From 698f8c2f01ea549d77d7dc3338a12e04c11057b9 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:02:58 +0200 Subject: Adding upstream version 1.64.0+dfsg1. Signed-off-by: Daniel Baumann --- compiler/rustc_data_structures/src/flock/linux.rs | 40 +++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 compiler/rustc_data_structures/src/flock/linux.rs (limited to 'compiler/rustc_data_structures/src/flock/linux.rs') diff --git a/compiler/rustc_data_structures/src/flock/linux.rs b/compiler/rustc_data_structures/src/flock/linux.rs new file mode 100644 index 000000000..bb3ecfbc3 --- /dev/null +++ b/compiler/rustc_data_structures/src/flock/linux.rs @@ -0,0 +1,40 @@ +//! We use `flock` rather than `fcntl` on Linux, because WSL1 does not support +//! `fcntl`-style advisory locks properly (rust-lang/rust#72157). For other Unix +//! targets we still use `fcntl` because it's more portable than `flock`. + +use std::fs::{File, OpenOptions}; +use std::io; +use std::os::unix::prelude::*; +use std::path::Path; + +#[derive(Debug)] +pub struct Lock { + _file: File, +} + +impl Lock { + pub fn new(p: &Path, wait: bool, create: bool, exclusive: bool) -> io::Result { + let file = OpenOptions::new() + .read(true) + .write(true) + .create(create) + .mode(libc::S_IRWXU as u32) + .open(p)?; + + let mut operation = if exclusive { libc::LOCK_EX } else { libc::LOCK_SH }; + if !wait { + operation |= libc::LOCK_NB + } + + let ret = unsafe { libc::flock(file.as_raw_fd(), operation) }; + if ret == -1 { Err(io::Error::last_os_error()) } else { Ok(Lock { _file: file }) } + } + + pub fn error_unsupported(err: &io::Error) -> bool { + matches!(err.raw_os_error(), Some(libc::ENOTSUP) | Some(libc::ENOSYS)) + } +} + +// Note that we don't need a Drop impl to execute `flock(fd, LOCK_UN)`. A lock acquired by +// `flock` is associated with the file descriptor and closing the file releases it +// automatically. -- cgit v1.2.3