Some initial work towards https://codeberg.org/ziglang/zig/issues/31414.
Conclusion from this: Only x86-freebsd, x86-haiku, and x86-illumos remain time32
and are currently unfixable. I don't think the upstreams for any of these
targets actually care about them anymore (probably why they weren't migrated to
time64), so this is not a particularly big concern.
I split UTIME constants out from timespec because they were causing unreasonable
code duplication by being there.
Importantly, adds ability to get Clock resolution, which may be zero.
This allows error.Unexpected and error.ClockUnsupported to be removed
from timeout and clock reading error sets.
This error is actually only ever directly returned from `std.posix.getcwd` (and only on POSIX systems, so never on Windows). Its inclusion in almost all of the error sets its currently found in is a leftover from when `std.fs.path.resolve` called `std.process.getCwdAlloc` (https://github.com/ziglang/zig/issues/13613).
- change offset to u64
- make len non-optional
- make write take a file_size parameter
- std.Io.Threaded: introduce disable_memory_mapping flag to force it to
take the fallback path.
Additionally:
- introduce BlockSize to File.Stat. On Windows, based on cached call to
NtQuerySystemInformation. On unsupported OS's, set to 1.
- support File.NLink on Windows. this was available the whole time, we
just didn't see the field at first.
- remove EBADF / INVALID_HANDLE from reading/writing file error sets
by defining the pointer contents to only be synchronized after explicit
sync points, makes it legal to have a fallback implementation based on
file operations while still supporting a handful of use cases for memory
mapping.
furthermore, it makes it legal for evented I/O implementations to use
evented file I/O for the sync points rather than memory mapping.
not yet done:
- implement checking the length when options.len is null
- some windows impl work
- some wasi impl work
- unit tests
- integration with compiler
This allows stack overflows to print stack traces. The size of the
sigaltstack (and whether it is actually set) can be configured by
setting `std.Options.signal_stack_size`.
The default value for the signal stack size was chosen experimentally by
doubling the value required to get stack traces on stack overflow with
the self-hosted x86_64 backend. While some targets may typically use
more stack space than x86_64-linux, the self-hosted x86_64 backend is
quite wasteful with stack at the moment, making it a fair benchmark.
Executables produced by the LLVM backend should have lower stack usage.
These are handled by Io.Dir now. This is part of an effort to eliminate
error.OperationCanceled from the std lib. Also an effort to delete
all std.posix functions.
this gets the build runner compiling again on linux
this work is incomplete; it only moves code around so that environment
variables can be wrangled properly. a future commit will need to audit
the cancelation and error handling of this moved logic.
The most interesting thing here is the replacement of the pthread futex
implementation with an implementation based on thread park/unpark APIs.
Thread parking tends to be the primitive provided by systems which do
not have a futex primitive, such as NetBSD, so this implementation is
far more efficient than the pthread one. It is also useful on Windows,
where `RtlWaitOnAddress` is itself a userland implementation based on
thread park/unpark; we can implement it ourselves including support for
features which Windows' implementation lacks, such as cancelation and
waking a number of waiters with 1<n<infinity.
Compared to the pthread implementation, this thread-parking-based one
also supports full robust cancelation. Thread parking also turns out to
be useful for implementing `sleep`, so is now used for that on Windows
and NetBSD.
This commit also introduces proper cancelation support for most Windows
operations. The most notable omission right now is DNS lookups through
`GetAddrInfoEx`, just because they're a little more work due to having
a unique cancelation mechanism---but the machinery is all there, so I'll
finish gluing it together soon.
As of this commit, there are very few parts of `Io.Threaded` which do
not support full robust cancelation. The only ones which actually really
matter (because they could block for a prolonged period of time) are DNS
lookups on Windows (as discussed above) and futex waits on WASM.
David Gonzalez Martin