| use crate::ffi::CStr; |
| use crate::mem::{self, ManuallyDrop}; |
| use crate::num::NonZero; |
| #[cfg(all(target_os = "linux", target_env = "gnu"))] |
| use crate::sys::weak::dlsym; |
| #[cfg(any(target_os = "solaris", target_os = "illumos", target_os = "nto",))] |
| use crate::sys::weak::weak; |
| use crate::sys::{os, stack_overflow}; |
| use crate::time::{Duration, Instant}; |
| use crate::{cmp, io, ptr}; |
| #[cfg(not(any( |
| target_os = "l4re", |
| target_os = "vxworks", |
| target_os = "espidf", |
| target_os = "nuttx" |
| )))] |
| pub const DEFAULT_MIN_STACK_SIZE: usize = 2 * 1024 * 1024; |
| #[cfg(target_os = "l4re")] |
| pub const DEFAULT_MIN_STACK_SIZE: usize = 1024 * 1024; |
| #[cfg(target_os = "vxworks")] |
| pub const DEFAULT_MIN_STACK_SIZE: usize = 256 * 1024; |
| #[cfg(any(target_os = "espidf", target_os = "nuttx"))] |
| pub const DEFAULT_MIN_STACK_SIZE: usize = 0; // 0 indicates that the stack size configured in the ESP-IDF/NuttX menuconfig system should be used |
| |
| pub struct Thread { |
| id: libc::pthread_t, |
| } |
| |
| // Some platforms may have pthread_t as a pointer in which case we still want |
| // a thread to be Send/Sync |
| unsafe impl Send for Thread {} |
| unsafe impl Sync for Thread {} |
| |
| impl Thread { |
| // unsafe: see thread::Builder::spawn_unchecked for safety requirements |
| #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces |
| pub unsafe fn new(stack: usize, p: Box<dyn FnOnce()>) -> io::Result<Thread> { |
| let p = Box::into_raw(Box::new(p)); |
| let mut native: libc::pthread_t = mem::zeroed(); |
| let mut attr: mem::MaybeUninit<libc::pthread_attr_t> = mem::MaybeUninit::uninit(); |
| assert_eq!(libc::pthread_attr_init(attr.as_mut_ptr()), 0); |
| |
| #[cfg(any(target_os = "espidf", target_os = "nuttx"))] |
| if stack > 0 { |
| // Only set the stack if a non-zero value is passed |
| // 0 is used as an indication that the default stack size configured in the ESP-IDF/NuttX menuconfig system should be used |
| assert_eq!( |
| libc::pthread_attr_setstacksize( |
| attr.as_mut_ptr(), |
| cmp::max(stack, min_stack_size(attr.as_ptr())) |
| ), |
| 0 |
| ); |
| } |
| |
| #[cfg(not(any(target_os = "espidf", target_os = "nuttx")))] |
| { |
| let stack_size = cmp::max(stack, min_stack_size(attr.as_ptr())); |
| |
| match libc::pthread_attr_setstacksize(attr.as_mut_ptr(), stack_size) { |
| 0 => {} |
| n => { |
| assert_eq!(n, libc::EINVAL); |
| // EINVAL means |stack_size| is either too small or not a |
| // multiple of the system page size. Because it's definitely |
| // >= PTHREAD_STACK_MIN, it must be an alignment issue. |
| // Round up to the nearest page and try again. |
| let page_size = os::page_size(); |
| let stack_size = |
| (stack_size + page_size - 1) & (-(page_size as isize - 1) as usize - 1); |
| assert_eq!(libc::pthread_attr_setstacksize(attr.as_mut_ptr(), stack_size), 0); |
| } |
| }; |
| } |
| |
| let ret = libc::pthread_create(&mut native, attr.as_ptr(), thread_start, p as *mut _); |
| // Note: if the thread creation fails and this assert fails, then p will |
| // be leaked. However, an alternative design could cause double-free |
| // which is clearly worse. |
| assert_eq!(libc::pthread_attr_destroy(attr.as_mut_ptr()), 0); |
| |
| return if ret != 0 { |
