1use crate::ffi::CStr;
2use crate::mem::{self, ManuallyDrop};
3use crate::num::NonZero;
4#[cfg(all(target_os = "linux", target_env = "gnu"))]
5use crate::sys::weak::dlsym;
6#[cfg(any(target_os = "solaris", target_os = "illumos", target_os = "nto",))]
7use crate::sys::weak::weak;
8use crate::sys::{os, stack_overflow};
9use crate::time::Duration;
10use crate::{cmp, io, ptr};
11#[cfg(not(any(target_os = "l4re", target_os = "vxworks", target_os = "espidf")))]
12pub const DEFAULT_MIN_STACK_SIZE: usize = 2 * 1024 * 1024;
13#[cfg(target_os = "l4re")]
14pub const DEFAULT_MIN_STACK_SIZE: usize = 1024 * 1024;
15#[cfg(target_os = "vxworks")]
16pub const DEFAULT_MIN_STACK_SIZE: usize = 256 * 1024;
17#[cfg(target_os = "espidf")]
18pub const DEFAULT_MIN_STACK_SIZE: usize = 0; #[cfg(target_os = "fuchsia")]
21mod zircon {
22 type zx_handle_t = u32;
23 type zx_status_t = i32;
24 pub const ZX_PROP_NAME: u32 = 3;
25
26 unsafe extern "C" {
27 pub fn zx_object_set_property(
28 handle: zx_handle_t,
29 property: u32,
30 value: *const libc::c_void,
31 value_size: libc::size_t,
32 ) -> zx_status_t;
33 pub fn zx_thread_self() -> zx_handle_t;
34 }
35}
36
37pub struct Thread {
38 id: libc::pthread_t,
39}
40
41unsafe impl Send for Thread {}
44unsafe impl Sync for Thread {}
45
46impl Thread {
47 #[cfg_attr(miri, track_caller)] pub unsafe fn new(stack: usize, p: Box<dyn FnOnce()>) -> io::Result<Thread> {
50 let p = Box::into_raw(Box::new(p));
51 let mut native: libc::pthread_t = mem::zeroed();
52 let mut attr: mem::MaybeUninit<libc::pthread_attr_t> = mem::MaybeUninit::uninit();
53 assert_eq!(libc::pthread_attr_init(attr.as_mut_ptr()), 0);
54
55 #[cfg(target_os = "espidf")]
56 if stack > 0 {
57 assert_eq!(
60 libc::pthread_attr_setstacksize(
61 attr.as_mut_ptr(),
62 cmp::max(stack, min_stack_size(attr.as_ptr()))
63 ),
64 0
65 );
66 }
67
68 #[cfg(not(target_os = "espidf"))]
69 {
70 let stack_size = cmp::max(stack, min_stack_size(attr.as_ptr()));
71
72 match libc::pthread_attr_setstacksize(attr.as_mut_ptr(), stack_size) {
73 0 => {}
74 n => {
75 assert_eq!(n, libc::EINVAL);
76 let page_size = os::page_size();
81 let stack_size =
82 (stack_size + page_size - 1) & (-(page_size as isize - 1) as usize - 1);
83 assert_eq!(libc::pthread_attr_setstacksize(attr.as_mut_ptr(), stack_size), 0);
84 }
85 };
86 }
87
88 let ret = libc::pthread_create(&mut native, attr.as_ptr(), thread_start, p as *mut _);
89 assert_eq!(libc::pthread_attr_destroy(attr.as_mut_ptr()), 0);
93
94 return if ret != 0 {
95 drop(Box::from_raw(p));
98 Err(io::Error::from_raw_os_error(ret))
99 } else {
100 Ok(Thread { id: native })
101 };
102
103 extern "C" fn thread_start(main: *mut libc::c_void) -> *mut libc::c_void {
104 unsafe {
105 let _handler = stack_overflow::Handler::new();
108 Box::from_raw(main as *mut Box<dyn FnOnce()>)();
110 }
111 ptr::null_mut()
112 }
113 }
114
115 pub fn yield_now() {
116 let ret = unsafe { libc::sched_yield() };
117 debug_assert_eq!(ret, 0);
118 }
119
120 #[cfg(target_os = "android")]
121 pub fn set_name(name: &CStr) {
