1 files changed, 335 insertions, 0 deletions
diff --git a/library/std/src/sys/windows/handle.rs b/library/std/src/sys/windows/handle.rs
new file mode 100644
index 000000000..e24b09cc9
--- /dev/null
+++ b/library/std/src/sys/windows/handle.rs
@@ -0,0 +1,335 @@
+#![unstable(issue = "none", feature = "windows_handle")]
+
+#[cfg(test)]
+mod tests;
+
+use crate::cmp;
+use crate::io::{self, ErrorKind, IoSlice, IoSliceMut, Read, ReadBuf};
+use crate::mem;
+use crate::os::windows::io::{
+    AsHandle, AsRawHandle, BorrowedHandle, FromRawHandle, IntoRawHandle, OwnedHandle, RawHandle,
+};
+use crate::ptr;
+use crate::sys::c;
+use crate::sys::cvt;
+use crate::sys_common::{AsInner, FromInner, IntoInner};
+
+/// An owned container for `HANDLE` object, closing them on Drop.
+///
+/// All methods are inherited through a `Deref` impl to `RawHandle`
+pub struct Handle(OwnedHandle);
+
+impl Handle {
+    pub fn new_event(manual: bool, init: bool) -> io::Result<Handle> {
+        unsafe {
+            let event =
+                c::CreateEventW(ptr::null_mut(), manual as c::BOOL, init as c::BOOL, ptr::null());
+            if event.is_null() {
+                Err(io::Error::last_os_error())
+            } else {
+                Ok(Handle::from_raw_handle(event))
+            }
+        }
+    }
+}
+
+impl AsInner<OwnedHandle> for Handle {
+    fn as_inner(&self) -> &OwnedHandle {
+        &self.0
+    }
+}
+
+impl IntoInner<OwnedHandle> for Handle {
+    fn into_inner(self) -> OwnedHandle {
+        self.0
+    }
+}
+
+impl FromInner<OwnedHandle> for Handle {
+    fn from_inner(file_desc: OwnedHandle) -> Self {
+        Self(file_desc)
+    }
+}
+
+impl AsHandle for Handle {
+    fn as_handle(&self) -> BorrowedHandle<'_> {
+        self.0.as_handle()
+    }
+}
+
+impl AsRawHandle for Handle {
+    fn as_raw_handle(&self) -> RawHandle {
+        self.0.as_raw_handle()
+    }
+}
+
+impl IntoRawHandle for Handle {
+    fn into_raw_handle(self) -> RawHandle {
+        self.0.into_raw_handle()
+    }
+}
+
+impl FromRawHandle for Handle {
+    unsafe fn from_raw_handle(raw_handle: RawHandle) -> Self {
+        Self(FromRawHandle::from_raw_handle(raw_handle))
+    }
+}
+
+impl Handle {
+    pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
+        let res = unsafe { self.synchronous_read(buf.as_mut_ptr().cast(), buf.len(), None) };
+
+        match res {
+            Ok(read) => Ok(read as usize),
+
+            // The special treatment of BrokenPipe is to deal with Windows
+            // pipe semantics, which yields this error when *reading* from
+            // a pipe after the other end has closed; we interpret that as
+            // EOF on the pipe.
+            Err(ref e) if e.kind() == ErrorKind::BrokenPipe => Ok(0),
+
+            Err(e) => Err(e),
+        }
+    }
+
+    pub fn read_vectored(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
+        crate::io::default_read_vectored(|buf| self.read(buf), bufs)
+    }
+
+    #[inline]
+    pub fn is_read_vectored(&self) -> bool {
+        false
+    }
+
+    pub fn read_at(&self, buf: &mut [u8], offset: u64) -> io::Result<usize> {
+        let res =
+            unsafe { self.synchronous_read(buf.as_mut_ptr().cast(), buf.len(), Some(offset)) };
+
+        match res {
+            Ok(read) => Ok(read as usize),
+            Err(ref e) if e.raw_os_error() == Some(c::ERROR_HANDLE_EOF as i32) => Ok(0),
+            Err(e) => Err(e),
+        }
+    }
+
+    pub fn read_buf(&self, buf: &mut ReadBuf<'_>) -> io::Result<()> {
+        let res = unsafe {
+            self.synchronous_read(buf.unfilled_mut().as_mut_ptr(), buf.remaining(), None)
+        };
+
+        match res {
+            Ok(read) => {
+                // Safety: `read` bytes were written to the initialized portion of the buffer
+                unsafe {
+                    buf.assume_init(read as usize);
+                }
+                buf.add_filled(read as usize);
+                Ok(())
+            }
+
+            // The special treatment of BrokenPipe is to deal with Windows
+            // pipe semantics, which yields this error when *reading* from
+            // a pipe after the other end has closed; we interpret that as
+            // EOF on the pipe.
