diff options
Diffstat (limited to 'library/std/src/sys/thread')
| -rw-r--r-- | library/std/src/sys/thread/hermit.rs | 92 | ||||
| -rw-r--r-- | library/std/src/sys/thread/mod.rs | 152 | ||||
| -rw-r--r-- | library/std/src/sys/thread/sgx.rs | 131 | ||||
| -rw-r--r-- | library/std/src/sys/thread/solid.rs | 348 | ||||
| -rw-r--r-- | library/std/src/sys/thread/teeos.rs | 126 | ||||
| -rw-r--r-- | library/std/src/sys/thread/uefi.rs | 25 | ||||
| -rw-r--r-- | library/std/src/sys/thread/unix.rs | 908 | ||||
| -rw-r--r-- | library/std/src/sys/thread/unsupported.rs | 43 | ||||
| -rw-r--r-- | library/std/src/sys/thread/wasip1.rs | 185 | ||||
| -rw-r--r-- | library/std/src/sys/thread/wasip2.rs | 32 | ||||
| -rw-r--r-- | library/std/src/sys/thread/wasm.rs | 23 | ||||
| -rw-r--r-- | library/std/src/sys/thread/windows.rs | 140 | ||||
| -rw-r--r-- | library/std/src/sys/thread/xous.rs | 137 |
13 files changed, 2342 insertions, 0 deletions
diff --git a/library/std/src/sys/thread/hermit.rs b/library/std/src/sys/thread/hermit.rs new file mode 100644 index 00000000000..4d9f3b114c2 --- /dev/null +++ b/library/std/src/sys/thread/hermit.rs @@ -0,0 +1,92 @@ +use crate::num::NonZero; +use crate::time::Duration; +use crate::{io, ptr}; + +pub type Tid = hermit_abi::Tid; + +pub struct Thread { + tid: Tid, +} + +unsafe impl Send for Thread {} +unsafe impl Sync for Thread {} + +pub const DEFAULT_MIN_STACK_SIZE: usize = 1 << 20; + +impl Thread { + pub unsafe fn new_with_coreid( + stack: usize, + p: Box<dyn FnOnce()>, + core_id: isize, + ) -> io::Result<Thread> { + let p = Box::into_raw(Box::new(p)); + let tid = unsafe { + hermit_abi::spawn2( + thread_start, + p.expose_provenance(), + hermit_abi::Priority::into(hermit_abi::NORMAL_PRIO), + stack, + core_id, + ) + }; + + return if tid == 0 { + // The thread failed to start and as a result p was not consumed. Therefore, it is + // safe to reconstruct the box so that it gets deallocated. + unsafe { + drop(Box::from_raw(p)); + } + Err(io::const_error!(io::ErrorKind::Uncategorized, "unable to create thread!")) + } else { + Ok(Thread { tid }) + }; + + extern "C" fn thread_start(main: usize) { + unsafe { + // Finally, let's run some code. + Box::from_raw(ptr::with_exposed_provenance::<Box<dyn FnOnce()>>(main).cast_mut())(); + + // run all destructors + crate::sys::thread_local::destructors::run(); + crate::rt::thread_cleanup(); + } + } + } + + pub unsafe fn new( + stack: usize, + _name: Option<&str>, + p: Box<dyn FnOnce()>, + ) -> io::Result<Thread> { + unsafe { + Thread::new_with_coreid(stack, p, -1 /* = no specific core */) + } + } + + pub fn join(self) { + unsafe { + let _ = hermit_abi::join(self.tid); + } + } +} + +pub fn available_parallelism() -> io::Result<NonZero<usize>> { + unsafe { Ok(NonZero::new_unchecked(hermit_abi::available_parallelism())) } +} + +#[inline] +pub fn sleep(dur: Duration) { + let micros = dur.as_micros() + if dur.subsec_nanos() % 1_000 > 0 { 1 } else { 0 }; + let micros = u64::try_from(micros).unwrap_or(u64::MAX); + + unsafe { + hermit_abi::usleep(micros); + } +} + +#[inline] +pub fn yield_now() { + unsafe { + hermit_abi::yield_now(); + } +} diff --git a/library/std/src/sys/thread/mod.rs b/library/std/src/sys/thread/mod.rs new file mode 100644 index 00000000000..6bb7fc1a20e --- /dev/null +++ b/library/std/src/sys/thread/mod.rs @@ -0,0 +1,152 @@ +cfg_select! { + target_os = "hermit" => { + mod hermit; + pub use hermit::{Thread, available_parallelism, sleep, yield_now, DEFAULT_MIN_STACK_SIZE}; + #[expect(dead_code)] + mod unsupported; + pub use unsupported::{current_os_id, set_name}; + } + all(target_vendor = "fortanix", target_env = "sgx") => { + mod sgx; + pub use sgx::{Thread, current_os_id, sleep, yield_now, DEFAULT_MIN_STACK_SIZE}; + + // SGX should protect in-enclave data from outside attackers, so there + // must not be any data leakage to the OS, particularly no 1-1 mapping + // between SGX thread names and OS thread names. Hence `set_name` is + // intentionally a no-op. + // + // Note that the internally visible SGX thread name is already provided + // by the platform-agnostic Rust thread code. This can be observed in + // the [`std::thread::tests::test_named_thread`] test, which succeeds + // as-is with the SGX target. + #[expect(dead_code)] + mod unsupported; + pub use unsupported::{available_parallelism, set_name}; + } + target_os = "solid_asp3" => { + mod solid; + pub use solid::{Thread, sleep, yield_now, DEFAULT_MIN_STACK_SIZE}; + #[expect(dead_code)] + mod unsupported; + pub use unsupported::{available_parallelism, current_os_id, set_name}; + } + target_os = "teeos" => { + mod teeos; + pub use teeos::{Thread, sleep, yield_now, DEFAULT_MIN_STACK_SIZE}; + #[expect(dead_code)] + mod unsupported; + pub use unsupported::{available_parallelism, current_os_id, set_name}; + } + target_os = "uefi" => { + mod uefi; + pub use uefi::{available_parallelism, sleep}; + #[expect(dead_code)] + mod unsupported; + pub use unsupported::{Thread, current_os_id, set_name, yield_now, DEFAULT_MIN_STACK_SIZE}; + } + target_family = "unix" => { + mod unix; + pub use unix::{Thread, available_parallelism, current_os_id, sleep, yield_now, DEFAULT_MIN_STACK_SIZE}; + #[cfg(not(any( + target_env = "newlib", + target_os = "l4re", + target_os = "emscripten", + target_os = "redox", + target_os = "hurd", + target_os = "aix", + )))] + pub use unix::set_name; + #[cfg(any( + target_os = "freebsd", + target_os = "netbsd", + target_os = "linux", + target_os = "android", + target_os = "solaris", + target_os = "illumos", + target_os = "dragonfly", + target_os = "hurd", + target_os = "fuchsia", + target_os = "vxworks", + ))] + pub use unix::sleep_until; + #[expect(dead_code)] + mod unsupported; + #[cfg(any( + target_env = "newlib", + target_os = "l4re", + target_os = "emscripten", + target_os = "redox", + target_os = "hurd", + target_os = "aix", + ))] + pub use unsupported::set_name; + } + all(target_os = "wasi", target_env = "p1") => { + mod wasip1; + pub use wasip1::{DEFAULT_MIN_STACK_SIZE, sleep, yield_now}; + #[cfg(target_feature = "atomics")] + pub use wasip1::{Thread, available_parallelism}; + #[expect(dead_code)] + mod unsupported; + pub use unsupported::{current_os_id, set_name}; + #[cfg(not(target_feature = "atomics"))] + pub use unsupported::{Thread, available_parallelism}; + } + all(target_os = "wasi", target_env = "p2") => { + mod wasip2; + pub use wasip2::{sleep, sleep_until}; + #[expect(dead_code)] + mod unsupported; + // Note that unlike WASIp1 even if the wasm `atomics` feature is enabled + // there is no support for threads, not even experimentally, not even in + // wasi-libc. Thus this is unconditionally unsupported. + pub use unsupported::{Thread, available_parallelism, current_os_id, set_name, yield_now, DEFAULT_MIN_STACK_SIZE}; + } + all(target_family = "wasm", target_feature = "atomics") => { + mod wasm; + pub use wasm::sleep; + + #[expect(dead_code)] + mod unsupported; + pub use unsupported::{Thread, available_parallelism, current_os_id, set_name, yield_now, DEFAULT_MIN_STACK_SIZE}; + } + target_os = "windows" => { + mod windows; + pub use windows::{Thread, available_parallelism, current_os_id, set_name, set_name_wide, sleep, yield_now, DEFAULT_MIN_STACK_SIZE}; + } + target_os = "xous" => { + mod xous; + pub use xous::{Thread, available_parallelism, sleep, yield_now, DEFAULT_MIN_STACK_SIZE}; + + #[expect(dead_code)] + mod unsupported; + pub use unsupported::{current_os_id, set_name}; + } + _ => { + mod unsupported; + pub use unsupported::{Thread, available_parallelism, current_os_id, set_name, sleep, yield_now, DEFAULT_MIN_STACK_SIZE}; + } +} + +#[cfg(not(any( + target_os = "freebsd", + target_os = "netbsd", + target_os = "linux", + target_os = "android", + target_os = "solaris", + target_os = "illumos", + target_os = "dragonfly", + target_os = "hurd", + target_os = "fuchsia", + target_os = "vxworks", + all(target_os = "wasi", target_env = "p2"), +)))] +pub fn sleep_until(deadline: crate::time::Instant) { + use crate::time::Instant; + + let now = Instant::now(); + + if let Some(delay) = deadline.checked_duration_since(now) { + sleep(delay); + } +} diff --git a/library/std/src/sys/thread/sgx.rs b/library/std/src/sys/thread/sgx.rs new file mode 100644 index 00000000000..f20ef7d86b9 --- /dev/null +++ b/library/std/src/sys/thread/sgx.rs @@ -0,0 +1,131 @@ +#![cfg_attr(test, allow(dead_code))] // why is this necessary? + +use crate::io; +use crate::sys::pal::abi::{thread, usercalls}; +use crate::time::Duration; + +pub struct Thread(task_queue::JoinHandle); + +pub const DEFAULT_MIN_STACK_SIZE: usize = 4096; + +pub use self::task_queue::JoinNotifier; + +mod task_queue { + use super::wait_notify; + use crate::sync::{Mutex, MutexGuard}; + + pub type JoinHandle = wait_notify::Waiter; + + pub struct JoinNotifier(Option<wait_notify::Notifier>); + + impl Drop for JoinNotifier { + fn drop(&mut self) { + self.0.take().unwrap().notify(); + } + } + + pub(super) struct Task { + p: Box<dyn FnOnce() + Send>, + done: JoinNotifier, + } + + impl Task { + pub(super) fn new(p: Box<dyn FnOnce() + Send>) -> (Task, JoinHandle) { + let (done, recv) = wait_notify::new(); + let