* Link to `process::Command` from `process::Child`.
* Move out inline Markdown link in doc comment.
* Link to `process::Child::wait` from `process::Child`.
* Link to `process::Child` from `process::ChildStdin`.
* Link to `process::Child` from `process::ChildStdout`.
* Link to `process::Child` from `process::ChildStderr`.
std: Allow creating ExitStatus from raw values
Sometimes a process may be waited on externally from the standard library, in
which case it can be useful to create a raw `ExitStatus` structure to return.
This commit extends the existing Unix `ExitStatusExt` extension trait and adds a
new Windows-specific `ExitStatusExt` extension trait to do this. The methods are
currently called `ExitStatus::from_raw`.
cc #32713
Sometimes a process may be waited on externally from the standard library, in
which case it can be useful to create a raw `ExitStatus` structure to return.
This commit extends the existing Unix `ExitStatusExt` extension trait and adds a
new Windows-specific `ExitStatusExt` extension trait to do this. The methods are
currently called `ExitStatus::from_raw`.
cc #32713
Extends rustdoc on how to caputure output
- The documentation is quite about how to caputure a process' output when using
` std::process::Child::wait_with_output()`.
- This PR adds an example for this particular use case.
Automated conversion using the untry tool [1] and the following command:
```
$ find -name '*.rs' -type f | xargs untry
```
at the root of the Rust repo.
[1]: https://github.com/japaric/untry
Since I changed no_run to should_panic on some tests, the were run but
two lacked an actual assertion. Further, I missed to check the return
type on another test.
- All Rust Doc tests execute the same command `/bin/cat file.txt` which
`should_panic` on all platforms consistently, because either
`/bin/cat` or `file.txt` do not exist.
Semantically there's actually no reason for us to spawn threads as part of the
call to `wait_with_output`, and that's generally an incredibly heavyweight
operation for just reading a few bytes (especially when stderr probably rarely
has bytes!). An equivalent operation in terms of what's implemented today would
be to just drain both pipes of all contents and then call `wait` on the child
process itself.
On Unix we can implement this through some convenient use of the `select`
function, whereas on Windows we can make use of overlapped I/O. Note that on
Windows this requires us to use named pipes instead of anonymous pipes, but
they're semantically the same under the hood.
For example if `Command::output` or `Command::status` is used then stdin is just
immediately closed. Add an option for this so as an optimization we can avoid
creating pipes entirely.
This should help reduce the number of active file descriptors when spawning
processes on Unix and the number of active handles on Windows.
This pushes the implementation detail of proxying `read_to_end` through to
`read_to_end_uninitialized` all the way down to the `FileDesc` and `Handle`
implementations on Unix/Windows. This way intermediate layers will also be able
to take advantage of this optimized implementation.
This commit also adds the optimized implementation for `ChildStdout` and
`ChildStderr`.
Most of this is platform-specific anyway, and we generally have to jump through
fewer hoops to do the equivalent operation on Windows. One benefit for Windows
today is that this new structure avoids an extra `DuplicateHandle` when creating
pipes. For Unix, however, the behavior should be the same.
Note that this is just a pure refactoring, no functionality was added or
removed.
On Unix we have to be careful to not call `waitpid` twice, but we don't have to
be careful on Windows due to the way process handles work there. As a result the
cached `Option<ExitStatus>` is only necessary on Unix, and it's also just an
implementation detail of the Unix module.
At the same time. also update some code in `kill` on Unix to avoid a wonky
waitpid with WNOHANG. This was added in 0e190b9a to solve #13124, but the
`signal(0)` method is not supported any more so there's no need to for this
workaround. I believe that this is no longer necessary as it's not really doing
anything.
This is a Unix-specific function which adds the ability to register a closure to
run pre-exec to configure the child process as required (note that these
closures are run post-fork).
cc #31398
* Build up the argp/envp pointers while the `Command` is being constructed
rather than only when `spawn` is called. This will allow better sharing of
code between fork/exec paths.
* Rename `child_after_fork` to `exec` and have it only perform the exec half of
the spawning. This also means the return type has changed to `io::Error`
rather than `!` to represent errors that happen.
There is no `Drop` implemented for `Child`, so if it goes out
of scope in Rust-land and gets deallocated, the child process
will continue to exist and execute. If users want a guarantee
that the process has finished running and exited they must
manually use `kill`, `wait`, or `wait_with_output`.
Fixes#31289.
Previously this function used channels but this isn't necessary any more now
that threads have return values. This also has the added bonus of appropriately
waiting for the thread to exit to ensure that the function doesn't still have
running threads once it returns.
Travis CI has new infrastructure using the Google Compute Engine which has both
faster CPUs and more memory, and we've been encouraged to switch as it should
help our build times! The only downside currently, however, is that IPv6 is
disabled, causing a number of standard library tests to fail.
Consequently this commit tweaks our travis config in a few ways:
* ccache is disabled as it's not working on GCE just yet
* Docker is used to run tests inside which reportedly will get IPv6 working
* A system LLVM installation is used instead of building LLVM itself. This is
primarily done to reduce build times, but we want automation for this sort of
behavior anyway and we can extend this in the future with building from source
as well if needed.
* gcc-specific logic is removed as the docker image for Ubuntu gives us a
recent-enough gcc by default.
This commit does some refactoring to make almost all of the `std::rt` private.
Specifically, the following items are no longer part of its API:
* DEFAULT_ERROR_CODE
* backtrace
* unwind
* args
* at_exit
* cleanup
* heap (this is just alloc::heap)
* min_stack
* util
The module is now tagged as `#[doc(hidden)]` as the only purpose it's serve is
an entry point for the `panic!` macro via the `begin_unwind` and
`begin_unwind_fmt` reexports.
This commit removes the injection of `std::env::args()` from `--test` expanded
code, relying on the test runner itself to call this funciton. This is more
hygienic because we can't assume that `std` exists at the top layer all the
time, and it meaks the injected test module entirely self contained.
The following APIs were all marked with a `#[stable]` tag:
* process::Child::id
* error::Error::is
* error::Error::downcast
* error::Error::downcast_ref
* error::Error::downcast_mut
* io::Error::get_ref
* io::Error::get_mut
* io::Error::into_inner
* hash::Hash::hash_slice
* hash::Hasher::write_{i,u}{8,16,32,64,size}
This isn't actually necessary any more with the advent of `$crate` and changes
in the compiler to expand macros to `::core::$foo` in the context of a
`#![no_std]` crate.
The libcore inner module was also trimmed down a bit to the bare bones.
The following APIs were all marked with a `#[stable]` tag:
* process::Child::id
* error::Error::is
* error::Error::downcast
* error::Error::downcast_ref
* error::Error::downcast_mut
* io::Error::get_ref
* io::Error::get_mut
* io::Error::into_inner
* hash::Hash::hash_slice
* hash::Hasher::write_{i,u}{8,16,32,64,size}
These aren't really used for anything any more, so there doesn't seem to be much
reason to leave them around in the `rt` directory. There was some limiting of
threads spawned or tests when run under valgrind, but very little is run under
valgrind nowadays so there's also no real use keeping these around.
This commit is an implementation of [RFC 1174][rfc] which adds three new traits
to the standard library:
* `IntoRawFd` - implemented on Unix for all I/O types (files, sockets, etc)
* `IntoRawHandle` - implemented on Windows for files, processes, etc
* `IntoRawSocket` - implemented on Windows for networking types
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/1174-into-raw-fd-socket-handle-traits.mdCloses#27062
