This change registers new snapshots, allowing `*T` to be removed from the language. This is a large breaking change, and it is recommended that if compiler errors are seen that any FFI calls are audited to determine whether they should be actually taking `*mut T`.
Most of the comments are available on the Task structure itself, but this commit
is aimed at making FFI-style usage of Rust tasks a little nicer.
Primarily, this commit enables re-use of tasks across multiple invocations. The
method `run` will no longer unconditionally destroy the task itself. Rather, the
task will be internally re-usable if the closure specified did not fail. Once a
task has failed once it is considered poisoned and it can never be used again.
Along the way I tried to document shortcomings of the current method of tearing
down a task, opening a few issues as well. For now none of the behavior is a
showstopper, but it's useful to acknowledge it. Also along the way I attempted
to remove as much `unsafe` code as possible, opting for safer abstractions.
This change starts denying `*T` in the parser. All code using `*T` should ensure
that the FFI call does indeed take `const T*` on the other side before renaming
the type to `*const T`.
Otherwise, all code can rename `*T` to `*const T`.
[breaking-change]
If you define lang items in your crate, add `#[feature(lang_items)]`.
If you define intrinsics (`extern "rust-intrinsic"`), add
`#[feature(intrinsics)]`.
Closes#12858.
[breaking-change]
Closes#8142.
This is not the semantics we want long-term. You can continue to use
`#[unsafe_destructor]`, but you'll need to add
`#![feature(unsafe_destructor)]` to the crate attributes.
[breaking-change]
This creates a stability baseline for all crates that we distribute that are not `std`. In general, all library code must start as experimental and progress in stages to become stable.
This patch consolidates and cleans up the task spawning APIs:
* Removes the problematic `future_result` method from `std::task::TaskBuilder`,
and adds a `try_future` that both spawns the task and returns a future
representing its eventual result (or failure).
* Removes the public `opts` field from `TaskBuilder`, instead adding appropriate
builder methods to configure the task.
* Adds extension traits to libgreen and libnative that add methods to
`TaskBuilder` for spawning the task as a green or native thread.
Previously, there was no way to benefit from the `TaskBuilder` functionality and
also set the scheduler to spawn within.
With this change, all task spawning scenarios are supported through the
`TaskBuilder` interface.
Closes#3725.
[breaking-change]
This commit moves reflection (as well as the {:?} format modifier) to a new
libdebug crate, all of which is marked experimental.
This is a breaking change because it now requires the debug crate to be
explicitly linked if the :? format qualifier is used. This means that any code
using this feature will have to add `extern crate debug;` to the top of the
crate. Any code relying on reflection will also need to do this.
Closes#12019
[breaking-change]
This implements set_timeout() for std::io::Process which will affect wait()
operations on the process. This follows the same pattern as the rest of the
timeouts emerging in std::io::net.
The implementation was super easy for everything except libnative on unix
(backwards from usual!), which required a good bit of signal handling. There's a
doc comment explaining the strategy in libnative. Internally, this also required
refactoring the "helper thread" implementation used by libnative to allow for an
extra helper thread (not just the timer).
This is a breaking change in terms of the io::Process API. It is now possible
for wait() to fail, and subsequently wait_with_output(). These two functions now
return IoResult<T> due to the fact that they can time out.
Additionally, the wait_with_output() function has moved from taking `&mut self`
to taking `self`. If a timeout occurs while waiting with output, the semantics
are undesirable in almost all cases if attempting to re-wait on the process.
Equivalent functionality can still be achieved by dealing with the output
handles manually.
[breaking-change]
cc #13523
This addresses #12842 by offering fallback implementations for functions that aren't available.
In this case, as Windows XP simply doesn't support symbolic links at all, the fallbacks simply return an error code indicating that the function hasn't been implemented. This should allow programs written in Rust to run under XP while still offering full support for symbolic links under newer versions of Windows with the same binary, but due to LLVM using stderror_s(), which isn't available in msvcrt.dll in XP, rustc itself will not.