done = JoinNotifier(Some(done)); + (Task { p, done }, recv) + } + + pub(super) fn run(self) -> JoinNotifier { + (self.p)(); + self.done + } + } + + // Specifying linkage/symbol name is solely to ensure a single instance between this crate and its unit tests + #[cfg_attr(test, linkage = "available_externally")] + #[unsafe(export_name = "_ZN16__rust_internals3std3sys3pal3sgx6thread10TASK_QUEUEE")] + static TASK_QUEUE: Mutex<Vec<Task>> = Mutex::new(Vec::new()); + + pub(super) fn lock() -> MutexGuard<'static, Vec<Task>> { + TASK_QUEUE.lock().unwrap() + } +} + +/// This module provides a synchronization primitive that does not use thread +/// local variables. This is needed for signaling that a thread has finished +/// execution. The signal is sent once all TLS destructors have finished at +/// which point no new thread locals should be created. +pub mod wait_notify { + use crate::pin::Pin; + use crate::sync::Arc; + use crate::sys::sync::Parker; + + pub struct Notifier(Arc<Parker>); + + impl Notifier { + /// Notify the waiter. The waiter is either notified right away (if + /// currently blocked in `Waiter::wait()`) or later when it calls the + /// `Waiter::wait()` method. + pub fn notify(self) { + Pin::new(&*self.0).unpark() + } + } + + pub struct Waiter(Arc<Parker>); + + impl Waiter { + /// Wait for a notification. If `Notifier::notify()` has already been + /// called, this will return immediately, otherwise the current thread + /// is blocked until notified. + pub fn wait(self) { + // SAFETY: + // This is only ever called on one thread. + unsafe { Pin::new(&*self.0).park() } + } + } + + pub fn new() -> (Notifier, Waiter) { + let inner = Arc::new(Parker::new()); + (Notifier(inner.clone()), Waiter(inner)) + } +} + +impl Thread { + // unsafe: see thread::Builder::spawn_unchecked for safety requirements + pub unsafe fn new( + _stack: usize, + _name: Option<&str>, + p: Box<dyn FnOnce() + Send>, + ) -> io::Result<Thread> { + let mut queue_lock = task_queue::lock(); + unsafe { usercalls::launch_thread()? }; + let (task, handle) = task_queue::Task::new(p); + queue_lock.push(task); + Ok(Thread(handle)) + } + + pub(crate) fn entry() -> JoinNotifier { + let mut pending_tasks = task_queue::lock(); + let task = rtunwrap!(Some, pending_tasks.pop()); + drop(pending_tasks); // make sure to not hold the task queue lock longer than necessary + task.run() + } + + pub fn join(self) { + self.0.wait(); + } +} + +pub fn current_os_id() -> Option<u64> { + Some(thread::current().addr().get() as u64) +} + +pub fn sleep(dur: Duration) { + usercalls::wait_timeout(0, dur, || true); +} + +pub fn yield_now() { + let wait_error = rtunwrap!(Err, usercalls::wait(0, usercalls::raw::WAIT_NO)); + rtassert!(wait_error.kind() == io::ErrorKind::WouldBlock); +} diff --git a/library/std/src/sys/thread/solid.rs b/library/std/src/sys/thread/solid.rs new file mode 100644 index 00000000000..46a84faa802 --- /dev/null +++ b/library/std/src/sys/thread/solid.rs @@ -0,0 +1,348 @@ +//! Thread implementation backed by μITRON tasks. Assumes `acre_tsk` and +//! `exd_tsk` are available. + +use crate::cell::UnsafeCell; +use crate::mem::ManuallyDrop; +use crate::ptr::NonNull; +use crate::sync::atomic::{Atomic, AtomicUsize, Ordering}; +use crate::sys::pal::itron::error::{ItronError, expect_success, expect_success_aborting}; +use crate::sys::pal::itron::time::dur2reltims; +use crate::sys::pal::itron::{abi, task}; +use crate::time::Duration; +use crate::{hint, io}; + +pub struct Thread { + p_inner: NonNull<ThreadInner>, + + /// The ID of the underlying task. + task: abi::ID, +} + +// Safety: There's nothing in `Thread` that ties it to the original creator. It +// can be dropped by any threads. +unsafe impl Send for Thread {} +// Safety: `Thread` provides no methods that take `&self`. +unsafe impl Sync for Thread {} + +/// State data shared between a parent thread and child thread. It's dropped on +/// a transition to one of the final states. +struct ThreadInner { + /// This field is used on thread creation to pass a closure from + /// `Thread::new` to the created task. + start: UnsafeCell<ManuallyDrop<Box<dyn FnOnce()>>>, + + /// A state machine. Each transition is annotated with `[...]` in the + /// source code. + /// + /// ```text + /// + /// <P>: parent, <C>: child, (?): don't-care + /// + /// DETACHED (-1) --------------------> EXITED (?) + /// <C>finish/exd_tsk + /// ^ + /// | + /// | <P>detach + /// | + /// + /// INIT (0) -----------------------> FINISHED (-1) + /// <C>finish + /// | | + /// | <P>join/slp_tsk | <P>join/del_tsk + /// | | <P>detach/del_tsk + /// v v + /// + /// JOINING JOINED (?) + /// (parent_tid) + /// ^ + /// \ / + /// \ <C>finish/wup_tsk / <P>slp_tsk-complete/ter_tsk + /// \ / & del_tsk + /// \ / + /// '--> JOIN_FINALIZE ---' + /// (-1) + /// + lifecycle: Atomic<usize>, +} + +// Safety: The only `!Sync` field, `ThreadInner::start`, is only touched by +// the task represented by `ThreadInner`. +unsafe impl Sync for ThreadInner {} + +const LIFECYCLE_INIT: usize = 0; +const LIFECYCLE_FINISHED: usize = usize::MAX; +const LIFECYCLE_DETACHED: usize = usize::MAX; +const LIFECYCLE_JOIN_FINALIZE: usize = usize::MAX; +const LIFECYCLE_DETACHED_OR_JOINED: usize = usize::MAX; +const LIFECYCLE_EXITED_OR_FINISHED_OR_JOIN_FINALIZE: usize = usize::MAX; +// there's no single value for `JOINING` + +// 64KiB for 32-bit ISAs, 128KiB for 64-bit ISAs. +pub const DEFAULT_MIN_STACK_SIZE: usize = 0x4000 * size_of::<usize>(); + +impl Thread { + /// # Safety + /// + /// See `thread::Builder::spawn_unchecked` for safety requirements. + pub unsafe fn new( + stack: usize, + _name: Option<&str>, + p: Box<dyn FnOnce()>, + ) -> io::Result<Thread> { + let inner = Box::new(ThreadInner { + start: UnsafeCell::new(ManuallyDrop::new(p)), + lifecycle: AtomicUsize::new(LIFECYCLE_INIT), + }); + + unsafe extern "C" fn trampoline(exinf: isize) { + let p_inner: *mut ThreadInner = crate::ptr::with_exposed_provenance_mut(exinf as usize); + // Safety: `ThreadInner` is alive at this point + let inner = unsafe { &*p_inner }; + + // Safety: Since `trampoline` is called only once for each + // `ThreadInner` and only `trampoline` touches `start`, + // `start` contains contents and is safe to mutably borrow. + let p = unsafe { ManuallyDrop::take(&mut *inner.start.get()) }; + p(); + + // Fix the current thread's state just in case, so that the + // destructors won't abort + // Safety: Not really unsafe + let _ = unsafe { abi::unl_cpu() }; + let _ = unsafe { abi::ena_dsp() }; + + // Run TLS destructors now because they are not + // called automatically for terminated tasks. + unsafe { crate::sys::thread_local::destructors::run() }; + + let old_lifecycle = inner + .lifecycle + .swap(LIFECYCLE_EXITED_OR_FINISHED_OR_JOIN_FINALIZE, Ordering::AcqRel); + + match old_lifecycle { + LIFECYCLE_DETACHED => { + // [DETACHED → EXITED] + // No one will ever join, so we'll ask the collector task to + // delete the task. + + // In this case, `*p_inner`'s ownership has been moved to + // us, and we are responsible for dropping it. The acquire + // ordering ensures that the swap operation that wrote + // `LIFECYCLE_DETACHED` happens-before `Box::from_raw( + // p_inner)`. + // Safety: See above. + let _ = unsafe { Box::from_raw(p_inner) }; + + // Safety: There are no pinned references to the stack + unsafe { terminate_and_delete_current_task() }; + } + LIFECYCLE_INIT => { + // [INIT → FINISHED] + // The parent hasn't decided whether to join or detach this + // thread yet. Whichever option the parent chooses, + // it'll have to delete this task. + // Since the parent might drop `*inner` as soon as it sees + // `FINISHED`, the release ordering must be used in the + // above `swap` call. + } + parent_tid => { + // Since the parent might drop `*inner` and terminate us as + // soon as it sees `JOIN_FINALIZE`, the release ordering + // must be used in the above `swap` call. + // + // To make the task referred to by `parent_tid` visible, we + // must use the acquire ordering in the above `swap` call. + + // [JOINING → JOIN_FINALIZE] + // Wake up the parent task. + expect_success( + unsafe { + let mut er = abi::wup_tsk(parent_tid as _); + if er == abi::E_QOVR { + // `E_QOVR` indicates there's already + // a parking token + er = abi::E_OK; + } + er + }, + &"wup_tsk", + ); + } + } + } + + // Safety: `Box::into_raw` returns a non-null pointer + let p_inner = unsafe { NonNull::new_unchecked(Box::into_raw(inner)) }; + + let new_task = ItronError::err_if_negative(unsafe { + abi::acre_tsk(&abi::T_CTSK { + // Activate this task immediately + tskatr: abi::TA_ACT, + exinf: p_inner.as_ptr().expose_provenance() as abi::EXINF, + // The entry point + task: Some(trampoline), + // Inherit the calling task's base priority + itskpri: abi::TPRI_SELF, + stksz: stack, + // Let the kernel allocate the stack, + stk: crate::ptr::null_mut(), + }) + }) + .map_err(|e| e.as_io_error())?; + + Ok(Self { p_inner, task: new_task }) + } + + pub fn join(self) { + // Safety: `ThreadInner` is alive at this point + let inner = unsafe { self.p_inner.as_ref() }; + // Get the current task ID. Panicking here would cause a resource leak, + // so just abort on failure. + let current_task = task::current_task_id_aborting(); + debug_assert!