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| -rw-r--r-- | ctru-rs/src/lib.rs | 4 | ||||
| -rw-r--r-- | ctru-rs/src/thread.rs | 1139 |
2 files changed, 1143 insertions, 0 deletions
diff --git a/ctru-rs/src/lib.rs b/ctru-rs/src/lib.rs index 57635f6..56ac370 100644 --- a/ctru-rs/src/lib.rs +++ b/ctru-rs/src/lib.rs @@ -1,6 +1,9 @@ #![crate_type = "rlib"] #![crate_name = "ctru"] +#![feature(fnbox)] +#![feature(thread_local_state)] + #[macro_use] extern crate bitflags; extern crate libc; @@ -14,6 +17,7 @@ pub mod srv; pub mod gfx; pub mod services; pub mod sdmc; +pub mod thread; pub use error::{Result, Error}; diff --git a/ctru-rs/src/thread.rs b/ctru-rs/src/thread.rs new file mode 100644 index 0000000..ee7e819 --- /dev/null +++ b/ctru-rs/src/thread.rs @@ -0,0 +1,1139 @@ +// Copyright 2014 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +//! 3DS-specific threading API +//! +//! While it is possible to create threads on the 3DS using functions found in +//! `std::thread`, the standard API does not expose the ability to set a thread's +//! priority level and to pin a thread to a specific CPU core. This module exists +//! to address those and other shortcomings. +//! +//! All 3DS models have at least two CPU cores available to spawn threads on: +//! The application core (appcore) and the system core (syscore). The New 3DS +//! has an additional two cores, the first of which can also run user-created +//! threads. +//! +//! Threads spawned on the appcore are cooperative rather than preemptive. This +//! means that threads must explicitly yield control to other threads (whether +//! via synchronization primitives or explicit calls to `yield_now`) when they +//! are not actively performing work. Failure to do so may result in control +//! flow being stuck in an inactive thread while the other threads are powerless +//! to continue their work. +//! +//! However, it is possible to spawn one fully preemptive thread on the syscore +//! by using `apt::set_app_cpu_time_limit` to reserve a slice of time for a +//! thread to run. Attempting to run more than one thread at a time on the syscore +//! will result in an error. + +use std::any::Any; +use std::cell::UnsafeCell; +use std::ffi::{CStr, CString}; +use std::fmt; +use std::io; +use std::panic; +use std::str; +use std::sync::{Arc, Condvar, Mutex}; +use std::sync::atomic::AtomicUsize; +use std::sync::atomic::Ordering::SeqCst; +use std::thread as std_thread; +use std::time::Duration; + +use libctru::{svcGetProcessorID, svcGetThreadId, svcGetThreadPriority}; + +//////////////////////////////////////////////////////////////////////////////// +// Builder +//////////////////////////////////////////////////////////////////////////////// + +/// Thread factory, which can be used in order to configure the properties of +/// a new thread. +#[derive(Debug)] +pub struct Builder { + // A name for the thread-to-be, for identification in panic messages + name: Option<String>, + // The size of the stack for the spawned thread in bytes + stack_size: Option<usize>, + // The spawned thread's priority value + priority: Option<i32>, + // The spawned thread's CPU affinity value + affinity: Option<i32>, +} + +impl Builder { + /// Generates the base configuration for spawning a thread, from which + /// configuration methods can be chained. + /// + /// # Examples + /// + /// ``` + /// use ctru::thread; + /// + /// let builder = thread::Builder::new() + /// .name("foo".into()) + /// .stack_size(10); + /// + /// let handler = builder.spawn(|| { + /// // thread code + /// }).unwrap(); + /// + /// handler.join().unwrap(); + /// ``` + pub fn new() -> Builder { + Builder { + name: None, + stack_size: None, + priority: None, + affinity: None, + } + } + + /// Names the thread-to-be. Currently the name is used for identification + /// only in panic messages. + /// + /// The name must not contain null bytes (`\0`). + /// + /// For more information about named threads, see + /// [this module-level documentation][naming-threads]. + /// + /// # Examples + /// + /// ``` + /// use ctru::thread; + /// + /// let builder = thread::Builder::new() + /// .name("foo".into()); + /// + /// let handler = builder.spawn(|| { + /// assert_eq!