mv std libs to library/
This commit is contained in:
parent
9be8ffcb02
commit
2c31b45ae8
875 changed files with 1255 additions and 1223 deletions
94
library/std/src/sys/unix/thread_local_dtor.rs
Normal file
94
library/std/src/sys/unix/thread_local_dtor.rs
Normal file
|
@ -0,0 +1,94 @@
|
|||
#![cfg(target_thread_local)]
|
||||
#![unstable(feature = "thread_local_internals", issue = "none")]
|
||||
|
||||
//! Provides thread-local destructors without an associated "key", which
|
||||
//! can be more efficient.
|
||||
|
||||
// Since what appears to be glibc 2.18 this symbol has been shipped which
|
||||
// GCC and clang both use to invoke destructors in thread_local globals, so
|
||||
// let's do the same!
|
||||
//
|
||||
// Note, however, that we run on lots older linuxes, as well as cross
|
||||
// compiling from a newer linux to an older linux, so we also have a
|
||||
// fallback implementation to use as well.
|
||||
#[cfg(any(
|
||||
target_os = "linux",
|
||||
target_os = "fuchsia",
|
||||
target_os = "redox",
|
||||
target_os = "emscripten"
|
||||
))]
|
||||
pub unsafe fn register_dtor(t: *mut u8, dtor: unsafe extern "C" fn(*mut u8)) {
|
||||
use crate::mem;
|
||||
use crate::sys_common::thread_local_dtor::register_dtor_fallback;
|
||||
|
||||
extern "C" {
|
||||
#[linkage = "extern_weak"]
|
||||
static __dso_handle: *mut u8;
|
||||
#[linkage = "extern_weak"]
|
||||
static __cxa_thread_atexit_impl: *const libc::c_void;
|
||||
}
|
||||
if !__cxa_thread_atexit_impl.is_null() {
|
||||
type F = unsafe extern "C" fn(
|
||||
dtor: unsafe extern "C" fn(*mut u8),
|
||||
arg: *mut u8,
|
||||
dso_handle: *mut u8,
|
||||
) -> libc::c_int;
|
||||
mem::transmute::<*const libc::c_void, F>(__cxa_thread_atexit_impl)(
|
||||
dtor,
|
||||
t,
|
||||
&__dso_handle as *const _ as *mut _,
|
||||
);
|
||||
return;
|
||||
}
|
||||
register_dtor_fallback(t, dtor);
|
||||
}
|
||||
|
||||
// This implementation is very similar to register_dtor_fallback in
|
||||
// sys_common/thread_local.rs. The main difference is that we want to hook into
|
||||
// macOS's analog of the above linux function, _tlv_atexit. OSX will run the
|
||||
// registered dtors before any TLS slots get freed, and when the main thread
|
||||
// exits.
|
||||
//
|
||||
// Unfortunately, calling _tlv_atexit while tls dtors are running is UB. The
|
||||
// workaround below is to register, via _tlv_atexit, a custom DTOR list once per
|
||||
// thread. thread_local dtors are pushed to the DTOR list without calling
|
||||
// _tlv_atexit.
|
||||
#[cfg(target_os = "macos")]
|
||||
pub unsafe fn register_dtor(t: *mut u8, dtor: unsafe extern "C" fn(*mut u8)) {
|
||||
use crate::cell::Cell;
|
||||
use crate::ptr;
|
||||
|
||||
#[thread_local]
|
||||
static REGISTERED: Cell<bool> = Cell::new(false);
|
||||
if !REGISTERED.get() {
|
||||
_tlv_atexit(run_dtors, ptr::null_mut());
|
||||
REGISTERED.set(true);
|
||||
}
|
||||
|
||||
type List = Vec<(*mut u8, unsafe extern "C" fn(*mut u8))>;
|
||||
|
||||
#[thread_local]
|
||||
static DTORS: Cell<*mut List> = Cell::new(ptr::null_mut());
|
||||
if DTORS.get().is_null() {
|
||||
let v: Box<List> = box Vec::new();
|
||||
DTORS.set(Box::into_raw(v));
|
||||
}
|
||||
|
||||
extern "C" {
|
||||
fn _tlv_atexit(dtor: unsafe extern "C" fn(*mut u8), arg: *mut u8);
|
||||
}
|
||||
|
||||
let list: &mut List = &mut *DTORS.get();
|
||||
list.push((t, dtor));
|
||||
|
||||
unsafe extern "C" fn run_dtors(_: *mut u8) {
|
||||
let mut ptr = DTORS.replace(ptr::null_mut());
|
||||
while !ptr.is_null() {
|
||||
let list = Box::from_raw(ptr);
|
||||
for (ptr, dtor) in list.into_iter() {
|
||||
dtor(ptr);
|
||||
}
|
||||
ptr = DTORS.replace(ptr::null_mut());
|
||||
}
|
||||
}
|
||||
}
|
Loading…
Add table
Add a link
Reference in a new issue