(usize::try_from(current_task).is_ok()); + debug_assert_ne!(current_task as usize, LIFECYCLE_INIT); + debug_assert_ne!(current_task as usize, LIFECYCLE_DETACHED); + + let current_task = current_task as usize; + + match inner.lifecycle.swap(current_task, Ordering::AcqRel) { + LIFECYCLE_INIT => { + // [INIT → JOINING] + // The child task will transition the state to `JOIN_FINALIZE` + // and wake us up. + // + // To make the task referred to by `current_task` visible from + // the child task's point of view, we must use the release + // ordering in the above `swap` call. + loop { + expect_success_aborting(unsafe { abi::slp_tsk() }, &"slp_tsk"); + // To synchronize with the child task's memory accesses to + // `inner` up to the point of the assignment of + // `JOIN_FINALIZE`, `Ordering::Acquire` must be used for the + // `load`. + if inner.lifecycle.load(Ordering::Acquire) == LIFECYCLE_JOIN_FINALIZE { + break; + } + } + + // [JOIN_FINALIZE → JOINED] + } + LIFECYCLE_FINISHED => { + // [FINISHED → JOINED] + // To synchronize with the child task's memory accesses to + // `inner` up to the point of the assignment of `FINISHED`, + // `Ordering::Acquire` must be used for the above `swap` call. + } + _ => unsafe { hint::unreachable_unchecked() }, + } + + // Terminate and delete the task + // Safety: `self.task` still represents a task we own (because this + // method or `detach_inner` is called only once for each + // `Thread`). The task indicated that it's safe to delete by + // entering the `FINISHED` or `JOIN_FINALIZE` state. + unsafe { terminate_and_delete_task(self.task) }; + + // In either case, we are responsible for dropping `inner`. + // Safety: The contents of `*p_inner` will not be accessed hereafter + let _inner = unsafe { Box::from_raw(self.p_inner.as_ptr()) }; + + // Skip the destructor (because it would attempt to detach the thread) + crate::mem::forget(self); + } +} + +impl Drop for Thread { + fn drop(&mut self) { + // Safety: `ThreadInner` is alive at this point + let inner = unsafe { self.p_inner.as_ref() }; + + // Detach the thread. + match inner.lifecycle.swap(LIFECYCLE_DETACHED_OR_JOINED, Ordering::AcqRel) { + LIFECYCLE_INIT => { + // [INIT → DETACHED] + // When the time comes, the child will figure out that no + // one will ever join it. + // The ownership of `*p_inner` is moved to the child thread. + // The release ordering ensures that the above swap operation on + // `lifecycle` happens-before the child thread's + // `Box::from_raw(p_inner)`. + } + LIFECYCLE_FINISHED => { + // [FINISHED → JOINED] + // The task has already decided that we should delete the task. + // To synchronize with the child task's memory accesses to + // `inner` up to the point of the assignment of `FINISHED`, + // the acquire ordering is required for the above `swap` call. + + // Terminate and delete the task + // Safety: `self.task` still represents a task we own (because + // this method or `join_inner` is called only once for + // each `Thread`). The task indicated that it's safe to + // delete by entering the `FINISHED` state. + unsafe { terminate_and_delete_task(self.task) }; + + // Wwe are responsible for dropping `*p_inner`. + // Safety: The contents of `*p_inner` will not be accessed hereafter + let _ = unsafe { Box::from_raw(self.p_inner.as_ptr()) }; + } + _ => unsafe { hint::unreachable_unchecked() }, + } + } +} + +/// Terminates and deletes the specified task. +/// +/// This function will abort if `deleted_task` refers to the calling task. +/// +/// It is assumed that the specified task is solely managed by the caller - +/// i.e., other threads must not "resuscitate" the specified task or delete it +/// prematurely while this function is still in progress. It is allowed for the +/// specified task to exit by its own. +/// +/// # Safety +/// +/// The task must be safe to terminate. This is in general not true +/// because there might be pinned references to the task's stack. +unsafe fn terminate_and_delete_task(deleted_task: abi::ID) { + // Terminate the task + // Safety: Upheld by the caller + match unsafe { abi::ter_tsk(deleted_task) } { + // Indicates the task is already dormant, ignore it + abi::E_OBJ => {} + er => { + expect_success_aborting(er, &"ter_tsk"); + } + } + + // Delete the task + // Safety: Upheld by the caller + expect_success_aborting(unsafe { abi::del_tsk(deleted_task) }, &"del_tsk"); +} + +/// Terminates and deletes the calling task. +/// +/// Atomicity is not required - i.e., it can be assumed that other threads won't +/// `ter_tsk` the calling task while this function is still in progress. (This +/// property makes it easy to implement this operation on μITRON-derived kernels +/// that don't support `exd_tsk`.) +/// +/// # Safety +/// +/// The task must be safe to terminate. This is in general not true +/// because there might be pinned references to the task's stack. +unsafe fn terminate_and_delete_current_task() -> ! { + expect_success_aborting(unsafe { abi::exd_tsk() }, &"exd_tsk"); + // Safety: `exd_tsk` never returns on success + unsafe { crate::hint::unreachable_unchecked() }; +} + +pub fn yield_now() { + expect_success(unsafe { abi::rot_rdq(abi::TPRI_SELF) }, &"rot_rdq"); +} + +pub fn sleep(dur: Duration) { + for timeout in dur2reltims(dur) { + expect_success(unsafe { abi::dly_tsk(timeout) }, &"dly_tsk"); + } +} diff --git a/library/std/src/sys/thread/teeos.rs b/library/std/src/sys/thread/teeos.rs new file mode 100644 index 00000000000..cad100395c9 --- /dev/null +++ b/library/std/src/sys/thread/teeos.rs @@ -0,0 +1,126 @@ +use crate::mem::{self, ManuallyDrop}; +use crate::sys::os; +use crate::time::Duration; +use crate::{cmp, io, ptr}; + +pub const DEFAULT_MIN_STACK_SIZE: usize = 8 * 1024; + +unsafe extern "C" { + safe fn TEE_Wait(timeout: u32) -> u32; +} + +fn min_stack_size(_: *const libc::pthread_attr_t) -> usize { + libc::PTHREAD_STACK_MIN.try_into().expect("Infallible") +} + +pub struct Thread { + id: libc::pthread_t, +} + +// Some platforms may have pthread_t as a pointer in which case we still want +// a thread to be Send/Sync +unsafe impl Send for Thread {} +unsafe impl Sync for Thread {} + +impl Thread { + // unsafe: see thread::Builder::spawn_unchecked for safety requirements + pub unsafe fn new( + stack: usize, + _name: Option<&str>, + p: Box<dyn FnOnce()>, + ) -> io::Result<Thread> { + let p = Box::into_raw(Box::new(p)); + let mut native: libc::pthread_t = unsafe { mem::zeroed() }; + let mut attr: libc::pthread_attr_t = unsafe { mem::zeroed() }; + assert_eq!(unsafe { libc::pthread_attr_init(&mut attr) }, 0); + assert_eq!( + unsafe { + libc::pthread_attr_settee( + &mut attr, + libc::TEESMP_THREAD_ATTR_CA_INHERIT, + libc::TEESMP_THREAD_ATTR_TASK_ID_INHERIT, + libc::TEESMP_THREAD_ATTR_HAS_SHADOW, + ) + }, + 0, + ); + + let stack_size = cmp::max(stack, min_stack_size(&attr)); + + match unsafe { libc::pthread_attr_setstacksize(&mut attr, stack_size) } { + 0 => {} + n => { + assert_eq!(n, libc::EINVAL); + // EINVAL means |stack_size| is either too small or not a + // multiple of the system page size. Because it's definitely + // >= PTHREAD_STACK_MIN, it must be an alignment issue. + // Round up to the nearest page and try again. + let page_size = os::page_size(); + let stack_size = + (stack_size + page_size - 1) & (-(page_size as isize - 1) as usize - 1); + assert_eq!(unsafe { libc::pthread_attr_setstacksize(&mut attr, stack_size) }, 0); + } + }; + + let ret = unsafe { libc::pthread_create(&mut native, &attr, thread_start, p as *mut _) }; + // Note: if the thread creation fails and this assert fails, then p will + // be leaked. However, an alternative design could cause double-free + // which is clearly worse. + assert_eq!(unsafe { libc::pthread_attr_destroy(&mut attr) }, 0); + + return if ret != 0 { + // The thread failed to start and as a result p was not consumed. Therefore, it is + // safe to reconstruct the box so that it gets deallocated. + drop(unsafe { Box::from_raw(p) }); + Err(io::Error::from_raw_os_error(ret)) + } else { + // The new thread will start running earliest after the next yield. + // We add a yield here, so that the user does not have to. + yield_now(); + Ok(Thread { id: native }) + }; + + extern "C" fn thread_start(main: *mut libc::c_void) -> *mut libc::c_void { + unsafe { + // Next, set up our stack overflow handler which may get triggered if we run + // out of stack. + // this is not necessary in TEE. + //let _handler = stack_overflow::Handler::new(); + // Finally, let's run some code. + Box::from_raw(main as *mut Box<dyn FnOnce()>)(); + } + ptr::null_mut() + } + } + + /// must join, because no pthread_detach supported + pub fn join(self) { + let id = self.into_id(); + let ret = unsafe { libc::pthread_join(id, ptr::null_mut()) }; + assert!(ret == 0, "failed to join thread: {}", io::Error::from_raw_os_error(ret)); + } + + pub fn into_id(self) -> libc::pthread_t { + ManuallyDrop::new(self).id + } +} + +impl Drop for Thread { + fn drop(&mut self) { + // we can not call detach, so just panic if thread spawn without join + panic!