Organize everything around a Fetch task which does a bunch of stuff in a
worker thread without touching any shared state, and then queues up
Fetch tasks for its dependencies.
This isn't the theoretical optimal package fetching performance because
CPU cores don't necessarily map 1:1 with I/O tasks, and each fetch task
contains a mixture of computations and I/O. However, it is expected for
this to significantly outperform master branch, which fetches everything
recursively with only one thread.
The logic is now a lot more linear and easy to follow. Everything that
is embarassingly parallel is done on the thread pool, and then after
everything is fetched, the worker threads are joined and the main thread
does the finishing touches of stitching together the dependencies.zig
import files. There is only one tiny little critical section and it does
not even have any error handling in it.
This also lays the groundwork for #14281 because in system mode, all
this fetching logic will be skipped, but the "finishing touches"
mentioned above still need to be done. With this branch, that logic is
separated out and no longer recursively tangled with fetching stuff.
Additionally, this branch:
* Implements inclusion directives in `build.zig.zon` for deciding which
files belong the package (#14311).
* Adds basic documentation for `build.zig.zon` files.
* Adds support for fetching dependencies with the `file://` protocol
scheme (#17364).
* Adds a workaround for a Linux/btrfs file system bug (#17282).
This commit is a work-in-progress. Still todo:
1. Hook up the CLI to the new system.
2. Restore the module table creation logic after all the fetching is
done.
3. Fix compilation errors, get the tests passing, and regression test
against real world projects.
This hashmap value used to be assigned much later during `flushModule`,
which never happens if an error is returned by the backend, and
attempting to the undefined values would cause a crash.
Originally inspired by Go's `utf8.Valid` function. Includes some test cases from Go's test suite.
Further optimized to be faster in all tested cases (short/long ascii/UTF8), in all release modes.
Takes advantage of SIMD for the ASCII fast path.
`nextAfter()` returns the next representable value after `x` in the direction of `y` and is a standard math library function ([C++](https://en.cppreference.com/w/cpp/numeric/math/nextafter), [Java](https://docs.oracle.com/javase/8/docs/api/java/lang/Math.html#nextAfter-double-double-)). It is primarily useful for bitwise incrementing/decrementing floats.
This implementation supports runtime integers, runtime floats and `comptime_int`. `comptime_float` is not supported because NaNs/infinities are intentionally difficult to obtain and because I'm not sure if the fact that it's backed by `f128` is supposed to be an implementation detail. Either way, the user could just call the function with the floating-point type whose behavior they want at comptime and then cast the result to `comptime_float`.
The float implementation was ported from mingw-w64 with some slight changes made possible because the Zig standard library doesn't care about raising FP exceptions.
The number of test cases may seem excessive but they should cover every normal and edge case for every float type and are especially important for verifying that `f80` works.
Until now, we would pass `candidate: NativeTargetInfo` which creates
a copy of the `NativeTargetInfo.DynamicLinker` buffer. We would then
return this buffer in `bad_dl: []const u8` which would goes out-of-scope
the moment we leave this function frame yielding garbage. To fix this,
we just need to remember to pass by const-pointer
`candidate: *const NativeTargetInfo`.
Follow up to #17383. This is a minor optimization that only matters when a small allocation is resized/free'd soon after it is allocated.
The only real difference I was able to observe with this was via a synthetic benchmark that allocates a full bucket and then frees all but one of the slots, over and over in a loop:
Debug build:
Benchmark 1 (9 runs): gpa-degen-master.exe
measurement mean ± σ min … max outliers delta
wall_time 575ms ± 5.19ms 569ms … 583ms 0 ( 0%) 0%
peak_rss 43.8MB ± 1.37KB 43.8MB … 43.8MB 1 (11%) 0%
Benchmark 2 (10 runs): gpa-degen-search-cur.exe
measurement mean ± σ min … max outliers delta
wall_time 532ms ± 5.55ms 520ms … 539ms 0 ( 0%) ⚡- 7.5% ± 0.9%
peak_rss 43.8MB ± 65.2KB 43.8MB … 44.0MB 1 (10%) + 0.0% ± 0.1%
ReleaseFast build:
Benchmark 1 (129 runs): gpa-degen-master-release.exe
measurement mean ± σ min … max outliers delta
wall_time 38.9ms ± 1.12ms 36.7ms … 42.4ms 8 ( 6%) 0%
peak_rss 23.2MB ± 2.39KB 23.2MB … 23.2MB 0 ( 0%) 0%
Benchmark 2 (151 runs): gpa-degen-search-cur-release.exe
measurement mean ± σ min … max outliers delta
wall_time 33.2ms ± 999us 31.9ms … 36.3ms 20 (13%) ⚡- 14.7% ± 0.6%
peak_rss 23.2MB ± 2.26KB 23.2MB … 23.2MB 0 ( 0%) + 0.0% ± 0.0%
