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. Threads can be named, and
17 //! provide some built-in support for low-level synchronization.
19 //! Communication between threads can be done through
20 //! [channels](../../std/sync/mpsc/index.html), Rust's message-passing
21 //! types, along with [other forms of thread
22 //! synchronization](../../std/sync/index.html) and shared-memory data
23 //! structures. In particular, types that are guaranteed to be
24 //! threadsafe are easily shared between threads using the
25 //! atomically-reference-counted container,
26 //! [`Arc`](../../std/sync/struct.Arc.html).
28 //! Fatal logic errors in Rust cause *thread panic*, during which
29 //! a thread will unwind the stack, running destructors and freeing
30 //! owned resources. Thread panic is unrecoverable from within
31 //! the panicking thread (i.e. there is no 'try/catch' in Rust), but
32 //! the panic may optionally be detected from a different thread. If
33 //! the main thread panics, the application will exit with a non-zero
36 //! When the main thread of a Rust program terminates, the entire program shuts
37 //! down, even if other threads are still running. However, this module provides
38 //! convenient facilities for automatically waiting for the termination of a
39 //! child thread (i.e., join).
41 //! ## Spawning a thread
43 //! A new thread can be spawned using the `thread::spawn` function:
48 //! thread::spawn(move || {
53 //! In this example, the spawned thread is "detached" from the current
54 //! thread. This means that it can outlive its parent (the thread that spawned
55 //! it), unless this parent is the main thread.
57 //! The parent thread can also wait on the completion of the child
58 //! thread; a call to `spawn` produces a `JoinHandle`, which provides
59 //! a `join` method for waiting:
64 //! let child = thread::spawn(move || {
68 //! let res = child.join();
71 //! The `join` method returns a `Result` containing `Ok` of the final
72 //! value produced by the child thread, or `Err` of the value given to
73 //! a call to `panic!` if the child panicked.
75 //! ## Configuring threads
77 //! A new thread can be configured before it is spawned via the `Builder` type,
78 //! which currently allows you to set the name and stack size for the child thread:
81 //! # #![allow(unused_must_use)]
84 //! thread::Builder::new().name("child1".to_string()).spawn(move || {
85 //! println!("Hello, world!");
89 //! ## The `Thread` type
91 //! Threads are represented via the `Thread` type, which you can get in one of
94 //! * By spawning a new thread, e.g. using the `thread::spawn` function, and
95 //! calling `thread()` on the `JoinHandle`.
96 //! * By requesting the current thread, using the `thread::current` function.
98 //! The `thread::current()` function is available even for threads not spawned
99 //! by the APIs of this module.
101 //! ## Blocking support: park and unpark
103 //! Every thread is equipped with some basic low-level blocking support, via the
104 //! `thread::park()` function and `thread::Thread::unpark()` method. `park()`
105 //! blocks the current thread, which can then be resumed from another thread by
106 //! calling the `unpark()` method on the blocked thread's handle.
108 //! Conceptually, each `Thread` handle has an associated token, which is
109 //! initially not present:
111 //! * The `thread::park()` function blocks the current thread unless or until
112 //! the token is available for its thread handle, at which point it atomically
113 //! consumes the token. It may also return *spuriously*, without consuming the
114 //! token. `thread::park_timeout()` does the same, but allows specifying a
115 //! maximum time to block the thread for.
117 //! * The `unpark()` method on a `Thread` atomically makes the token available
118 //! if it wasn't already.
120 //! In other words, each `Thread` acts a bit like a semaphore with initial count
121 //! 0, except that the semaphore is *saturating* (the count cannot go above 1),
122 //! and can return spuriously.
124 //! The API is typically used by acquiring a handle to the current thread,
125 //! placing that handle in a shared data structure so that other threads can
126 //! find it, and then `park`ing. When some desired condition is met, another
127 //! thread calls `unpark` on the handle.
