The previous method was unsound because you could very easily create two mutable
pointers which alias the same location (not sound behavior). This hides the
function which does so and then exports an explicit flush() function (with
documentation about how it works).
Fix the implementation of `std::rand::Rng::fill_bytes()` for
`std::rand::reseeding::ReseedingRng` to call the `fill_bytes()` method
of the underlying RNG rather than itself, which causes infinite
recursion.
Fixes#10202.
The code was using (in the notation of Doornik 2005) `f(x_{i+1}) -
f(x_{i+2})` rather than `f(x_i) - f(x_{i+1})`. This corrects that, and
removes the F_DIFF tables which caused this problem in the first place.
They `F_DIFF` tables are a micro-optimisation (in theory, they could
easily be a micro-pessimisation): that `if` gets hit about 1% of the
time for Exp/Normal, and the rest of the condition involves RNG calls
and a floating point `exp`, so it is unlikely that saving a single FP
subtraction will be very useful (especially as more tables means more
memory reads and higher cache pressure, as well as taking up space in
the binary (although only ~2k in this case)).
Closes#10084. Notably, unlike that issue suggests, this wasn't a
problem with the Exp tables. It affected Normal too, but since it is
symmetric, there was no bias in the mean (as the bias was equal on the
positive and negative sides and so cancelled out) but it was visible as
a variance slightly lower than it should be.
New plot:
I've started writing some tests in [huonw/random-tests](https://github.com/huonw/random-tests) (not in the main repo because they can and do fail occasionally, due to randomness, but it is on Travis and Rust-CI so it will hopefully track the language), unsurprisingly, they're [currently failing](https://travis-ci.org/huonw/random-tests/builds/13313987) (note that both exp and norm are failing, the former due to both mean and variance the latter due to just variance), but pass at the 0.01 level reliably with this change.
(Currently the only test is essentially a quantitative version of the plots I've been showing, which is run on the `f64` `Rand` instance (uniform 0 to 1), and the Normal and Exp distributions.)
The previous method was unsound because you could very easily create two mutable
pointers which alias the same location (not sound behavior). This hides the
function which does so and then exports an explicit flush() function (with
documentation about how it works).
Fix the implementation of `std::rand::Rng::fill_bytes()` for
`std::rand::reseeding::ReseedingRng` to call the `fill_bytes()` method
of the underlying RNG rather than itself, which causes infinite
recursion.
Fixes#10202.
The code was using (in the notation of Doornik 2005) `f(x_{i+1}) -
f(x_{i+2})` rather than `f(x_i) - f(x_{i+1})`. This corrects that, and
removes the F_DIFF tables which caused this problem in the first place.
They `F_DIFF` tables are a micro-optimisation (in theory, they could
easily be a micro-pessimisation): that `if` gets hit about 1% of the
time for Exp/Normal, and the rest of the condition involves RNG calls
and a floating point `exp`, so it is unlikely that saving a single FP
subtraction will be very useful (especially as more tables means more
memory reads and higher cache pressure, as well as taking up space in
the binary (although only ~2k in this case)).
Closes#10084. Notably, unlike that issue suggests, this wasn't a
problem with the Exp tables. It affected Normal too, but since it is
symmetric, there was no bias in the mean (as the bias was equal on the
positive and negative sides and so cancelled out) but it was visible as
a variance slightly lower than it should be.
- `begin_unwind` and `fail!` is now generic over any `T: Any + Send`.
- Every value you fail with gets boxed as an `~Any`.
- Because of implementation issues, `&'static str` and `~str` are still
handled specially behind the scenes.
- Changed the big macro source string in libsyntax to a raw string
literal, and enabled doc comments there.
- `begin_unwind` is now generic over any `T: Any + Send`.
- Every value you fail with gets boxed as an `~Any`.
- Because of implementation details, `&'static str` and `~str` are still
handled specially behind the scenes.
- Changed the big macro source string in libsyntax to a raw string
literal, and enabled doc comments there.
Allows an enum with a discriminant to use any of the primitive integer types to store it. By default the smallest usable type is chosen, but this can be overridden with an attribute: `#[repr(int)]` etc., or `#[repr(C)]` to match the target's C ABI for the equivalent C enum.
Also adds a lint pass for using non-FFI safe enums in extern declarations, checks that specified discriminants can be stored in the specified type if any, and fixes assorted code that was assuming int.
This is one of the final steps needed to complete #9128. It still needs a little bit of polish before closing that issue, but it's in a pretty much "done" state now.
The idea here is that the entire event loop implementation using libuv is now housed in `librustuv` as a completely separate library. This library is then injected (via `extern mod rustv`) into executable builds (similarly to how libstd is injected, tunable via `#[no_uv]`) to bring in the "rust blessed event loop implementation."
