std/sys/thread_local/key/
unix.rs

1use crate::mem;
2
3// For WASI add a few symbols not in upstream `libc` just yet.
4#[cfg(all(target_os = "wasi", target_env = "p1", target_feature = "atomics"))]
5mod libc {
6    use crate::ffi;
7
8    #[allow(non_camel_case_types)]
9    pub type pthread_key_t = ffi::c_uint;
10
11    unsafe extern "C" {
12        pub fn pthread_key_create(
13            key: *mut pthread_key_t,
14            destructor: unsafe extern "C" fn(*mut ffi::c_void),
15        ) -> ffi::c_int;
16        #[allow(dead_code)]
17        pub fn pthread_getspecific(key: pthread_key_t) -> *mut ffi::c_void;
18        pub fn pthread_setspecific(key: pthread_key_t, value: *const ffi::c_void) -> ffi::c_int;
19        pub fn pthread_key_delete(key: pthread_key_t) -> ffi::c_int;
20    }
21}
22
23pub type Key = libc::pthread_key_t;
24
25#[inline]
26pub fn create(dtor: Option<unsafe extern "C" fn(*mut u8)>) -> Key {
27    let mut key = 0;
28    assert_eq!(unsafe { libc::pthread_key_create(&mut key, mem::transmute(dtor)) }, 0);
29    key
30}
31
32#[inline]
33pub unsafe fn set(key: Key, value: *mut u8) {
34    let r = unsafe { libc::pthread_setspecific(key, value as *mut _) };
35    debug_assert_eq!(r, 0);
36}
37
38#[inline]
39#[cfg(any(not(target_thread_local), test))]
40pub unsafe fn get(key: Key) -> *mut u8 {
41    unsafe { libc::pthread_getspecific(key) as *mut u8 }
42}
43
44#[inline]
45pub unsafe fn destroy(key: Key) {
46    let r = unsafe { libc::pthread_key_delete(key) };
47    debug_assert_eq!(r, 0);
48}