(thread::current().name(), Some("foo")) + /// }).unwrap(); + /// + /// handler.join().unwrap(); + /// ``` + /// + /// [naming-threads]: ./index.html#naming-threads + pub fn name(mut self, name: String) -> Builder { + self.name = Some(name); + self + } + + /// Sets the size of the stack (in bytes) for the new thread. + /// + /// The actual stack size may be greater than this value if + /// the platform specifies minimal stack size. + /// + /// For more information about the stack size for threads, see + /// [this module-level documentation][stack-size]. + /// + /// # Examples + /// + /// ``` + /// use ctru::thread; + /// + /// let builder = thread::Builder::new().stack_size(32 * 1024); + /// ``` + /// + /// [stack-size]: ./index.html#stack-size + pub fn stack_size(mut self, size: usize) -> Builder { + self.stack_size = Some(size); + self + } + + /// Sets the priority level for the new thread + /// + /// Low values gives the thread higher priority. For userland apps, this has + /// to be within the range of 0x18 to 0x3F inclusive. The main thread usually + /// has a priority of 0x30, but not always. + pub fn priority(mut self, priority: i32) -> Builder { + self.priority = Some(priority); + self + } + + /// Sets the ID of the processor the thread should be ran on. + /// + /// Processor IDs are labeled starting from 0. On Old3DS it must be <2, and + /// on New3DS it must be <4. Pass -1 to execute the thread on all CPUs and + /// -2 to execute the thread on the default CPU (set in the application's Exheader). + /// + /// *Processor #0 is the application core. It is always possible to create a thread on this + /// core. + /// *Processor #1 is the system core. If APT_SetAppCpuTimeLimit is used, it is possible + /// to create a single thread on this core. + /// *Processor #2 is New3DS exclusive. Normal applications can create threads on + /// this core if the exheader kernel flags bitmask has 0x2000 set. + /// *Processor #3 is New3DS exclusive. Normal applications cannot create threads + /// on this core. + /// + /// Processes in the BASE memory region can always create threads on + /// processors #2 and #3. + pub fn affinity(mut self, affinity: i32) -> Builder { + self.affinity = Some(affinity); + self + } + + /// Spawns a new thread by taking ownership of the `Builder`, and returns an + /// [`io::Result`] to its [`JoinHandle`]. + /// + /// The spawned thread may outlive the caller (unless the caller thread + /// is the main thread; the whole process is terminated when the main + /// thread finishes). The join handle can be used to block on + /// termination of the child thread, including recovering its panics. + /// + /// For a more complete documentation see [`thread::spawn`][`spawn`]. + /// + /// # Errors + /// + /// Unlike the [`spawn`] free function, this method yields an + /// [`io::Result`] to capture any failure to create the thread at + /// the OS level. + /// + /// [`spawn`]: ../../std/thread/fn.spawn.html + /// [`io::Result`]: ../../std/io/type.Result.html + /// [`JoinHandle`]: ../../std/thread/struct.JoinHandle.html + /// + /// # Panics + /// + /// Panics if a thread name was set and it contained null bytes. + /// + /// # Examples + /// + /// ``` + /// use ctru::thread; + /// + /// let builder = thread::Builder::new(); + /// + /// let handler = builder.spawn(|| { + /// // thread code + /// }).unwrap(); + /// + /// handler.join().unwrap(); + /// ``` + pub fn spawn<F, T>(self, f: F) -> io::Result<JoinHandle<T>> + where + F: FnOnce() -> T, + F: Send + 'static, + T: Send + 'static, + { + let Builder { + name, + stack_size, + priority, + affinity, + } = self; + + let stack_size = stack_size.unwrap_or(imp::DEFAULT_MIN_STACK_SIZE); + + // If no priority value is specified, spawn with the same + // priority as the parent thread + let priority = priority.unwrap_or_else(|| unsafe { + let mut default_priority = 0; + svcGetThreadPriority(&mut default_priority, 0xFFFF8000); + default_priority + }); + + // If no affinity is specified, spawn on the default core (determined by + // the application's Exheader) + let affinity = affinity.unwrap_or(-2); + + let my_thread = Thread::new(name); + let their_thread = my_thread.clone(); + + let my_packet: Arc<UnsafeCell<Option<Result<T>>>> = Arc::new(UnsafeCell::new(None)); + let their_packet = my_packet.clone(); + + let main = move || { + if let