122 const PR_SET_NAME: libc::c_int = 15;
123 unsafe {
124 let res = libc::prctl(
125 PR_SET_NAME,
126 name.as_ptr(),
127 0 as libc::c_ulong,
128 0 as libc::c_ulong,
129 0 as libc::c_ulong,
130 );
131 debug_assert_eq!(res, 0);
133 }
134 }
135
136 #[cfg(any(
137 target_os = "linux",
138 target_os = "freebsd",
139 target_os = "dragonfly",
140 target_os = "nuttx"
141 ))]
142 pub fn set_name(name: &CStr) {
143 unsafe {
144 cfg_if::cfg_if! {
145 if #[cfg(target_os = "linux")] {
146 const TASK_COMM_LEN: usize = 16;
148 let name = truncate_cstr::<{ TASK_COMM_LEN }>(name);
149 } else {
150 }
152 };
153 let res = libc::pthread_setname_np(libc::pthread_self(), name.as_ptr());
156 debug_assert_eq!(res, 0);
158 }
159 }
160
161 #[cfg(target_os = "openbsd")]
162 pub fn set_name(name: &CStr) {
163 unsafe {
164 libc::pthread_set_name_np(libc::pthread_self(), name.as_ptr());
165 }
166 }
167
168 #[cfg(target_vendor = "apple")]
169 pub fn set_name(name: &CStr) {
170 unsafe {
171 let name = truncate_cstr::<{ libc::MAXTHREADNAMESIZE }>(name);
172 let res = libc::pthread_setname_np(name.as_ptr());
173 debug_assert_eq!(res, 0);
175 }
176 }
177
178 #[cfg(target_os = "netbsd")]
179 pub fn set_name(name: &CStr) {
180 unsafe {
181 let res = libc::pthread_setname_np(
182 libc::pthread_self(),
183 c"%s".as_ptr(),
184 name.as_ptr() as *mut libc::c_void,
185 );
186 debug_assert_eq!(res, 0);
187 }
188 }
189
190 #[cfg(any(target_os = "solaris", target_os = "illumos", target_os = "nto"))]
191 pub fn set_name(name: &CStr) {
192 weak! {
193 fn pthread_setname_np(
194 libc::pthread_t, *const libc::c_char
195 ) -> libc::c_int
196 }
197
198 if let Some(f) = pthread_setname_np.get() {
199 #[cfg(target_os = "nto")]
200 const THREAD_NAME_MAX: usize = libc::_NTO_THREAD_NAME_MAX as usize;
201 #[cfg(any(target_os = "solaris", target_os = "illumos"))]
202 const THREAD_NAME_MAX: usize = 32;
203
204 let name = truncate_cstr::<{ THREAD_NAME_MAX }>(name);
205 let res = unsafe { f(libc::pthread_self(), name.as_ptr()) };
206 debug_assert_eq!(res, 0);
207 }
208 }
209
210 #[cfg(target_os = "fuchsia")]
211 pub fn set_name(name: &CStr) {
212 use self::zircon::*;
213 unsafe {
214 zx_object_set_property(
215 zx_thread_self(),
216 ZX_PROP_NAME,
217 name.as_ptr() as *const libc::c_void,
218 name.to_bytes().len(),
219 );
220 }
221 }
222
223 #[cfg(target_os = "haiku")]
224 pub fn set_name(name: &CStr) {
225 unsafe {
226 let thread_self = libc::find_thread(ptr::null_mut());
227 let res = libc::rename_thread(thread_self, name.as_ptr());
228 debug_assert_eq!(res, libc::B_OK);
230 }
231 }
232
233 #[cfg(target_os = "vxworks")]
234 pub fn set_name(name: &CStr) {
235 unsafe extern "C" {
237 fn taskNameSet(task_id: libc::TASK_ID, task_name: *mut libc::c_char) -> libc::c_int;
238 }
239
240 const VX_TASK_NAME_LEN: usize = 31;
242
243 let mut name = truncate_cstr::<{ VX_TASK_NAME_LEN }>(name);
244 let res = unsafe { taskNameSet(libc::taskIdSelf(), name.as_mut_ptr()) };
245 debug_assert_eq!(res, libc::OK);
246 }
247
248 #[cfg(any(
249 target_env = "newlib",
