src/libstd/sys_common/thread_info.rs

   1 #![allow(dead_code)] // stack_guard isn't used right now on all platforms
   2
   3 use crate::cell::RefCell;
   4 use crate::sys::thread::guard::Guard;
   5 use crate::thread::Thread;
   6
   7 struct ThreadInfo {
   8     stack_guard: Option<Guard>,
   9     thread: Thread,
  10 }
  11
  12 thread_local! { static THREAD_INFO: RefCell<Option<ThreadInfo>> = RefCell::new(None) }
  13
  14 impl ThreadInfo {
  15     fn with<R, F>(f: F) -> Option<R>
  16     where
  17         F: FnOnce(&mut ThreadInfo) -> R,
  18     {
  19         THREAD_INFO
  20             .try_with(move |c| {
  21                 if c.borrow().is_none() {
  22                     *c.borrow_mut() =
  23                         Some(ThreadInfo { stack_guard: None, thread: Thread::new(None) })
  24                 }
  25                 f(c.borrow_mut().as_mut().unwrap())
  26             })
  27             .ok()
  28     }
  29 }
  30
  31 pub fn current_thread() -> Option<Thread> {
  32     ThreadInfo::with(|info| info.thread.clone())
  33 }
  34
  35 pub fn stack_guard() -> Option<Guard> {
  36     ThreadInfo::with(|info| info.stack_guard.clone()).and_then(|o| o)
  37 }
  38
  39 pub fn set(stack_guard: Option<Guard>, thread: Thread) {
  40     THREAD_INFO.with(|c| assert!(c.borrow().is_none()));
  41     THREAD_INFO.with(move |c| *c.borrow_mut() = Some(ThreadInfo { stack_guard, thread }));
  42 }
  43
  44 pub fn reset_guard(stack_guard: Option<Guard>) {
  45     THREAD_INFO.with(move |c| c.borrow_mut().as_mut().unwrap().stack_guard = stack_guard);
  46 }