| use crate::ffi::CStr; |
| use crate::io; |
| use crate::mem; |
| use crate::num::NonZeroUsize; |
| use crate::sys::unsupported; |
| use crate::time::Duration; |
| |
| cfg_if::cfg_if! { |
| if #[cfg(target_feature = "atomics")] { |
| use crate::cmp; |
| use crate::ptr; |
| use crate::sys::os; |
| // Add a few symbols not in upstream `libc` just yet. |
| mod libc { |
| pub use crate::ffi; |
| pub use crate::mem; |
| pub use libc::*; |
| |
| // 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 mem::size_of::<ffi::c_long>() == 8 { 14 } else { 9 }], |
| __vi: [ffi::c_int; if mem::size_of::<ffi::c_long>() == 8 { 14 } else { 9 }], |
| __s: [ffi::c_ulong; if mem::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; |
| |
| 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; |
| } |
| } |
| |
| pub struct Thread { |
| id: libc::pthread_t, |
| } |
| |
| impl Drop for Thread { |
| fn drop(&mut self) { |
| let ret = unsafe { libc::pthread_detach(self.id) }; |
| debug_assert_eq!(ret, 0); |
| } |
| } |
| } else { |
| pub struct Thread(!); |
| } |
| } |
| |
| pub const DEFAULT_MIN_STACK_SIZE: usize = 4096; |
| |
| impl Thread { |
| // unsafe: see thread::Builder::spawn_unchecked for safety requirements |
| cfg_if::cfg_if! { |
| if #[cfg(target_feature = "atomics")] { |
| pub unsafe fn new(stack: usize, p: Box<dyn FnOnce()>) -> io::Result<Thread> { |
| let p = Box::into_raw(Box::new(p)); |
| let mut native: libc::pthread_t = mem::zeroed(); |
| let mut attr: libc::pthread_attr_t = mem::zeroed(); |
| assert_eq!(libc::pthread_attr_init(&mut attr), 0); |
| |
| let stack_size = cmp::max(stack, DEFAULT_MIN_STACK_SIZE); |
| |
| match 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!(libc::pthread_attr_setstacksize(&mut attr, stack_size), 0); |
| } |
| }; |
| |
| let ret = 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!(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(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() |
| } |
| } |
| } else { |
| pub unsafe fn new(_stack: usize, _p: Box<dyn FnOnce()>) -> io::Result<Thread> { |
| unsupported() |
| } |
| } |
| } |
| |
| pub fn yield_now() { |
| let ret = unsafe { wasi::sched_yield() }; |
| debug_assert_eq!(ret, Ok(())); |
| } |
| |
| pub fn set_name(_name: &CStr) { |
| // nope |
| } |
| |
| pub fn sleep(dur: Duration) { |
| let nanos = dur.as_nanos(); |
| assert!(nanos <= u64::MAX as u128); |
| |
| const USERDATA: wasi::Userdata = 0x0123_45678; |
| |
| let clock = wasi::SubscriptionClock { |
| id: wasi::CLOCKID_MONOTONIC, |
| timeout: nanos as u64, |
| precision: 0, |
| flags: 0, |
| }; |
| |
| 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"), |
| } |
| } |
| } |
| |
| pub fn join(self) { |
| cfg_if::cfg_if! { |
| if #[cfg(target_feature = "atomics")] { |
| unsafe { |
| let ret = libc::pthread_join(self.id, ptr::null_mut()); |
| mem::forget(self); |
| if ret != 0 { |
| rtabort!("failed to join thread: {}", io::Error::from_raw_os_error(ret)); |
| } |
| } |
| } else { |
| self.0 |
| } |
| } |
| } |
| } |
| |
| pub fn available_parallelism() -> io::Result<NonZeroUsize> { |
| unsupported() |
| } |
| |
| pub mod guard { |
| pub type Guard = !; |
| pub unsafe fn current() -> Option<Guard> { |
| None |
| } |
| pub unsafe fn init() -> Option<Guard> { |
| None |
| } |
| } |
