alnyan/yggdrasil: add PollChannel for fd polling

library/std/src/os/yggdrasil/io/mod.rs

@@ -3,6 +3,7 @@
 
 mod net;
 pub mod owned;
+mod poll;
 pub(crate) mod raw;
 
 use crate::io::StdinLock;
@@ -28,6 +29,9 @@ pub use owned::*;
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use raw::*;
 
+#[unstable(feature = "yggdrasil_os", issue = "none")]
+pub use poll::PollChannel;
+
 #[unstable(feature = "yggdrasil_os", issue = "none")]
 pub trait FdDeviceRequest {
     #[unstable(feature = "yggdrasil_os", issue = "none")]

library/std/src/os/yggdrasil/io/poll.rs

@@ -0,0 +1,34 @@
+use crate::io;
+use crate::os::yggdrasil::io::{AsRawFd, FromRawFd, OwnedFd, RawFd};
+use crate::sys::cvt_io;
+use crate::time::Duration;
+
+use yggdrasil_rt::io::PollControl;
+
+#[unstable(feature = "yggdrasil_os", issue = "none")]
+pub struct PollChannel(OwnedFd);
+
+impl PollChannel {
+    #[unstable(feature = "yggdrasil_os", issue = "none")]
+    pub fn new() -> io::Result<Self> {
+        let raw_fd = cvt_io(unsafe { yggdrasil_rt::sys::create_poll_channel() })?;
+        let fd = unsafe { OwnedFd::from_raw_fd(raw_fd) };
+        Ok(Self(fd))
+    }
+
+    #[unstable(feature = "yggdrasil_os", issue = "none")]
+    pub fn add(&mut self, fd: RawFd) -> io::Result<()> {
+        cvt_io(unsafe {
+            yggdrasil_rt::sys::poll_channel_control(self.0.as_raw_fd(), PollControl::AddFd, fd)
+        })
+    }
+
+    #[unstable(feature = "yggdrasil_os", issue = "none")]
+    pub fn wait(&mut self, timeout: Option<Duration>) -> io::Result<Option<RawFd>> {
+        let mut output = None;
+        cvt_io(unsafe {
+            yggdrasil_rt::sys::poll_channel_wait(self.0.as_raw_fd(), &timeout, &mut output)
+        })?;
+        Ok(output)
+    }
+}

library/std/src/sys/yggdrasil/mod.rs

@@ -157,7 +157,7 @@ pub fn decode_error_kind(errno: i32) -> ErrorKind {
         Ok(OsError::WouldBlock) => ErrorKind::WouldBlock,
         Ok(OsError::ReadOnly) => ErrorKind::ReadOnlyFilesystem,
         Ok(OsError::PermissionDenied) => ErrorKind::PermissionDenied,
-        Ok(OsError::UnrecognizedExecutable) => ErrorKind::InvalidData,
+        Ok(OsError::UnrecognizedExecutable) | Ok(OsError::MissingData) => ErrorKind::InvalidData,
 
         // Memory and general
         Ok(OsError::OutOfMemory) => ErrorKind::OutOfMemory,