("thread must join, detach is not supported!"); + } +} + +pub fn yield_now() { + let ret = unsafe { libc::sched_yield() }; + debug_assert_eq!(ret, 0); +} + +/// only main thread could wait for sometime in teeos +pub fn sleep(dur: Duration) { + let sleep_millis = dur.as_millis(); + let final_sleep: u32 = + if sleep_millis >= u32::MAX as u128 { u32::MAX } else { sleep_millis as u32 }; + TEE_Wait(final_sleep); +} diff --git a/library/std/src/sys/thread/uefi.rs b/library/std/src/sys/thread/uefi.rs new file mode 100644 index 00000000000..94f67d7ace2 --- /dev/null +++ b/library/std/src/sys/thread/uefi.rs @@ -0,0 +1,25 @@ +use crate::io; +use crate::num::NonZero; +use crate::ptr::NonNull; +use crate::time::Duration; + +pub fn available_parallelism() -> io::Result<NonZero<usize>> { + // UEFI is single threaded + Ok(NonZero::new(1).unwrap()) +} + +pub fn sleep(dur: Duration) { + let boot_services: NonNull<r_efi::efi::BootServices> = + crate::os::uefi::env::boot_services().expect("can't sleep").cast(); + let mut dur_ms = dur.as_micros(); + // ceil up to the nearest microsecond + if dur.subsec_nanos() % 1000 > 0 { + dur_ms += 1; + } + + while dur_ms > 0 { + let ms = crate::cmp::min(dur_ms, usize::MAX as u128); + let _ = unsafe { ((*boot_services.as_ptr()).stall)(ms as usize) }; + dur_ms -= ms; + } +} diff --git a/library/std/src/sys/thread/unix.rs b/library/std/src/sys/thread/unix.rs new file mode 100644 index 00000000000..2d2c4f90212 --- /dev/null +++ b/library/std/src/sys/thread/unix.rs @@ -0,0 +1,908 @@ +#[cfg(not(any( + target_env = "newlib", + target_os = "l4re", + target_os = "emscripten", + target_os = "redox", + target_os = "hurd", + target_os = "aix", +)))] +use crate::ffi::CStr; +use crate::mem::{self, ManuallyDrop}; +use crate::num::NonZero; +#[cfg(all(target_os = "linux", target_env = "gnu"))] +use crate::sys::weak::dlsym; +#[cfg(any(target_os = "solaris", target_os = "illumos", target_os = "nto",))] +use crate::sys::weak::weak; +use crate::sys::{os, stack_overflow}; +use crate::time::Duration; +use crate::{cmp, io, ptr}; +#[cfg(not(any( + target_os = "l4re", + target_os = "vxworks", + target_os = "espidf", + target_os = "nuttx" +)))] +pub const DEFAULT_MIN_STACK_SIZE: usize = 2 * 1024 * 1024; +#[cfg(target_os = "l4re")] +pub const DEFAULT_MIN_STACK_SIZE: usize = 1024 * 1024; +#[cfg(target_os = "vxworks")] +pub const DEFAULT_MIN_STACK_SIZE: usize = 256 * 1024; +#[cfg(any(target_os = "espidf", target_os = "nuttx"))] +pub const DEFAULT_MIN_STACK_SIZE: usize = 0; // 0 indicates that the stack size configured in the ESP-IDF/NuttX menuconfig system should be used + +struct ThreadData { + name: Option<Box<str>>, + f: Box<dyn FnOnce()>, +} + +pub struct Thread { + id: libc::pthread_t, +} + +// Some platforms may have pthread_t as a pointer in which case we still want +// a thread to be Send/Sync +unsafe impl Send for Thread {} +unsafe impl Sync for Thread {} + +impl Thread { + // unsafe: see thread::Builder::spawn_unchecked for safety requirements + #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces + pub unsafe fn new( + stack: usize, + name: Option<&str>, + f: Box<dyn FnOnce()>, + ) -> io::Result<Thread> { + let data = Box::into_raw(Box::new(ThreadData { name: name.map(Box::from), f })); + let mut native: libc::pthread_t = mem::zeroed(); + let mut attr: mem::MaybeUninit<libc::pthread_attr_t> = mem::MaybeUninit::uninit(); + assert_eq!(libc::pthread_attr_init(attr.as_mut_ptr()), 0); + + #[cfg(any(target_os = "espidf", target_os = "nuttx"))] + if stack > 0 { + // Only set the stack if a non-zero value is passed + // 0 is used as an indication that the default stack size configured in the ESP-IDF/NuttX menuconfig system should be used + assert_eq!( + libc::pthread_attr_setstacksize( + attr.as_mut_ptr(), + cmp::max(stack, min_stack_size(attr.as_ptr())) + ), + 0 + ); + } + + #[cfg(not(any(target_os = "espidf", target_os = "nuttx")))] + { + let stack_size = cmp::max(stack, min_stack_size(attr.as_ptr())); + + match libc::pthread_attr_setstacksize(attr.as_mut_ptr(), stack_size) { + 0 => {} + n => { + assert_eq!(n, libc::EINVAL); + // EINVAL means |stack_size| is either too small or not a + // multiple of the system page size. Because it's definitely + // >= PTHREAD_STACK_MIN, it must be an alignment issue. + // Round up to the nearest page and try again. + let page_size = os::page_size(); + let stack_size = + (stack_size + page_size - 1) & (-(page_size as isize - 1) as usize - 1); + + // Some libc implementations, e.g. musl, place an upper bound + // on the stack size, in which case we can only gracefully return + // an error here. + if libc::pthread_attr_setstacksize(attr.as_mut_ptr(), stack_size) != 0 { + assert_eq!(libc::pthread_attr_destroy(attr.as_mut_ptr()), 0); + drop(Box::from_raw(data)); + return Err(io::const_error!( + io::ErrorKind::InvalidInput, + "invalid stack size" + )); + } + } + }; + } + + let ret = libc::pthread_create(&mut native, attr.as_ptr(), thread_start, data as *mut _); + // Note: if the thread creation fails and this assert fails, then p will + // be leaked. However, an alternative design could cause double-free + // which is clearly worse. + assert_eq!(libc::pthread_attr_destroy(attr.as_mut_ptr()), 0); + + return if ret != 0 { + // The thread failed to start and as a result p was not consumed. Therefore, it is + // safe to reconstruct the box so that it gets deallocated. + drop(Box::from_raw(data)); + Err(io::Error::from_raw_os_error(ret)) + } else { + Ok(Thread { id: native }) + }; + + extern "C" fn thread_start(data: *mut libc::c_void) -> *mut libc::c_void { + unsafe { + let data = Box::from_raw(data as *mut ThreadData); + // Next, set up our stack overflow handler which may get triggered if we run + // out of stack. + let _handler = stack_overflow::Handler::new(data.name); + // Finally, let's run some code. + (data.f)(); + } + ptr::null_mut() + } + } + + pub fn join(self) { + let id = self.into_id(); + let ret = unsafe { libc::pthread_join(id, ptr::null_mut()) }; + assert!(ret == 0, "failed to join thread: {}", io::Error::from_raw_os_error(ret)); + } + + pub fn id(&self) -> libc::pthread_t { + self.id + } + + pub fn into_id(self) -> libc::pthread_t { + ManuallyDrop::new(self).id + } +} + +impl Drop for Thread { + fn drop(&mut self) { + let ret = unsafe { libc::pthread_detach(self.id) }; + debug_assert_eq!(ret, 0); + } +} + +pub fn available_parallelism() -> io::Result<NonZero<usize>> { + cfg_select! { + any( + target_os = "android", + target_os = "emscripten", + target_os = "fuchsia", + target_os = "hurd", + target_os = "linux", + target_os = "aix", + target_vendor = "apple", + target_os = "cygwin", + ) => { + #[allow(unused_assignments)] + #[allow(unused_mut)] + let mut quota = usize::MAX; + + #[cfg(any(target_os = "android", target_os = "linux"))] + { + quota = cgroups::quota().max(1); + let mut set: libc::cpu_set_t = unsafe { mem::zeroed() }; + unsafe { + if libc::sched_getaffinity(0, size_of::<libc::cpu_set_t>(), &mut set) == 0 { + let count = libc::CPU_COUNT(&set) as usize; + let count = count.min(quota); + + // According to sched_getaffinity's API it should always be non-zero, but + // some old MIPS kernels were buggy and zero-initialized the mask if + // none was explicitly set. + // In that case we use the sysconf fallback. + if let Some(count) = NonZero::new(count) { + return Ok(count) + } + } + } + } + match unsafe { libc::sysconf(libc::_SC_NPROCESSORS_ONLN) } { + -1 => Err(io::Error::last_os_error()), + 0 => Err(io::Error::UNKNOWN_THREAD_COUNT), + cpus => { + let count = cpus as usize; + // Cover the unusual situation where we were able to get the quota but not the affinity mask + let count = count.min(quota); + Ok(unsafe { NonZero::new_unchecked(count) }) + } + } + } + any( + target_os = "freebsd", + target_os = "dragonfly", + target_os = "openbsd", + target_os = "netbsd", + ) => { + use crate::ptr; + + #[cfg(target_os = "freebsd")] + { + let mut set: libc::cpuset_t = unsafe { mem::zeroed() }; + unsafe { + if libc::cpuset_getaffinity( + libc::CPU_LEVEL_WHICH, + libc::CPU_WHICH_PID, + -1, + size_of::<libc::cpuset_t>(), + &mut set, + ) == 0 { + let count = libc::CPU_COUNT(&set) as usize; + if count > 0 { + return Ok(NonZero::new_unchecked(count)); + } + } + } + } + + #[cfg(target_os = "netbsd")] + { + unsafe { + let set = libc::_cpuset_create(); + if !set.is_null() { + let mut count: usize = 0; + if libc::pthread_getaffinity_np(libc::pthread_self(), libc::_cpuset_size(set), set) == 0 { + for i in 0..libc::cpuid_t::MAX { + match libc::_cpuset_isset(i, set) { + -1 => break, + 0 => continue, + _ => count = count + 1, + } + } + } + libc::_cpuset_destroy(set); + if let Some(count) = NonZero::new(count) { + return Ok(count); + } + } + } + } + + let mut cpus: libc::c_uint = 0; + let mut cpus_size = size_of_val(&cpus); + + unsafe { + cpus = libc::sysconf(libc::_SC_NPROCESSORS_ONLN) as libc::c_uint; + } + + // Fallback approach in case of errors or no hardware threads. + if cpus < 1 { + let mut mib = [libc::CTL_HW, libc::HW_NCPU, 0, 0]; + let res = unsafe { + libc::sysctl( + mib.as_mut_ptr(), + 2, + (&raw mut cpus) as *mut _, + (&raw mut cpus_size) as *mut _, + ptr::null_mut(), + 0, + ) + }; + + // Handle errors if any. + if res == -1 { + return Err(io::Error::last_os_error()); + } else if cpus == 0 { + return Err(io::Error::UNKNOWN_THREAD_COUNT); + } + } + + Ok(unsafe { NonZero::new_unchecked(cpus as usize) }) + } + target_os = "nto" => { + unsafe { + use libc::_syspage_ptr; + if _syspage_ptr.is_null() { + Err(io::const_error!