250 target_os = "l4re",
251 target_os = "emscripten",
252 target_os = "redox",
253 target_os = "hurd",
254 target_os = "aix",
255 ))]
256 pub fn set_name(_name: &CStr) {
257 }
259
260 #[cfg(not(target_os = "espidf"))]
261 pub fn sleep(dur: Duration) {
262 let mut secs = dur.as_secs();
263 let mut nsecs = dur.subsec_nanos() as _;
264
265 unsafe {
268 while secs > 0 || nsecs > 0 {
269 let mut ts = libc::timespec {
270 tv_sec: cmp::min(libc::time_t::MAX as u64, secs) as libc::time_t,
271 tv_nsec: nsecs,
272 };
273 secs -= ts.tv_sec as u64;
274 let ts_ptr = &raw mut ts;
275 if libc::nanosleep(ts_ptr, ts_ptr) == -1 {
276 assert_eq!(os::errno(), libc::EINTR);
277 secs += ts.tv_sec as u64;
278 nsecs = ts.tv_nsec;
279 } else {
280 nsecs = 0;
281 }
282 }
283 }
284 }
285
286 #[cfg(target_os = "espidf")]
287 pub fn sleep(dur: Duration) {
288 const MAX_MICROS: u32 = u32::MAX - 1_000_000 - 1;
298
299 let mut micros = dur.as_micros() + if dur.subsec_nanos() % 1_000 > 0 { 1 } else { 0 };
306
307 while micros > 0 {
308 let st = if micros > MAX_MICROS as u128 { MAX_MICROS } else { micros as u32 };
309 unsafe {
310 libc::usleep(st);
311 }
312
313 micros -= st as u128;
314 }
315 }
316
317 pub fn join(self) {
318 let id = self.into_id();
319 let ret = unsafe { libc::pthread_join(id, ptr::null_mut()) };
320 assert!(ret == 0, "failed to join thread: {}", io::Error::from_raw_os_error(ret));
321 }
322
323 pub fn id(&self) -> libc::pthread_t {
324 self.id
325 }
326
327 pub fn into_id(self) -> libc::pthread_t {
328 ManuallyDrop::new(self).id
329 }
330}
331
332impl Drop for Thread {
333 fn drop(&mut self) {
334 let ret = unsafe { libc::pthread_detach(self.id) };
335 debug_assert_eq!(ret, 0);
336 }
337}
338
339#[cfg(any(
340 target_os = "linux",
341 target_os = "nto",
342 target_os = "solaris",
343 target_os = "illumos",
344 target_os = "vxworks",
345 target_vendor = "apple",
346))]
347fn truncate_cstr<const MAX_WITH_NUL: usize>(cstr: &CStr) -> [libc::c_char; MAX_WITH_NUL] {
348 let mut result = [0; MAX_WITH_NUL];
349 for (src, dst) in cstr.to_bytes().iter().zip(&mut result[..MAX_WITH_NUL - 1]) {
350 *dst = *src as libc::c_char;
351 }
352 result
353}
354
355pub fn available_parallelism() -> io::Result<NonZero<usize>> {
356 cfg_if::cfg_if! {
357 if #[cfg(any(
358 target_os = "android",
359 target_os = "emscripten",
360 target_os = "fuchsia",
361 target_os = "hurd",
362 target_os = "linux",
363 target_os = "aix",
364 target_vendor = "apple",
365 ))] {
366 #[allow(unused_assignments)]
367 #[allow(unused_mut)]
368 let mut quota = usize::MAX;
369
370 #[cfg(any(target_os = "android", target_os = "linux"))]
371 {
372 quota = cgroups::quota().max(1);
373 let mut set: libc::cpu_set_t = unsafe { mem::zeroed() };
374 unsafe {
375 if libc::sched_getaffinity(0, mem::size_of::<libc::cpu_set_t>(), &mut set) == 0 {
376 let count = libc::CPU_COUNT(&set) as usize;
377 let count = count.min(quota);
378
379 if let Some(count) = NonZero::new(count) {
384 return Ok(count)
385 }
386 }
387 }
388 }
