This commit starts to set the CLOEXEC flag for all files and sockets opened by
the standard library by default on all unix platforms. There are a few points of
note in this commit:
* The implementation is not 100% satisfactory in the face of threads. File
descriptors only have the `F_CLOEXEC` flag set *after* they are opened,
allowing for a fork/exec to happen in the middle and leak the descriptor.
Some platforms do support atomically opening a descriptor while setting the
`CLOEXEC` flag, and it is left as a future extension to bind these apis as it
is unclear how to do so nicely at this time.
* The implementation does not offer a method of opting into the old behavior of
not setting `CLOEXEC`. This will possibly be added in the future through
extensions on `OpenOptions`, for example.
* This change does not yet audit any Windows APIs to see if the handles are
inherited by default by accident.
This is a breaking change for users who call `fork` or `exec` outside of the
standard library itself and expect file descriptors to be inherted. All file
descriptors created by the standard library will no longer be inherited.
[breaking-change]
This commit is an implementation of [RFC 807][rfc] which adds a `std::net`
module for basic neworking based on top of `std::io`. This module serves as a
replacement for the `std::old_io::net` module and networking primitives in
`old_io`.
[rfc]: fillmein
The major focus of this redesign is to cut back on the level of abstraction to
the point that each of the networking types is just a bare socket. To this end
functionality such as timeouts and cloning has been removed (although cloning
can be done through `duplicate`, it may just yield an error).
With this `net` module comes a new implementation of `SocketAddr` and `IpAddr`.
This work is entirely based on #20785 and the only changes were to alter the
in-memory representation to match the `libc`-expected variants and to move from
public fields to accessors.
This commit is an implementation of [RFC 739][rfc] which adds a new `std::fs`
module to the standard library. This module provides much of the same
functionality as `std::old_io::fs` but it has many tweaked APIs as well as uses
the new `std::path` module.
[rfc]: https://github.com/rust-lang/rfcs/pull/739
