bjoernager/rust
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Run destructors from existing tls callback

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This commit is contained in:
Chris Denton 2021-11-01 15:05:57 +00:00
parent 9212f4070e
commit 1048651fa3
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GPG key ID: 713472F2F45627DE
2 changed files with 14 additions and 23 deletions
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35
library/std/src/sys/windows/thread_local_dtor.rs
View file

@ -3,7 +3,6 @@
#![unstable(feature = "thread_local_internals", issue = "none")]
#![cfg(target_thread_local)]
use super::c;
// Using a per-thread list avoids the problems in synchronizing global state.
#[thread_local]
@ -13,27 +12,17 @@ pub unsafe fn register_dtor(t: *mut u8, dtor: unsafe extern "C" fn(*mut u8)) {
DESTRUCTORS.push((t, dtor));
}
// See windows/thread_local_keys.rs for an explanation of this callback function.
// The short version is that all the function pointers in the `.CRT$XL*` array
// will be called whenever a thread or process starts or ends.
#[link_section = ".CRT$XLD"]
#[doc(hidden)]
#[used]
pub static TLS_CALLBACK: unsafe extern "system" fn(c::LPVOID, c::DWORD, c::LPVOID) = tls_callback;
unsafe extern "system" fn tls_callback(_: c::LPVOID, reason: c::DWORD, _: c::LPVOID) {
if reason == c::DLL_THREAD_DETACH || reason == c::DLL_PROCESS_DETACH {
// Drop all the destructors.
//
// Note: While this is potentially an infinite loop, 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.
while let Some((ptr, dtor)) = DESTRUCTORS.pop() {
(dtor)(ptr);
}
// We're done so free the memory.
DESTRUCTORS.shrink_to_fit();
/// Runs destructors. This should not be called until thread exit.
pub unsafe fn run_keyless_dtors() {
// Drop all the destructors.
//
// Note: While this is potentially an infinite loop, 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.
while let Some((ptr, dtor)) = DESTRUCTORS.pop() {
(dtor)(ptr);
}
// We're done so free the memory.
DESTRUCTORS = Vec::new();
}

2
library/std/src/sys/windows/thread_local_key.rs
View file

@ -196,6 +196,8 @@ pub static p_thread_callback: unsafe extern "system" fn(c::LPVOID, c::DWORD, c::
unsafe extern "system" fn on_tls_callback(h: c::LPVOID, dwReason: c::DWORD, pv: c::LPVOID) {
if dwReason == c::DLL_THREAD_DETACH || dwReason == c::DLL_PROCESS_DETACH {
run_dtors();
#[cfg(target_thread_local)]
super::thread_local_dtor::run_keyless_dtors();
}
// See comments above for what this is doing. Note that we don't need this