async_std/os/unix/
io.rs

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

async_std/os/unix/
io.rs