| // The thread failed to start and as a result p was not consumed. Therefore, it is |
| // safe to reconstruct the box so that it gets deallocated. |
| drop(Box::from_raw(p)); |
| Err(io::Error::from_raw_os_error(ret)) |
| } else { |
| Ok(Thread { id: native }) |
| }; |
| |
| extern "C" fn thread_start(main: *mut libc::c_void) -> *mut libc::c_void { |
| unsafe { |
| // Next, set up our stack overflow handler which may get triggered if we run |
| // out of stack. |
| let _handler = stack_overflow::Handler::new(); |
| // Finally, let's run some code. |
| Box::from_raw(main as *mut Box<dyn FnOnce()>)(); |
| } |
| ptr::null_mut() |
| } |
| } |
| |
| pub fn yield_now() { |
| let ret = unsafe { libc::sched_yield() }; |
| debug_assert_eq!(ret, 0); |
| } |
| |
| #[cfg(target_os = "android")] |
| pub fn set_name(name: &CStr) { |
| const PR_SET_NAME: libc::c_int = 15; |
| unsafe { |
| let res = libc::prctl( |
| PR_SET_NAME, |
| name.as_ptr(), |
| 0 as libc::c_ulong, |
| 0 as libc::c_ulong, |
| 0 as libc::c_ulong, |
| ); |
| // We have no good way of propagating errors here, but in debug-builds let's check that this actually worked. |
| debug_assert_eq!(res, 0); |
| } |
| } |
| |
| #[cfg(any( |
| target_os = "linux", |
| target_os = "freebsd", |
| target_os = "dragonfly", |
| target_os = "nuttx", |
| target_os = "cygwin" |
| ))] |
| pub fn set_name(name: &CStr) { |
| unsafe { |
| cfg_if::cfg_if! { |
| if #[cfg(any(target_os = "linux", target_os = "cygwin"))] { |
| // Linux and Cygwin limits the allowed length of the name. |
| const TASK_COMM_LEN: usize = 16; |
| let name = truncate_cstr::<{ TASK_COMM_LEN }>(name); |
| } else { |
| // FreeBSD, DragonFly BSD and NuttX do not enforce length limits. |
| } |
| }; |
| // Available since glibc 2.12, musl 1.1.16, and uClibc 1.0.20 for Linux, |
| // FreeBSD 12.2 and 13.0, and DragonFly BSD 6.0. |
| let res = libc::pthread_setname_np(libc::pthread_self(), name.as_ptr()); |
| // We have no good way of propagating errors here, but in debug-builds let's check that this actually worked. |
| debug_assert_eq!(res, 0); |
| } |
| } |
| |
| #[cfg(target_os = "openbsd")] |
| pub fn set_name(name: &CStr) { |
| unsafe { |
| libc::pthread_set_name_np(libc::pthread_self(), name.as_ptr()); |
| } |
| } |
| |
| #[cfg(target_vendor = "apple")] |
| pub fn set_name(name: &CStr) { |
| unsafe { |
| let name = truncate_cstr::<{ libc::MAXTHREADNAMESIZE }>(name); |
| let res = libc::pthread_setname_np(name.as_ptr()); |
| // We have no good way of propagating errors here, but in debug-builds let's check that this actually worked. |
| debug_assert_eq!(res, 0); |
| } |
| } |
| |
| #[cfg(target_os = "netbsd")] |
| pub fn set_name(name: &CStr) { |
| unsafe { |
| let res = libc::pthread_setname_np( |
| libc::pthread_self(), |
| c"%s".as_ptr(), |
| name.as_ptr() as *mut libc::c_void, |
| ); |
| debug_assert_eq!(res, 0); |
| } |
| } |
| |
| #[cfg(any(target_os = "solaris", target_os = "illumos", target_os = "nto"))] |
| pub fn set_name(name: &CStr) { |
| weak!( |
| fn pthread_setname_np( |
| thread: libc::pthread_t, |
| name: *const libc::c_char, |
| ) -> libc::c_int; |
| ); |
| |
| if let Some(f) = pthread_setname_np.get() { |
| #[cfg(target_os = "nto")] |
| const THREAD_NAME_MAX: usize = libc::_NTO_THREAD_NAME_MAX as usize; |
| #[cfg(any(target_os = "solaris", target_os = "illumos"))] |