(io::ErrorKind::NotFound, "no syspage available")) + } else { + let cpus = (*_syspage_ptr).num_cpu; + NonZero::new(cpus as usize) + .ok_or(io::Error::UNKNOWN_THREAD_COUNT) + } + } + } + any(target_os = "solaris", target_os = "illumos") => { + let mut cpus = 0u32; + if unsafe { libc::pset_info(libc::PS_MYID, core::ptr::null_mut(), &mut cpus, core::ptr::null_mut()) } != 0 { + return Err(io::Error::UNKNOWN_THREAD_COUNT); + } + Ok(unsafe { NonZero::new_unchecked(cpus as usize) }) + } + target_os = "haiku" => { + // system_info cpu_count field gets the static data set at boot time with `smp_set_num_cpus` + // `get_system_info` calls then `smp_get_num_cpus` + unsafe { + let mut sinfo: libc::system_info = crate::mem::zeroed(); + let res = libc::get_system_info(&mut sinfo); + + if res != libc::B_OK { + return Err(io::Error::UNKNOWN_THREAD_COUNT); + } + + Ok(NonZero::new_unchecked(sinfo.cpu_count as usize)) + } + } + target_os = "vxworks" => { + // Note: there is also `vxCpuConfiguredGet`, closer to _SC_NPROCESSORS_CONF + // expectations than the actual cores availability. + unsafe extern "C" { + fn vxCpuEnabledGet() -> libc::cpuset_t; + } + + // SAFETY: `vxCpuEnabledGet` always fetches a mask with at least one bit set + unsafe{ + let set = vxCpuEnabledGet(); + Ok(NonZero::new_unchecked(set.count_ones() as usize)) + } + } + _ => { + // FIXME: implement on Redox, l4re + Err(io::const_error!(io::ErrorKind::Unsupported, "getting the number of hardware threads is not supported on the target platform")) + } + } +} + +pub fn current_os_id() -> Option<u64> { + // Most Unix platforms have a way to query an integer ID of the current thread, all with + // slightly different spellings. + // + // The OS thread ID is used rather than `pthread_self` so as to match what will be displayed + // for process inspection (debuggers, trace, `top`, etc.). + cfg_select! { + // Most platforms have a function returning a `pid_t` or int, which is an `i32`. + any(target_os = "android", target_os = "linux") => { + use crate::sys::pal::weak::syscall; + + // `libc::gettid` is only available on glibc 2.30+, but the syscall is available + // since Linux 2.4.11. + syscall!(fn gettid() -> libc::pid_t;); + + // SAFETY: FFI call with no preconditions. + let id: libc::pid_t = unsafe { gettid() }; + Some(id as u64) + } + target_os = "nto" => { + // SAFETY: FFI call with no preconditions. + let id: libc::pid_t = unsafe { libc::gettid() }; + Some(id as u64) + } + target_os = "openbsd" => { + // SAFETY: FFI call with no preconditions. + let id: libc::pid_t = unsafe { libc::getthrid() }; + Some(id as u64) + } + target_os = "freebsd" => { + // SAFETY: FFI call with no preconditions. + let id: libc::c_int = unsafe { libc::pthread_getthreadid_np() }; + Some(id as u64) + } + target_os = "netbsd" => { + // SAFETY: FFI call with no preconditions. + let id: libc::lwpid_t = unsafe { libc::_lwp_self() }; + Some(id as u64) + } + any(target_os = "illumos", target_os = "solaris") => { + // On Illumos and Solaris, the `pthread_t` is the same as the OS thread ID. + // SAFETY: FFI call with no preconditions. + let id: libc::pthread_t = unsafe { libc::pthread_self() }; + Some(id as u64) + } + target_vendor = "apple" => { + // Apple allows querying arbitrary thread IDs, `thread=NULL` queries the current thread. + let mut id = 0u64; + // SAFETY: `thread_id` is a valid pointer, no other preconditions. + let status: libc::c_int = unsafe { libc::pthread_threadid_np(0, &mut id) }; + if status == 0 { + Some(id) + } else { + None + } + } + // Other platforms don't have an OS thread ID or don't have a way to access it. + _ => None, + } +} + +#[cfg(any( + target_os = "linux", + target_os = "nto", + target_os = "solaris", + target_os = "illumos", + target_os = "vxworks", + target_os = "cygwin", + target_vendor = "apple", +))] +fn truncate_cstr<const MAX_WITH_NUL: usize>(cstr: &CStr) -> [libc::c_char; MAX_WITH_NUL] { + let mut result = [0; MAX_WITH_NUL]; + for (src, dst) in cstr.to_bytes().iter().zip(&mut result[..MAX_WITH_NUL - 1]) { + *dst = *src as libc::c_char; + } + result +} + +#[cfg(target_os = "android")] +pub fn set_name(name: &CStr) { + const PR_SET_NAME: libc::c_int = 15; + unsafe { + let res = libc::prctl( + PR_SET_NAME, + name.as_ptr(), + 0 as libc::c_ulong, + 0 as libc::c_ulong, + 0 as libc::c_ulong, + ); + // We have no good way of propagating errors here, but in debug-builds let's check that this actually worked. + debug_assert_eq!(res, 0); + } +} + +#[cfg(any( + target_os = "linux", + target_os = "freebsd", + target_os = "dragonfly", + target_os = "nuttx", + target_os = "cygwin" +))] +pub fn set_name(name: &CStr) { + unsafe { + cfg_select! { + any(target_os = "linux", target_os = "cygwin") => { + // Linux and Cygwin limits the allowed length of the name. + const TASK_COMM_LEN: usize = 16; + let name = truncate_cstr::<{ TASK_COMM_LEN }>(name); + } + _ => { + // FreeBSD, DragonFly BSD and NuttX do not enforce length limits. + } + }; + // Available since glibc 2.12, musl 1.1.16, and uClibc 1.0.20 for Linux, + // FreeBSD 12.2 and 13.0, and DragonFly BSD 6.0. + let res = libc::pthread_setname_np(libc::pthread_self(), name.as_ptr()); + // We have no good way of propagating errors here, but in debug-builds let's check that this actually worked. + debug_assert_eq!(res, 0); + } +} + +#[cfg(target_os = "openbsd")] +pub fn set_name(name: &CStr) { + unsafe { + libc::pthread_set_name_np(libc::pthread_self(), name.as_ptr()); + } +} + +#[cfg(target_vendor = "apple")] +pub fn set_name(name: &CStr) { + unsafe { + let name = truncate_cstr::<{ libc::MAXTHREADNAMESIZE }>(name); + let res = libc::pthread_setname_np(name.as_ptr()); + // We have no good way of propagating errors here, but in debug-builds let's check that this actually worked. + debug_assert_eq!(res, 0); + } +} + +#[cfg(target_os = "netbsd")] +pub fn set_name(name: &CStr) { + unsafe { + let res = libc::pthread_setname_np( + libc::pthread_self(), + c"%s".as_ptr(), + name.as_ptr() as *mut libc::c_void, + ); + debug_assert_eq!(res, 0); + } +} + +#[cfg(any(target_os = "solaris", target_os = "illumos", target_os = "nto"))] +pub fn set_name(name: &CStr) { + weak!( + fn pthread_setname_np(thread: libc::pthread_t, name: *const libc::c_char) -> libc::c_int; + ); + + if let Some(f) = pthread_setname_np.get() { + #[cfg(target_os = "nto")] + const THREAD_NAME_MAX: usize = libc::_NTO_THREAD_NAME_MAX as usize; + #[cfg(any(target_os = "solaris", target_os = "illumos"))] + const THREAD_NAME_MAX: usize = 32; + + let name = truncate_cstr::<{ THREAD_NAME_MAX }>(name); + let res = unsafe { f(libc::pthread_self(), name.as_ptr()) }; + debug_assert_eq!(res, 0); + } +} + +#[cfg(target_os = "fuchsia")] +pub fn set_name(name: &CStr) { + use crate::sys::pal::fuchsia::*; + unsafe { + zx_object_set_property( + zx_thread_self(), + ZX_PROP_NAME, + name.as_ptr() as *const libc::c_void, + name.to_bytes().len(), + ); + } +} + +#[cfg(target_os = "haiku")] +pub fn set_name(name: &CStr) { + unsafe { + let thread_self = libc::find_thread(ptr::null_mut()); + let res = libc::rename_thread(thread_self, name.as_ptr()); + // We have no good way of propagating errors here, but in debug-builds let's check that this actually worked. + debug_assert_eq!(res, libc::B_OK); + } +} + +#[cfg(target_os = "vxworks")] +pub fn set_name(name: &CStr) { + let mut name = truncate_cstr::<{ (libc::VX_TASK_RENAME_LENGTH - 1) as usize }>(name); + let res = unsafe { libc::taskNameSet(libc::taskIdSelf(), name.as_mut_ptr()) }; + debug_assert_eq!(res, libc::OK); +} + +#[cfg(not(target_os = "espidf"))] +pub fn sleep(dur: Duration) { + let mut secs = dur.as_secs(); + let mut nsecs = dur.subsec_nanos() as _; + + // If we're awoken with a signal then the return value will be -1 and + // nanosleep will fill in `ts` with the remaining time. + unsafe { + while secs > 0 || nsecs > 0 { + let mut ts = libc::timespec { + tv_sec: cmp::min(libc::time_t::MAX as u64, secs) as libc::time_t, + tv_nsec: nsecs, + }; + secs -= ts.tv_sec as u64; + let ts_ptr = &raw mut ts; + if libc::nanosleep(ts_ptr, ts_ptr) == -1 { + assert_eq!