Codegen-wise, there is a new `event_loop_factory` language item which is tagged on a function with 0 arguments returning `~EventLoop`. This function's symbol is then inserted into the crate map for an executable crate, and if there is no definition of the `event_loop_factory` language item then the value is null.
What this means is that embedding rust as a library in another language just got a little harder. Libraries don't have crate maps, which means that there's no way to find the event loop implementation to spin up the runtime. That being said, it's always possible to build the runtime manually. This request also makes more runtime components public which should probably be public anyway. This new public-ness should allow custom scheduler setups everywhere regardless of whether you follow the `rt::start `path.
Otherwise, run-pass/deriving-primitive.rs breaks on 32-bit platforms,
because `int::min_value` is `0xffffffff7fffffff` when evaluated for the
discriminant declaration.
Not only can discriminants be smaller than int now, but they can be
larger than int on 32-bit targets. This has obvious implications for the
reflection interface. Without this change, things fail with LLVM
assertions when we try to "extend" i64 to i32.
There are a few reasons that this is a desirable move to take:
1. Proof of concept that a third party event loop is possible
2. Clear separation of responsibility between rt::io and the uv-backend
3. Enforce in the future that the event loop is "pluggable" and replacable
Here's a quick summary of the points of this pull request which make this
possible:
* Two new lang items were introduced: event_loop, and event_loop_factory.
The idea of a "factory" is to define a function which can be called with no
arguments and will return the new event loop as a trait object. This factory
is emitted to the crate map when building an executable. The factory doesn't
have to exist, and when it doesn't then an empty slot is in the crate map and
a basic event loop with no I/O support is provided to the runtime.
* When building an executable, then the rustuv crate will be linked by default
(providing a default implementation of the event loop) via a similar method to
injecting a dependency on libstd. This is currently the only location where
the rustuv crate is ever linked.
* There is a new #[no_uv] attribute (implied by #[no_std]) which denies
implicitly linking to rustuv by default
Closes#5019
Primarily this makes the Scheduler and all of its related interfaces public. The
reason for doing this is that currently any extern event loops had no access to
the scheduler at all. This allows third-party event loops to manipulate the
scheduler, along with allowing the uv event loop to live inside of its own
crate.
This drops more of the old C++ runtime to rather be written in rust. A few
features were lost along the way, but hopefully not too many. The main loss is
that there are no longer backtraces associated with allocations (rust doesn't
have a way of acquiring those just yet). Other than that though, I believe that
the rest of the debugging utilities made their way over into rust.
Closes#8704
Some code cleanup, sorting of import blocks
Removed std::unstable::UnsafeArc's use of Either
Added run-fail tests for the new FailWithCause impls
Changed future_result and try to return Result<(), ~Any>.
- Internally, there is an enum of possible fail messages passend around.
- In case of linked failure or a string message, the ~Any gets
lazyly allocated in future_results recv method.
- For that, future result now returns a wrapper around a Port.
- Moved and renamed task::TaskResult into rt::task::UnwindResult
and made it an internal enum.
- Introduced a replacement typedef `type TaskResult = Result<(), ~Any>`.
Remove the Sha1, Sha2, MD5, and MD4 algorithms. SipHash is also cryptographically secure hash function and IsaacRng is a cryptographically secure RNG - I left those alone but removed comments that implied they were suitable for cryptographic use. I thought that MD4 was used for something by the compiler, but everything still seems to work with it removed, so, I guess not.
One thing that I'm not sure about - workcache.rs and workcache_support.rs (in librustpkg) both depend on Sha1. Without Sha1, the only hash function left is SipHash, so I switched that code over to use SipHash. The output size of SipHash is only 64-bits, however - much less than 160 for Sha1. I'm not sure this is a problem. Without other cryptographic hashes in the tree, I'm not sure what else to do. I considered moved Sha1 into librustpkg, but I don't know if that makes sense.
If merged, this closes#9300.
I'm not entirely sure why this is happening, but the server task is never seeing
the second send of the client task, and this test will very reliably fail to
complete on windows.
It was pretty much a miracle that these tests were ever passing. They would
never have passed in the single threaded case because only one sigint in the
tests is ever generated, but when run in parallel two sigints will be generated.
This drops more of the old C++ runtime to rather be written in rust. A few
features were lost along the way, but hopefully not too many. The main loss is
that there are no longer backtraces associated with allocations (rust doesn't
have a way of acquiring those just yet). Other than that though, I believe that
the rest of the debugging utilities made their way over into rust.
Closes#8704
