This is something that is plausibly useful, and is provided by libuv. This is
not currently surfaced as part of the `TcpStream` type, but it may possibly
appear in the future. For now only the raw functionality is provided through the
Rtio objects.
This is something that is plausibly useful, and is provided by libuv. This is
not currently surfaced as part of the `TcpStream` type, but it may possibly
appear in the future. For now only the raw functionality is provided through the
Rtio objects.
This is part of the overall strategy I would like to take when approaching
issue #11165. The only two I/O objects that reasonably want to be "split" are
the network stream objects. Everything else can be "split" by just creating
another version.
The initial idea I had was the literally split the object into a reader and a
writer half, but that would just introduce lots of clutter with extra interfaces
that were a little unnnecssary, or it would return a ~Reader and a ~Writer which
means you couldn't access things like the remote peer name or local socket name.
The solution I found to be nicer was to just clone the stream itself. The clone
is just a clone of the handle, nothing fancy going on at the kernel level.
Conceptually I found this very easy to wrap my head around (everything else
supports clone()), and it solved the "split" problem at the same time.
The cloning support is pretty specific per platform/lib combination:
* native/win32 - uses some specific WSA apis to clone the SOCKET handle
* native/unix - uses dup() to get another file descriptor
* green/all - This is where things get interesting. When we support full clones
of a handle, this implies that we're allowing simultaneous writes
and reads to happen. It turns out that libuv doesn't support two
simultaneous reads or writes of the same object. It does support
*one* read and *one* write at the same time, however. Some extra
infrastructure was added to just block concurrent writers/readers
until the previous read/write operation was completed.
I've added tests to the tcp/unix modules to make sure that this functionality is
supported everywhere.
* All I/O now returns IoResult<T> = Result<T, IoError>
* All formatting traits now return fmt::Result = IoResult<()>
* The if_ok!() macro was added to libstd
`Times::times` was always a second-class loop because it did not support the `break` and `continue` operations. Its playful appeal was then lost after `do` was disabled for closures. It's time to let this one go.
libnative erroneously would attempt to fill the entire buffer in a call to
`read` before returning, when rather it should return immediately because
there's not guaranteed to be any data that will ever be received again.
Close#11328
Move the tests into libstd, use the `iotest!` macro to test both native and uv
bindings, and use the cloexec trick to figure out when the child process fails
in exec.
It is not the case that all programs will always be able to acquire an instance
of the LocalIo borrow, so this commit exposes this limitation by returning
Option<LocalIo> from LocalIo::borrow().
At the same time, a helper method LocalIo::maybe_raise() has been added in order
to encapsulate the functionality of raising on io_error if there is on local I/O
available.
This module contains many M:N specific concepts. This will no longer be
available with libgreen, and most functions aren't really that necessary today
anyway. New testing primitives will be introduced as they become available for
1:1 and M:N.
A new io::test module is introduced with the new ip4/ip6 address helpers to
continue usage in io tests.