129 //! The motivation for this design is twofold:
131 //! * It avoids the need to allocate mutexes and condvars when building new
132 //! synchronization primitives; the threads already provide basic blocking/signaling.
134 //! * It can be implemented very efficiently on many platforms.
136 //! ## Thread-local storage
138 //! This module also provides an implementation of thread-local storage for Rust
139 //! programs. Thread-local storage is a method of storing data into a global
140 //! variable that each thread in the program will have its own copy of.
141 //! Threads do not share this data, so accesses do not need to be synchronized.
143 //! A thread-local key owns the value it contains and will destroy the value when the
144 //! thread exits. It is created with the [`thread_local!`] macro and can contain any
145 //! value that is `'static` (no borrowed pointers). It provides an accessor function,
146 //! [`with`], that yields a shared reference to the value to the specified
147 //! closure. Thread-local keys allow only shared access to values, as there would be no
148 //! way to guarantee uniqueness if mutable borrows were allowed. Most values
149 //! will want to make use of some form of **interior mutability** through the
150 //! [`Cell`] or [`RefCell`] types.
152 //! [`Cell`]: ../cell/struct.Cell.html
153 //! [`RefCell`]: ../cell/struct.RefCell.html
154 //! [`thread_local!`]: ../macro.thread_local!.html
155 //! [`with`]: struct.LocalKey.html#method.with
157 #![stable(feature = "rust1", since = "1.0.0")]
160 use cell
::UnsafeCell
;
161 use ffi
::{CStr, CString}
;
167 use sync
::{Mutex, Condvar, Arc}
;
168 use sys
::thread
as imp
;
169 use sys_common
::thread_info
;
170 use sys_common
::util
;
171 use sys_common
::{AsInner, IntoInner}
;
174 ////////////////////////////////////////////////////////////////////////////////
175 // Thread-local storage
176 ////////////////////////////////////////////////////////////////////////////////
178 #[macro_use] mod local;
180 #[stable(feature = "rust1", since = "1.0.0")]
181 pub use self::local
::{LocalKey, LocalKeyState}
;
183 #[unstable(feature = "libstd_thread_internals", issue = "0")]
184 #[cfg(target_thread_local)]
185 #[doc(hidden)] pub use self::local::elf::Key as __ElfLocalKeyInner;
186 #[unstable(feature = "libstd_thread_internals", issue = "0")]
187 #[doc(hidden)] pub use self::local::os::Key as __OsLocalKeyInner;
189 ////////////////////////////////////////////////////////////////////////////////
191 ////////////////////////////////////////////////////////////////////////////////
193 /// Thread configuration. Provides detailed control over the properties
194 /// and behavior of new threads.
195 #[stable(feature = "rust1", since = "1.0.0")]
197 // A name for the thread-to-be, for identification in panic messages
198 name
: Option
<String
>,
199 // The size of the stack for the spawned thread
200 stack_size
: Option
<usize>,
204 /// Generates the base configuration for spawning a thread, from which
205 /// configuration methods can be chained.
206 #[stable(feature = "rust1", since = "1.0.0")]
207 pub fn new() -> Builder
{
214 /// Names the thread-to-be. Currently the name is used for identification
215 /// only in panic messages.
222 /// let builder = thread::Builder::new()
223 /// .name("foo".into());
225 /// let handler = builder.spawn(|| {
226 /// assert_eq!(thread::current().name(), Some("foo"))
229 /// handler.join().unwrap();
231 #[stable(feature = "rust1", since = "1.0.0")]
232 pub fn name(mut self, name
: String
) -> Builder
{
233 self.name
= Some(name
);
237 /// Sets the size of the stack for the new thread.
238 #[stable(feature = "rust1", since = "1.0.0")]
239 pub fn stack_size(mut self, size
: usize) -> Builder
{
240 self.stack_size
= Some(size
);
244 /// Spawns a new thread, and returns a join handle for it.
