1 // Copyright 2014-2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
21 use sys_common::thread::*;
23 #[cfg(not(target_os = "l4re"))]
24 pub const DEFAULT_MIN_STACK_SIZE: usize = 2 * 1024 * 1024;
25 #[cfg(target_os = "l4re")]
26 pub const DEFAULT_MIN_STACK_SIZE: usize = 1024 * 1024;
32 // Some platforms may have pthread_t as a pointer in which case we still want
33 // a thread to be Send/Sync
34 unsafe impl Send for Thread {}
35 unsafe impl Sync for Thread {}
37 // The pthread_attr_setstacksize symbol doesn't exist in the emscripten libc,
38 // so we have to not link to it to satisfy emcc's ERROR_ON_UNDEFINED_SYMBOLS.
39 #[cfg(not(target_os = "emscripten"))]
40 unsafe fn pthread_attr_setstacksize(attr: *mut libc::pthread_attr_t,
41 stack_size: libc::size_t) -> libc::c_int {
42 libc::pthread_attr_setstacksize(attr, stack_size)
45 #[cfg(target_os = "emscripten")]
46 unsafe fn pthread_attr_setstacksize(_attr: *mut libc::pthread_attr_t,
47 _stack_size: libc::size_t) -> libc::c_int {
52 pub unsafe fn new<'a>(stack: usize, p: Box<FnBox() + 'a>)
53 -> io::Result<Thread> {
55 let mut native: libc::pthread_t = mem::zeroed();
56 let mut attr: libc::pthread_attr_t = mem::zeroed();
57 assert_eq!(libc::pthread_attr_init(&mut attr), 0);
59 let stack_size = cmp::max(stack, min_stack_size(&attr));
61 match pthread_attr_setstacksize(&mut attr,
65 assert_eq!(n, libc::EINVAL);
66 // EINVAL means |stack_size| is either too small or not a
67 // multiple of the system page size. Because it's definitely
68 // >= PTHREAD_STACK_MIN, it must be an alignment issue.
69 // Round up to the nearest page and try again.
70 let page_size = os::page_size();
71 let stack_size = (stack_size + page_size - 1) &
72 (-(page_size as isize - 1) as usize - 1);
73 assert_eq!(libc::pthread_attr_setstacksize(&mut attr,
78 let ret = libc::pthread_create(&mut native, &attr, thread_start,
79 &*p as *const _ as *mut _);
80 assert_eq!(libc::pthread_attr_destroy(&mut attr), 0);
83 Err(io::Error::from_raw_os_error(ret))
85 mem::forget(p); // ownership passed to pthread_create
86 Ok(Thread { id: native })
89 extern fn thread_start(main: *mut libc::c_void) -> *mut libc::c_void {
90 unsafe { start_thread(main as *mut u8); }
96 let ret = unsafe { libc::sched_yield() };
97 debug_assert_eq!(ret, 0);
100 #[cfg(any(target_os = "linux",
101 target_os = "android"))]
102 pub fn set_name(name: &CStr) {
103 const PR_SET_NAME: libc::c_int = 15;
104 // pthread wrapper only appeared in glibc 2.12, so we use syscall
107 libc::prctl(PR_SET_NAME, name.as_ptr() as libc::c_ulong, 0, 0, 0);
111 #[cfg(any(target_os = "freebsd",
112 target_os = "dragonfly",
113 target_os = "bitrig",
114 target_os = "openbsd"))]
115 pub fn set_name(name: &CStr) {
117 libc::pthread_set_name_np(libc::pthread_self(), name.as_ptr());
121 #[cfg(any(target_os = "macos", target_os = "ios"))]
122 pub fn set_name(name: &CStr) {
124 libc::pthread_setname_np(name.as_ptr());
128 #[cfg(target_os = "netbsd")]
129 pub fn set_name(name: &CStr) {
131 let cname = CString::new(&b"%s"[..]).unwrap();
133 libc::pthread_setname_np(libc::pthread_self(), cname.as_ptr(),
134 name.as_ptr() as *mut libc::c_void);
137 #[cfg(any(target_env = "newlib",
138 target_os = "solaris",
141 target_os = "emscripten"))]
142 pub fn set_name(_name: &CStr) {
143 // Newlib, Illumos, Haiku, and Emscripten have no way to set a thread name.
