Split sys_common::Mutex in StaticMutex and MovableMutex.
The (unsafe) `Mutex` from `sys_common` had a rather complicated interface. You were supposed to call `init()` manually, unless you could guarantee it was neither moved nor used reentrantly.
Calling `destroy()` was also optional, although it was unclear if 1) resources might be leaked or not, and 2) if `destroy()` should only be called when `init()` was called.
This allowed for a number of interesting (confusing?) different ways to use this `Mutex`, all captured in a single type.
In practice, this type was only ever used in two ways:
1. As a static variable. In this case, neither `init()` nor `destroy()` are called. The variable is never moved, and it is never used reentrantly. It is only ever locked using the `LockGuard`, never with `raw_lock`.
2. As a `Box`ed variable. In this case, both `init()` and `destroy()` are called, it will be moved and possibly used reentrantly.
No other combinations are used anywhere in `std`.
This change simplifies things by splitting this `Mutex` type into two types matching the two use cases: `StaticMutex` and `MovableMutex`.
The interface of both new types is now both safer and simpler. The first one does not call nor expose `init`/`destroy`, and the second one calls those automatically in its `new()` and `Drop` functions. Also, the locking functions of `MovableMutex` are no longer unsafe.
---
This will also make it easier to conditionally box mutexes later, by moving that decision into sys/sys_common. Some of the mutex implementations (at least those of Wasm and 'sys/unsupported') are safe to move, so wouldn't need a box. ~~(But that's blocked on #76932 for now.)~~ (See #77380.)
Make RawFd implement the RawFd traits
This PR makes `RawFd` implement `AsRawFd`, `IntoRawFd` and `FromRawFd`, so it can be passed to interfaces that use one of those traits as a bound.
Use futex-based thread::park/unpark on Linux.
This moves the parking/unparking logic out of `thread/mod.rs` into a module named `thread_parker` in `sys_common`. The current implementation is moved to `sys_common/thread_parker/generic.rs` and the new implementation using futexes is added in `sys_common/thread_parker/futex.rs`.
Use `rtassert!` instead of `assert!` from the child process after fork() in std::sys::unix::process::Command::spawn()
As discussed in #73894, `assert!` panics on failure, which is not signal-safe, and `rtassert!` is a suitable replacement.
Fixes#73894.
r? @Amanieu @cuviper @joshtriplett
The syscalls returning a new file descriptors generally use
lowest-numbered file descriptor not currently opened, without any
exceptions for those corresponding to the standard streams.
Previously when any of standard streams has been closed before starting
the application, operations on std::io::{stderr,stdin,stdout} objects
were likely to operate on other logically unrelated file resources
opened afterwards.
Avoid the issue by reopening the standard streams when they are closed.
The (unsafe) Mutex from sys_common had a rather complicated interface.
You were supposed to call init() manually, unless you could guarantee it
was neither moved nor used reentrantly.
Calling `destroy()` was also optional, although it was unclear if 1)
resources might be leaked or not, and 2) if destroy() should only be
called when `init()` was called.
This allowed for a number of interesting (confusing?) different ways to
use this Mutex, all captured in a single type.
In practice, this type was only ever used in two ways:
1. As a static variable. In this case, neither init() nor destroy() are
called. The variable is never moved, and it is never used
reentrantly. It is only ever locked using the LockGuard, never with
raw_lock.
2. As a Boxed variable. In this case, both init() and destroy() are
called, it will be moved and possibly used reentrantly.
No other combinations are used anywhere in `std`.
This change simplifies things by splitting this Mutex type into
two types matching the two use cases: StaticMutex and MovableMutex.
The interface of both new types is now both safer and simpler. The first
one does not call nor expose init/destroy, and the second one calls
those automatically in its new() and Drop functions. Also, the locking
functions of MovableMutex are no longer unsafe.
Function to convert OpenOptions to c_int
Fixes: #74943
The creation_mode and access_mode function were already available in the OpenOptions struct, but currently private. I've added a new free functions to unix/fs.rs which takes the OpenOptions, and returns the c_int to be used as parameter for the `open` call.
[fuchsia] Propagate the userspace UTC clock
On Fuchsia, spawning a subprocess does not automatically
clone all of the parent process' capabilities. UTC time on
Fuchsia is managed by a top-level userspace clock capability
that is cloned and passed to subprocesses.
This change ensures that any Rust subprocess gets access to the
UTC clock, if the parent had access to it. This is critical for
tests, which on Fuchsia, use panic=abort and spawn subprocesses
per test.
Consolidate some duplicate code in the sys modules.
This consolidates some modules which were duplicated throughout the sys module. The intent is to make it easier to update and maintain this code. This mainly affects the wasi, sgx, and "unsupported" targets.
I explicitly skipped hermit, cloudabi, and vxworks. These tier-3 targets have copied large sections of the sys tree. I don't think they should have, but I don't want to put effort into changing them. It also doesn't help that there aren't any scripts or instructions for building them.
There are still sections of duplicate code here and there, but this PR covers the easy parts where entire modules are the same.
On Fuchsia, spawning a subprocess does not automatically
clone all of the parent process' capabilities. UTC time on
Fuchsia is managed by a top-level userspace clock capability
that is cloned and passed to subprocesses.
This change ensures that any Rust subprocess gets access to the
UTC clock, if the parent had access to it. This is critical for
tests, which on Fuchsia, use panic=abort and spawn subprocesses
per test.
Implementation of peer credentials for Unix sockets
The code in `ucred.rs` is based on the work done in [PR 13](https://github.com/tokio-rs/tokio-uds/pull/13) in the tokio-uds repository on GitHub.
This commit is effectively a port to the stdlib, so credit to Martin Habovštiak (`@Kixunil)` and contributors for the meat of this work. 🥇
Happy to make changes as needed. 🙂
The code in `ucred.rs` is based on the work done in PR 13 in the
tokio-uds repository on GitHub. Link below for reference:
https://github.com/tokio-rs/tokio-uds/pull/13
Credit to Martin Habovštiak (GitHub username Kixunil) and contributors
for this work!
Use IOV_MAX and UIO_MAXIOV constants in limit vectored I/O
Also updates the libc dependency to 0.2.77 (from 0.2.74) as the
constants were only recently added.
Related #68042, #75005
r? `@Amanieu` (also reviewed #75005)
Update `std::os` module documentation.
Adds missing descriptions for the modules `std::os::linux::fs` and `std::os::windows::io`.
Also adds punctuation for consistency with other descriptions.
The calling convention of pthread_getattr_np() is to initialize the
pthread_attr_t, so _destroy() is only necessary on success (and _init()
isn't necessary beforehand). On the other hand, FreeBSD wants the
attr_t to be initialized before pthread_attr_get_np(), and therefore it
should always be destroyed afterwards.
- Use intra-doc links for `std::io` in `std::fs`
- Use intra-doc links for File::read in unix/ext/fs.rs
- Remove explicit intra-doc links for `true` in `net/addr.rs`
- Use intra-doc links in alloc/src/sync.rs
- Use intra-doc links in src/ascii.rs
- Switch to intra-doc links in alloc/rc.rs
- Use intra-doc links in core/pin.rs
- Use intra-doc links in std/prelude
- Use shorter links in `std/fs.rs`
`io` is already in scope.