246 /// The child thread may outlive the parent (unless the parent thread
247 /// is the main thread; the whole process is terminated when the main
248 /// thread finishes). The join handle can be used to block on
249 /// termination of the child thread, including recovering its panics.
253 /// Unlike the `spawn` free function, this method yields an
254 /// `io::Result` to capture any failure to create the thread at
256 #[stable(feature = "rust1", since = "1.0.0")]
257 pub fn spawn
<F
, T
>(self, f
: F
) -> io
::Result
<JoinHandle
<T
>> where
258 F
: FnOnce() -> T
, F
: Send
+ '
static, T
: Send
+ '
static
260 let Builder { name, stack_size }
= self;
262 let stack_size
= stack_size
.unwrap_or(util
::min_stack());
264 let my_thread
= Thread
::new(name
);
265 let their_thread
= my_thread
.clone();
267 let my_packet
: Arc
<UnsafeCell
<Option
<Result
<T
>>>>
268 = Arc
::new(UnsafeCell
::new(None
));
269 let their_packet
= my_packet
.clone();
272 if let Some(name
) = their_thread
.cname() {
273 imp
::Thread
::set_name(name
);
276 thread_info
::set(imp
::guard
::current(), their_thread
);
277 let try_result
= panic
::catch_unwind(panic
::AssertUnwindSafe(f
));
278 *their_packet
.get() = Some(try_result
);
282 Ok(JoinHandle(JoinInner
{
284 Some(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.
321 /// Getting a handle to the current thread with `thread::current()`:
326 /// let handler = thread::Builder::new()
327 /// .name("named thread".into())
329 /// let handle = thread::current();
330 /// assert_eq!(handle.name(), Some("named thread"));
334 /// handler.join().unwrap();
336 #[stable(feature = "rust1", since = "1.0.0")]
337 pub fn current() -> Thread
{
338 thread_info
::current_thread().expect("use of std::thread::current() is not \
339 possible after the thread's local \
340 data has been destroyed")
343 /// Cooperatively gives up a timeslice to the OS scheduler.
344 #[stable(feature = "rust1", since = "1.0.0")]
346 imp
::Thread
::yield_now()
349 /// Determines whether the current thread is unwinding because of panic.
353 /// ```rust,should_panic
356 /// struct SomeStruct;
358 /// impl Drop for SomeStruct {
359 /// fn drop(&mut self) {
360 /// if thread::panicking() {
361 /// println!("dropped while unwinding");
363 /// println!("dropped while not unwinding");
370 /// let a = SomeStruct;
375 /// let b = SomeStruct;
380 #[stable(feature = "rust1", since = "1.0.0")]
381 pub fn panicking() -> bool
{
382 panicking
::panicking()
385 /// Puts the current thread to sleep for the specified amount of time.
387 /// The thread may sleep longer than the duration specified due to scheduling
388 /// specifics or platform-dependent functionality. Note that on unix platforms
389 /// this function will not return early due to a signal being received or a
391 #[stable(feature = "rust1", since = "1.0.0")]
392 #[rustc_deprecated(since = "1.6.0", reason = "replaced by `std::thread::sleep`")]
393 pub fn sleep_ms(ms
: u32) {
394 sleep(Duration
::from_millis(ms
as u64))
397 /// Puts the current thread to sleep for the specified amount of time.
399 /// The thread may sleep longer than the duration specified due to scheduling
400 /// specifics or platform-dependent functionality.
402 /// # Platform behavior
404 /// On Unix platforms this function will not return early due to a
405 /// signal being received or a spurious wakeup. Platforms which do not support
406 /// nanosecond precision for sleeping will have `dur` rounded up to the nearest
407 /// granularity of time they can sleep for.
412 /// use std::{thread, time};
414 /// let ten_millis = time::Duration::from_millis(10);
415 /// let now = time::Instant::now();
417 /// thread::sleep(ten_millis);
419 /// assert!(now.elapsed() >= ten_millis);
421 #[stable(feature = "thread_sleep", since = "1.4.0")]
422 pub fn sleep(dur
: Duration
) {
423 imp
::Thread
::sleep(dur
)
426 /// Blocks unless or until the current thread's token is made available.