(os::errno(), libc::EINTR); + secs += ts.tv_sec as u64; + nsecs = ts.tv_nsec; + } else { + nsecs = 0; + } + } + } +} + +#[cfg(target_os = "espidf")] +pub fn sleep(dur: Duration) { + // ESP-IDF does not have `nanosleep`, so we use `usleep` instead. + // As per the documentation of `usleep`, it is expected to support + // sleep times as big as at least up to 1 second. + // + // ESP-IDF does support almost up to `u32::MAX`, but due to a potential integer overflow in its + // `usleep` implementation + // (https://github.com/espressif/esp-idf/blob/d7ca8b94c852052e3bc33292287ef4dd62c9eeb1/components/newlib/time.c#L210), + // we limit the sleep time to the maximum one that would not cause the underlying `usleep` implementation to overflow + // (`portTICK_PERIOD_MS` can be anything between 1 to 1000, and is 10 by default). + const MAX_MICROS: u32 = u32::MAX - 1_000_000 - 1; + + // Add any nanoseconds smaller than a microsecond as an extra microsecond + // so as to comply with the `std::thread::sleep` contract which mandates + // implementations to sleep for _at least_ the provided `dur`. + // We can't overflow `micros` as it is a `u128`, while `Duration` is a pair of + // (`u64` secs, `u32` nanos), where the nanos are strictly smaller than 1 second + // (i.e. < 1_000_000_000) + let mut micros = dur.as_micros() + if dur.subsec_nanos() % 1_000 > 0 { 1 } else { 0 }; + + while micros > 0 { + let st = if micros > MAX_MICROS as u128 { MAX_MICROS } else { micros as u32 }; + unsafe { + libc::usleep(st); + } + + micros -= st as u128; + } +} + +// Any unix that has clock_nanosleep +// If this list changes update the MIRI chock_nanosleep shim +#[cfg(any( + target_os = "freebsd", + target_os = "netbsd", + target_os = "linux", + target_os = "android", + target_os = "solaris", + target_os = "illumos", + target_os = "dragonfly", + target_os = "hurd", + target_os = "fuchsia", + target_os = "vxworks", +))] +pub fn sleep_until(deadline: crate::time::Instant) { + use crate::time::Instant; + + let Some(ts) = deadline.into_inner().into_timespec().to_timespec() else { + // The deadline is further in the future then can be passed to + // clock_nanosleep. We have to use Self::sleep instead. This might + // happen on 32 bit platforms, especially closer to 2038. + let now = Instant::now(); + if let Some(delay) = deadline.checked_duration_since(now) { + sleep(delay); + } + return; + }; + + unsafe { + // When we get interrupted (res = EINTR) call clock_nanosleep again + loop { + let res = libc::clock_nanosleep( + crate::sys::time::Instant::CLOCK_ID, + libc::TIMER_ABSTIME, + &ts, + core::ptr::null_mut(), // not required with TIMER_ABSTIME + ); + + if res == 0 { + break; + } else { + assert_eq!( + res, + libc::EINTR, + "timespec is in range, + clockid is valid and kernel should support it" + ); + } + } + } +} + +pub fn yield_now() { + let ret = unsafe { libc::sched_yield() }; + debug_assert_eq!(ret, 0); +} + +#[cfg(any(target_os = "android", target_os = "linux"))] +mod cgroups { + //! Currently not covered + //! * cgroup v2 in non-standard mountpoints + //! * paths containing control characters or spaces, since those would be escaped in procfs + //! output and we don't unescape + + use crate::borrow::Cow; + use crate::ffi::OsString; + use crate::fs::{File, exists}; + use crate::io::{BufRead, Read}; + use crate::os::unix::ffi::OsStringExt; + use crate::path::{Path, PathBuf}; + use crate::str::from_utf8; + + #[derive(PartialEq)] + enum Cgroup { + V1, + V2, + } + + /// Returns cgroup CPU quota in core-equivalents, rounded down or usize::MAX if the quota cannot + /// be determined or is not set. + pub(super) fn quota() -> usize { + let mut quota = usize::MAX; + if cfg!(miri) { + // Attempting to open a file fails under default flags due to isolation. + // And Miri does not have parallelism anyway. + return quota; + } + + let _: Option<()> = try { + let mut buf = Vec::with_capacity(128); + // find our place in the cgroup hierarchy + File::open("/proc/self/cgroup").ok()?.read_to_end(&mut buf).ok()?; + let (cgroup_path, version) = + buf.split(|&c| c == b'\n').fold(None, |previous, line| { + let mut fields = line.splitn(3, |&c| c == b':'); + // 2nd field is a list of controllers for v1 or empty for v2 + let version = match fields.nth(1) { + Some(b"") => Cgroup::V2, + Some(controllers) + if from_utf8(controllers) + .is_ok_and(|c| c.split(',').any(|c| c == "cpu")) => + { + Cgroup::V1 + } + _ => return previous, + }; + + // already-found v1 trumps v2 since it explicitly specifies its controllers + if previous.is_some() && version == Cgroup::V2 { + return previous; + } + + let path = fields.last()?; + // skip leading slash + Some((path[1..].to_owned(), version)) + })?; + let cgroup_path = PathBuf::from(OsString::from_vec(cgroup_path)); + + quota = match version { + Cgroup::V1 => quota_v1(cgroup_path), + Cgroup::V2 => quota_v2(cgroup_path), + }; + }; + + quota + } + + fn quota_v2(group_path: PathBuf) -> usize { + let mut quota = usize::MAX; + + let mut path = PathBuf::with_capacity(128); + let mut read_buf = String::with_capacity(20); + + // standard mount location defined in file-hierarchy(7) manpage + let cgroup_mount = "/sys/fs/cgroup"; + + path.push(cgroup_mount); + path.push(&group_path); + + path.push("cgroup.controllers"); + + // skip if we're not looking at cgroup2 + if matches!(exists(&path), Err(_) | Ok(false)) { + return usize::MAX; + }; + + path.pop(); + + let _: Option<()> = try { + while path.starts_with(cgroup_mount) { + path.push("cpu.max"); + + read_buf.clear(); + + if File::open(&path).and_then(|mut f| f.read_to_string(&mut read_buf)).is_ok() { + let raw_quota = read_buf.lines().next()?; + let mut raw_quota = raw_quota.split(' '); + let limit = raw_quota.next()?; + let period = raw_quota.next()?; + match (limit.parse::<usize>(), period.parse::<usize>()) { + (Ok(limit), Ok(period)) if period > 0 => { + quota = quota.min(limit / period); + } + _ => {} + } + } + + path.pop(); // pop filename + path.pop(); // pop dir + } + }; + + quota + } + + fn quota_v1(group_path: PathBuf) -> usize { + let mut quota = usize::MAX; + let mut path = PathBuf::with_capacity(128); + let mut read_buf = String::with_capacity(20); + + // Hardcode commonly used locations mentioned in the cgroups(7) manpage + // if that doesn't work scan mountinfo and adjust `group_path` for bind-mounts + let mounts: &[fn(&Path) -> Option<(_, &Path)>] = &[ + |p| Some((Cow::Borrowed("/sys/fs/cgroup/cpu"), p)), + |p| Some((Cow::Borrowed("/sys/fs/cgroup/cpu,cpuacct"), p)), + // this can be expensive on systems with tons of mountpoints + // but we only get to this point when /proc/self/cgroups explicitly indicated + // this process belongs to a cpu-controller cgroup v1 and the defaults didn't work + find_mountpoint, + ]; + + for mount in mounts { + let Some((mount, group_path)) = mount(&group_path) else { continue }; + + path.clear(); + path.push(mount.as_ref()); + path.push(&group_path); + + // skip if we guessed the mount incorrectly + if matches!(exists(&path), Err(_) | Ok(false)) { + continue; + } + + while path.starts_with(mount.as_ref()) { + let mut parse_file = |name| { + path.push(name); + read_buf.clear(); + + let f = File::open(&path); + path.pop(); // restore buffer before any early returns + f.ok()?.read_to_string(&mut read_buf).ok()?; + let parsed = read_buf.trim().parse::<usize>().ok()?; + + Some(parsed) + }; + + let limit = parse_file("cpu.cfs_quota_us"); + let period = parse_file("cpu.cfs_period_us"); + + match (limit, period) { + (Some(limit), Some(period)) if period > 0 => quota = quota.min(limit / period), + _ => {} + } + + path.pop(); + } + + // we passed the try_exists above so we should have traversed the correct hierarchy + // when reaching this line + break; + } + + quota + } + + /// Scan mountinfo for cgroup v1 mountpoint with a cpu controller + /// + /// If the cgroupfs is a bind mount then `group_path` is adjusted to skip + /// over the already-included prefix + fn find_mountpoint(group_path: &Path) -> Option<(Cow<'static, str>, &Path)> { + let mut reader = File::open_buffered("/proc/self/mountinfo").ok()?; + let mut line = String::with_capacity(256); + loop { + line.clear(); + if reader.read_line(&mut line).ok()? == 0 { + break; + } + + let line = line.trim(); + let mut items = line.split(' '); + + let sub_path = items.nth(3)?; + let mount_point = items.next()?; + let mount_opts = items.next_back()?; + let filesystem_type = items.nth_back(1)?; + + if filesystem_type != "cgroup" || !mount_opts.split(',').any(|opt| opt == "cpu") { + // not a cgroup / not a cpu-controller + continue; + } + + let sub_path = Path::new(sub_path).strip_prefix("/").ok()?; + + if !group_path.starts_with(sub_path) { + // this is a bind-mount and the bound subdirectory + // does not contain the cgroup this process belongs to + continue; + } + + let trimmed_group_path = group_path.strip_prefix(sub_path).ok()?; + + return Some((Cow::Owned(mount_point.to_owned()), trimmed_group_path)); + } + + None + } +} + +// glibc >= 2.15 has a __pthread_get_minstack() function that returns +// PTHREAD_STACK_MIN plus bytes needed for thread-local storage. +// We need that information to avoid blowing up when a small stack +// is created in an application with big thread-local storage requirements. +// See #6233 for rationale and details. +#[cfg(all(target_os = "linux", target_env = "gnu"))] +unsafe fn min_stack_size(attr: *const libc::pthread_attr_t) -> usize { + // We use dlsym to avoid an ELF version dependency on GLIBC_PRIVATE. (#23628) + // We shouldn't really be using such an internal symbol, but there's currently + // no other way to account for the TLS size. + dlsym!