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| author | Vivian Lim <[email protected]> | 2021-02-06 22:11:59 -0800 |
|---|---|---|
| committer | Vivian Lim <[email protected]> | 2021-02-06 22:11:59 -0800 |
| commit | 64423f0e34cc4a7d78c15b345b3b8f58243d8286 (patch) | |
| tree | cc20e2e7f0fc35abf470e20e61d3d48f0d954f3b /ctr-std/src/sys/redox/fast_thread_local.rs | |
| parent | Support libctru 2.0 (diff) | |
| download | archived-ctru-rs-64423f0e34cc4a7d78c15b345b3b8f58243d8286.tar.xz archived-ctru-rs-64423f0e34cc4a7d78c15b345b3b8f58243d8286.zip | |
Delete ctr-std to use my fork of the rust repo instead
Diffstat (limited to 'ctr-std/src/sys/redox/fast_thread_local.rs')
| -rw-r--r-- | ctr-std/src/sys/redox/fast_thread_local.rs | 121 |
1 files changed, 0 insertions, 121 deletions
diff --git a/ctr-std/src/sys/redox/fast_thread_local.rs b/ctr-std/src/sys/redox/fast_thread_local.rs deleted file mode 100644 index 6a007e9..0000000 --- a/ctr-std/src/sys/redox/fast_thread_local.rs +++ /dev/null @@ -1,121 +0,0 @@ -// Copyright 2016 The Rust Project Developers. See the COPYRIGHT -// file at the top-level directory of this distribution and at -// http://rust-lang.org/COPYRIGHT. -// -// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or -// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license -// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your -// option. This file may not be copied, modified, or distributed -// except according to those terms. - -#![cfg(target_thread_local)] -#![unstable(feature = "thread_local_internals", issue = "0")] - -use cell::{Cell, UnsafeCell}; -use mem; -use ptr; - - -pub struct Key<T> { - inner: UnsafeCell<Option<T>>, - - // Metadata to keep track of the state of the destructor. Remember that - // these variables are thread-local, not global. - dtor_registered: Cell<bool>, - dtor_running: Cell<bool>, -} - -unsafe impl<T> ::marker::Sync for Key<T> { } - -impl<T> Key<T> { - pub const fn new() -> Key<T> { - Key { - inner: UnsafeCell::new(None), - dtor_registered: Cell::new(false), - dtor_running: Cell::new(false) - } - } - - pub fn get(&'static self) -> Option<&'static UnsafeCell<Option<T>>> { - unsafe { - if mem::needs_drop::<T>() && self.dtor_running.get() { - return None - } - self.register_dtor(); - } - Some(&self.inner) - } - - unsafe fn register_dtor(&self) { - if !mem::needs_drop::<T>() || self.dtor_registered.get() { - return - } - - register_dtor(self as *const _ as *mut u8, - destroy_value::<T>); - self.dtor_registered.set(true); - } -} - -pub unsafe fn register_dtor(t: *mut u8, dtor: unsafe extern fn(*mut u8)) { - // The fallback implementation uses a vanilla OS-based TLS key to track - // the list of destructors that need to be run for this thread. The key - // then has its own destructor which runs all the other destructors. - // - // The destructor for DTORS is a little special in that it has a `while` - // loop to continuously drain the list of registered destructors. It - // *should* be the case that this loop always terminates because we - // provide the guarantee that a TLS key cannot be set after it is - // flagged for destruction. - use sys_common::thread_local as os; - - static DTORS: os::StaticKey = os::StaticKey::new(Some(run_dtors)); - type List = Vec<(*mut u8, unsafe extern fn(*mut u8))>; - if DTORS.get().is_null() { - let v: Box<List> = box Vec::new(); - DTORS.set(Box::into_raw(v) as *mut u8); - } - let list: &mut List = &mut *(DTORS.get() as *mut List); - list.push((t, dtor)); - - unsafe extern fn run_dtors(mut ptr: *mut u8) { - while !ptr.is_null() { - let list: Box<List> = Box::from_raw(ptr as *mut List); - for (ptr, dtor) in list.into_iter() { - dtor(ptr); - } - ptr = DTORS.get(); - DTORS.set(ptr::null_mut()); - } - } -} - -pub unsafe extern fn destroy_value<T>(ptr: *mut u8) { - let ptr = ptr as *mut Key<T>; - // Right before we run the user destructor be sure to flag the - // destructor as running for this thread so calls to `get` will return - // `None`. - (*ptr).dtor_running.set(true); - - // The macOS implementation of TLS apparently had an odd aspect to it - // where the pointer we have may be overwritten while this destructor - // is running. Specifically if a TLS destructor re-accesses TLS it may - // trigger a re-initialization of all TLS variables, paving over at - // least some destroyed ones with initial values. - // - // This means that if we drop a TLS value in place on macOS that we could - // revert the value to its original state halfway through the - // destructor, which would be bad! - // - // Hence, we use `ptr::read` on macOS (to move to a "safe" location) - // instead of drop_in_place. - if cfg!(target_os = "macos") { - ptr::read((*ptr).inner.get()); - } else { - ptr::drop_in_place((*ptr).inner.get()); - } -} - -pub fn requires_move_before_drop() -> bool { - false -} |