428 /// Every thread is equipped with some basic low-level blocking support, via
429 /// the `park()` function and the [`unpark()`][unpark] method. These can be
430 /// used as a more CPU-efficient implementation of a spinlock.
432 /// [unpark]: struct.Thread.html#method.unpark
434 /// The API is typically used by acquiring a handle to the current thread,
435 /// placing that handle in a shared data structure so that other threads can
436 /// find it, and then parking (in a loop with a check for the token actually
439 /// A call to `park` does not guarantee that the thread will remain parked
440 /// forever, and callers should be prepared for this possibility.
442 /// See the [module documentation][thread] for more detail.
444 /// [thread]: index.html
446 // The implementation currently uses the trivial strategy of a Mutex+Condvar
447 // with wakeup flag, which does not actually allow spurious wakeups. In the
448 // future, this will be implemented in a more efficient way, perhaps along the lines of
449 // http://cr.openjdk.java.net/~stefank/6989984.1/raw_files/new/src/os/linux/vm/os_linux.cpp
450 // or futuxes, and in either case may allow spurious wakeups.
451 #[stable(feature = "rust1", since = "1.0.0")]
453 let thread
= current();
454 let mut guard
= thread
.inner
.lock
.lock().unwrap();
456 guard
= thread
.inner
.cvar
.wait(guard
).unwrap();
461 /// Use [park_timeout].
463 /// Blocks unless or until the current thread's token is made available or
464 /// the specified duration has been reached (may wake spuriously).
466 /// The semantics of this function are equivalent to `park()` except that the
467 /// thread will be blocked for roughly no longer than `ms`. This method
468 /// should not be used for precise timing due to anomalies such as
469 /// preemption or platform differences that may not cause the maximum
470 /// amount of time waited to be precisely `ms` long.
472 /// See the [module documentation][thread] for more detail.
474 /// [thread]: index.html
475 /// [park_timeout]: fn.park_timeout.html
476 #[stable(feature = "rust1", since = "1.0.0")]
477 #[rustc_deprecated(since = "1.6.0", reason = "replaced by `std::thread::park_timeout`")]
478 pub fn park_timeout_ms(ms
: u32) {
479 park_timeout(Duration
::from_millis(ms
as u64))
482 /// Blocks unless or until the current thread's token is made available or
483 /// the specified duration has been reached (may wake spuriously).
485 /// The semantics of this function are equivalent to `park()` except that the
486 /// thread will be blocked for roughly no longer than `dur`. This method
487 /// should not be used for precise timing due to anomalies such as
488 /// preemption or platform differences that may not cause the maximum
489 /// amount of time waited to be precisely `dur` long.
491 /// See the module doc for more detail.
493 /// # Platform behavior
495 /// Platforms which do not support nanosecond precision for sleeping will have
496 /// `dur` rounded up to the nearest granularity of time they can sleep for.
500 /// Waiting for the complete expiration of the timeout:
503 /// use std::thread::park_timeout;
504 /// use std::time::{Instant, Duration};
506 /// let timeout = Duration::from_secs(2);
507 /// let beginning_park = Instant::now();
508 /// park_timeout(timeout);
510 /// while beginning_park.elapsed() < timeout {
511 /// println!("restarting park_timeout after {:?}", beginning_park.elapsed());
512 /// let timeout = timeout - beginning_park.elapsed();
513 /// park_timeout(timeout);
516 #[stable(feature = "park_timeout", since = "1.4.0")]
517 pub fn park_timeout(dur
: Duration
) {
518 let thread
= current();
519 let mut guard
= thread
.inner
.lock
.lock().unwrap();
521 let (g
, _
) = thread
.inner
.cvar
.wait_timeout(guard
, dur
).unwrap();
527 ////////////////////////////////////////////////////////////////////////////////
529 ////////////////////////////////////////////////////////////////////////////////
531 /// The internal representation of a `Thread` handle
533 name
: Option
<CString
>, // Guaranteed to be UTF-8
534 lock
: Mutex
<bool
>, // true when there is a buffered unpark
539 #[stable(feature = "rust1", since = "1.0.0")]
540 /// A handle to a thread.