| const THREAD_NAME_MAX: usize = 32; |
| |
| let name = truncate_cstr::<{ THREAD_NAME_MAX }>(name); |
| let res = unsafe { f(libc::pthread_self(), name.as_ptr()) }; |
| debug_assert_eq!(res, 0); |
| } |
| } |
| |
| #[cfg(target_os = "fuchsia")] |
| pub fn set_name(name: &CStr) { |
| use super::fuchsia::*; |
| unsafe { |
| zx_object_set_property( |
| zx_thread_self(), |
| ZX_PROP_NAME, |
| name.as_ptr() as *const libc::c_void, |
| name.to_bytes().len(), |
| ); |
| } |
| } |
| |
| #[cfg(target_os = "haiku")] |
| pub fn set_name(name: &CStr) { |
| unsafe { |
| let thread_self = libc::find_thread(ptr::null_mut()); |
| let res = libc::rename_thread(thread_self, name.as_ptr()); |
| // We have no good way of propagating errors here, but in debug-builds let's check that this actually worked. |
| debug_assert_eq!(res, libc::B_OK); |
| } |
| } |
| |
| #[cfg(target_os = "vxworks")] |
| pub fn set_name(name: &CStr) { |
| let mut name = truncate_cstr::<{ (libc::VX_TASK_RENAME_LENGTH - 1) as usize }>(name); |
| let res = unsafe { libc::taskNameSet(libc::taskIdSelf(), name.as_mut_ptr()) }; |
| debug_assert_eq!(res, libc::OK); |
| } |
| |
| #[cfg(any( |
| target_env = "newlib", |
| target_os = "l4re", |
| target_os = "emscripten", |
| target_os = "redox", |
| target_os = "hurd", |
| target_os = "aix", |
| ))] |
| pub fn set_name(_name: &CStr) { |
| // Newlib and Emscripten have no way to set a thread name. |
| } |
| |
| #[cfg(not(target_os = "espidf"))] |
| pub fn sleep(dur: Duration) { |
| let mut secs = dur.as_secs(); |
| let mut nsecs = dur.subsec_nanos() as _; |
| |
| // If we're awoken with a signal then the return value will be -1 and |
| // nanosleep will fill in `ts` with the remaining time. |
| unsafe { |
| while secs > 0 || nsecs > 0 { |
| let mut ts = libc::timespec { |
| tv_sec: cmp::min(libc::time_t::MAX as u64, secs) as libc::time_t, |
| tv_nsec: nsecs, |
| }; |
| secs -= ts.tv_sec as u64; |
| let ts_ptr = &raw mut ts; |
| if libc::nanosleep(ts_ptr, ts_ptr) == -1 { |
| assert_eq!(os::errno(), libc::EINTR); |
| secs += ts.tv_sec as u64; |
| nsecs = ts.tv_nsec; |
| } else { |
| nsecs = 0; |
| } |
| } |
| } |
| } |
| |
| #[cfg(target_os = "espidf")] |
| pub fn sleep(dur: Duration) { |
| // ESP-IDF does not have `nanosleep`, so we use `usleep` instead. |
| // As per the documentation of `usleep`, it is expected to support |
| // sleep times as big as at least up to 1 second. |
| // |
| // ESP-IDF does support almost up to `u32::MAX`, but due to a potential integer overflow in its |
| // `usleep` implementation |
| // (https://github.com/espressif/esp-idf/blob/d7ca8b94c852052e3bc33292287ef4dd62c9eeb1/components/newlib/time.c#L210), |
| // we limit the sleep time to the maximum one that would not cause the underlying `usleep` implementation to overflow |
| // (`portTICK_PERIOD_MS` can be anything between 1 to 1000, and is 10 by default). |
| const MAX_MICROS: u32 = u32::MAX - 1_000_000 - 1; |
| |
| // Add any nanoseconds smaller than a microsecond as an extra microsecond |
| // so as to comply with the `std::thread::sleep` contract which mandates |
| // implementations to sleep for _at least_ the provided `dur`. |
| // We can't overflow `micros` as it is a `u128`, while `Duration` is a pair of |
