diff options
Diffstat (limited to 'src/libstd/sys/unix/thread.rs')
| -rw-r--r-- | src/libstd/sys/unix/thread.rs | 465 |
1 files changed, 0 insertions, 465 deletions
diff --git a/src/libstd/sys/unix/thread.rs b/src/libstd/sys/unix/thread.rs deleted file mode 100644 index c1bda6b430e..00000000000 --- a/src/libstd/sys/unix/thread.rs +++ /dev/null @@ -1,465 +0,0 @@ -use crate::cmp; -use crate::ffi::CStr; -use crate::io; -use crate::mem; -use crate::ptr; -use crate::sys::{os, stack_overflow}; -use crate::time::Duration; - -#[cfg(not(target_os = "l4re"))] -pub const DEFAULT_MIN_STACK_SIZE: usize = 2 * 1024 * 1024; -#[cfg(target_os = "l4re")] -pub const DEFAULT_MIN_STACK_SIZE: usize = 1024 * 1024; - -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 {} - -// The pthread_attr_setstacksize symbol doesn't exist in the emscripten libc, -// so we have to not link to it to satisfy emcc's ERROR_ON_UNDEFINED_SYMBOLS. -#[cfg(not(target_os = "emscripten"))] -unsafe fn pthread_attr_setstacksize( - attr: *mut libc::pthread_attr_t, - stack_size: libc::size_t, -) -> libc::c_int { - libc::pthread_attr_setstacksize(attr, stack_size) -} - -#[cfg(target_os = "emscripten")] -unsafe fn pthread_attr_setstacksize( - _attr: *mut libc::pthread_attr_t, - _stack_size: libc::size_t, -) -> libc::c_int { - panic!() -} - -impl Thread { - // unsafe: see thread::Builder::spawn_unchecked for safety requirements - pub unsafe fn new(stack: usize, p: Box<dyn FnOnce()>) -> io::Result<Thread> { - let p = Box::into_raw(box p); - let mut native: libc::pthread_t = mem::zeroed(); - let mut attr: libc::pthread_attr_t = mem::zeroed(); - assert_eq!(libc::pthread_attr_init(&mut attr), 0); - - let stack_size = cmp::max(stack, min_stack_size(&attr)); - - match pthread_attr_setstacksize(&mut attr, 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(&mut attr, stack_size), 0); - } - }; - - let ret = libc::pthread_create(&mut native, &attr, 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(&mut attr), 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(any(target_os = "linux", target_os = "android"))] - pub fn set_name(name: &CStr) { - const PR_SET_NAME: libc::c_int = 15; - // pthread wrapper only appeared in glibc 2.12, so we use syscall - // directly. - unsafe { - libc::prctl(PR_SET_NAME, name.as_ptr() as libc::c_ulong, 0, 0, 0); - } - } - - #[cfg(any(target_os = "freebsd", target_os = "dragonfly", target_os = "openbsd"))] - pub fn set_name(name: &CStr) { - unsafe { - libc::pthread_set_name_np(libc::pthread_self(), name.as_ptr()); - } - } - - #[cfg(any(target_os = "macos", target_os = "ios"))] - pub fn set_name(name: &CStr) { - unsafe { - libc::pthread_setname_np(name.as_ptr()); - } - } - - #[cfg(target_os = "netbsd")] - pub fn set_name(name: &CStr) { - use crate::ffi::CString; - let cname = CString::new(&b"%s"[..]).unwrap(); - unsafe { - libc::pthread_setname_np( - libc::pthread_self(), - cname.as_ptr(), - name.as_ptr() as *mut libc::c_void, - ); - } - } - - #[cfg(any(target_os = "solaris", target_os = "illumos"))] - pub fn set_name(name: &CStr) { - weak! { - fn pthread_setname_np( - libc::pthread_t, *const libc::c_char - ) -> libc::c_int - } - - if let Some(f) = pthread_setname_np.get() { - unsafe { - f(libc::pthread_self(), name.as_ptr()); - } - } - } - - #[cfg(any( - target_env = "newlib", - target_os = "haiku", - target_os = "l4re", - target_os = "emscripten", - target_os = "redox" - ))] - pub fn set_name(_name: &CStr) { - // Newlib, Haiku, and Emscripten have no way to set a thread name. - } - #[cfg(target_os = "fuchsia")] - pub fn set_name(_name: &CStr) { - // FIXME: determine whether Fuchsia has a way to set a thread name. - } - - 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; - if libc::nanosleep(&ts, &mut ts) == -1 { - assert_eq!(os::errno(), libc::EINTR); - secs += ts.tv_sec as u64; - nsecs = ts.tv_nsec; - } else { - nsecs = 0; - } - } - } - } - - pub fn join(self) { - unsafe { - let ret = libc::pthread_join(self.id, ptr::null_mut()); - mem::forget(self); - 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 { - let id = self.id; - mem::forget(self); - id - } -} - -impl Drop for Thread { - fn drop(&mut self) { - let ret = unsafe { libc::pthread_detach(self.id) }; - debug_assert_eq!