546 // Used only internally to construct a thread object without spawning
547 fn new(name
: Option
<String
>) -> Thread
{
548 let cname
= name
.map(|n
| {
549 CString
::new(n
).expect("thread name may not contain interior null bytes")
552 inner
: Arc
::new(Inner
{
554 lock
: Mutex
::new(false),
555 cvar
: Condvar
::new(),
560 /// Atomically makes the handle's token available if it is not already.
562 /// See the module doc for more detail.
563 #[stable(feature = "rust1", since = "1.0.0")]
564 pub fn unpark(&self) {
565 let mut guard
= self.inner
.lock
.lock().unwrap();
568 self.inner
.cvar
.notify_one();
572 /// Gets the thread's name.
576 /// Threads by default have no name specified:
581 /// let builder = thread::Builder::new();
583 /// let handler = builder.spawn(|| {
584 /// assert!(thread::current().name().is_none());
587 /// handler.join().unwrap();
590 /// Thread with a specified name:
595 /// let builder = thread::Builder::new()
596 /// .name("foo".into());
598 /// let handler = builder.spawn(|| {
599 /// assert_eq!(thread::current().name(), Some("foo"))
602 /// handler.join().unwrap();
604 #[stable(feature = "rust1", since = "1.0.0")]
605 pub fn name(&self) -> Option
<&str> {
606 self.cname().map(|s
| unsafe { str::from_utf8_unchecked(s.to_bytes()) }
)
609 fn cname(&self) -> Option
<&CStr
> {
610 self.inner
.name
.as_ref().map(|s
| &**s
)
614 #[stable(feature = "rust1", since = "1.0.0")]
615 impl fmt
::Debug
for Thread
{
616 fn fmt(&self, f
: &mut fmt
::Formatter
) -> fmt
::Result
{
617 fmt
::Debug
::fmt(&self.name(), f
)
621 // a hack to get around privacy restrictions
622 impl thread_info
::NewThread
for Thread
{
623 fn new(name
: Option
<String
>) -> Thread { Thread::new(name) }
626 ////////////////////////////////////////////////////////////////////////////////
628 ////////////////////////////////////////////////////////////////////////////////
630 /// Indicates the manner in which a thread exited.
632 /// A thread that completes without panicking is considered to exit successfully.
633 #[stable(feature = "rust1", since = "1.0.0")]
634 pub type Result
<T
> = ::result
::Result
<T
, Box
<Any
+ Send
+ '
static>>;
636 // This packet is used to communicate the return value between the child thread
637 // and the parent thread. Memory is shared through the `Arc` within and there's
638 // no need for a mutex here because synchronization happens with `join()` (the
639 // parent thread never reads this packet until the child has exited).
641 // This packet itself is then stored into a `JoinInner` which in turns is placed
642 // in `JoinHandle` and `JoinGuard`. Due to the usage of `UnsafeCell` we need to
643 // manually worry about impls like Send and Sync. The type `T` should
644 // already always be Send (otherwise the thread could not have been created) and
645 // this type is inherently Sync because no methods take &self. Regardless,
646 // however, we add inheriting impls for Send/Sync to this type to ensure it's
647 // Send/Sync and that future modifications will still appropriately classify it.
648 struct Packet
<T
>(Arc
<UnsafeCell
<Option
<Result
<T
>>>>);
650 unsafe impl<T
: Send
> Send
for Packet
<T
> {}
651 unsafe impl<T
: Sync
> Sync
for Packet
<T
> {}
653 /// Inner representation for JoinHandle
654 struct JoinInner
<T
> {
655 native
: Option
<imp
::Thread
>,
660 impl<T
> JoinInner
<T
> {
661 fn join(&mut self) -> Result
<T
> {
662 self.native
.take().unwrap().join();
664 (*self.packet
.0.get()).take().unwrap()
669 /// An owned permission to join on a thread (block on its termination).