| // (`u64` secs, `u32` nanos), where the nanos are strictly smaller than 1 second |
| // (i.e. < 1_000_000_000) |
| let mut micros = dur.as_micros() + if dur.subsec_nanos() % 1_000 > 0 { 1 } else { 0 }; |
| |
| while micros > 0 { |
| let st = if micros > MAX_MICROS as u128 { MAX_MICROS } else { micros as u32 }; |
| unsafe { |
| libc::usleep(st); |
| } |
| |
| micros -= st as u128; |
| } |
| } |
| |
| // Any unix that has clock_nanosleep |
| // If this list changes update the MIRI chock_nanosleep shim |
| #[cfg(any( |
| target_os = "freebsd", |
| target_os = "netbsd", |
| target_os = "linux", |
| target_os = "android", |
| target_os = "solaris", |
| target_os = "illumos", |
| target_os = "dragonfly", |
| target_os = "hurd", |
| target_os = "fuchsia", |
| target_os = "vxworks", |
| ))] |
| pub fn sleep_until(deadline: Instant) { |
| let Some(ts) = deadline.into_inner().into_timespec().to_timespec() else { |
| // The deadline is further in the future then can be passed to |
| // clock_nanosleep. We have to use Self::sleep instead. This might |
| // happen on 32 bit platforms, especially closer to 2038. |
| let now = Instant::now(); |
| if let Some(delay) = deadline.checked_duration_since(now) { |
| Self::sleep(delay); |
| } |
| return; |
| }; |
| |
| unsafe { |
| // When we get interrupted (res = EINTR) call clock_nanosleep again |
| loop { |
| let res = libc::clock_nanosleep( |
| super::time::Instant::CLOCK_ID, |
| libc::TIMER_ABSTIME, |
| &ts, |
| core::ptr::null_mut(), // not required with TIMER_ABSTIME |
| ); |
| |
| if res == 0 { |
| break; |
| } else { |
| assert_eq!( |
| res, |
| libc::EINTR, |
| "timespec is in range, |
| clockid is valid and kernel should support it" |
| ); |
| } |
| } |
| } |
| } |
| |
| // Any unix that does not have clock_nanosleep |
| #[cfg(not(any( |
| target_os = "freebsd", |
| target_os = "netbsd", |
| target_os = "linux", |
| target_os = "android", |
| target_os = "solaris", |
| target_os = "illumos", |
| target_os = "dragonfly", |
| target_os = "hurd", |
| target_os = "fuchsia", |
| target_os = "vxworks", |
| )))] |
| pub fn sleep_until(deadline: Instant) { |
| let now = Instant::now(); |
| if let Some(delay) = deadline.checked_duration_since(now) { |
| Self::sleep(delay); |
| } |
| } |
| |
| pub fn join(self) { |
| let id = self.into_id(); |
| let ret = unsafe { libc::pthread_join(id, ptr::null_mut()) }; |
| assert!(ret == 0, "failed to join thread: {}", io::Error::from_raw_os_error(ret)); |
| } |
| |
| pub fn id(&self) -> libc::pthread_t { |
| self.id |
| } |
| |
| pub fn into_id(self) -> libc::pthread_t { |
| ManuallyDrop::new(self).id |
| } |
| } |
| |
| impl Drop for Thread { |
| fn drop(&mut self) { |
| let ret = unsafe { libc::pthread_detach(self.id) }; |
| debug_assert_eq!(ret, 0); |
| } |
| } |
| |
| #[cfg(any( |
| target_os = "linux", |
| target_os = "nto", |
| target_os = "solaris", |
| target_os = "illumos", |
| target_os = "vxworks", |
| target_os = "cygwin", |
| target_vendor = "apple", |
| ))] |
| fn truncate_cstr<const MAX_WITH_NUL: usize>(cstr: &CStr) -> [libc::c_char; MAX_WITH_NUL] { |
| let mut result = [0; MAX_WITH_NUL]; |
| for (src, dst) in cstr.to_bytes().iter().zip(&mut result[..MAX_WITH_NUL - 1]) { |
| *dst = *src as libc::c_char; |
| } |
| result |
| } |
| |
| pub fn available_parallelism() -> io::Result<NonZero<usize>> { |