Some(name) = their_thread.cname() { + imp::Thread::set_name(name); + } + unsafe { + thread_info::set(their_thread); + let try_result = panic::catch_unwind(panic::AssertUnwindSafe(f)); + *their_packet.get() = Some(try_result); + } + }; + + Ok(JoinHandle(JoinInner { + native: unsafe { + Some(imp::Thread::new( + stack_size, + priority, + affinity, + Box::new(main), + )?) + }, + thread: my_thread, + packet: Packet(my_packet), + })) + } +} + +//////////////////////////////////////////////////////////////////////////////// +// Free functions +//////////////////////////////////////////////////////////////////////////////// + +/// Spawns a new thread, returning a [`JoinHandle`] for it. +/// +/// The join handle will implicitly *detach* the child thread upon being +/// dropped. In this case, the child thread may outlive the parent (unless +/// the parent thread is the main thread; the whole process is terminated when +/// the main thread finishes). Additionally, the join handle provides a [`join`] +/// method that can be used to join the child thread. If the child thread +/// panics, [`join`] will return an [`Err`] containing the argument given to +/// [`panic`]. +/// +/// This will create a thread using default parameters of [`Builder`], if you +/// want to specify the stack size or the name of the thread, use this API +/// instead. +/// +/// As you can see in the signature of `spawn` there are two constraints on +/// both the closure given to `spawn` and its return value, let's explain them: +/// +/// - The `'static` constraint means that the closure and its return value +/// must have a lifetime of the whole program execution. The reason for this +/// is that threads can `detach` and outlive the lifetime they have been +/// created in. +/// Indeed if the thread, and by extension its return value, can outlive their +/// caller, we need to make sure that they will be valid afterwards, and since +/// we *can't* know when it will return we need to have them valid as long as +/// possible, that is until the end of the program, hence the `'static` +/// lifetime. +/// - The [`Send`] constraint is because the closure will need to be passed +/// *by value* from the thread where it is spawned to the new thread. Its +/// return value will need to be passed from the new thread to the thread +/// where it is `join`ed. +/// As a reminder, the [`Send`] marker trait expresses that it is safe to be +/// passed from thread to thread. [`Sync`] expresses that it is safe to have a +/// reference be passed from thread to thread. +/// +/// # Panics +/// +/// Panics if the OS fails to create a thread; use [`Builder::spawn`] +/// to recover from such errors. +pub fn spawn<F, T>(f: F) -> JoinHandle<T> +where + F: FnOnce() -> T, + F: Send + 'static, + T: Send + 'static, +{ + Builder::new().spawn(f).unwrap() +} + +/// Gets a handle to the thread that invokes it. +/// +/// # Examples +/// +/// Getting a handle to the current thread with `thread::current()`: +/// +/// ``` +/// use ctru::thread; +/// +/// let handler = thread::Builder::new() +/// .name("named thread".into()) +/// .spawn(|| { +/// let handle = thread::current(); +/// assert_eq!(handle.name(), Some("named thread")); +/// }) +/// .unwrap(); +/// +/// handler.join().unwrap(); +/// ``` +pub fn current() -> Thread { + thread_info::current_thread().expect( + "use of ctru::thread::current() is not \ + possible after the thread's local \ + data has been destroyed", + ) +} + +/// Cooperatively gives up a timeslice to the OS scheduler. +pub fn yield_now() { + imp::Thread::yield_now() +} + +/// Determines whether the current thread is unwinding because of panic. +/// +/// A common use of this feature is to poison shared resources when writing +/// unsafe code, by checking `panicking` when the `drop` is called. +/// +/// This is usually not needed when writing safe code, as [`Mutex`es][Mutex] +/// already poison themselves when a thread panics while holding the lock. +/// +/// This can also be used in multithreaded applications, in order to send a +/// message to other threads warning that a thread has panicked (e.g. for +/// monitoring purposes). +#[inline] +pub fn panicking() -> bool { + std_thread::panicking() +} + +/// Puts the current thread to sleep for the specified amount of time. +/// +/// The thread may sleep longer than