They all have to go into a single module at the moment unfortunately.
Ideally, the logging macros would live in std::logging, condition! would
live in std::condition, format! in std::fmt, etc. However, this
introduces cyclic dependencies between those modules and the macros they
use which the current expansion system can't deal with. We may be able
to get around this by changing the expansion phase to a two-pass system
but that's for a later PR.
Closes#2247
cc #11763
Before this commit, rustc looked in `dirname $0`/../lib for libraries
but that doesn't work when rustc is invoked through a symlink.
This commit makes rustc look in `dirname $(readlink $0)`/../lib, i.e.
it first canonicalizes the symlink before walking up the directory tree.
Fixes#3632.
Renamed the invert() function in iter.rs to flip().
Also renamed the Invert<T> type to Flip<T>.
Some related code comments changed. Documentation that I could find has
been updated, and all the instances I could locate where the
function/type were called have been updated as well.
This is just an initial implementation and does not yet fully replace `~[T]`. A generic initialization syntax for containers is missing, and the slice functionality needs to be reworked to make auto-slicing unnecessary.
Traits for supporting indexing properly are also required. This also needs to be fixed to make ring buffers as easy to use as vectors.
The tests and documentation for `~[T]` can be ported over to this type when it is removed. I don't really expect DST to happen for vectors as having both `~[T]` and `Vec<T>` is overcomplicated and changing the slice representation to 3 words is not at all appealing. Unlike with traits, it's possible (and easy) to implement `RcSlice<T>` and `GcSlice<T>` without compiler help.
Fixes#6593
Currently, Rust provides no way to print very large or very small floating point values which come up routinely in scientific and modeling work. The classical solution to this is to use the scientific/exponential notation, which not-coincidentally, corresponds to how floating point values are encoded in memory. Given this, there are two solutions to the problem. One is what, as far as I understand it, Python does. I.e. for floating point numbers in a certain range it does what we do today with the `'f'` formatting flag, otherwise it switches to exponential notation. The other way is to provide a set of formatting flags to explicitly choose the exponential notation, like it is done in C. I've chosen the second way as I think its important to provide that kind of control to the user.
This pull request changes the `std::num::strconv::float_to_str_common` function to optionally format floating point numbers using the exponential (scientific) notation. The base of the significant can be varied between 2 and 25, while the base of the exponent can be 2 or 10.
Additionally this adds two new formatting specifiers to `format!` and friends: `'e'` and `'E'` which switch between outputs like `1.0e5` and `1.0E5`. Mostly parroting C stdlib in this sense, although I wasn't going for an exact output match.
Native timers are a much hairier thing to deal with than green timers due to the
interface that we would like to expose (both a blocking sleep() and a
channel-based interface). I ended up implementing timers in three different ways
for the various platforms that we supports.
In all three of the implementations, there is a worker thread which does send()s
on channels for timers. This worker thread is initialized once and then
communicated to in a platform-specific manner, but there's always a shared
channel available for sending messages to the worker thread.
* Windows - I decided to use windows kernel timer objects via
CreateWaitableTimer and SetWaitableTimer in order to provide sleeping
capabilities. The worker thread blocks via WaitForMultipleObjects where one of
the objects is an event that is used to wake up the helper thread (which then
drains the incoming message channel for requests).
* Linux/(Android?) - These have the ideal interface for implementing timers,
timerfd_create. Each timer corresponds to a timerfd, and the helper thread
uses epoll to wait for all active timers and then send() for the next one that
wakes up. The tricky part in this implementation is updating a timerfd, but
see the implementation for the fun details
* OSX/FreeBSD - These obviously don't have the windows APIs, and sadly don't
have the timerfd api available to them, so I have thrown together a solution
which uses select() plus a timeout in order to ad-hoc-ly implement a timer
solution for threads. The implementation is backed by a sorted array of timers
which need to fire. As I said, this is an ad-hoc solution which is certainly
not accurate timing-wise. I have done this implementation due to the lack of
other primitives to provide an implementation, and I've done it the best that
I could, but I'm sure that there's room for improvement.
I'm pretty happy with how these implementations turned out. In theory we could
drop the timerfd implementation and have linux use the select() + timeout
implementation, but it's so inaccurate that I would much rather continue to use
timerfd rather than my ad-hoc select() implementation.
The only change that I would make to the API in general is to have a generic
sleep() method on an IoFactory which doesn't require allocating a Timer object.
For everything but windows it's super-cheap to request a blocking sleep for a
set amount of time, and it's probably worth it to provide a sleep() which
doesn't do something like allocate a file descriptor on linux.
This routine is currently only used to clean up the timer helper thread in the
libnative implementation, but there are possibly other uses for this.
The documentation is clear that the procedures are *not* run with any task
context and hence have very little available to them. I also opted to disallow
at_exit inside of at_exit and just abort the process at that point.
* Stop using hardcoded numbers that have to all get updated when something changes (inevitable errors and rebase conflicts) as well as removes some unneeded -Z options (obsoleted over time).
* Remove `std::rt::borrowck`
The implementation has been made more succinct and no longer requires Clone. The coverage of the associated unit test has also been increased to check more combinations of bases, exponents, and expected results.
There was an old and barely used implementation of pow, which expected
both parameters to be uint and required more traits to be implemented.
Since a new implementation for `pow` landed, I'm proposing to remove
this old impl in favor of the new one.
The benchmark shows that the new implementation is faster than the one being removed:
```
test num::bench::bench_pow_function ..bench: 9429 ns/iter (+/- 2055)
test num::bench::bench_pow_with_uint_function ...bench: 28476 ns/iter (+/- 2202)
```
The `malloc` family of functions may return a null pointer for a
zero-size allocation, which should not be interpreted as an
out-of-memory error.
If the implementation does not return a null pointer, then handling
this will result in memory savings for zero-size types.
This also switches some code to `malloc_raw` in order to maintain a
centralized point for handling out-of-memory in `rt::global_heap`.
Closes#11634
There was an old and barely used implementation of pow, which expected
both parameters to be uint and required more traits to be implemented.
Since a new implementation for `pow` landed, I'm proposing to remove
this old impl in favor of the new one.
The benchmark shows that the new implementation is faster than the one
being removed:
test num::bench::bench_pow_function ..bench: 9429 ns/iter (+/- 2055)
test num::bench::bench_pow_with_uint_function ...bench: 28476 ns/iter (+/- 2202)
As part of #10387, this removes the `Primitive::{bits, bytes, is_signed}` methods and removes the trait's operator trait constraints for the reasons outlined below:
- The `Primitive::{bits, bytes}` associated functions were originally added to reflect the existing `BITS` and `BYTES`statics included in the numeric modules. These statics are only exist as a workaround for Rust's lack of CTFE, and should be deprecated in the future in favor of using the `std::mem::size_of` function (see #11621).
- `Primitive::is_signed` seems to be of little utility and does not seem to be used anywhere in the Rust compiler or libraries. It is also rather ugly to call due to the `Option<Self>` workaround for #8888.
- The operator trait constraints are already covered by the `Num` trait.
The `malloc` family of functions may return a null pointer for a
zero-size allocation, which should not be interpreted as an
out-of-memory error.
If the implementation does not return a null pointer, then handling
this will result in memory savings for zero-size types.
This also switches some code to `malloc_raw` in order to maintain a
centralized point for handling out-of-memory in `rt::global_heap`.
Closes#11634
