1//! Unix-specific I/O extensions.
2
3cfg_not_docs! {
4 pub use std::os::unix::io::{AsRawFd, FromRawFd, IntoRawFd, RawFd};
5
6 cfg_io_safety! {
7 pub use std::os::unix::io::{AsFd, BorrowedFd, OwnedFd};
8 }
9}
10
11cfg_docs! {
12 /// Raw file descriptors.
13 pub type RawFd = std::os::raw::c_int;
14
15 /// A trait to extract the raw unix file descriptor from an underlying
16 /// object.
17 ///
18 /// This is only available on unix platforms and must be imported in order
19 /// to call the method. Windows platforms have a corresponding `AsRawHandle`
20 /// and `AsRawSocket` set of traits.
21 pub trait AsRawFd {
22 /// Extracts the raw file descriptor.
23 ///
24 /// This method does **not** pass ownership of the raw file descriptor
25 /// to the caller. The descriptor is only guaranteed to be valid while
26 /// the original object has not yet been destroyed.
27 fn as_raw_fd(&self) -> RawFd;
28 }
29
30 /// A trait to express the ability to construct an object from a raw file
31 /// descriptor.
32 pub trait FromRawFd {
33 /// Constructs a new instance of `Self` from the given raw file
34 /// descriptor.
35 ///
36 /// This function **consumes ownership** of the specified file
37 /// descriptor. The returned object will take responsibility for closing
38 /// it when the object goes out of scope.
39 ///
40 /// This function is also unsafe as the primitives currently returned
41 /// have the contract that they are the sole owner of the file
42 /// descriptor they are wrapping. Usage of this function could
43 /// accidentally allow violating this contract which can cause memory
44 /// unsafety in code that relies on it being true.
45 unsafe fn from_raw_fd(fd: RawFd) -> Self;
46 }
47
48 /// A trait to express the ability to consume an object and acquire ownership of
49 /// its raw file descriptor.
50 pub trait IntoRawFd {
51 /// Consumes this object, returning the raw underlying file descriptor.
52 ///
53 /// This function **transfers ownership** of the underlying file descriptor
54 /// to the caller. Callers are then the unique owners of the file descriptor
55 /// and must close the descriptor once it's no longer needed.
56 fn into_raw_fd(self) -> RawFd;
57 }
58
59 cfg_io_safety! {
60 #[doc(inline)]
61 pub use std::os::unix::io::{AsFd, BorrowedFd, OwnedFd};
62 }
63}
64