145 #[cfg(target_os = "fuchsia")]
146 pub fn set_name(_name: &CStr) {
147 // FIXME: determine whether Fuchsia has a way to set a thread name.
150 pub fn sleep(dur: Duration) {
151 let mut secs = dur.as_secs();
152 let mut nsecs = dur.subsec_nanos() as _;
154 // If we're awoken with a signal then the return value will be -1 and
155 // nanosleep will fill in `ts` with the remaining time.
157 while secs > 0 || nsecs > 0 {
158 let mut ts = libc::timespec {
159 tv_sec: cmp::min(libc::time_t::max_value() as u64, secs) as libc::time_t,
162 secs -= ts.tv_sec as u64;
163 if libc::nanosleep(&ts, &mut ts) == -1 {
164 assert_eq!(os::errno(), libc::EINTR);
165 secs += ts.tv_sec as u64;
176 let ret = libc::pthread_join(self.id, ptr::null_mut());
179 "failed to join thread: {}", io::Error::from_raw_os_error(ret));
183 pub fn id(&self) -> libc::pthread_t { self.id }
185 pub fn into_id(self) -> libc::pthread_t {
192 impl Drop for Thread {
194 let ret = unsafe { libc::pthread_detach(self.id) };
195 debug_assert_eq!(ret, 0);
199 #[cfg(all(not(all(target_os = "linux", not(target_env = "musl"))),
200 not(target_os = "freebsd"),
201 not(target_os = "macos"),
202 not(target_os = "bitrig"),
203 not(all(target_os = "netbsd", not(target_vendor = "rumprun"))),
204 not(target_os = "openbsd"),
205 not(target_os = "solaris")))]
206 #[cfg_attr(test, allow(dead_code))]
209 pub type Guard = Range<usize>;
210 pub unsafe fn current() -> Option<Guard> { None }
211 pub unsafe fn init() -> Option<Guard> { None }
212 pub unsafe fn deinit() {}
216 #[cfg(any(all(target_os = "linux", not(target_env = "musl")),
217 target_os = "freebsd",
219 target_os = "bitrig",
220 all(target_os = "netbsd", not(target_vendor = "rumprun")),
221 target_os = "openbsd",
222 target_os = "solaris"))]
223 #[cfg_attr(test, allow(dead_code))]
226 use libc::{mmap, mprotect};
227 use libc::{PROT_NONE, PROT_READ, PROT_WRITE, MAP_PRIVATE, MAP_ANON, MAP_FAILED, MAP_FIXED};
231 // This is initialized in init() and only read from after
232 static mut PAGE_SIZE: usize = 0;
234 pub type Guard = Range<usize>;
236 #[cfg(target_os = "solaris")]
237 unsafe fn get_stack_start() -> Option<*mut libc::c_void> {
238 let mut current_stack: libc::stack_t = ::mem::zeroed();
239 assert_eq!(libc::stack_getbounds(&mut current_stack), 0);
240 Some(current_stack.ss_sp)
243 #[cfg(target_os = "macos")]
244 unsafe fn get_stack_start() -> Option<*mut libc::c_void> {
245 let stackaddr = libc::pthread_get_stackaddr_np(libc::pthread_self()) as usize -
246 libc::pthread_get_stacksize_np(libc::pthread_self());
247 Some(stackaddr as *mut libc::c_void)
250 #[cfg(any(target_os = "openbsd", target_os = "bitrig"))]
251 unsafe fn get_stack_start() -> Option<*mut libc::c_void> {
252 let mut current_stack: libc::stack_t = ::mem::zeroed();
253 assert_eq!(libc::pthread_stackseg_np(libc::pthread_self(),
254 &mut current_stack), 0);
256 let extra = if cfg!(target_os = "bitrig") {3} else {1} * PAGE_SIZE;
257 let stackaddr = if libc::pthread_main_np() == 1 {
259 current_stack.ss_sp as usize - current_stack.ss_size + extra
262 current_stack.ss_sp as usize - current_stack.ss_size
264 Some(stackaddr as *mut libc::c_void)
267 #[cfg(any(target_os = "android", target_os = "freebsd",