the duration specified due to scheduling +/// specifics or platform-dependent functionality. +pub fn sleep(dur: Duration) { + imp::Thread::sleep(dur) +} + +// constants for park/unpark +const EMPTY: usize = 0; +const PARKED: usize = 1; +const NOTIFIED: usize = 2; + +/// Blocks unless or until the current thread's token is made available. +/// +/// A call to `park` does not guarantee that the thread will remain parked +/// forever, and callers should be prepared for this possibility. +/// +/// # park and unpark +/// +/// Every thread is equipped with some basic low-level blocking support, via the +/// [`thread::park`][`park`] function and [`thread::Thread::unpark`][`unpark`] +/// method. [`park`] blocks the current thread, which can then be resumed from +/// another thread by calling the [`unpark`] method on the blocked thread's +/// handle. +/// +/// Conceptually, each [`Thread`] handle has an associated token, which is +/// initially not present: +/// +/// * The [`thread::park`][`park`] function blocks the current thread unless or +/// until the token is available for its thread handle, at which point it +/// atomically consumes the token. It may also return *spuriously*, without +/// consuming the token. [`thread::park_timeout`] does the same, but allows +/// specifying a maximum time to block the thread for. +/// +/// * The [`unpark`] method on a [`Thread`] atomically makes the token available +/// if it wasn't already. +/// +/// In other words, each [`Thread`] acts a bit like a spinlock that can be +/// locked and unlocked using `park` and `unpark`. +/// +/// The API is typically used by acquiring a handle to the current thread, +/// placing that handle in a shared data structure so that other threads can +/// find it, and then `park`ing. When some desired condition is met, another +/// thread calls [`unpark`] on the handle. +/// +/// The motivation for this design is twofold: +/// +/// * It avoids the need to allocate mutexes and condvars when building new +/// synchronization primitives; the threads already provide basic +/// blocking/signaling. +/// +/// * It can be implemented very efficiently on many platforms. +/// +/// # Examples +/// +/// ``` +/// use ctru::thread; +/// use std::time::Duration; +/// +/// let parked_thread = thread::Builder::new() +/// .spawn(|| { +/// println!("Parking thread"); +/// thread::park(); +/// println!("Thread unparked"); +/// }) +/// .unwrap(); +/// +/// // Let some time pass for the thread to be spawned. +/// thread::sleep(Duration::from_millis(10)); +/// +/// println!("Unpark the thread"); +/// parked_thread.thread().unpark(); +/// +/// parked_thread.join().unwrap(); +/// ``` +/// +/// [`Thread`]: ../../std/thread/struct.Thread.html +/// [`park`]: ../../std/thread/fn.park.html +/// [`unpark`]: ../../std/thread/struct.Thread.html#method.unpark +/// [`thread::park_timeout`]: ../../std/thread/fn.park_timeout.html +// +// The implementation currently uses the trivial strategy of a Mutex+Condvar +// with wakeup flag, which does not actually allow spurious wakeups. In the +// future, this will be implemented in a more efficient way, perhaps along the lines of +// http://cr.openjdk.java.net/~stefank/6989984.1/raw_files/new/src/os/linux/vm/os_linux.cpp +// or futuxes, and in either case may allow spurious wakeups. +pub fn park() { + let thread = current(); + + // If we were previously notified then we consume this notification and + // return quickly. + if thread + .inner + .state + .compare_exchange(NOTIFIED, EMPTY, SeqCst, SeqCst) + .is_ok() + { + return; + } + + // Otherwise we need to coordinate going to sleep + let mut m = thread.inner.lock.lock().unwrap(); + match thread + .inner + .state + .compare_exchange(EMPTY, PARKED, SeqCst, SeqCst) + { + Ok(_) => {} + Err(NOTIFIED) => return, // notified after we locked + Err(_) => panic!