src/libstd/sys/cloudabi/thread.rs

   1 // Copyright 2014-2018 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.
   4 //
   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.
  10
  11 use boxed::FnBox;
  12 use cmp;
  13 use ffi::CStr;
  14 use io;
  15 use libc;
  16 use mem;
  17 use ptr;
  18 use sys::cloudabi::abi;
  19 use sys::time::dur2intervals;
  20 use sys_common::thread::*;
  21 use time::Duration;
  22
  23 pub const DEFAULT_MIN_STACK_SIZE: usize = 2 * 1024 * 1024;
  24
  25 pub struct Thread {
  26     id: libc::pthread_t,
  27 }
  28
  29 // CloudABI has pthread_t as a pointer in which case we still want
  30 // a thread to be Send/Sync
  31 unsafe impl Send for Thread {}
  32 unsafe impl Sync for Thread {}
  33
  34 impl Thread {
  35     pub unsafe fn new<'a>(stack: usize, p: Box<dyn FnBox() + 'a>) -> io::Result<Thread> {
  36         let p = box p;
  37         let mut native: libc::pthread_t = mem::zeroed();
  38         let mut attr: libc::pthread_attr_t = mem::zeroed();
  39         assert_eq!(libc::pthread_attr_init(&mut attr), 0);
  40
  41         let stack_size = cmp::max(stack, min_stack_size(&attr));
  42         assert_eq!(libc::pthread_attr_setstacksize(&mut attr, stack_size), 0);
  43
  44         let ret = libc::pthread_create(&mut native, &attr, thread_start, &*p as *const _ as *mut _);
  45         assert_eq!(libc::pthread_attr_destroy(&mut attr), 0);
  46
  47         return if ret != 0 {
  48             Err(io::Error::from_raw_os_error(ret))
  49         } else {
  50             mem::forget(p); // ownership passed to pthread_create
  51             Ok(Thread { id: native })
  52         };
  53
  54         extern "C" fn thread_start(main: *mut libc::c_void) -> *mut libc::c_void {
  55             unsafe {
  56                 start_thread(main as *mut u8);
  57             }
  58             ptr::null_mut()
  59         }
  60     }
  61
  62     pub fn yield_now() {
  63         let ret = unsafe { abi::thread_yield() };
  64         debug_assert_eq!(ret, abi::errno::SUCCESS);
  65     }
  66
  67     pub fn set_name(_name: &CStr) {
  68         // CloudABI has no way to set a thread name.
  69     }
  70
  71     pub fn sleep(dur: Duration) {
  72         unsafe {
  73             let subscription = abi::subscription {
  74                 type_: abi::eventtype::CLOCK,
  75                 union: abi::subscription_union {
  76                     clock: abi::subscription_clock {
  77                         clock_id: abi::clockid::MONOTONIC,
  78                         timeout: dur2intervals(&dur),
  79                         ..mem::zeroed()
  80                     },
  81                 },
  82                 ..mem::zeroed()
  83             };
  84             let mut event: abi::event = mem::uninitialized();
  85             let mut nevents: usize = mem::uninitialized();
  86             let ret = abi::poll(&subscription, &mut event, 1, &mut nevents);
  87             assert_eq!(ret, abi::errno::SUCCESS);
  88             assert_eq!(event.error, abi::errno::SUCCESS);
  89         }
  90     }
  91
  92     pub fn join(self) {
  93         unsafe {
  94             let ret = libc::pthread_join(self.id, ptr::null_mut());
  95             mem::forget(self);
  96             assert!(
  97                 ret == 0,
  98                 "failed to join thread: {}",
  99                 io::Error::from_raw_os_error(ret)
 100             );
 101         }
 102     }
 103 }
 104
 105 impl Drop for Thread {
 106     fn drop(&mut self) {
 107         let ret = unsafe { libc::pthread_detach(self.id) };
 108         debug_assert_eq!(ret, 0);
 109     }
 110 }
 111
 112 #[cfg_attr(test, allow(dead_code))]
 113 pub mod guard {
 114     pub type Guard = !;
 115     pub unsafe fn current() -> Option<Guard> {
 116         None
 117     }
 118     pub unsafe fn init() -> Option<Guard> {
 119         None
 120     }
 121     pub unsafe fn deinit() {}
 122 }
 123
 124 fn min_stack_size(_: *const libc::pthread_attr_t) -> usize {
 125     libc::PTHREAD_STACK_MIN
 126 }