( + fn __pthread_get_minstack(attr: *const libc::pthread_attr_t) -> libc::size_t; + ); + + match __pthread_get_minstack.get() { + None => libc::PTHREAD_STACK_MIN, + Some(f) => unsafe { f(attr) }, + } +} + +// No point in looking up __pthread_get_minstack() on non-glibc platforms. +#[cfg(all( + not(all(target_os = "linux", target_env = "gnu")), + not(any(target_os = "netbsd", target_os = "nuttx")) +))] +unsafe fn min_stack_size(_: *const libc::pthread_attr_t) -> usize { + libc::PTHREAD_STACK_MIN +} + +#[cfg(any(target_os = "netbsd", target_os = "nuttx"))] +unsafe fn min_stack_size(_: *const libc::pthread_attr_t) -> usize { + static STACK: crate::sync::OnceLock<usize> = crate::sync::OnceLock::new(); + + *STACK.get_or_init(|| { + let mut stack = unsafe { libc::sysconf(libc::_SC_THREAD_STACK_MIN) }; + if stack < 0 { + stack = 2048; // just a guess + } + + stack as usize + }) +} diff --git a/library/std/src/sys/thread/unsupported.rs b/library/std/src/sys/thread/unsupported.rs new file mode 100644 index 00000000000..a5001efa3b4 --- /dev/null +++ b/library/std/src/sys/thread/unsupported.rs @@ -0,0 +1,43 @@ +use crate::ffi::CStr; +use crate::io; +use crate::num::NonZero; +use crate::time::Duration; + +pub struct Thread(!); + +pub const DEFAULT_MIN_STACK_SIZE: usize = 64 * 1024; + +impl Thread { + // unsafe: see thread::Builder::spawn_unchecked for safety requirements + pub unsafe fn new( + _stack: usize, + _name: Option<&str>, + _p: Box<dyn FnOnce()>, + ) -> io::Result<Thread> { + Err(io::Error::UNSUPPORTED_PLATFORM) + } + + pub fn join(self) { + self.0 + } +} + +pub fn available_parallelism() -> io::Result<NonZero<usize>> { + Err(io::Error::UNKNOWN_THREAD_COUNT) +} + +pub fn current_os_id() -> Option<u64> { + None +} + +pub fn yield_now() { + // do nothing +} + +pub fn set_name(_name: &CStr) { + // nope +} + +pub fn sleep(_dur: Duration) { + panic!("can't sleep"); +} diff --git a/library/std/src/sys/thread/wasip1.rs b/library/std/src/sys/thread/wasip1.rs new file mode 100644 index 00000000000..83001fad49c --- /dev/null +++ b/library/std/src/sys/thread/wasip1.rs @@ -0,0 +1,185 @@ +#![forbid(unsafe_op_in_unsafe_fn)] + +#[cfg(target_feature = "atomics")] +use crate::io; +use crate::mem; +#[cfg(target_feature = "atomics")] +use crate::num::NonZero; +#[cfg(target_feature = "atomics")] +use crate::sys::os; +use crate::time::Duration; +#[cfg(target_feature = "atomics")] +use crate::{cmp, ptr}; + +// Add a few symbols not in upstream `libc` just yet. +#[cfg(target_feature = "atomics")] +mod libc { + pub use libc::*; + + pub use crate::ffi; + + // defined in wasi-libc + // https://github.com/WebAssembly/wasi-libc/blob/a6f871343313220b76009827ed0153586361c0d5/libc-top-half/musl/include/alltypes.h.in#L108 + #[repr(C)] + union pthread_attr_union { + __i: [ffi::c_int; if size_of::<ffi::c_long>() == 8 { 14 } else { 9 }], + __vi: [ffi::c_int; if size_of::<ffi::c_long>() == 8 { 14 } else { 9 }], + __s: [ffi::c_ulong; if size_of::<ffi::c_long>() == 8 { 7 } else { 9 }], + } + + #[repr(C)] + pub struct pthread_attr_t { + __u: pthread_attr_union, + } + + #[allow(non_camel_case_types)] + pub type pthread_t = *mut ffi::c_void; + + pub const _SC_NPROCESSORS_ONLN: ffi::c_int = 84; + + unsafe extern "C" { + pub fn pthread_create( + native: *mut pthread_t, + attr: *const pthread_attr_t, + f: extern "C" fn(*mut ffi::c_void) -> *mut ffi::c_void, + value: *mut ffi::c_void, + ) -> ffi::c_int; + pub fn pthread_join(native: pthread_t, value: *mut *mut ffi::c_void) -> ffi::c_int; + pub fn pthread_attr_init(attrp: *mut pthread_attr_t) -> ffi::c_int; + pub fn pthread_attr_setstacksize( + attr: *mut pthread_attr_t, + stack_size: libc::size_t, + ) -> ffi::c_int; + pub fn pthread_attr_destroy(attr: *mut pthread_attr_t) -> ffi::c_int; + pub fn pthread_detach(thread: pthread_t) -> ffi::c_int; + } +} + +#[cfg(target_feature = "atomics")] +pub struct Thread { + id: libc::pthread_t, +} + +#[cfg(target_feature = "atomics")] +impl Drop for Thread { + fn drop(&mut self) { + let ret = unsafe { libc::pthread_detach(self.id) }; + debug_assert_eq!(ret, 0); + } +} + +pub const DEFAULT_MIN_STACK_SIZE: usize = 1024 * 1024; + +#[cfg(target_feature = "atomics")] +impl Thread { + // unsafe: see thread::Builder::spawn_unchecked for safety requirements + pub unsafe fn new( + stack: usize, + _name: Option<&str>, + p: Box<dyn FnOnce()>, + ) -> io::Result<Thread> { + let p = Box::into_raw(Box::new(p)); + let mut native: libc::pthread_t = unsafe { mem::zeroed() }; + let mut attr: libc::pthread_attr_t = unsafe { mem::zeroed() }; + assert_eq!(unsafe { libc::pthread_attr_init(&mut attr) }, 0); + + let stack_size = cmp::max(stack, DEFAULT_MIN_STACK_SIZE); + + match unsafe { libc::pthread_attr_setstacksize(&mut attr, stack_size) } { + 0 => {} + n => { + assert_eq!(n, libc::EINVAL); + // EINVAL means |stack_size| is either too small or not a + // multiple of the system page size. Because it's definitely + // >= PTHREAD_STACK_MIN, it must be an alignment issue. + // Round up to the nearest page and try again. + let page_size = os::page_size(); + let stack_size = + (stack_size + page_size - 1) & (-(page_size as isize - 1) as usize - 1); + assert_eq!(unsafe { libc::pthread_attr_setstacksize(&mut attr, stack_size) }, 0); + } + }; + + let ret = unsafe { libc::pthread_create(&mut native, &attr, thread_start, p as *mut _) }; + // Note: if the thread creation fails and this assert fails, then p will + // be leaked. However, an alternative design could cause double-free + // which is clearly worse. + assert_eq!(unsafe { libc::pthread_attr_destroy(&mut attr) }, 0); + + return if ret != 0 { + // The thread failed to start and as a result p was not consumed. Therefore, it is + // safe to reconstruct the box so that it gets deallocated. + unsafe { + drop(Box::from_raw(p)); + } + Err(io::Error::from_raw_os_error(ret)) + } else { + Ok(Thread { id: native }) + }; + + extern "C" fn thread_start(main: *mut libc::c_void) -> *mut libc::c_void { + unsafe { + // Finally, let's run some code. + Box::from_raw(main as *mut Box<dyn FnOnce()>)(); + } + ptr::null_mut() + } + } + + pub fn join(self) { + let id = mem::ManuallyDrop::new(self).id; + let ret = unsafe { libc::pthread_join(id, ptr::null_mut()) }; + if ret != 0 { + rtabort!("failed to join thread: {}", io::Error::from_raw_os_error(ret)); + } + } +} + +#[cfg(target_feature = "atomics")] +pub fn available_parallelism() -> io::Result<NonZero<usize>> { + match unsafe { libc::sysconf(libc::_SC_NPROCESSORS_ONLN) } { + -1 => Err(io::Error::last_os_error()), + cpus => NonZero::new(cpus as usize).ok_or(io::Error::UNKNOWN_THREAD_COUNT), + } +} + +pub fn yield_now() { + let ret = unsafe { wasi::sched_yield() }; + debug_assert_eq!(ret, Ok(())); +} + +pub fn sleep(dur: Duration) { + let mut nanos = dur.as_nanos(); + while nanos > 0 { + const USERDATA: wasi::Userdata = 0x0123_45678; + + let clock = wasi::SubscriptionClock { + id: wasi::CLOCKID_MONOTONIC, + timeout: u64::try_from(nanos).unwrap_or(u64::MAX), + precision: 0, + flags: 0, + }; + nanos -= u128::from(clock.timeout); + + let in_ = wasi::Subscription { + userdata: USERDATA, + u: wasi::SubscriptionU { tag: 0, u: wasi::SubscriptionUU { clock } }, + }; + unsafe { + let mut event: wasi::Event = mem::zeroed(); + let res = wasi::poll_oneoff(&in_, &mut event, 1); + match (res, event) { + ( + Ok(1), + wasi::Event { + userdata: USERDATA, + error: wasi::ERRNO_SUCCESS, + type_: wasi::EVENTTYPE_CLOCK, + .. + }, + ) => {} + _ => panic!("thread::sleep(): unexpected result of poll_oneoff"), + } + } + } +} diff --git a/library/std/src/sys/thread/wasip2.rs b/library/std/src/sys/thread/wasip2.rs new file mode 100644 index 00000000000..420cad2a5e4 --- /dev/null +++ b/library/std/src/sys/thread/wasip2.rs @@ -0,0 +1,32 @@ +use crate::time::{Duration, Instant}; + +pub fn sleep(dur: Duration) { + // Sleep in increments of `u64::MAX` nanoseconds until the `dur` is + // entirely drained. + let mut remaining = dur.as_nanos(); + while remaining > 0 { + let amt = u64::try_from(remaining).unwrap_or(u64::MAX); + wasip2::clocks::monotonic_clock::subscribe_duration(amt).block(); + remaining -= u128::from(amt); + } +} + +pub fn sleep_until(deadline: Instant) { + match u64::try_from(deadline.into_inner().as_duration().as_nanos()) { + // If the point in time we're sleeping to fits within a 64-bit + // number of nanoseconds then directly use `subscribe_instant`. + Ok(deadline) => { + wasip2::clocks::monotonic_clock::subscribe_instant(deadline).block(); + } + // ... otherwise we're sleeping for 500+ years relative to the + // "start" of what the system is using as a clock so speed/accuracy + // is not so much of a concern. Use `sleep` instead. + Err(_) => { + let now = Instant::now(); + + if let Some(delay) = deadline.checked_duration_since(now) { + sleep(delay); + } + } + } +} diff --git a/library/std/src/sys/thread/wasm.rs b/library/std/src/sys/thread/wasm.rs new file mode 100644 index 00000000000..e843bc992ba --- /dev/null +++ b/library/std/src/sys/thread/wasm.rs @@ -0,0 +1,23 @@ +use crate::cmp; +use crate::time::Duration; + +pub fn sleep(dur: Duration) { + #[cfg(target_arch = "wasm32")] + use core::arch::wasm32 as wasm; + #[cfg(target_arch = "wasm64")] + use core::arch::wasm64 as wasm; + + // Use an atomic wait to block the current thread artificially with a + // timeout listed. Note that we should never be notified (return value + // of 0) or our comparison should never fail (return value of 1) so we + // should always only resume execution through a timeout (return value + // 2). + let mut nanos = dur.as_nanos(); + while nanos > 0 { + let amt = cmp::min(i64::MAX as u128, nanos); + let mut x = 0; + let val = unsafe { wasm::memory_atomic_wait32(&mut x, 0, amt as i64) }; + debug_assert_eq!