389 match unsafe { libc::sysconf(libc::_SC_NPROCESSORS_ONLN) } {
390 -1 => Err(io::Error::last_os_error()),
391 0 => Err(io::Error::UNKNOWN_THREAD_COUNT),
392 cpus => {
393 let count = cpus as usize;
394 let count = count.min(quota);
396 Ok(unsafe { NonZero::new_unchecked(count) })
397 }
398 }
399 } else if #[cfg(any(
400 target_os = "freebsd",
401 target_os = "dragonfly",
402 target_os = "openbsd",
403 target_os = "netbsd",
404 ))] {
405 use crate::ptr;
406
407 #[cfg(target_os = "freebsd")]
408 {
409 let mut set: libc::cpuset_t = unsafe { mem::zeroed() };
410 unsafe {
411 if libc::cpuset_getaffinity(
412 libc::CPU_LEVEL_WHICH,
413 libc::CPU_WHICH_PID,
414 -1,
415 mem::size_of::<libc::cpuset_t>(),
416 &mut set,
417 ) == 0 {
418 let count = libc::CPU_COUNT(&set) as usize;
419 if count > 0 {
420 return Ok(NonZero::new_unchecked(count));
421 }
422 }
423 }
424 }
425
426 #[cfg(target_os = "netbsd")]
427 {
428 unsafe {
429 let set = libc::_cpuset_create();
430 if !set.is_null() {
431 let mut count: usize = 0;
432 if libc::pthread_getaffinity_np(libc::pthread_self(), libc::_cpuset_size(set), set) == 0 {
433 for i in 0..libc::cpuid_t::MAX {
434 match libc::_cpuset_isset(i, set) {
435 -1 => break,
436 0 => continue,
437 _ => count = count + 1,
438 }
439 }
440 }
441 libc::_cpuset_destroy(set);
442 if let Some(count) = NonZero::new(count) {
443 return Ok(count);
444 }
445 }
446 }
447 }
448
449 let mut cpus: libc::c_uint = 0;
450 let mut cpus_size = crate::mem::size_of_val(&cpus);
451
452 unsafe {
453 cpus = libc::sysconf(libc::_SC_NPROCESSORS_ONLN) as libc::c_uint;
454 }
455
456 if cpus < 1 {
458 let mut mib = [libc::CTL_HW, libc::HW_NCPU, 0, 0];
459 let res = unsafe {
460 libc::sysctl(
461 mib.as_mut_ptr(),
462 2,
463 (&raw mut cpus) as *mut _,
464 (&raw mut cpus_size) as *mut _,
465 ptr::null_mut(),
466 0,
467 )
468 };
469
470 if res == -1 {
472 return Err(io::Error::last_os_error());
473 } else if cpus == 0 {
474 return Err(io::Error::UNKNOWN_THREAD_COUNT);
475 }
476 }
477
478 Ok(unsafe { NonZero::new_unchecked(cpus as usize) })
479 } else if #[cfg(target_os = "nto")] {
480 unsafe {
481 use libc::_syspage_ptr;
482 if _syspage_ptr.is_null() {
483 Err(io::const_error!(io::ErrorKind::NotFound, "no syspage available"))
484 } else {
485 let cpus = (*_syspage_ptr).num_cpu;
486 NonZero::new(cpus as usize)
487 .ok_or(io::Error::UNKNOWN_THREAD_COUNT)
488 }
489 }
490 } else if #[cfg(any(target_os = "solaris", target_os = "illumos"))] {
491 let mut cpus = 0u32;
492 if unsafe { libc::pset_info(libc::PS_MYID, core::ptr::null_mut(), &mut cpus, core::ptr::null_mut()) } != 0 {
493 return Err(io::Error::UNKNOWN_THREAD_COUNT);
494 }
495 Ok(unsafe { NonZero::new_unchecked(cpus as usize) })
496 } else if #[cfg(target_os = "haiku")] {
497 unsafe {
500 let mut sinfo: libc::system_info = crate::mem::zeroed();
501 let res = libc::get_system_info(&mut sinfo);
502
503 if res != libc::B_OK {
504 return Err(io::Error::UNKNOWN_THREAD_COUNT);
505 }
506
507 Ok(NonZero::new_unchecked(sinfo.cpu_count as usize))
508 }
