- change all uses of Path in fn args to &P
- FileStream.read assumptions were wrong (libuv file io is non-positional)
- the above will mean that we "own" Seek impl info .. should probably
push it in UvFileDescriptor..
- needs more tests
Implement CharIterator as a separate struct, so that it can be .clone()'d. Fix `.char_range_at_reverse` so that it performs better, closer to the forwards version. This makes the reverse iterators and users like `.rfind()` perform better.
Before
test str::bench::char_iterator ... bench: 146 ns/iter (+/- 0)
test str::bench::char_iterator_ascii ... bench: 397 ns/iter (+/- 49)
test str::bench::char_iterator_rev ... bench: 576 ns/iter (+/- 8)
test str::bench::char_offset_iterator ... bench: 128 ns/iter (+/- 2)
test str::bench::char_offset_iterator_rev ... bench: 425 ns/iter (+/- 59)
After
test str::bench::char_iterator ... bench: 130 ns/iter (+/- 1)
test str::bench::char_iterator_ascii ... bench: 307 ns/iter (+/- 5)
test str::bench::char_iterator_rev ... bench: 185 ns/iter (+/- 8)
test str::bench::char_offset_iterator ... bench: 131 ns/iter (+/- 13)
test str::bench::char_offset_iterator_rev ... bench: 183 ns/iter (+/- 2)
To be able to use a string slice to represent the CharIterator, a function `slice_unchecked` is added, that does the same as `slice_bytes` but without any boundary checks.
It would be possible to implement CharIterator with pointer arithmetic to make it *much more efficient*, but since vec iterator is still improving, it's too early to attempt to re-implement it in other places. Hopefully CharIterator can be implemented on top of vec iterator without any unsafe code later.
Additional changes fix the documentation about null termination.
This adds support for performing Unicode Normalization Forms D and KD on strings.
To enable this the decomposition and canonical combining class properties are added to std::unicode.
On my system this increases libstd's size by ~250KiB.
Linux and Android share the kernel, but not the C library, so sysconf constants are different. For example, _SC_PAGESIZE is 30 on Linux, but 39 on Android.
This patch
* splits sysconf constants to sysconf module
* merges non-MIPS and MIPS sysconf constants (they are same)
* adds Android sysconf constants
This patch also lets mmap tests to pass on Android.
Fixed a memory leak caused by the singleton idle callback failing to close correctly. The problem was that the close function requires running inside a callback in the event loop, but we were trying to close the idle watcher after the loop returned from run. The fix was to just call run again to process this callback. There is an additional tweak to move the initialization logic fully into bootstrap, so tasks that do not ever call run do not have problems destructing.
libuv handles are tied to the event loop that created them. In order to perform IO, the handle must be on the thread with its home event loop. Thus, when as task wants to do IO it must first go to the IO handle's home event loop and pin itself to the corresponding scheduler while the IO action is in flight. Once the IO action completes, the task is unpinned and either returns to its home scheduler if it is a pinned task, or otherwise stays on the current scheduler.
Making new blocking IO implementations (i.e. files) thread safe is rather simple. Add a home field to the IO handle's struct in uvio and implement the HomingIO trait. Wrap every IO call in the HomingIO.home_for_io method, which will take care of the scheduling.
I'm not sure if this remains thread safe in the presence of asynchronous IO at the libuv level. If we decide to do that, then this set up should be revisited.
Instead of a furious storm of idle callbacks we just have one. This is a major performance gain - around 40% on my machine for the ping pong bench.
Also in this PR is a cleanup commit for the scheduler code. Was previously up as a separate PR, but bors load + imminent merge hell led me to roll them together. Was #8549.
Each IO handle has a home event loop, which created it.
When a task wants to use an IO handle, it must first make sure it is on that home event loop.
It uses the scheduler handle in the IO handle to send itself there before starting the IO action.
Once the IO action completes, the task restores its previous home state.
If it is an AnySched task, then it will be executed on the new scheduler.
If it has a normal home, then it will return there before executing any more code after the IO action.
Long-standing branch to remove foreign function wrappers altogether. Calls to C functions are done "in place" with no stack manipulation; the scheme relies entirely on the correct use of `#[fixed_stack_segment]` to guarantee adequate stack space. A linter is added to detect when `#[fixed_stack_segment]` annotations are missing. An `externfn!` macro is added to make it easier to declare foreign fns and wrappers in one go: this macro may need some refinement, though, for example it might be good to be able to declare a group of foreign fns. I leave that for future work (hopefully somebody else's work :) ).
Fixes#3678.
