take into account the num of processes by ulimit

[klim-iv]

No description provided.

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[klim-iv]

due to ulimit restrictions is not used in std::thread
apears crashes like this one:
thread 'main' panicked at .../.cargo/registry/.../rayon-core-1.12.1/src/registry.rs:168:10:
The global thread pool has not been initialized.: ThreadPoolBuildError
 { kind: IOError(Os { code: 11, kind: WouldBlock, message: "Resource temporarily unavailable" }) }

[tgross35]

The type is rlim_t, this won't work on x86-32

[klim-iv]

fixed

[tgross35]

The above block has the same cfg, this can be combined

[klim-iv]

fixed

[tgross35]

Could you please put a more detailed description of how the problem is reproduced in the PR description? Or open a separate issue for it.

The change here also needs comments, and the docs at https://doc.rust-lang.org/beta/std/thread/fn.available_parallelism.html should be updated if this winds up being accepted.

Since this is a user-visible change this will need libs-api signoff, but first cc @cuviper since it looks like the issue shows up in Rayon (possibly rayon-rs/rayon#694?)

[cuviper]

I doubt that this will be useful -- e.g. starting a number of threads equal to the current RLIMIT_NPROC is already doomed by the existence of the current thread, nevermind any other threads or even other processes.

[cuviper]

Note, the "soft" rlim_cur is the value that is currently enforced, while the "hard" rlim_max is a limit on how high an unprivileged process can adjust its own rlim_cur.

[klim-iv]

ok

[klim-iv]

I doubt that this will be useful -- e.g. starting a number of threads equal to the current RLIMIT_NPROC is already doomed by the existence of the current thread, nevermind any other threads or even other processes.

I see, patchset updated according this comment (will count working threads)

[klim-iv]

Could you please put a more detailed description of how the problem is reproduced in the PR description? Or open a separate issue for it.

The change here also needs comments, and the docs at https://doc.rust-lang.org/beta/std/thread/fn.available_parallelism.html should be updated if this winds up being accepted.

Since this is a user-visible change this will need libs-api signoff, but first cc @cuviper since it looks like the issue shows up in Rayon (possibly rayon-rs/rayon#694?)

bug here: rust-lang/rustup#4403

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[RUSTC-TIMING] object test:false 9.953
error: variable does not need to be mutable
   --> library/std/src/sys/pal/unix/thread.rs:458:17
    |
458 |             let mut ulimit = libc::rlim_t::MAX;
    |                 ----^^^^^^
    |                 |
    |                 help: remove this `mut`
    |
    = note: `-D unused-mut` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(unused_mut)]`

error: function `count_user_threads` is never used
   --> library/std/src/sys/pal/unix/thread.rs:408:4
    |
408 | fn count_user_threads() -> Result<usize, io::Error> {
    |    ^^^^^^^^^^^^^^^^^^
    |
    = note: `-D dead-code` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(dead_code)]`