268 target_os = "linux", target_os = "netbsd", target_os = "l4re"))]
269 unsafe fn get_stack_start() -> Option<*mut libc::c_void> {
271 let mut attr: libc::pthread_attr_t = ::mem::zeroed();
272 assert_eq!(libc::pthread_attr_init(&mut attr), 0);
273 #[cfg(target_os = "freebsd")]
274 let e = libc::pthread_attr_get_np(libc::pthread_self(), &mut attr);
275 #[cfg(not(target_os = "freebsd"))]
276 let e = libc::pthread_getattr_np(libc::pthread_self(), &mut attr);
278 let mut stackaddr = ::ptr::null_mut();
279 let mut stacksize = 0;
280 assert_eq!(libc::pthread_attr_getstack(&attr, &mut stackaddr,
282 ret = Some(stackaddr);
284 assert_eq!(libc::pthread_attr_destroy(&mut attr), 0);
288 // Precondition: PAGE_SIZE is initialized.
289 unsafe fn get_stack_start_aligned() -> Option<*mut libc::c_void> {
290 assert!(PAGE_SIZE != 0);
291 let stackaddr = get_stack_start()?;
293 // Ensure stackaddr is page aligned! A parent process might
294 // have reset RLIMIT_STACK to be non-page aligned. The
295 // pthread_attr_getstack() reports the usable stack area
296 // stackaddr < stackaddr + stacksize, so if stackaddr is not
297 // page-aligned, calculate the fix such that stackaddr <
298 // new_page_aligned_stackaddr < stackaddr + stacksize
299 let remainder = (stackaddr as usize) % PAGE_SIZE;
300 Some(if remainder == 0 {
303 ((stackaddr as usize) + PAGE_SIZE - remainder) as *mut libc::c_void
307 pub unsafe fn init() -> Option<Guard> {
308 PAGE_SIZE = os::page_size();
310 let stackaddr = get_stack_start_aligned()?;
312 if cfg!(target_os = "linux") {
313 // Linux doesn't allocate the whole stack right away, and
314 // the kernel has its own stack-guard mechanism to fault
315 // when growing too close to an existing mapping. If we map
316 // our own guard, then the kernel starts enforcing a rather
317 // large gap above that, rendering much of the possible
318 // stack space useless. See #43052.
320 // Instead, we'll just note where we expect rlimit to start
321 // faulting, so our handler can report "stack overflow", and
322 // trust that the kernel's own stack guard will work.
323 let stackaddr = stackaddr as usize;
324 Some(stackaddr - PAGE_SIZE..stackaddr)
326 // Reallocate the last page of the stack.
327 // This ensures SIGBUS will be raised on
329 // Systems which enforce strict PAX MPROTECT do not allow
330 // to mprotect() a mapping with less restrictive permissions
331 // than the initial mmap() used, so we mmap() here with
332 // read/write permissions and only then mprotect() it to
333 // no permissions at all. See issue #50313.
334 let result = mmap(stackaddr, PAGE_SIZE, PROT_READ | PROT_WRITE,
335 MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0);
336 if result != stackaddr || result == MAP_FAILED {
337 panic!("failed to allocate a guard page");
340 let result = mprotect(stackaddr, PAGE_SIZE, PROT_NONE);
342 panic!("failed to protect the guard page");
345 let guardaddr = stackaddr as usize;
346 let offset = if cfg!(target_os = "freebsd") {
352 Some(guardaddr..guardaddr + offset * PAGE_SIZE)
356 pub unsafe fn deinit() {
357 if !cfg!(target_os = "linux") {
358 if let Some(stackaddr) = get_stack_start_aligned() {
359 // Remove the protection on the guard page.
