xref: /aosp_15_r20/external/llvm-libc/src/stdlib/atexit.cpp (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
1 //===-- Implementation of atexit ------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "src/stdlib/atexit.h"
10 #include "hdr/types/atexithandler_t.h"
11 #include "src/__support/common.h"
12 #include "src/__support/macros/config.h"
13 #include "src/stdlib/exit_handler.h"
14 
15 namespace LIBC_NAMESPACE_DECL {
16 
17 constinit ExitCallbackList atexit_callbacks;
18 Mutex handler_list_mtx(false, false, false, false);
19 [[gnu::weak]] extern void teardown_main_tls();
20 
21 extern "C" {
22 
__cxa_atexit(AtExitCallback * callback,void * payload,void *)23 int __cxa_atexit(AtExitCallback *callback, void *payload, void *) {
24   return add_atexit_unit(atexit_callbacks, {callback, payload});
25 }
26 
__cxa_finalize(void * dso)27 void __cxa_finalize(void *dso) {
28   if (!dso) {
29     call_exit_callbacks(atexit_callbacks);
30     if (teardown_main_tls)
31       teardown_main_tls();
32   }
33 }
34 
35 } // extern "C"
36 
37 LLVM_LIBC_FUNCTION(int, atexit, (__atexithandler_t callback)) {
38   return add_atexit_unit(
39       atexit_callbacks,
40       {&stdc_at_exit_func, reinterpret_cast<void *>(callback)});
41 }
42 
43 } // namespace LIBC_NAMESPACE_DECL
44