671 /// A `JoinHandle` *detaches* the child thread when it is dropped.
673 /// Due to platform restrictions, it is not possible to `Clone` this
674 /// handle: the ability to join a child thread is a uniquely-owned
677 /// This `struct` is created by the [`thread::spawn`] function and the
678 /// [`thread::Builder::spawn`] method.
682 /// Creation from [`thread::spawn`]:
687 /// let join_handle: thread::JoinHandle<_> = thread::spawn(|| {
688 /// // some work here
692 /// Creation from [`thread::Builder::spawn`]:
697 /// let builder = thread::Builder::new();
699 /// let join_handle: thread::JoinHandle<_> = builder.spawn(|| {
700 /// // some work here
704 /// [`thread::spawn`]: fn.spawn.html
705 /// [`thread::Builder::spawn`]: struct.Builder.html#method.spawn
706 #[stable(feature = "rust1", since = "1.0.0")]
707 pub struct JoinHandle
<T
>(JoinInner
<T
>);
709 impl<T
> JoinHandle
<T
> {
710 /// Extracts a handle to the underlying thread
711 #[stable(feature = "rust1", since = "1.0.0")]
712 pub fn thread(&self) -> &Thread
{
716 /// Waits for the associated thread to finish.
718 /// If the child thread panics, `Err` is returned with the parameter given
720 #[stable(feature = "rust1", since = "1.0.0")]
721 pub fn join(mut self) -> Result
<T
> {
726 impl<T
> AsInner
<imp
::Thread
> for JoinHandle
<T
> {
727 fn as_inner(&self) -> &imp
::Thread { self.0.native.as_ref().unwrap() }
730 impl<T
> IntoInner
<imp
::Thread
> for JoinHandle
<T
> {
731 fn into_inner(self) -> imp
::Thread { self.0.native.unwrap() }
734 fn _assert_sync_and_send() {
735 fn _assert_both
<T
: Send
+ Sync
>() {}
736 _assert_both
::<JoinHandle
<()>>();
737 _assert_both
::<Thread
>();
740 ////////////////////////////////////////////////////////////////////////////////
742 ////////////////////////////////////////////////////////////////////////////////
747 use sync
::mpsc
::{channel, Sender}
;
749 use super::{Builder}
;
754 // !!! These tests are dangerous. If something is buggy, they will hang, !!!
755 // !!! instead of exiting cleanly. This might wedge the buildbots. !!!
758 fn test_unnamed_thread() {
759 thread
::spawn(move|| {
760 assert
!(thread
::current().name().is_none());
761 }).join().ok().unwrap();
765 fn test_named_thread() {
766 Builder
::new().name("ada lovelace".to_string()).spawn(move|| {
767 assert
!(thread
::current().name().unwrap() == "ada lovelace".to_string());
768 }).unwrap().join().unwrap();
773 fn test_invalid_named_thread() {
774 let _
= Builder
::new().name("ada l\0velace".to_string()).spawn(|| {}
);
778 fn test_run_basic() {
779 let (tx
, rx
) = channel();
780 thread
::spawn(move|| {
781 tx
.send(()).unwrap();
787 fn test_join_panic() {
788 match thread
::spawn(move|| {
791 result
::Result
::Err(_
) => (),
792 result
::Result
::Ok(()) => panic
!()
797 fn test_spawn_sched() {
798 let (tx
, rx
) = channel();
800 fn f(i
: i32, tx
: Sender
<()>) {
802 thread
::spawn(move|| {
804 tx
.send(()).unwrap();
816 fn test_spawn_sched_childs_on_default_sched() {
817 let (tx
, rx
) = channel();
819 thread
::spawn(move|| {
