compiletest/
raise_fd_limit.rs

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1/// darwin_fd_limit exists to work around an issue where launchctl on macOS
2/// defaults the rlimit maxfiles to 256/unlimited. The default soft limit of 256
3/// ends up being far too low for our multithreaded scheduler testing, depending
4/// on the number of cores available.
5///
6/// This fixes issue #7772.
7#[cfg(target_vendor = "apple")]
8#[allow(non_camel_case_types)]
9pub unsafe fn raise_fd_limit() {
10    use std::ptr::null_mut;
11    use std::{cmp, io};
12
13    static CTL_KERN: libc::c_int = 1;
14    static KERN_MAXFILESPERPROC: libc::c_int = 29;
15
16    // The strategy here is to fetch the current resource limits, read the
17    // kern.maxfilesperproc sysctl value, and bump the soft resource limit for
18    // maxfiles up to the sysctl value.
19
20    // Fetch the kern.maxfilesperproc value
21    let mut mib: [libc::c_int; 2] = [CTL_KERN, KERN_MAXFILESPERPROC];
22    let mut maxfiles: libc::c_int = 0;
23    let mut size: libc::size_t = size_of_val(&maxfiles) as libc::size_t;
24    if libc::sysctl(&mut mib[0], 2, &mut maxfiles as *mut _ as *mut _, &mut size, null_mut(), 0)
25        != 0
26    {
27        let err = io::Error::last_os_error();
28        panic!("raise_fd_limit: error calling sysctl: {}", err);
29    }
30
31    // Fetch the current resource limits
32    let mut rlim = libc::rlimit { rlim_cur: 0, rlim_max: 0 };
33    if libc::getrlimit(libc::RLIMIT_NOFILE, &mut rlim) != 0 {
34        let err = io::Error::last_os_error();
35        panic!("raise_fd_limit: error calling getrlimit: {}", err);
36    }
37
38    // Make sure we're only ever going to increase the rlimit.
39    if rlim.rlim_cur < maxfiles as libc::rlim_t {
40        // Bump the soft limit to the smaller of kern.maxfilesperproc and the hard limit.
41        rlim.rlim_cur = cmp::min(maxfiles as libc::rlim_t, rlim.rlim_max);
42
43        // Set our newly-increased resource limit.
44        if libc::setrlimit(libc::RLIMIT_NOFILE, &rlim) != 0 {
45            let err = io::Error::last_os_error();
46            panic!("raise_fd_limit: error calling setrlimit: {}", err);
47        }
48    }
49}
50
51#[cfg(not(target_vendor = "apple"))]
52pub unsafe fn raise_fd_limit() {}
compiletest/raise_fd_limit.rs

compiletest/
raise_fd_limit.rs