("inconsistent park state"), + } + loop { + m = thread.inner.cvar.wait(m).unwrap(); + match thread + .inner + .state + .compare_exchange(NOTIFIED, EMPTY, SeqCst, SeqCst) + { + Ok(_) => return, // got a notification + Err(_) => {} // spurious wakeup, go back to sleep + } + } +} + +/// Blocks unless or until the current thread's token is made available or +/// the specified duration has been reached (may wake spuriously). +/// +/// The semantics of this function are equivalent to [`park`][park] except +/// that the thread will be blocked for roughly no longer than `dur`. This +/// method should not be used for precise timing due to anomalies such as +/// preemption or platform differences that may not cause the maximum +/// amount of time waited to be precisely `dur` long. +/// +/// See the [park documentation][park] for more details. +/// +/// # Platform-specific behavior +/// +/// Platforms which do not support nanosecond precision for sleeping will have +/// `dur` rounded up to the nearest granularity of time they can sleep for. +/// +/// # Examples +/// +/// Waiting for the complete expiration of the timeout: +/// +/// ```rust,no_run +/// use ctru::thread::park_timeout; +/// use std::time::{Instant, Duration}; +/// +/// let timeout = Duration::from_secs(2); +/// let beginning_park = Instant::now(); +/// +/// let mut timeout_remaining = timeout; +/// loop { +/// park_timeout(timeout_remaining); +/// let elapsed = beginning_park.elapsed(); +/// if elapsed >= timeout { +/// break; +/// } +/// println!("restarting park_timeout after {:?}", elapsed); +/// timeout_remaining = timeout - elapsed; +/// } +/// ``` +/// +/// [park]: fn.park.html +pub fn park_timeout(dur: Duration) { + let thread = current(); + + // Like `park` above we have a fast path for an already-notified thread, and + // afterwards we start coordinating for a sleep. + // return quickly. + if thread + .inner + .state + .compare_exchange(NOTIFIED, EMPTY, SeqCst, SeqCst) + .is_ok() + { + return; + } + let m = thread.inner.lock.lock().unwrap(); + match thread + .inner + .state + .compare_exchange(EMPTY, PARKED, SeqCst, SeqCst) + { + Ok(_) => {} + Err(NOTIFIED) => return, // notified after we locked + Err(_) => panic!("inconsistent park_timeout state"), + } + + // Wait with a timeout, and if we spuriously wake up or otherwise wake up + // from a notification we just want to unconditionally set the state back to + // empty, either consuming a notification or un-flagging ourselves as + // parked. + let (_m, _result) = thread.inner.cvar.wait_timeout(m, dur).unwrap(); + match thread.inner.state.swap(EMPTY, SeqCst) { + NOTIFIED => {} // got a notification, hurray! + PARKED => {} // no notification, alas + n => panic!("inconsistent park_timeout state: {}", n), + } +} + +//////////////////////////////////////////////////////////////////////////////// +// ThreadId +//////////////////////////////////////////////////////////////////////////////// + +/// A unique identifier for a running thread. +/// +/// # Examples +/// +/// ``` +/// use ctru::thread; +/// +/// let other_thread = thread::spawn(|| { +/// thread::current().id() +/// }); +/// +/// let other_thread_id = other_thread.join().unwrap(); +/// assert!(thread::current().id() != other_thread_id); +/// ``` +/// +/// [`id`]: ../../std/thread/struct.Thread.html#method.id +/// [`Thread`]: ../../std/thread/struct.Thread.html +#[derive(Eq, PartialEq, Clone, Copy, Hash, Debug)] +pub struct ThreadId(u32); + +//////////////////////////////////////////////////////////////////////////////// +// Thread +//////////////////////////////////////////////////////////////////////////////// + +/// The internal representation of a `Thread` handle +struct Inner { + name: Option<CString>, // Guaranteed to be UTF-8 + + // state for thread park/unpark + state: AtomicUsize, + lock: Mutex<()>, + cvar: Condvar, +} + +#[derive(Clone)] +/// A handle to a thread. +/// +/// Threads are represented via the `Thread` type, which you can get in one of +/// two ways: +/// +/// * By spawning a new thread, e.g. using the [`thread::spawn`][`spawn`] +/// function, and calling [`thread`][`JoinHandle::thread`] on the +/// [`JoinHandle`]. +/// * By requesting the current thread, using the [`thread::current`] function. +/// +/// The [`thread::current`] function is available even for threads not spawned +/// by the APIs of this module. +/// +/// There is usually no need to create a `Thread` struct yourself, one +/// should instead use a function like `spawn` to create new threads, see the +/// docs of [`Builder`] and [`spawn`] for more details. +/// +/// [`Builder`]: ../../std/thread/struct.Builder.html +/// [`JoinHandle::thread`]: ../../std/thread/struct.JoinHandle.html#method.thread +/// [`JoinHandle`]: ../../std/thread/struct.JoinHandle.html +/// [`thread::current`]: ../../std/thread/fn.current.html +/// [`spawn`]: ../../std/thread/fn.spawn.html + +pub struct Thread { + inner: Arc<Inner>, +} + +impl Thread { + // Used only internally to construct a thread object without spawning + // Panics if the name contains nuls. + pub(crate) fn new(name: Option<String>) -> Thread { + let cname = name + .map(|n| CString::new(n) + .expect("thread name may not contain interior null bytes")); + Thread { + inner: Arc::new(Inner { + name: cname, + state: AtomicUsize::new(EMPTY), + lock: Mutex::new(()), + cvar: Condvar::new(), + }), + } + } + + /// Atomically makes the handle's token available if it is not already. + /// + /// Every thread is equipped with some basic low-level blocking support, via + /// the [`park`][park] function and the `unpark()` method. These can be + /// used as a more CPU-efficient implementation of a spinlock. + /// + /// See the [park documentation][park] for more details. + /// + /// # Examples + /// + /// ``` + /// use ctru::thread; + /// use std::time::Duration; + /// + /// let parked_thread = thread::Builder::new() + /// .spawn(|| { + /// println!("Parking thread"); + /// thread::park(); + /// println!("Thread unparked"); + /// }) + /// .unwrap(); + /// + /// // Let some time pass for the thread to be spawned. + /// thread::sleep(Duration::from_millis(10)); + /// + /// println!("Unpark the thread"); + /// parked_thread.thread().unpark(); + /// + /// parked_thread.join().unwrap(); + /// ``` + /// + /// [park]: fn.park.html + pub fn unpark(&self) { + loop { + match self.inner + .state + .compare_exchange(EMPTY, NOTIFIED, SeqCst, SeqCst) + { + Ok(_) => return, // no one was waiting + Err(NOTIFIED) => return, // already unparked + Err(PARKED) => {} // gotta go wake someone up + _ => panic!("inconsistent state in unpark"), + } + + // Coordinate wakeup through the mutex and a condvar notification + let _lock = self.inner.lock.lock().unwrap(); + match self.inner + .state + .compare_exchange(PARKED, NOTIFIED, SeqCst, SeqCst) + { + Ok(_) => return self.inner.cvar.notify_one(), + Err(NOTIFIED) => return, // a different thread unparked + Err(EMPTY) => {} // parked thread went away, try again + _ => panic!("inconsistent state in unpark"), + } + } + } + + /// Gets the thread's unique identifier. + /// + /// # Examples + /// + /// ``` + /// use ctru::thread; + /// + /// let other_thread = thread::spawn(|| { + /// thread::current().id() + /// }); + /// + /// let other_thread_id = other_thread.join().unwrap(); + /// assert!(thread::current().id() != other_thread_id); + /// ``` + pub fn id(&self) -> ThreadId { + unsafe { + let mut id = 0; + svcGetThreadId(&mut id, 0xFFFF8000); + ThreadId(id) + } + } + + /// Gets the thread's name. + /// + /// For more information about named threads, see + /// [this module-level documentation][naming-threads]. + /// + /// # Examples + /// + /// Threads by default have no name specified: + /// + /// ``` + /// use ctru::thread; + /// + /// let builder = thread::Builder::new(); + /// + /// let handler = builder.spawn(|| { + /// assert!(thread::current().name().is_none()); + /// }).unwrap(); + /// + /// handler.join().unwrap(); + /// ``` + /// + /// Thread with a specified name: + /// + /// ``` + /// use ctru::thread; + /// + /// let builder = thread::Builder::new() + /// .name("foo".into()); + /// + /// let handler = builder.spawn(|| { + /// assert_eq!(thread::current().name(), Some("foo")) + /// }).unwrap(); + /// + /// handler.join().unwrap(); + /// ``` + /// + /// [naming-threads]: ./index.html#naming-threads + pub fn name(&self) -> Option<&str> { + self.cname() + .map(|s| unsafe { str::from_utf8_unchecked(s.to_bytes()) }) + } + + /// Get the current thread's priority level. Lower values correspond to higher + /// priority levels. The main thread's priority is typically 0x30, but not always. + pub fn priority(&self) -> i32 { + unsafe { + let mut priority = 0; + svcGetThreadPriority(&mut priority, 0xFFFF8000); + priority + } + } + + /// Returns the ID of the processor the current thread is running on. + pub fn affinity(&self) -> i32 { + unsafe { + svcGetProcessorID() + } + } + + fn cname(&self) -> Option<&CStr> { + self.inner.name.as_ref().map(|s| &**s) + } +} + +impl fmt::Debug for Thread { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + fmt::Debug::fmt(&self.name(), f) + } +} + +//////////////////////////////////////////////////////////////////////////////// +// JoinHandle +//////////////////////////////////////////////////////////////////////////////// + +/// A specialized [`Result`] type for threads. +/// +/// Indicates the manner in which a thread exited. +/// +/// A thread that completes without panicking is considered to exit successfully. +/// +/// # Examples +/// +/// ```no_run +/// use ctru::thread; +/// use std::fs; +/// +/// fn copy_in_thread() -> thread::Result<()> { +/// thread::spawn(move || { fs::copy("foo.txt", "bar.txt").unwrap(); }).join() +/// } +/// +/// fn main() { +/// match copy_in_thread() { +/// Ok(_) => println!("this is fine"), +/// Err(_) => println!("thread panicked"), +/// } +/// } +/// ``` +/// +/// [`Result`]: ../../std/result/enum.Result.html +pub type Result<T> = ::std::result::Result<T, Box<Any + Send + 'static>>; + +// This packet is used to communicate the return value between the child thread +// and the parent thread. Memory is shared through the `Arc` within and there's +// no need for a mutex here because synchronization happens with `join()` (the +// parent thread never reads this packet until the child has exited). +// +// This packet itself is then stored into a `JoinInner` which in turns is placed +// in `JoinHandle` and `JoinGuard`. Due to the usage of `UnsafeCell` we need to +// manually worry about impls like Send and Sync. The type `T` should +// already always be Send (otherwise the thread could not have been created) and +// this type is inherently Sync because no methods take &self. Regardless, +// however, we add inheriting impls for Send/Sync to this type to ensure it's +// Send/Sync and that future modifications will still appropriately classify it. +struct Packet<T>(Arc<UnsafeCell<Option<Result<T>>>>); + +unsafe impl<T: Send> Send for Packet<T> {} +unsafe impl<T: Sync> Sync for Packet<T> {} + +/// Inner representation for JoinHandle +struct JoinInner<T> { + native: Option<imp::Thread>, + thread: Thread, + packet: Packet<T>, +} + +impl<T> JoinInner<T> { + fn join(&mut self) -> Result<T> { + self.native.take().unwrap().join(); + unsafe { (*self.packet.0.get()).take().unwrap() } + } +} + +/// An owned permission to join on a thread (block on its termination). +/// +/// A `JoinHandle` *detaches* the associated thread when it is dropped, which +/// means that there is no longer any handle to thread and no way to `join` +/// on it. +/// +/// Due to platform restrictions, it is not possible to [`Clone`] this +/// handle: the ability to join a thread is a uniquely-owned permission. +/// +/// This `struct` is created by the [`thread::spawn`] function and the +/// [`thread::Builder::spawn`] method. +/// +/// # Examples +/// +/// Creation from [`thread::spawn`]: +/// +/// ``` +/// use ctru::thread; +/// +/// let join_handle: thread::JoinHandle<_> = thread::spawn(|| { +/// // some work here +/// }); +/// ``` +/// +/// Creation from [`thread::Builder::spawn`]: +/// +/// ``` +/// use ctru::thread; +/// +/// let builder = thread::Builder::new(); +/// +/// let join_handle: thread::JoinHandle<_> = builder.spawn(|| { +/// // some work here +/// }).unwrap(); +/// ``` +/// +/// Child being detached and outliving its parent: +/// +/// ```no_run +/// use ctru::thread; +/// use std::time::Duration; +/// +/// let original_thread = thread::spawn(|| { +/// let _detached_thread = thread::spawn(|| { +/// // Here we sleep to make sure that the first thread returns before. +/// thread::sleep(Duration::from_millis(10)); +/// // This will be called, even though the JoinHandle is dropped. +/// println!("♫ Still alive ♫"); +/// }); +/// }); +/// +/// original_thread.join().expect("The thread being joined has panicked"); +/// println!("Original thread is joined."); +/// +/// // We make sure that the new thread has time to run, before the main +/// // thread returns. +/// +/// thread::sleep(Duration::from_millis(1000)); +/// ``` +/// +/// [`Clone`]: ../../std/clone/trait.Clone.html +/// [`thread::spawn`]: fn.spawn.html +/// [`thread::Builder::spawn`]: struct.Builder.html#method.spawn +pub struct JoinHandle<T>(JoinInner<T>); + +impl<T> JoinHandle<T> { + /// Extracts a handle to the underlying thread. + /// + /// # Examples + /// + /// ``` + /// use ctru::thread; + /// + /// let builder = thread::Builder::new(); + /// + /// let join_handle: thread::JoinHandle<_> = builder.spawn(|| { + /// // some work here + /// }).unwrap(); + /// + /// let thread = join_handle.thread(); + /// println!