820 thread
::spawn(move|| {
821 tx
.send(()).unwrap();
828 fn avoid_copying_the_body
<F
>(spawnfn
: F
) where F
: FnOnce(Box
<Fn() + Send
>) {
829 let (tx
, rx
) = channel();
831 let x
: Box
<_
> = box 1;
832 let x_in_parent
= (&*x
) as *const i32 as usize;
834 spawnfn(Box
::new(move|| {
835 let x_in_child
= (&*x
) as *const i32 as usize;
836 tx
.send(x_in_child
).unwrap();
839 let x_in_child
= rx
.recv().unwrap();
840 assert_eq
!(x_in_parent
, x_in_child
);
844 fn test_avoid_copying_the_body_spawn() {
845 avoid_copying_the_body(|v
| {
846 thread
::spawn(move || v());
851 fn test_avoid_copying_the_body_thread_spawn() {
852 avoid_copying_the_body(|f
| {
853 thread
::spawn(move|| {
860 fn test_avoid_copying_the_body_join() {
861 avoid_copying_the_body(|f
| {
862 let _
= thread
::spawn(move|| {
869 fn test_child_doesnt_ref_parent() {
870 // If the child refcounts the parent thread, this will stack overflow when
871 // climbing the thread tree to dereference each ancestor. (See #1789)
872 // (well, it would if the constant were 8000+ - I lowered it to be more
873 // valgrind-friendly. try this at home, instead..!)
874 const GENERATIONS
: u32 = 16;
875 fn child_no(x
: u32) -> Box
<Fn() + Send
> {
876 return Box
::new(move|| {
878 thread
::spawn(move|| child_no(x
+1)());
882 thread
::spawn(|| child_no(0)());
886 fn test_simple_newsched_spawn() {
887 thread
::spawn(move || {}
);
891 fn test_try_panic_message_static_str() {
892 match thread
::spawn(move|| {
893 panic
!("static string");
896 type T
= &'
static str;
897 assert
!(e
.is
::<T
>());
898 assert_eq
!(*e
.downcast
::<T
>().unwrap(), "static string");
905 fn test_try_panic_message_owned_str() {
906 match thread
::spawn(move|| {
907 panic
!("owned string".to_string());
911 assert
!(e
.is
::<T
>());
912 assert_eq
!(*e
.downcast
::<T
>().unwrap(), "owned string".to_string());
919 fn test_try_panic_message_any() {
920 match thread
::spawn(move|| {
921 panic
!(box 413u16 as Box
<Any
+ Send
>);
924 type T
= Box
<Any
+ Send
>;
925 assert
!(e
.is
::<T
>());
926 let any
= e
.downcast
::<T
>().unwrap();
927 assert
!(any
.is
::<u16>());
928 assert_eq
!(*any
.downcast
::<u16>().unwrap(), 413);
935 fn test_try_panic_message_unit_struct() {
938 match thread
::spawn(move|| {
941 Err(ref e
) if e
.is
::<Juju
>() => {}
942 Err(_
) | Ok(()) => panic
!()
947 fn test_park_timeout_unpark_before() {
949 thread
::current().unpark();
950 thread
::park_timeout(Duration
::from_millis(u32::MAX
as u64));
955 fn test_park_timeout_unpark_not_called() {
957 thread
::park_timeout(Duration
::from_millis(10));
962 fn test_park_timeout_unpark_called_other_thread() {
964 let th
= thread
::current();
966 let _guard
= thread
::spawn(move || {
967 super::sleep(Duration
::from_millis(50));
971 thread
::park_timeout(Duration
::from_millis(u32::MAX
as u64));
976 fn sleep_ms_smoke() {
977 thread
::sleep(Duration
::from_millis(2));
980 // NOTE: the corresponding test for stderr is in run-pass/thread-stderr, due
981 // to the test harness apparently interfering with stderr configuration.