(ret, 0); - } -} - -#[cfg(all( - not(all(target_os = "linux", not(target_env = "musl"))), - not(target_os = "freebsd"), - not(target_os = "macos"), - not(all(target_os = "netbsd", not(target_vendor = "rumprun"))), - not(target_os = "openbsd"), - not(target_os = "solaris") -))] -#[cfg_attr(test, allow(dead_code))] -pub mod guard { - use crate::ops::Range; - pub type Guard = Range<usize>; - pub unsafe fn current() -> Option<Guard> { - None - } - pub unsafe fn init() -> Option<Guard> { - None - } -} - -#[cfg(any( - all(target_os = "linux", not(target_env = "musl")), - target_os = "freebsd", - target_os = "macos", - all(target_os = "netbsd", not(target_vendor = "rumprun")), - target_os = "openbsd", - target_os = "solaris" -))] -#[cfg_attr(test, allow(dead_code))] -pub mod guard { - use libc::{mmap, mprotect}; - use libc::{MAP_ANON, MAP_FAILED, MAP_FIXED, MAP_PRIVATE, PROT_NONE, PROT_READ, PROT_WRITE}; - - use crate::ops::Range; - use crate::sync::atomic::{AtomicUsize, Ordering}; - use crate::sys::os; - - // This is initialized in init() and only read from after - static PAGE_SIZE: AtomicUsize = AtomicUsize::new(0); - - pub type Guard = Range<usize>; - - #[cfg(target_os = "solaris")] - unsafe fn get_stack_start() -> Option<*mut libc::c_void> { - let mut current_stack: libc::stack_t = crate::mem::zeroed(); - assert_eq!(libc::stack_getbounds(&mut current_stack), 0); - Some(current_stack.ss_sp) - } - - #[cfg(target_os = "macos")] - unsafe fn get_stack_start() -> Option<*mut libc::c_void> { - let th = libc::pthread_self(); - let stackaddr = - libc::pthread_get_stackaddr_np(th) as usize - libc::pthread_get_stacksize_np(th); - Some(stackaddr as *mut libc::c_void) - } - - #[cfg(target_os = "openbsd")] - unsafe fn get_stack_start() -> Option<*mut libc::c_void> { - let mut current_stack: libc::stack_t = crate::mem::zeroed(); - assert_eq!(libc::pthread_stackseg_np(libc::pthread_self(), &mut current_stack), 0); - - let stackaddr = if libc::pthread_main_np() == 1 { - // main thread - current_stack.ss_sp as usize - current_stack.ss_size + PAGE_SIZE.load(Ordering::Relaxed) - } else { - // new thread - current_stack.ss_sp as usize - current_stack.ss_size - }; - Some(stackaddr as *mut libc::c_void) - } - - #[cfg(any( - target_os = "android", - target_os = "freebsd", - target_os = "linux", - target_os = "netbsd", - target_os = "l4re" - ))] - unsafe fn get_stack_start() -> Option<*mut libc::c_void> { - let mut ret = None; - let mut attr: libc::pthread_attr_t = crate::mem::zeroed(); - assert_eq!(libc::pthread_attr_init(&mut attr), 0); - #[cfg(target_os = "freebsd")] - let e = libc::pthread_attr_get_np(libc::pthread_self(), &mut attr); - #[cfg(not(target_os = "freebsd"))] - let e = libc::pthread_getattr_np(libc::pthread_self(), &mut attr); - if e == 0 { - let mut stackaddr = crate::ptr::null_mut(); - let mut stacksize = 0; - assert_eq!(libc::pthread_attr_getstack(&attr, &mut stackaddr, &mut stacksize), 0); - ret = Some(stackaddr); - } - assert_eq!(libc::pthread_attr_destroy(&mut attr), 0); - ret - } - - // Precondition: PAGE_SIZE is initialized. - unsafe fn get_stack_start_aligned() -> Option<*mut libc::c_void> { - let page_size = PAGE_SIZE.load(Ordering::Relaxed); - assert!(page_size != 0); - let stackaddr = get_stack_start()?; - - // Ensure stackaddr is page aligned! A parent process might - // have reset RLIMIT_STACK to be non-page aligned. The - // pthread_attr_getstack() reports the usable stack area - // stackaddr < stackaddr + stacksize, so if stackaddr is not - // page-aligned, calculate the fix such that stackaddr < - // new_page_aligned_stackaddr < stackaddr + stacksize - let remainder = (stackaddr as usize) % page_size; - Some(if remainder == 0 { - stackaddr - } else { - ((stackaddr as usize) + page_size - remainder) as *mut libc::c_void - }) - } - - pub unsafe fn init() -> Option<Guard> { - let page_size = os::page_size(); - PAGE_SIZE.store(page_size, Ordering::Relaxed); - - let stackaddr = get_stack_start_aligned()?; - - if cfg!