 #[stable(feature = "rust1", since = "1.0.0")]
642 unsafe impl<'a, T: Send + 'a> Sync for JoinGuard<'a, T> {}
644 impl<'a, T: Send + 'a> JoinGuard<'a, T> {
645 /// Extract a handle to the thread this guard will join on.
646 #[stable(feature = "rust1", since = "1.0.0")]
647 pub fn thread(&self) -> &Thread {
651 /// Wait for the associated thread to finish, returning the result of the thread's
656 /// Panics on the child thread are propagated by panicking the parent.
657 #[stable(feature = "rust1", since = "1.0.0")]
658 pub fn join(mut self) -> T {
659 match self.inner.join() {
661 Err(_) => panic!("child thread {:?} panicked", self.thread()),
666 #[stable(feature = "rust1", since = "1.0.0")]
667 impl<T: Send> JoinGuard<'static, T> {
668 /// Detaches the child thread, allowing it to outlive its parent.
669 #[deprecated(since = "1.0.0", reason = "use spawn instead")]
670 #[unstable(feature = "std_misc")]
671 pub fn detach(mut self) {
672 unsafe { imp::detach(self.inner.native) };
673 self.inner.joined = true; // avoid joining in the destructor
678 #[stable(feature = "rust1", since = "1.0.0")]
679 impl<'a, T: Send + 'a> Drop for JoinGuard<'a, T> {
681 if !self.inner.joined {
682 if self.inner.join().is_err() {
683 panic!("child thread {:?} panicked", self.thread());
694 use sync::mpsc::{channel, Sender};
697 use std::old_io::{ChanReader, ChanWriter};
698 use super::{Builder};
703 // !!! These tests are dangerous. If something is buggy, they will hang, !!!
704 // !!! instead of exiting cleanly. This might wedge the buildbots. !!!
707 fn test_unnamed_thread() {
708 thread::spawn(move|| {
709 assert!(thread::current().name().is_none());
710 }).join().ok().unwrap();
714 fn test_named_thread() {
715 Builder::new().name("ada lovelace".to_string()).scoped(move|| {
716 assert!(thread::current().name().unwrap() == "ada lovelace".to_string());
721 fn test_run_basic() {
722 let (tx, rx) = channel();
723 thread::spawn(move|| {
724 tx.send(()).unwrap();
730 fn test_join_success() {
731 assert!(thread::scoped(move|| -> String {
732 "Success!".to_string()
733 }).join() == "Success!");
737 fn test_join_panic() {
738 match thread::spawn(move|| {
741 result::Result::Err(_) => (),
742 result::Result::Ok(()) => panic!()
747 fn test_scoped_success() {
748 let res = thread::scoped(move|| -> String {
749 "Success!".to_string()
751 assert!(res == "Success!");
756 fn test_scoped_panic() {
757 thread::scoped(|| panic!()).join();
762 fn test_scoped_implicit_panic() {
763 let _ = thread::scoped(|| panic!());
767 fn test_spawn_sched() {
770 let (tx, rx) = channel();
772 fn f(i: i32, tx: Sender<()>) {
774 thread::spawn(move|| {
776 tx.send(()).unwrap();
788 fn test_spawn_sched_childs_on_default_sched() {
789 let (tx, rx) = channel();
791 thread::spawn(move|| {
792 thread::spawn(move|| {
793 tx.send(()).unwrap();
800 fn avoid_copying_the_body<F>(spawnfn: F) where F: FnOnce(Thunk<'static>) {
801 let (tx, rx) = channel();
803 let x: Box<_> = box 1;
804 let x_in_parent = (&*x) as *const i32 as usize;
806 spawnfn(Thunk::new(move|| {
807 let x_in_child = (&*x) as *const i32 as usize;
808 tx.send(x_in_child).unwrap();
811 let x_in_child = rx.recv().unwrap();
812 assert_eq!(x_in_parent, x_in_child);
816 fn test_avoid_copying_the_body_spawn() {
817 avoid_copying_the_body(|v| {
818 thread::spawn(move || v.invoke(()));
823 fn test_avoid_copying_the_body_thread_spawn() {
824 avoid_copying_the_body(|f| {
825 thread::spawn(move|| {
832 fn test_avoid_copying_the_body_join() {
833 avoid_copying_the_body(|f| {
834 let _ = thread::spawn(move|| {
841 fn test_child_doesnt_ref_parent() {
842 // If the child refcounts the parent task, this will stack overflow when
843 // climbing the task tree to dereference each ancestor. (See #1789)
844 // (well, it would if the constant were 8000+ - I lowered it to be more
845 // valgrind-friendly. try this at home, instead..!)
846 const GENERATIONS: u32 = 16;
847 fn child_no(x: u32) -> Thunk<'static> {
848 return Thunk::new(move|| {
850 thread::spawn(move|| child_no(x+1).invoke(()));
854 thread::spawn(|| child_no(0).invoke(()));
858 fn test_simple_newsched_spawn() {
859 thread::spawn(move || {});
863 fn test_try_panic_message_static_str() {
864 match thread::spawn(move|| {
865 panic!("static string");
868 type T = &'static str;
869 assert!(e.is::<T>());
870 assert_eq!(*e.downcast::<T>().ok().unwrap(), "static string");
877 fn test_try_panic_message_owned_str() {
878 match thread::spawn(move|| {
879 panic!("owned string".to_string());
883 assert!(e.is::<T>());
884 assert_eq!(*e.downcast::<T>().ok().unwrap(), "owned string".to_string());
891 fn test_try_panic_message_any() {
892 match thread::spawn(move|| {
893 panic!(box 413u16 as Box<Any + Send>);
896 type T = Box<Any + Send>;
897 assert!(e.is::<T>());
898 let any = e.downcast::<T>().ok().unwrap();
899 assert!(any.is::<u16>());
900 assert_eq!(*any.downcast::<u16>().ok().unwrap(), 413);
907 fn test_try_panic_message_unit_struct() {
910 match thread::spawn(move|| {
913 Err(ref e) if e.is::<Juju>() => {}
914 Err(_) | Ok(()) => panic!()
920 let (tx, rx) = channel();
921 let mut reader = ChanReader::new(rx);
922 let stdout = ChanWriter::new(tx);
924 Builder::new().stdout(box stdout as Box<Writer + Send>).scoped(move|| {
925 print!("Hello, world!");
928 let output = reader.read_to_string().unwrap();
929 assert_eq!(output, "Hello, world!".to_string());
933 fn test_park_timeout_unpark_before() {
935 thread::current().unpark();
936 thread::park_timeout(Duration::seconds(10_000_000));
941 fn test_park_timeout_unpark_not_called() {
943 thread::park_timeout(Duration::milliseconds(10));
948 fn test_park_timeout_unpark_called_other_thread() {
952 let th = thread::current();
954 let _guard = thread::spawn(move || {
955 old_io::timer::sleep(Duration::milliseconds(50));
959 thread::park_timeout(Duration::seconds(10_000_000));
963 // NOTE: the corresponding test for stderr is in run-pass/task-stderr, due
964 // to the test harness apparently interfering with stderr configuration.