//! Windows-specific extensions to general I/O primitives. //! //! Just like raw pointers, raw Windows handles and sockets point to resources //! with dynamic lifetimes, and they can dangle if they outlive their resources //! or be forged if they're created from invalid values. //! //! This module provides three types for representing raw handles and sockets //! with different ownership properties: raw, borrowed, and owned, which are //! analogous to types used for representing pointers. These types reflect concepts of [I/O //! safety][io-safety] on Windows. //! //! | Type | Analogous to | //! | ---------------------- | ------------ | //! | [`RawHandle`] | `*const _` | //! | [`RawSocket`] | `*const _` | //! | | | //! | [`BorrowedHandle<'a>`] | `&'a _` | //! | [`BorrowedSocket<'a>`] | `&'a _` | //! | | | //! | [`OwnedHandle`] | `Box<_>` | //! | [`OwnedSocket`] | `Box<_>` | //! //! Like raw pointers, `RawHandle` and `RawSocket` values are primitive values. //! And in new code, they should be considered unsafe to do I/O on (analogous //! to dereferencing them). Rust did not always provide this guidance, so //! existing code in the Rust ecosystem often doesn't mark `RawHandle` and //! `RawSocket` usage as unsafe. //! Libraries are encouraged to migrate, either by adding `unsafe` to APIs //! that dereference `RawHandle` and `RawSocket` values, or by using to //! `BorrowedHandle`, `BorrowedSocket`, `OwnedHandle`, or `OwnedSocket`. //! //! Like references, `BorrowedHandle` and `BorrowedSocket` values are tied to a //! lifetime, to ensure that they don't outlive the resource they point to. //! These are safe to use. `BorrowedHandle` and `BorrowedSocket` values may be //! used in APIs which provide safe access to any system call except for //! `CloseHandle`, `closesocket`, or any other call that would end the //! dynamic lifetime of the resource without ending the lifetime of the //! handle or socket. //! //! `BorrowedHandle` and `BorrowedSocket` values may be used in APIs which //! provide safe access to `DuplicateHandle` and `WSADuplicateSocketW` and //! related functions, so types implementing `AsHandle`, `AsSocket`, //! `From`, or `From` should not assume they always //! have exclusive access to the underlying object. //! //! Like boxes, `OwnedHandle` and `OwnedSocket` values conceptually own the //! resource they point to, and free (close) it when they are dropped. //! //! See the [`io` module docs][io-safety] for a general explanation of I/O safety. //! //! [`BorrowedHandle<'a>`]: crate::os::windows::io::BorrowedHandle //! [`BorrowedSocket<'a>`]: crate::os::windows::io::BorrowedSocket //! [io-safety]: crate::io#io-safety #![stable(feature = "rust1", since = "1.0.0")] mod handle; mod raw; mod socket; #[stable(feature = "io_safety", since = "1.63.0")] pub use handle::*; #[stable(feature = "rust1", since = "1.0.0")] pub use raw::*; #[stable(feature = "io_safety", since = "1.63.0")] pub use socket::*; #[cfg(test)] mod tests;