(target_os = "linux") { - // Linux doesn't allocate the whole stack right away, and - // the kernel has its own stack-guard mechanism to fault - // when growing too close to an existing mapping. If we map - // our own guard, then the kernel starts enforcing a rather - // large gap above that, rendering much of the possible - // stack space useless. See #43052. - // - // Instead, we'll just note where we expect rlimit to start - // faulting, so our handler can report "stack overflow", and - // trust that the kernel's own stack guard will work. - let stackaddr = stackaddr as usize; - Some(stackaddr - page_size..stackaddr) - } else { - // Reallocate the last page of the stack. - // This ensures SIGBUS will be raised on - // stack overflow. - // Systems which enforce strict PAX MPROTECT do not allow - // to mprotect() a mapping with less restrictive permissions - // than the initial mmap() used, so we mmap() here with - // read/write permissions and only then mprotect() it to - // no permissions at all. See issue #50313. - let result = mmap( - stackaddr, - page_size, - PROT_READ | PROT_WRITE, - MAP_PRIVATE | MAP_ANON | MAP_FIXED, - -1, - 0, - ); - if result != stackaddr || result == MAP_FAILED { - panic!("failed to allocate a guard page"); - } - - let result = mprotect(stackaddr, page_size, PROT_NONE); - if result != 0 { - panic!("failed to protect the guard page"); - } - - let guardaddr = stackaddr as usize; - let offset = if cfg!(target_os = "freebsd") { 2 } else { 1 }; - - Some(guardaddr..guardaddr + offset * page_size) - } - } - - #[cfg(any(target_os = "macos", target_os = "openbsd", target_os = "solaris"))] - pub unsafe fn current() -> Option<Guard> { - let stackaddr = get_stack_start()? as usize; - Some(stackaddr - PAGE_SIZE.load(Ordering::Relaxed)..stackaddr) - } - - #[cfg(any( - target_os = "android", - target_os = "freebsd", - target_os = "linux", - target_os = "netbsd", - target_os = "l4re" - ))] - pub unsafe fn current() -> Option<Guard> { - let mut ret = None; - let mut attr: libc::pthread_attr_t = crate::mem::zeroed(); - assert_eq!(libc::pthread_attr_init(&mut attr), 0); - #[cfg(target_os = "freebsd")] - let e = libc::pthread_attr_get_np(libc::pthread_self(), &mut attr); - #[cfg(not(target_os = "freebsd"))] - let e = libc::pthread_getattr_np(libc::pthread_self(), &mut attr); - if e == 0 { - let mut guardsize = 0; - assert_eq!(libc::pthread_attr_getguardsize(&attr, &mut guardsize), 0); - if guardsize == 0 { - panic!("there is no guard page"); - } - let mut stackaddr = crate::ptr::null_mut(); - let mut size = 0; - assert_eq!(libc::pthread_attr_getstack(&attr, &mut stackaddr, &mut size), 0); - - let stackaddr = stackaddr as usize; - ret = if cfg!(target_os = "freebsd") { - // FIXME does freebsd really fault *below* the guard addr? - let guardaddr = stackaddr - guardsize; - Some(guardaddr - PAGE_SIZE.load(Ordering::Relaxed)..guardaddr) - } else if cfg!(target_os = "netbsd") { - Some(stackaddr - guardsize..stackaddr) - } else if cfg!(all(target_os = "linux", target_env = "gnu")) { - // glibc used to include the guard area within the stack, as noted in the BUGS - // section of `man pthread_attr_getguardsize`. This has been corrected starting - // with glibc 2.27, and in some distro backports, so the guard is now placed at the - // end (below) the stack. There's no easy way for us to know which we have at - // runtime, so we'll just match any fault in the range right above or below the - // stack base to call that fault a stack overflow. - Some(stackaddr - guardsize..stackaddr + guardsize) - } else { - Some(stackaddr..stackaddr + guardsize) - }; - } - assert_eq!(libc::pthread_attr_destroy(&mut attr), 0); - ret - } -} - -// 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(target_os = "linux")] -#[allow(deprecated)] -fn min_stack_size(attr: *const libc::pthread_attr_t) -> usize { - weak!(fn __pthread_get_minstack(*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(target_os = "linux"), not(target_os = "netbsd")))] -fn min_stack_size(_: *const libc::pthread_attr_t) -> usize { - libc::PTHREAD_STACK_MIN -} - -#[cfg(target_os = "netbsd")] -fn min_stack_size(_: *const libc::pthread_attr_t) -> usize { - 2048 // just a guess -} |