509 } else if #[cfg(target_os = "vxworks")] {
510 unsafe extern "C" {
513 fn vxCpuEnabledGet() -> libc::cpuset_t;
514 }
515
516 unsafe{
518 let set = vxCpuEnabledGet();
519 Ok(NonZero::new_unchecked(set.count_ones() as usize))
520 }
521 } else {
522 Err(io::const_error!(io::ErrorKind::Unsupported, "getting the number of hardware threads is not supported on the target platform"))
524 }
525 }
526}
527
528#[cfg(any(target_os = "android", target_os = "linux"))]
529mod cgroups {
530 use crate::borrow::Cow;
536 use crate::ffi::OsString;
537 use crate::fs::{File, exists};
538 use crate::io::{BufRead, Read};
539 use crate::os::unix::ffi::OsStringExt;
540 use crate::path::{Path, PathBuf};
541 use crate::str::from_utf8;
542
543 #[derive(PartialEq)]
544 enum Cgroup {
545 V1,
546 V2,
547 }
548
549 pub(super) fn quota() -> usize {
552 let mut quota = usize::MAX;
553 if cfg!(miri) {
554 return quota;
557 }
558
559 let _: Option<()> = try {
560 let mut buf = Vec::with_capacity(128);
561 File::open("/proc/self/cgroup").ok()?.read_to_end(&mut buf).ok()?;
563 let (cgroup_path, version) =
564 buf.split(|&c| c == b'\n').fold(None, |previous, line| {
565 let mut fields = line.splitn(3, |&c| c == b':');
566 let version = match fields.nth(1) {
568 Some(b"") => Cgroup::V2,
569 Some(controllers)
570 if from_utf8(controllers)
571 .is_ok_and(|c| c.split(',').any(|c| c == "cpu")) =>
572 {
573 Cgroup::V1
574 }
575 _ => return previous,
576 };
577
578 if previous.is_some() && version == Cgroup::V2 {
580 return previous;
581 }
582
583 let path = fields.last()?;
584 Some((path[1..].to_owned(), version))
586 })?;
587 let cgroup_path = PathBuf::from(OsString::from_vec(cgroup_path));
588
589 quota = match version {
590 Cgroup::V1 => quota_v1(cgroup_path),
591 Cgroup::V2 => quota_v2(cgroup_path),
592 };
593 };
594
595 quota
596 }
597
598 fn quota_v2(group_path: PathBuf) -> usize {
599 let mut quota = usize::MAX;
600
601 let mut path = PathBuf::with_capacity(128);
602 let mut read_buf = String::with_capacity(20);
603
604 let cgroup_mount = "/sys/fs/cgroup";
606
607 path.push(cgroup_mount);
608 path.push(&group_path);
609
610 path.push("cgroup.controllers");
611
612 if matches!(exists(&path), Err(_) | Ok(false)) {
614 return usize::MAX;
615 };
616
617 path.pop();
618
619 let _: Option<()> = try {
620 while path.starts_with(cgroup_mount) {
621 path.push("cpu.max");
622
623 read_buf.clear();
624
625 if File::open(&path).and_then(|mut f| f.read_to_string(&mut read_buf)).is_ok() {
626 let raw_quota = read_buf.lines().next()?;
627 let mut raw_quota = raw_quota.split(' ');
628 let limit = raw_quota.next()?;
629 let period = raw_quota.next()?;
630 match (limit.parse::<usize>(), period.parse::<usize>()) {
631 (Ok(limit), Ok(period)) if period > 0 => {
632 quota = quota.min(limit / period);
633 }
634 _ => {}
635 }
636 }
637
638 path.pop(); path.pop(); }
641 };
642
643 quota
644 }
645
646 fn quota_v1(group_path: PathBuf) -> usize {
647 let mut quota = usize::MAX;
648 let mut path = PathBuf::with_capacity(128);
649 let mut read_buf = String::with_capacity(20);