("thread id: {:?}", thread.id()); + /// ``` + pub fn thread(&self) -> &Thread { + &self.0.thread + } + + /// Waits for the associated thread to finish. + /// + /// If the child thread panics, [`Err`] is returned with the parameter given + /// to [`panic`]. + /// + /// [`Err`]: ../../std/result/enum.Result.html#variant.Err + /// [`panic`]: ../../std/macro.panic.html + /// + /// # Panics + /// + /// This function may panic on some platforms if a thread attempts to join + /// itself or otherwise may create a deadlock with joining threads. + /// + /// # Examples + /// + /// ``` + /// use ctru::thread; + /// + /// let builder = thread::Builder::new(); + /// + /// let join_handle: thread::JoinHandle<_> = builder.spawn(|| { + /// // some work here + /// }).unwrap(); + /// join_handle.join().expect("Couldn't join on the associated thread"); + /// ``` + pub fn join(mut self) -> Result<T> { + self.0.join() + } +} + +impl<T> fmt::Debug for JoinHandle<T> { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + f.pad("JoinHandle { .. }") + } +} + +fn _assert_sync_and_send() { + fn _assert_both<T: Send + Sync>() {} + _assert_both::<JoinHandle<()>>(); + _assert_both::<Thread>(); +} + +mod imp { + use std::boxed::FnBox; + use std::cmp; + use std::ffi::CStr; + use std::io; + use std::mem; + use std::ptr; + use std::time::Duration; + + use libc; + + use libctru::{Thread as ThreadHandle, svcSleepThread, threadCreate, threadDetach, + threadFree, threadJoin}; + + pub struct Thread { + handle: ThreadHandle, + } + + unsafe impl Send for Thread {} + unsafe impl Sync for Thread {} + + pub const DEFAULT_MIN_STACK_SIZE: usize = 4096; + + impl Thread { + pub unsafe fn new<'a>( + stack: usize, + priority: i32, + affinity: i32, + p: Box<FnBox() + 'a>, + ) -> io::Result<Thread> { + let p = Box::new(p); + let stack_size = cmp::max(stack, DEFAULT_MIN_STACK_SIZE); + + let handle = threadCreate( + Some(thread_func), + &*p as *const _ as *mut _, + stack_size, + priority, + affinity, + false, + ); + + return if handle == ptr::null_mut() { + Err(io::Error::from_raw_os_error(libc::EAGAIN)) + } else { + mem::forget(p); // ownership passed to the new thread + Ok(Thread { handle: handle }) + }; + + extern "C" fn thread_func(start: *mut libc::c_void) { + unsafe { Thread::_start_thread(start as *mut u8) } + } + } + + unsafe fn _start_thread(main: *mut u8) { + Box::from_raw(main as *mut Box<FnBox()>)() + } + + pub fn yield_now() { + unsafe { svcSleepThread(0) } + } + + pub fn set_name(_name: &CStr) { + // threads aren't named in libctru + } + + pub fn sleep(dur: Duration) { + unsafe { + let nanos = dur.as_secs() + .saturating_mul(1_000_000_000) + .saturating_add(dur.subsec_nanos() as u64); + svcSleepThread(nanos as i64) + } + } + + pub fn join(self) { + unsafe { + let ret = threadJoin(self.handle, u64::max_value()); + threadFree(self.handle); + mem::forget(self); + debug_assert_eq!(ret, 0); + } + } + + #[allow(dead_code)] + pub fn id(&self) -> ThreadHandle { + self.handle + } + + #[allow(dead_code)] + pub fn into_id(self) -> ThreadHandle { + let handle = self.handle; + mem::forget(self); + handle + } + } + + impl Drop for Thread { + fn drop(&mut self) { + unsafe { threadDetach(self.handle) } + } + } +} + +mod thread_info { + use std::cell::RefCell; + use thread::Thread; + + struct ThreadInfo { + thread: Thread, + } + + thread_local! { static THREAD_INFO: RefCell<Option<ThreadInfo>> = RefCell::new(None) } + + impl ThreadInfo { + fn with<R, F>(f: F) -> Option<R> + where + F: FnOnce(&mut ThreadInfo) -> R, + { + THREAD_INFO + .try_with(move |c| { + if c.borrow().is_none() { + *c.borrow_mut() = Some(ThreadInfo { + thread: Thread::new(None), + }) + } + f(c.borrow_mut().as_mut().unwrap()) + }) + .ok() + } + } + + pub fn current_thread() -> Option<Thread> { + ThreadInfo::with(|info| info.thread.clone()) + } + + pub fn set(thread: Thread) { + THREAD_INFO.with(|c| assert!(c.borrow().is_none())); + THREAD_INFO.with(move |c| *c.borrow_mut() = Some(ThreadInfo { thread })); + } +} |