(val, 2); + nanos -= amt; + } +} diff --git a/library/std/src/sys/thread/windows.rs b/library/std/src/sys/thread/windows.rs new file mode 100644 index 00000000000..a5640c51c4a --- /dev/null +++ b/library/std/src/sys/thread/windows.rs @@ -0,0 +1,140 @@ +use core::ffi::c_void; + +use crate::ffi::CStr; +use crate::num::NonZero; +use crate::os::windows::io::{AsRawHandle, HandleOrNull}; +use crate::sys::handle::Handle; +use crate::sys::pal::time::WaitableTimer; +use crate::sys::pal::{dur2timeout, to_u16s}; +use crate::sys::{c, stack_overflow}; +use crate::sys_common::FromInner; +use crate::time::Duration; +use crate::{io, ptr}; + +pub const DEFAULT_MIN_STACK_SIZE: usize = 2 * 1024 * 1024; + +pub struct Thread { + handle: Handle, +} + +impl Thread { + // unsafe: see thread::Builder::spawn_unchecked for safety requirements + #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces + pub unsafe fn new( + stack: usize, + _name: Option<&str>, + p: Box<dyn FnOnce()>, + ) -> io::Result<Thread> { + let p = Box::into_raw(Box::new(p)); + + // CreateThread rounds up values for the stack size to the nearest page size (at least 4kb). + // If a value of zero is given then the default stack size is used instead. + // SAFETY: `thread_start` has the right ABI for a thread's entry point. + // `p` is simply passed through to the new thread without being touched. + let ret = unsafe { + let ret = c::CreateThread( + ptr::null_mut(), + stack, + Some(thread_start), + p as *mut _, + c::STACK_SIZE_PARAM_IS_A_RESERVATION, + ptr::null_mut(), + ); + HandleOrNull::from_raw_handle(ret) + }; + return if let Ok(handle) = ret.try_into() { + Ok(Thread { handle: Handle::from_inner(handle) }) + } else { + // The thread failed to start and as a result p was not consumed. Therefore, it is + // safe to reconstruct the box so that it gets deallocated. + unsafe { drop(Box::from_raw(p)) }; + Err(io::Error::last_os_error()) + }; + + unsafe extern "system" fn thread_start(main: *mut c_void) -> u32 { + // Next, reserve some stack space for if we otherwise run out of stack. + stack_overflow::reserve_stack(); + // Finally, let's run some code. + // SAFETY: We are simply recreating the box that was leaked earlier. + // It's the responsibility of the one who call `Thread::new` to ensure this is safe to call here. + unsafe { Box::from_raw(main as *mut Box<dyn FnOnce()>)() }; + 0 + } + } + + pub fn join(self) { + let rc = unsafe { c::WaitForSingleObject(self.handle.as_raw_handle(), c::INFINITE) }; + if rc == c::WAIT_FAILED { + panic!("failed to join on thread: {}", io::Error::last_os_error()); + } + } + + pub fn handle(&self) -> &Handle { + &self.handle + } + + pub fn into_handle(self) -> Handle { + self.handle + } +} + +pub fn available_parallelism() -> io::Result<NonZero<usize>> { + let res = unsafe { + let mut sysinfo: c::SYSTEM_INFO = crate::mem::zeroed(); + c::GetSystemInfo(&mut sysinfo); + sysinfo.dwNumberOfProcessors as usize + }; + match res { + 0 => Err(io::Error::UNKNOWN_THREAD_COUNT), + cpus => Ok(unsafe { NonZero::new_unchecked(cpus) }), + } +} + +pub fn current_os_id() -> Option<u64> { + // SAFETY: FFI call with no preconditions. + let id: u32 = unsafe { c::GetCurrentThreadId() }; + + // A return value of 0 indicates failed lookup. + if id == 0 { None } else { Some(id.into()) } +} + +pub fn set_name(name: &CStr) { + if let Ok(utf8) = name.to_str() { + if let Ok(utf16) = to_u16s(utf8) { + unsafe { + // SAFETY: the vec returned by `to_u16s` ends with a zero value + set_name_wide(&utf16) + } + }; + }; +} + +/// # Safety +/// +/// `name` must end with a zero value +pub unsafe fn set_name_wide(name: &[u16]) { + unsafe { c::SetThreadDescription(c::GetCurrentThread(), name.as_ptr()) }; +} + +pub fn sleep(dur: Duration) { + fn high_precision_sleep(dur: Duration) -> Result<(), ()> { + let timer = WaitableTimer::high_resolution()?; + timer.set(dur)?; + timer.wait() + } + // Attempt to use high-precision sleep (Windows 10, version 1803+). + // On error fallback to the standard `Sleep` function. + // Also preserves the zero duration behavior of `Sleep`. + if dur.is_zero() || high_precision_sleep(dur).is_err() { + unsafe { c::Sleep(dur2timeout(dur)) } + } +} + +pub fn yield_now() { + // This function will return 0 if there are no other threads to execute, + // but this also means that the yield was useless so this isn't really a + // case that needs to be worried about. + unsafe { + c::SwitchToThread(); + } +} diff --git a/library/std/src/sys/thread/xous.rs b/library/std/src/sys/thread/xous.rs new file mode 100644 index 00000000000..133e15a0928 --- /dev/null +++ b/library/std/src/sys/thread/xous.rs @@ -0,0 +1,137 @@ +use core::arch::asm; + +use crate::io; +use crate::num::NonZero; +use crate::os::xous::ffi::{ + MemoryFlags, Syscall, ThreadId, blocking_scalar, create_thread, do_yield, join_thread, + map_memory, update_memory_flags, +}; +use crate::os::xous::services::{TicktimerScalar, ticktimer_server}; +use crate::time::Duration; + +pub struct Thread { + tid: ThreadId, +} + +pub const DEFAULT_MIN_STACK_SIZE: usize = 131072; +const MIN_STACK_SIZE: usize = 4096; +pub const GUARD_PAGE_SIZE: usize = 4096; + +impl Thread { + // unsafe: see thread::Builder::spawn_unchecked for safety requirements + pub unsafe fn new( + stack: usize, + _name: Option<&str>, + p: Box<dyn FnOnce()>, + ) -> io::Result<Thread> { + let p = Box::into_raw(Box::new(p)); + let mut stack_size = crate::cmp::max(stack, MIN_STACK_SIZE); + + if (stack_size & 4095) != 0 { + stack_size = (stack_size + 4095) & !4095; + } + + // Allocate the whole thing, then divide it up after the fact. This ensures that + // even if there's a context switch during this function, the whole stack plus + // guard pages will remain contiguous. + let stack_plus_guard_pages: &mut [u8] = unsafe { + map_memory( + None, + None, + GUARD_PAGE_SIZE + stack_size + GUARD_PAGE_SIZE, + MemoryFlags::R | MemoryFlags::W | MemoryFlags::X, + ) + } + .map_err(|code| io::Error::from_raw_os_error(code as i32))?; + + // No access to this page. Note: Write-only pages are illegal, and will + // cause an access violation. + unsafe { + update_memory_flags(&mut stack_plus_guard_pages[0..GUARD_PAGE_SIZE], MemoryFlags::W) + .map_err(|code| io::Error::from_raw_os_error(code as i32))? + }; + + // No access to this page. Note: Write-only pages are illegal, and will + // cause an access violation. + unsafe { + update_memory_flags( + &mut stack_plus_guard_pages[(GUARD_PAGE_SIZE + stack_size)..], + MemoryFlags::W, + ) + .map_err(|code| io::Error::from_raw_os_error(code as i32))? + }; + + let guard_page_pre = stack_plus_guard_pages.as_ptr() as usize; + let tid = create_thread( + thread_start as *mut usize, + &mut stack_plus_guard_pages[GUARD_PAGE_SIZE..(stack_size + GUARD_PAGE_SIZE)], + p as usize, + guard_page_pre, + stack_size, + 0, + ) + .map_err(|code| io::Error::from_raw_os_error(code as i32))?; + + extern "C" fn thread_start( + main: *mut usize, + guard_page_pre: usize, + stack_size: usize, + ) -> ! { + unsafe { + // Run the contents of the new thread. + Box::from_raw(main as *mut Box<dyn FnOnce()>)(); + } + + // Destroy TLS, which will free the TLS page and call the destructor for + // any thread local storage (if any). + unsafe { + crate::sys::thread_local::key::destroy_tls(); + } + + // Deallocate the stack memory, along with the guard pages. Afterwards, + // exit the thread by returning to the magic address 0xff80_3000usize, + // which tells the kernel to deallocate this thread. + let mapped_memory_base = guard_page_pre; + let mapped_memory_length = GUARD_PAGE_SIZE + stack_size + GUARD_PAGE_SIZE; + unsafe { + asm!( + "ecall", + "ret", + in("a0") Syscall::UnmapMemory as usize, + in("a1") mapped_memory_base, + in("a2") mapped_memory_length, + in("ra") 0xff80_3000usize, + options(nomem, nostack, noreturn) + ); + } + } + + Ok(Thread { tid }) + } + + pub fn join(self) { + join_thread(self.tid).unwrap(); + } +} + +pub fn available_parallelism() -> io::Result<NonZero<usize>> { + // We're unicore right now. + Ok(unsafe { NonZero::new_unchecked(1) }) +} + +pub fn yield_now() { + do_yield(); +} + +pub fn sleep(dur: Duration) { + // Because the sleep server works on units of `usized milliseconds`, split + // the messages up into these chunks. This means we may run into issues + // if you try to sleep a thread for more than 49 days on a 32-bit system. + let mut millis = dur.as_millis(); + while millis > 0 { + let sleep_duration = if millis > (usize::MAX as _) { usize::MAX } else { millis as usize }; + blocking_scalar(ticktimer_server(), TicktimerScalar::SleepMs(sleep_duration).into()) + .expect("failed to send message to ticktimer server"); + millis -= sleep_duration as u128; + } +} |