| cfg_if::cfg_if! { |
| if #[cfg(any( |
| target_os = "android", |
| target_os = "emscripten", |
| target_os = "fuchsia", |
| target_os = "hurd", |
| target_os = "linux", |
| target_os = "aix", |
| target_vendor = "apple", |
| target_os = "cygwin", |
| ))] { |
| #[allow(unused_assignments)] |
| #[allow(unused_mut)] |
| let mut quota = usize::MAX; |
| |
| #[cfg(any(target_os = "android", target_os = "linux"))] |
| { |
| quota = cgroups::quota().max(1); |
| let mut set: libc::cpu_set_t = unsafe { mem::zeroed() }; |
| unsafe { |
| if libc::sched_getaffinity(0, size_of::<libc::cpu_set_t>(), &mut set) == 0 { |
| let count = libc::CPU_COUNT(&set) as usize; |
| let count = count.min(quota); |
| |
| // According to sched_getaffinity's API it should always be non-zero, but |
| // some old MIPS kernels were buggy and zero-initialized the mask if |
| // none was explicitly set. |
| // In that case we use the sysconf fallback. |
| if let Some(count) = NonZero::new(count) { |
| return Ok(count) |
| } |
| } |
| } |
| } |
| match unsafe { libc::sysconf(libc::_SC_NPROCESSORS_ONLN) } { |
| -1 => Err(io::Error::last_os_error()), |
| 0 => Err(io::Error::UNKNOWN_THREAD_COUNT), |
| cpus => { |
| let count = cpus as usize; |
| // Cover the unusual situation where we were able to get the quota but not the affinity mask |
| let count = count.min(quota); |
| Ok(unsafe { NonZero::new_unchecked(count) }) |
| } |
| } |
| } else if #[cfg(any( |
| target_os = "freebsd", |
| target_os = "dragonfly", |
| target_os = "openbsd", |
| target_os = "netbsd", |
| ))] { |
| use crate::ptr; |
| |
| #[cfg(target_os = "freebsd")] |
| { |
| let mut set: libc::cpuset_t = unsafe { mem::zeroed() }; |
| unsafe { |
| if libc::cpuset_getaffinity( |
| libc::CPU_LEVEL_WHICH, |
| libc::CPU_WHICH_PID, |
| -1, |
| size_of::<libc::cpuset_t>(), |
| &mut set, |
| ) == 0 { |
| let count = libc::CPU_COUNT(&set) as usize; |
| if count > 0 { |
| return Ok(NonZero::new_unchecked(count)); |
| } |
| } |
| } |
| } |
| |
| #[cfg(target_os = "netbsd")] |
| { |
| unsafe { |
| let set = libc::_cpuset_create(); |
| if !set.is_null() { |
| let mut count: usize = 0; |
| if libc::pthread_getaffinity_np(libc::pthread_self(), libc::_cpuset_size(set), set) == 0 { |
| for i in 0..libc::cpuid_t::MAX { |
| match libc::_cpuset_isset(i, set) { |
| -1 => break, |
| 0 => continue, |
| _ => count = count + 1, |
| } |
| } |
| } |
| libc::_cpuset_destroy(set); |
| if let Some(count) = NonZero::new(count) { |
| return Ok(count); |
| } |
| } |
| } |
| } |
| |
| let mut cpus: libc::c_uint = 0; |
| let mut cpus_size = size_of_val(&cpus); |
| |
| unsafe { |
| cpus = libc::sysconf(libc::_SC_NPROCESSORS_ONLN) as libc::c_uint; |
| } |
| |
| // Fallback approach in case of errors or no hardware threads. |
| if cpus < 1 { |
| let mut mib = [libc::CTL_HW, libc::HW_NCPU, 0, 0]; |
| let res = unsafe { |
| libc::sysctl( |
| mib.as_mut_ptr(), |
| 2, |
| (&raw mut cpus) as *mut _, |
| (&raw mut cpus_size) as *mut _, |
| ptr::null_mut(), |
| 0, |
| ) |
| }; |
| |
| // Handle errors if any. |
| if res == -1 { |
| return Err(io::Error::last_os_error()); |
| } else if cpus == 0 { |
| return Err(io::Error::UNKNOWN_THREAD_COUNT); |
| } |
| } |
| |
| Ok(unsafe { NonZero::new_unchecked(cpus as usize) }) |
| } else if #[cfg(target_os = "nto")] { |