The fallback implementation is as follows:
Calling the function instead calls to a mutable function pointer. This in and of itself would not constitute a performance hit because DLL calls are implemented in a similar manner (see Import Address Table). The function pointer initially points to a thunk which tries to get the address of the associated function and write it back to the function pointer. If it fails to find the function, it instead writes the address to a fallback. As this operation is idempotent, reading and writing the pointer simply needs to be atomic. Subsequent calls to the function should be as fast as any other DLL call, as the pointer will then point directly to either the correct function or a fallback.
This commit revisits the `cast` module in libcore and libstd, and scrutinizes
all functions inside of it. The result was to remove the `cast` module entirely,
folding all functionality into the `mem` module. Specifically, this is the fate
of each function in the `cast` module.
* transmute - This function was moved to `mem`, but it is now marked as
#[unstable]. This is due to planned changes to the `transmute`
function and how it can be invoked (see the #[unstable] comment).
For more information, see RFC 5 and #12898
* transmute_copy - This function was moved to `mem`, with clarification that is
is not an error to invoke it with T/U that are different
sizes, but rather that it is strongly discouraged. This
function is now #[stable]
* forget - This function was moved to `mem` and marked #[stable]
* bump_box_refcount - This function was removed due to the deprecation of
managed boxes as well as its questionable utility.
* transmute_mut - This function was previously deprecated, and removed as part
of this commit.
* transmute_mut_unsafe - This function doesn't serve much of a purpose when it
can be achieved with an `as` in safe code, so it was
removed.
* transmute_lifetime - This function was removed because it is likely a strong
indication that code is incorrect in the first place.
* transmute_mut_lifetime - This function was removed for the same reasons as
`transmute_lifetime`
* copy_lifetime - This function was moved to `mem`, but it is marked
`#[unstable]` now due to the likelihood of being removed in
the future if it is found to not be very useful.
* copy_mut_lifetime - This function was also moved to `mem`, but had the same
treatment as `copy_lifetime`.
* copy_lifetime_vec - This function was removed because it is not used today,
and its existence is not necessary with DST
(copy_lifetime will suffice).
In summary, the cast module was stripped down to these functions, and then the
functions were moved to the `mem` module.
transmute - #[unstable]
transmute_copy - #[stable]
forget - #[stable]
copy_lifetime - #[unstable]
copy_mut_lifetime - #[unstable]
[breaking-change]
Some unix platforms will send a SIGPIPE signal instead of returning EPIPE from a
syscall by default. The native runtime doesn't install a SIGPIPE handler,
causing the program to die immediately in this case. This brings the behavior in
line with libgreen by ignoring SIGPIPE and propagating EPIPE upwards to the
application in the form of an IoError.
Closes#13123
The compiler will no longer inject libgreen as the default runtime for rust
programs, this commit switches it over to libnative by default. Now that
libnative has baked for some time, it is ready enough to start getting more
serious usage as the default runtime for rustc generated binaries.
We've found that there isn't really a correct decision in choosing a 1:1 or M:N
runtime as a default for all applications, but it seems that a larger number of
programs today would work more reasonable with a native default rather than a
green default.
With this commit come a number of bugfixes:
* The main native task is now named "<main>"
* The main native task has the stack bounds set up properly
* #[no_uv] was renamed to #[no_start]
* The core-run-destroy test was rewritten for both libnative and libgreen and
one of the tests was modified to be more robust.
* The process-detach test was locked to libgreen because it uses signal handling
When using tasks in Rust, the expectation is that the runtime does not exit
before all tasks have exited. This is enforced in libgreen through the
`SchedPool` type, and it is enforced in libnative through a `bookkeeping` module
and a global count/mutex pair. Unfortunately, this means that a process which
originates with libgreen will not wait for spawned native tasks.
In order to fix this problem, the bookkeeping module was moved from libnative to
libstd so the runtime itself can wait for native tasks to exit. Green tasks do
not manage themselves through this bookkeeping module, but native tasks will
continue to manage themselves through this module.
Closes#12684
This commit splits the file implementation into file_unix and file_win32. The
two implementations have diverged to the point that they share almost 0 code at
this point, so it's easier to maintain as separate files.
The other major change accompanied with this commit is that file::open is no
longer based on libc's open function on windows, but rather windows's CreateFile
function. This fixes dealing with binary files on windows (test added in
previous commit).
This also changes the read/write functions to use ReadFile and WriteFile instead
of libc's read/write.
Closes#12406