+            Err(ref e) if e.kind() == ErrorKind::BrokenPipe => Ok(()),
+
+            Err(e) => Err(e),
+        }
+    }
+
+    pub unsafe fn read_overlapped(
+        &self,
+        buf: &mut [u8],
+        overlapped: *mut c::OVERLAPPED,
+    ) -> io::Result<Option<usize>> {
+        let len = cmp::min(buf.len(), <c::DWORD>::MAX as usize) as c::DWORD;
+        let mut amt = 0;
+        let res = cvt(c::ReadFile(
+            self.as_handle(),
+            buf.as_ptr() as c::LPVOID,
+            len,
+            &mut amt,
+            overlapped,
+        ));
+        match res {
+            Ok(_) => Ok(Some(amt as usize)),
+            Err(e) => {
+                if e.raw_os_error() == Some(c::ERROR_IO_PENDING as i32) {
+                    Ok(None)
+                } else if e.raw_os_error() == Some(c::ERROR_BROKEN_PIPE as i32) {
+                    Ok(Some(0))
+                } else {
+                    Err(e)
+                }
+            }
+        }
+    }
+
+    pub fn overlapped_result(
+        &self,
+        overlapped: *mut c::OVERLAPPED,
+        wait: bool,
+    ) -> io::Result<usize> {
+        unsafe {
+            let mut bytes = 0;
+            let wait = if wait { c::TRUE } else { c::FALSE };
+            let res =
+                cvt(c::GetOverlappedResult(self.as_raw_handle(), overlapped, &mut bytes, wait));
+            match res {
+                Ok(_) => Ok(bytes as usize),
+                Err(e) => {
+                    if e.raw_os_error() == Some(c::ERROR_HANDLE_EOF as i32)
+                        || e.raw_os_error() == Some(c::ERROR_BROKEN_PIPE as i32)
+                    {
+                        Ok(0)
+                    } else {
+                        Err(e)
+                    }
+                }
+            }
+        }
+    }
+
+    pub fn cancel_io(&self) -> io::Result<()> {
+        unsafe { cvt(c::CancelIo(self.as_raw_handle())).map(drop) }
+    }
+
+    pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
+        self.synchronous_write(&buf, None)
+    }
+
+    pub fn write_vectored(&self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
+        crate::io::default_write_vectored(|buf| self.write(buf), bufs)
+    }
+
+    #[inline]
+    pub fn is_write_vectored(&self) -> bool {
+        false
+    }
+
+    pub fn write_at(&self, buf: &[u8], offset: u64) -> io::Result<usize> {
+        self.synchronous_write(&buf, Some(offset))
+    }
+
+    pub fn try_clone(&self) -> io::Result<Self> {
+        Ok(Self(self.0.try_clone()?))
+    }
+
+    pub fn duplicate(
+        &self,
+        access: c::DWORD,
+        inherit: bool,
+        options: c::DWORD,
+    ) -> io::Result<Self> {
+        Ok(Self(self.0.as_handle().duplicate(access, inherit, options)?))
+    }
+
+    /// Performs a synchronous read.
+    ///
+    /// If the handle is opened for asynchronous I/O then this abort the process.
+    /// See #81357.
+    ///
+    /// If `offset` is `None` then the current file position is used.
+    unsafe fn synchronous_read(
+        &self,
+        buf: *mut mem::MaybeUninit<u8>,
+        len: usize,
+        offset: Option<u64>,
+    ) -> io::Result<usize> {
+        let mut io_status = c::IO_STATUS_BLOCK::default();
+
+        // The length is clamped at u32::MAX.
+        let len = cmp::min(len, c::DWORD::MAX as usize) as c::DWORD;
+        let status = c::NtReadFile(
+            self.as_handle(),
+            ptr::null_mut(),
+            None,
+            ptr::null_mut(),
+            &mut io_status,
+            buf,
+            len,
+            offset.map(|n| n as _).as_ref(),
+            None,
+        );
+
+        let status = if status == c::STATUS_PENDING {
+            c::WaitForSingleObject(self.as_raw_handle(), c::INFINITE);
+            io_status.status()
+        } else {
+            status
+        };
+        match status {
+            // If the operation has not completed then abort the process.
+            // Doing otherwise means that the buffer and stack may be written to
+            // after this function returns.
+            c::STATUS_PENDING => rtabort!("I/O error: operation failed to complete synchronously"),
+
+            // Return `Ok(0)` when there's nothing more to read.
+            c::STATUS_END_OF_FILE => Ok(0),
+
+            // Success!
+            status if c::nt_success(status) => Ok(io_status.Information),
+
+            status => {
+                let error = c::RtlNtStatusToDosError(status);
+                Err(io::Error::from_raw_os_error(error as _))
+            }
+        }
+    }
+
+    /// Performs a synchronous write.
+    ///
+    /// If the handle is opened for asynchronous I/O then this abort the process.
+    /// See #81357.
+    ///
+    /// If `offset` is `None` then the current file position is used.
+    fn synchronous_write(&self, buf: &[u8], offset: Option<u64>) -> io::Result<usize> {
+        let mut io_status = c::IO_STATUS_BLOCK::default();
+
+        // The length is clamped at u32::MAX.
+        let len = cmp::min(buf.len(), c::DWORD::MAX as usize) as c::DWORD;
+        let status = unsafe {
+            c::NtWriteFile(
+                self.as_handle(),
+                ptr::null_mut(),
+                None,
+                ptr::null_mut(),
+                &mut io_status,
+                buf.as_ptr(),
+                len,
+                offset.map(|n| n as _).as_ref(),
+                None,
+            )
+        };
+        let status = if status == c::STATUS_PENDING {
+            unsafe { c::WaitForSingleObject(self.as_raw_handle(), c::INFINITE) };
+            io_status.status()
+        } else {
+            status
+        };
+        match status {
+            // If the operation has not completed then abort the process.
+            // Doing otherwise means that the buffer may be read and the stack
+            // written to after this function returns.
+            c::STATUS_PENDING => rtabort!("I/O error: operation failed to complete synchronously"),
+
+            // Success!
+            status if c::nt_success(status) => Ok(io_status.Information),
+
+            status => {
+                let error = unsafe { c::RtlNtStatusToDosError(status) };
+                Err(io::Error::from_raw_os_error(error as _))
+            }
+        }
+    }
+}
+
+impl<'a> Read for &'a Handle {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        (**self).read(buf)
+    }
+
+    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
+        (**self).read_vectored(bufs)
+    }
+}