1 files changed, 159 insertions, 0 deletions
diff --git a/library/std/src/sys/thread/teeos.rs b/library/std/src/sys/thread/teeos.rs
new file mode 100644
index 00000000000..1812d11e692
--- /dev/null
+++ b/library/std/src/sys/thread/teeos.rs
@@ -0,0 +1,159 @@
+use crate::ffi::CStr;
+use crate::mem::{self, ManuallyDrop};
+use crate::num::NonZero;
+use crate::sys::os;
+use crate::time::{Duration, Instant};
+use crate::{cmp, io, ptr};
+
+pub const DEFAULT_MIN_STACK_SIZE: usize = 8 * 1024;
+
+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 {}
+
+unsafe extern "C" {
+    pub fn TEE_Wait(timeout: u32) -> u32;
+}
+
+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.
+            Thread::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()
+        }
+    }
+
+    pub fn yield_now() {
+        let ret = unsafe { libc::sched_yield() };
+        debug_assert_eq!(ret, 0);
+    }
+
+    /// This does not do anything on teeos
+    pub fn set_name(_name: &CStr) {
+        // Both pthread_setname_np and prctl are not available to the TA,
+        // so we can't implement this currently. If the need arises please
+        // contact the teeos rustzone team.
+    }
+
+    /// 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 };
+        unsafe {
+            let _ = TEE_Wait(final_sleep);
+        }
+    }
+
+    pub fn sleep_until(deadline: Instant) {
+        let now = Instant::now();
+
+        if let Some(delay) = deadline.checked_duration_since(now) {
+            Self::sleep(delay);
+        }
+    }
+
+    /// 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 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) {
+        // we can not call detach, so just panic if thread spawn without join
+        panic!("thread must join, detach is not supported!");
+    }
+}
+
+pub(crate) fn current_os_id() -> Option<u64> {
+    None
+}
+
+// Note: Both `sched_getaffinity` and `sysconf` are available but not functional on
+// teeos, so this function always returns an Error!
+pub fn available_parallelism() -> io::Result<NonZero<usize>> {
+    Err(io::Error::UNKNOWN_THREAD_COUNT)
+}
+
+fn min_stack_size(_: *const libc::pthread_attr_t) -> usize {
+    libc::PTHREAD_STACK_MIN.try_into().expect("Infallible")
+}