| unsafe { |
| use libc::_syspage_ptr; |
| if _syspage_ptr.is_null() { |
| Err(io::const_error!(io::ErrorKind::NotFound, "no syspage available")) |
| } else { |
| let cpus = (*_syspage_ptr).num_cpu; |
| NonZero::new(cpus as usize) |
| .ok_or(io::Error::UNKNOWN_THREAD_COUNT) |
| } |
| } |
| } else if #[cfg(any(target_os = "solaris", target_os = "illumos"))] { |
| let mut cpus = 0u32; |
| if unsafe { libc::pset_info(libc::PS_MYID, core::ptr::null_mut(), &mut cpus, core::ptr::null_mut()) } != 0 { |
| return Err(io::Error::UNKNOWN_THREAD_COUNT); |
| } |
| Ok(unsafe { NonZero::new_unchecked(cpus as usize) }) |
| } else if #[cfg(target_os = "haiku")] { |
| // system_info cpu_count field gets the static data set at boot time with `smp_set_num_cpus` |
| // `get_system_info` calls then `smp_get_num_cpus` |
| unsafe { |
| let mut sinfo: libc::system_info = crate::mem::zeroed(); |
| let res = libc::get_system_info(&mut sinfo); |
| |
| if res != libc::B_OK { |
| return Err(io::Error::UNKNOWN_THREAD_COUNT); |
| } |
| |
| Ok(NonZero::new_unchecked(sinfo.cpu_count as usize)) |
| } |
| } else if #[cfg(target_os = "vxworks")] { |
| // Note: there is also `vxCpuConfiguredGet`, closer to _SC_NPROCESSORS_CONF |
| // expectations than the actual cores availability. |
| unsafe extern "C" { |
| fn vxCpuEnabledGet() -> libc::cpuset_t; |
| } |
| |
| // SAFETY: `vxCpuEnabledGet` always fetches a mask with at least one bit set |
| unsafe{ |
| let set = vxCpuEnabledGet(); |
| Ok(NonZero::new_unchecked(set.count_ones() as usize)) |
| } |
| } else { |
| // FIXME: implement on Redox, l4re |
| Err(io::const_error!(io::ErrorKind::Unsupported, "getting the number of hardware threads is not supported on the target platform")) |
| } |
| } |
| } |
| |
| #[cfg(any(target_os = "android", target_os = "linux"))] |
| mod cgroups { |
| //! Currently not covered |
| //! * cgroup v2 in non-standard mountpoints |
| //! * paths containing control characters or spaces, since those would be escaped in procfs |
| //! output and we don't unescape |
| |
| use crate::borrow::Cow; |
| use crate::ffi::OsString; |
| use crate::fs::{File, exists}; |
| use crate::io::{BufRead, Read}; |
| use crate::os::unix::ffi::OsStringExt; |
| use crate::path::{Path, PathBuf}; |
| use crate::str::from_utf8; |
| |
| #[derive(PartialEq)] |
| enum Cgroup { |
| V1, |
| V2, |
| } |
| |
| /// Returns cgroup CPU quota in core-equivalents, rounded down or usize::MAX if the quota cannot |
| /// be determined or is not set. |
| pub(super) fn quota() -> usize { |
| let mut quota = usize::MAX; |
| if cfg!(miri) { |
| // Attempting to open a file fails under default flags due to isolation. |
| // And Miri does not have parallelism anyway. |
| return quota; |
| } |
| |
| let _: Option<()> = try { |
| let mut buf = Vec::with_capacity(128); |
| // find our place in the cgroup hierarchy |
| File::open("/proc/self/cgroup").ok()?.read_to_end(&mut buf).ok()?; |
| let (cgroup_path, version) = |
| buf.split(|&c| c == b'\n').fold(None, |previous, line| { |
| let mut fields = line.splitn(3, |&c| c == b':'); |
| // 2nd field is a list of controllers for v1 or empty for v2 |
| let version = match fields.nth(1) { |
| Some(b"") => Cgroup::V2, |
| Some(controllers) |
| if from_utf8(controllers) |
| .is_ok_and(|c| c.split(',').any(|c| c == "cpu")) => |
