reasoning is that polling with large amount of operations will be rarely
done with std.Io.Threaded. However this still provides the opportunity
to provide concurrency for any real world use cases that need it.
This commit shows a proof-of-concept direction for std.Io.VTable to go,
which is to have general support for batching, timeouts, and
non-blocking.
I'm not sure if this is a good idea or not so I'm putting it up for
scrutiny.
This commit introduces `std.Io.operate`, `std.Io.Operation`, and
implements it experimentally for `FileReadStreaming`.
In `std.Io.Threaded`, the implementation is based on poll().
This commit shows how it can be used in `std.process.run` to collect
both stdout and stderr in a single-threaded program using
`std.Threaded.Io`.
It also demonstrates how to upgrade code that was previously using
`std.Io.poll` (*not* integrated with the interface!) using concurrency.
This may not be ideal since it makes the build runner no longer support
single-threaded mode. There is still a needed abstraction for
conveniently reading multiple File streams concurrently without
io.concurrent, but this commit demonstrates that such an API can be
built on top of the new `std.Io.operate` functionality.
The implementation of HostName.validate was too generous. It considered
strings like ".example.com", "exa..mple.com", and "-example.com" to be
valid hostnames, which is incorrect according to RFC 1123 (the currently
accepted standard).
Reviewed-on: https://github.com/ziglang/zig/pull/25710
The previous logic was made really messy by the fact that upon entry to
the step eval worker, the step may not be ready to run, we may be racing
with other workers doing the same check, and we had already acquired our
RSS requirement even though we might not run. It also required iterating
all dependencies each time we were called to check whether we were even
ready to run yet.
A much better strategy is for each step to have an atomic counter
representing how many of its dependencies are yet to complete. When a
step completes (successfully or otherwise), it decrements this value for
all of its dependants, and if it drops any to 0, it schedules that step
to run. This means each step is scheduled exactly once, and only when
all of its dependencies have finished, reducing redundant checks and
hence contention. If the step being scheduled needs to claim RSS which
isn't available, then it is instead added to `memory_blocked_steps`,
which is iterated by the step worker after a step with an RSS claim
finishes.
This logic is more concise than before, simpler to understand, generally
more efficient, and fixes a bug in the RSS tracking. Also, as a nice
side effect, it should also play a little bit nicer with `Io.Threaded`'s
scheduling strategy, because we no longer spawn extremely short-lived
tasks all the time as we previously did.
Resolves: https://codeberg.org/ziglang/zig/issues/30742
ABI detection previously did not take into account the non-standard
directory structure of Android. This has been fixed.
The API level is detected by running `getprop ro.build.version.sdk`,
since we don't want to depend on bionic, and reading system properties
ourselves is not trivially possible.
clock_nanosleep is specified by POSIX but not implemented on these
hereby shamed operating systems:
* macOS
* OpenBSD (which defines TIMER_ABSTIME for some reason...?)
RISC-V and LoongArch ELF psABIs define a kind of
RELAX relocations which are expected to have a normal
relocation at the same address.
Change-Id: I5737bfcfd3e5041fb6ab7d193c9fc57eeca1eec8