650
651 let mounts: &[fn(&Path) -> Option<(_, &Path)>] = &[
654 |p| Some((Cow::Borrowed("/sys/fs/cgroup/cpu"), p)),
655 |p| Some((Cow::Borrowed("/sys/fs/cgroup/cpu,cpuacct"), p)),
656 find_mountpoint,
660 ];
661
662 for mount in mounts {
663 let Some((mount, group_path)) = mount(&group_path) else { continue };
664
665 path.clear();
666 path.push(mount.as_ref());
667 path.push(&group_path);
668
669 if matches!(exists(&path), Err(_) | Ok(false)) {
671 continue;
672 }
673
674 while path.starts_with(mount.as_ref()) {
675 let mut parse_file = |name| {
676 path.push(name);
677 read_buf.clear();
678
679 let f = File::open(&path);
680 path.pop(); f.ok()?.read_to_string(&mut read_buf).ok()?;
682 let parsed = read_buf.trim().parse::<usize>().ok()?;
683
684 Some(parsed)
685 };
686
687 let limit = parse_file("cpu.cfs_quota_us");
688 let period = parse_file("cpu.cfs_period_us");
689
690 match (limit, period) {
691 (Some(limit), Some(period)) if period > 0 => quota = quota.min(limit / period),
692 _ => {}
693 }
694
695 path.pop();
696 }
697
698 break;
701 }
702
703 quota
704 }
705
706 fn find_mountpoint(group_path: &Path) -> Option<(Cow<'static, str>, &Path)> {
711 let mut reader = File::open_buffered("/proc/self/mountinfo").ok()?;
712 let mut line = String::with_capacity(256);
713 loop {
714 line.clear();
715 if reader.read_line(&mut line).ok()? == 0 {
716 break;
717 }
718
719 let line = line.trim();
720 let mut items = line.split(' ');
721
722 let sub_path = items.nth(3)?;
723 let mount_point = items.next()?;
724 let mount_opts = items.next_back()?;
725 let filesystem_type = items.nth_back(1)?;
726
727 if filesystem_type != "cgroup" || !mount_opts.split(',').any(|opt| opt == "cpu") {
728 continue;
730 }
731
732 let sub_path = Path::new(sub_path).strip_prefix("/").ok()?;
733
734 if !group_path.starts_with(sub_path) {
735 continue;
738 }
739
740 let trimmed_group_path = group_path.strip_prefix(sub_path).ok()?;
741
742 return Some((Cow::Owned(mount_point.to_owned()), trimmed_group_path));
743 }
744
745 None
746 }
747}
748
749#[cfg(all(target_os = "linux", target_env = "gnu"))]
755unsafe fn min_stack_size(attr: *const libc::pthread_attr_t) -> usize {
756 dlsym!(fn __pthread_get_minstack(*const libc::pthread_attr_t) -> libc::size_t);
760
761 match __pthread_get_minstack.get() {
762 None => libc::PTHREAD_STACK_MIN,
763 Some(f) => unsafe { f(attr) },
764 }
765}
766
767#[cfg(all(
769 not(all(target_os = "linux", target_env = "gnu")),
770 not(any(target_os = "netbsd", target_os = "nuttx"))
771))]
772unsafe fn min_stack_size(_: *const libc::pthread_attr_t) -> usize {
773 libc::PTHREAD_STACK_MIN
774}
775
776#[cfg(any(target_os = "netbsd", target_os = "nuttx"))]
777unsafe fn min_stack_size(_: *const libc::pthread_attr_t) -> usize {
778 static STACK: crate::sync::OnceLock<usize> = crate::sync::OnceLock::new();
779
780 *STACK.get_or_init(|| {
781 let mut stack = unsafe { libc::sysconf(libc::_SC_THREAD_STACK_MIN) };
782 if stack < 0 {
783 stack = 2048; }
785
786 stack as usize
787 })
788}