| { |
| Cgroup::V1 |
| } |
| _ => return previous, |
| }; |
| |
| // already-found v1 trumps v2 since it explicitly specifies its controllers |
| if previous.is_some() && version == Cgroup::V2 { |
| return previous; |
| } |
| |
| let path = fields.last()?; |
| // skip leading slash |
| Some((path[1..].to_owned(), version)) |
| })?; |
| let cgroup_path = PathBuf::from(OsString::from_vec(cgroup_path)); |
| |
| quota = match version { |
| Cgroup::V1 => quota_v1(cgroup_path), |
| Cgroup::V2 => quota_v2(cgroup_path), |
| }; |
| }; |
| |
| quota |
| } |
| |
| fn quota_v2(group_path: PathBuf) -> usize { |
| let mut quota = usize::MAX; |
| |
| let mut path = PathBuf::with_capacity(128); |
| let mut read_buf = String::with_capacity(20); |
| |
| // standard mount location defined in file-hierarchy(7) manpage |
| let cgroup_mount = "/sys/fs/cgroup"; |
| |
| path.push(cgroup_mount); |
| path.push(&group_path); |
| |
| path.push("cgroup.controllers"); |
| |
| // skip if we're not looking at cgroup2 |
| if matches!(exists(&path), Err(_) | Ok(false)) { |
| return usize::MAX; |
| }; |
| |
| path.pop(); |
| |
| let _: Option<()> = try { |
| while path.starts_with(cgroup_mount) { |
| path.push("cpu.max"); |
| |
| read_buf.clear(); |
| |
| if File::open(&path).and_then(|mut f| f.read_to_string(&mut read_buf)).is_ok() { |
| let raw_quota = read_buf.lines().next()?; |
| let mut raw_quota = raw_quota.split(' '); |
| let limit = raw_quota.next()?; |
| let period = raw_quota.next()?; |
| match (limit.parse::<usize>(), period.parse::<usize>()) { |
| (Ok(limit), Ok(period)) if period > 0 => { |
| quota = quota.min(limit / period); |
| } |
| _ => {} |
| } |
| } |
| |
| path.pop(); // pop filename |
| path.pop(); // pop dir |
| } |
| }; |
| |
| quota |
| } |
| |
| fn quota_v1(group_path: PathBuf) -> usize { |
| let mut quota = usize::MAX; |
| let mut path = PathBuf::with_capacity(128); |
| let mut read_buf = String::with_capacity(20); |
| |
| // Hardcode commonly used locations mentioned in the cgroups(7) manpage |
| // if that doesn't work scan mountinfo and adjust `group_path` for bind-mounts |
| let mounts: &[fn(&Path) -> Option<(_, &Path)>] = &[ |
| |p| Some((Cow::Borrowed("/sys/fs/cgroup/cpu"), p)), |
| |p| Some((Cow::Borrowed("/sys/fs/cgroup/cpu,cpuacct"), p)), |
| // this can be expensive on systems with tons of mountpoints |
| // but we only get to this point when /proc/self/cgroups explicitly indicated |
| // this process belongs to a cpu-controller cgroup v1 and the defaults didn't work |
| find_mountpoint, |
| ]; |
| |
| for mount in mounts { |
| let Some((mount, group_path)) = mount(&group_path) else { continue }; |
| |
| path.clear(); |
| path.push(mount.as_ref()); |
| path.push(&group_path); |
| |
| // skip if we guessed the mount incorrectly |
| if matches!(exists(&path), Err(_) | Ok(false)) { |
| continue; |
| } |
| |
| while path.starts_with(mount.as_ref()) { |
| let mut parse_file = |name| { |
| path.push(name); |
| read_buf.clear(); |
| |
| let f = File::open(&path); |
| path.pop(); // restore buffer before any early returns |
| f.ok()?.read_to_string(&mut read_buf).ok()?; |
| let parsed = read_buf.trim().parse::<usize>().ok()?; |
| |
| Some(parsed) |
| }; |
| |
| let limit = parse_file("cpu.cfs_quota_us"); |
| let period = parse_file("cpu.cfs_period_us"); |
