1 files changed, 57 insertions, 0 deletions
diff --git a/src/libstd/sys/wasi/thread.rs b/src/libstd/sys/wasi/thread.rs
new file mode 100644
index 00000000000..9d3c6ac59d1
--- /dev/null
+++ b/src/libstd/sys/wasi/thread.rs
@@ -0,0 +1,57 @@
+use crate::boxed::FnBox;
+use crate::cmp;
+use crate::ffi::CStr;
+use crate::io;
+use crate::sys::cvt;
+use crate::sys::{unsupported, Void};
+use crate::time::Duration;
+use libc;
+
+pub struct Thread(Void);
+
+pub const DEFAULT_MIN_STACK_SIZE: usize = 4096;
+
+impl Thread {
+    // unsafe: see thread::Builder::spawn_unchecked for safety requirements
+    pub unsafe fn new(_stack: usize, _p: Box<dyn FnBox()>)
+        -> io::Result<Thread>
+    {
+        unsupported()
+    }
+
+    pub fn yield_now() {
+        let ret = unsafe { libc::__wasi_sched_yield() };
+        debug_assert_eq!(ret, 0);
+    }
+
+    pub fn set_name(_name: &CStr) {
+        // nope
+    }
+
+    pub fn sleep(dur: Duration) {
+        let mut secs = dur.as_secs();
+        let mut nsecs = dur.subsec_nanos() as i32;
+
+        unsafe {
+            while secs > 0 || nsecs > 0 {
+                let mut ts = libc::timespec {
+                    tv_sec: cmp::min(libc::time_t::max_value() as u64, secs) as libc::time_t,
+                    tv_nsec: nsecs,
+                };
+                secs -= ts.tv_sec as u64;
+                cvt(libc::nanosleep(&ts, &mut ts)).unwrap();
+                nsecs = 0;
+            }
+        }
+    }
+
+    pub fn join(self) {
+        match self.0 {}
+    }
+}
+
+pub mod guard {
+    pub type Guard = !;
+    pub unsafe fn current() -> Option<Guard> { None }
+    pub unsafe fn init() -> Option<Guard> { None }
+}