Make `io::BorrowedCursor::advance` safe
This also keeps the old `advance` method under `advance_unchecked` name.
This makes pattern like `std::io::default_read_buf` safe to write.
std::thread update freebsd stack guard handling.
up to now, it had been assumed the stack guard setting default is not touched in the field but some user might just want to disable it or increase it. checking it once at runtime should be enough.
Replace pthread `RwLock` with custom implementation
This is one of the last items in #93740. I'm doing `RwLock` first because it is more self-contained and has less tradeoffs to make. The motivation is explained in the documentation, but in short: the pthread rwlock is slow and buggy and `std` can do much better. I considered implementing a parking lot, as was discussed in the tracking issue, but settled for the queue-based version because writing self-balancing binary trees is not fun in Rust...
This is a rather complex change, so I have added quite a bit of documentation to help explain it. Please point out any part that could be explained better.
~~The read performance is really good, I'm getting 4x the throughput of the pthread version and about the same performance as usync/parking_lot on an Apple M1 Max in the usync benchmark suite, but the write performance still falls way behind what usync and parking_lot achieve. I tried using a separate queue lock like what usync uses, but that didn't help. I'll try to investigate further in the future, but I wanted to get some eyes on this first.~~ [Resolved](https://github.com/rust-lang/rust/pull/110211#issuecomment-1513682336)
r? `@m-ou-se`
CC `@kprotty`
Introducing a new config for this purpose as NetBSD 9 or 8 will be still around
for a good while. For now, we re finally enabling sys::unix::rand::getrandom.
up to now, it had been assumed the stack guard setting default is not
touched in the field but some user might just want to disable it or
increase it. checking it once at runtime should be enough.
Always check the result of `pthread_mutex_lock`
Fixes#120147.
Instead of manually adding a list of "good" platforms, I've simply made the check unconditional. pthread's mutex is already quite slow on most platforms, so one single well-predictable branch shouldn't hurt performance too much.
std: thread_local::register_dtor fix proposal for FreeBSD.
following-up 5d3d347 commit, rust started to spin
__cxa_thread_call_dtors warnings even without any TLS usage. using instead home made TLS destructor handler `register_dtor_fallback`.
close#120413
following-up 5d3d347 commit, rust started to spin
__cxa_thread_call_dtors warnings even without any TLS usage.
using instead home made TLS destructor handler `register_dtor_fallback`.
close#120413
remove tests/ui/command/command-create-pidfd.rs . But it contains
very useful comment, so let's move the comment to library/std/src/sys/pal/unix/rand.rs ,
which contains another instance of the same Docker problem
Refactor uses of `objc_msgSend` to no longer have clashing definitions
This is very similar to what Apple's own headers encourage you to do (cast the function pointer before use instead of making new declarations).
Additionally, I'm documenting a few of the memory management rules we're following, ensuring that the `args` function doesn't leak memory (if you wrap it in an autorelease pool).
Motivation is to avoid issues with clashing definitions, like described in https://github.com/rust-lang/rust/issues/12707#issuecomment-1570735643 and https://github.com/rust-lang/rust/issues/46188#issuecomment-1288058453, CC ``@bjorn3.``
This is very similar to what Apple's own headers encourage you to do (cast the function pointer before use instead of making new declarations).
Additionally, I'm documenting a few of the memory management rules we're following, ensuring that the `args` function doesn't leak memory (if you wrap it in an autorelease pool).