| |
| match (limit, period) { |
| (Some(limit), Some(period)) if period > 0 => quota = quota.min(limit / period), |
| _ => {} |
| } |
| |
| path.pop(); |
| } |
| |
| // we passed the try_exists above so we should have traversed the correct hierarchy |
| // when reaching this line |
| break; |
| } |
| |
| quota |
| } |
| |
| /// Scan mountinfo for cgroup v1 mountpoint with a cpu controller |
| /// |
| /// If the cgroupfs is a bind mount then `group_path` is adjusted to skip |
| /// over the already-included prefix |
| fn find_mountpoint(group_path: &Path) -> Option<(Cow<'static, str>, &Path)> { |
| let mut reader = File::open_buffered("/proc/self/mountinfo").ok()?; |
| let mut line = String::with_capacity(256); |
| loop { |
| line.clear(); |
| if reader.read_line(&mut line).ok()? == 0 { |
| break; |
| } |
| |
| let line = line.trim(); |
| let mut items = line.split(' '); |
| |
| let sub_path = items.nth(3)?; |
| let mount_point = items.next()?; |
| let mount_opts = items.next_back()?; |
| let filesystem_type = items.nth_back(1)?; |
| |
| if filesystem_type != "cgroup" || !mount_opts.split(',').any(|opt| opt == "cpu") { |
| // not a cgroup / not a cpu-controller |
| continue; |
| } |
| |
| let sub_path = Path::new(sub_path).strip_prefix("/").ok()?; |
| |
| if !group_path.starts_with(sub_path) { |
| // this is a bind-mount and the bound subdirectory |
| // does not contain the cgroup this process belongs to |
| continue; |
| } |
| |
| let trimmed_group_path = group_path.strip_prefix(sub_path).ok()?; |
| |
| return Some((Cow::Owned(mount_point.to_owned()), trimmed_group_path)); |
| } |
| |
| None |
| } |
| } |
| |
| // glibc >= 2.15 has a __pthread_get_minstack() function that returns |
| // PTHREAD_STACK_MIN plus bytes needed for thread-local storage. |
| // We need that information to avoid blowing up when a small stack |
| // is created in an application with big thread-local storage requirements. |
| // See #6233 for rationale and details. |
| #[cfg(all(target_os = "linux", target_env = "gnu"))] |
| unsafe fn min_stack_size(attr: *const libc::pthread_attr_t) -> usize { |
| // We use dlsym to avoid an ELF version dependency on GLIBC_PRIVATE. (#23628) |
| // We shouldn't really be using such an internal symbol, but there's currently |
| // no other way to account for the TLS size. |
| dlsym!( |
| fn __pthread_get_minstack(attr: *const libc::pthread_attr_t) -> libc::size_t; |
| ); |
| |
| match __pthread_get_minstack.get() { |
| None => libc::PTHREAD_STACK_MIN, |
| Some(f) => unsafe { f(attr) }, |
| } |
| } |
| |
| // No point in looking up __pthread_get_minstack() on non-glibc platforms. |
| #[cfg(all( |
| not(all(target_os = "linux", target_env = "gnu")), |
| not(any(target_os = "netbsd", target_os = "nuttx")) |
| ))] |
| unsafe fn min_stack_size(_: *const libc::pthread_attr_t) -> usize { |
| libc::PTHREAD_STACK_MIN |
| } |
| |
| #[cfg(any(target_os = "netbsd", target_os = "nuttx"))] |
| unsafe fn min_stack_size(_: *const libc::pthread_attr_t) -> usize { |
| static STACK: crate::sync::OnceLock<usize> = crate::sync::OnceLock::new(); |
| |
| *STACK.get_or_init(|| { |
| let mut stack = unsafe { libc::sysconf(libc::_SC_THREAD_STACK_MIN) }; |
| if stack < 0 { |
| stack = 2048; // just a guess |
| } |
| |
| stack as usize |
| }) |
| } |