360 // FIXME: we cannot unmap the page, because when we mmap()
361 // above it may be already mapped by the OS, which we can't
362 // detect from mmap()'s return value. If we unmap this page,
363 // it will lead to failure growing stack size on platforms like
364 // macOS. Instead, just restore the page to a writable state.
365 // This ain't Linux, so we probably don't need to care about
367 let result = mprotect(stackaddr, PAGE_SIZE, PROT_READ | PROT_WRITE);
370 panic!("unable to reset the guard page");
376 #[cfg(any(target_os = "macos",
377 target_os = "bitrig",
378 target_os = "openbsd",
379 target_os = "solaris"))]
380 pub unsafe fn current() -> Option<Guard> {
381 let stackaddr = get_stack_start()? as usize;
382 Some(stackaddr - PAGE_SIZE..stackaddr)
385 #[cfg(any(target_os = "android", target_os = "freebsd",
386 target_os = "linux", target_os = "netbsd", target_os = "l4re"))]
387 pub unsafe fn current() -> Option<Guard> {
389 let mut attr: libc::pthread_attr_t = ::mem::zeroed();
390 assert_eq!(libc::pthread_attr_init(&mut attr), 0);
391 #[cfg(target_os = "freebsd")]
392 let e = libc::pthread_attr_get_np(libc::pthread_self(), &mut attr);
393 #[cfg(not(target_os = "freebsd"))]
394 let e = libc::pthread_getattr_np(libc::pthread_self(), &mut attr);
396 let mut guardsize = 0;
397 assert_eq!(libc::pthread_attr_getguardsize(&attr, &mut guardsize), 0);
399 panic!("there is no guard page");
401 let mut stackaddr = ::ptr::null_mut();
403 assert_eq!(libc::pthread_attr_getstack(&attr, &mut stackaddr,
406 let stackaddr = stackaddr as usize;
407 ret = if cfg!(target_os = "freebsd") {
408 // FIXME does freebsd really fault *below* the guard addr?
409 let guardaddr = stackaddr - guardsize;
410 Some(guardaddr - PAGE_SIZE..guardaddr)
411 } else if cfg!(target_os = "netbsd") {
412 Some(stackaddr - guardsize..stackaddr)
413 } else if cfg!(all(target_os = "linux", target_env = "gnu")) {
414 // glibc used to include the guard area within the stack, as noted in the BUGS
415 // section of `man pthread_attr_getguardsize`. This has been corrected starting
416 // with glibc 2.27, and in some distro backports, so the guard is now placed at the
417 // end (below) the stack. There's no easy way for us to know which we have at
418 // runtime, so we'll just match any fault in the range right above or below the
419 // stack base to call that fault a stack overflow.
420 Some(stackaddr - guardsize..stackaddr + guardsize)
422 Some(stackaddr..stackaddr + guardsize)
425 assert_eq!(libc::pthread_attr_destroy(&mut attr), 0);
430 // glibc >= 2.15 has a __pthread_get_minstack() function that returns
431 // PTHREAD_STACK_MIN plus however many bytes are needed for thread-local
432 // storage. We need that information to avoid blowing up when a small stack
433 // is created in an application with big thread-local storage requirements.
434 // See #6233 for rationale and details.
435 #[cfg(target_os = "linux")]
437 fn min_stack_size(attr: *const libc::pthread_attr_t) -> usize {
438 weak!(fn __pthread_get_minstack(*const libc::pthread_attr_t) -> libc::size_t);
440 match __pthread_get_minstack.get() {
441 None => libc::PTHREAD_STACK_MIN,
442 Some(f) => unsafe { f(attr) },
446 // No point in looking up __pthread_get_minstack() on non-glibc
448 #[cfg(all(not(target_os = "linux"),
449 not(target_os = "netbsd")))]
450 fn min_stack_size(_: *const libc::pthread_attr_t) -> usize {
451 libc::PTHREAD_STACK_MIN
454 #[cfg(target_os = "netbsd")]
455 fn min_stack_size(_: *const libc::pthread_attr_t) -> usize {