1 files changed, 53 insertions, 0 deletions
diff --git a/libc/src/stdlib/exit_handler.h b/libc/src/stdlib/exit_handler.h
new file mode 100644
index 000000000000..8494c2f2e526
--- /dev/null
+++ b/libc/src/stdlib/exit_handler.h
@@ -0,0 +1,53 @@
+//===-- Implementation header for exit_handler ------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_STDLIB_EXIT_HANDLER_H
+#define LLVM_LIBC_SRC_STDLIB_EXIT_HANDLER_H
+
+#include "src/__support/CPP/mutex.h" // lock_guard
+#include "src/__support/blockstore.h"
+#include "src/__support/common.h"
+#include "src/__support/fixedvector.h"
+#include "src/__support/threads/mutex.h"
+
+namespace LIBC_NAMESPACE {
+
+using AtExitCallback = void(void *);
+using StdCAtExitCallback = void(void);
+constexpr size_t CALLBACK_LIST_SIZE_FOR_TESTS = 1024;
+
+struct AtExitUnit {
+  AtExitCallback *callback = nullptr;
+  void *payload = nullptr;
+  LIBC_INLINE constexpr AtExitUnit() = default;
+  LIBC_INLINE constexpr AtExitUnit(AtExitCallback *c, void *p)
+      : callback(c), payload(p) {}
+};
+
+#if defined(LIBC_TARGET_ARCH_IS_GPU)
+using ExitCallbackList = FixedVector<AtExitUnit, 64>;
+#elif defined(LIBC_COPT_PUBLIC_PACKAGING)
+using ExitCallbackList = ReverseOrderBlockStore<AtExitUnit, 32>;
+#else
+using ExitCallbackList = FixedVector<AtExitUnit, CALLBACK_LIST_SIZE_FOR_TESTS>;
+#endif
+
+extern ExitCallbackList atexit_callbacks;
+extern ExitCallbackList at_quick_exit_callbacks;
+
+extern Mutex handler_list_mtx;
+
+void stdc_at_exit_func(void *payload);
+
+void call_exit_callbacks(ExitCallbackList &callbacks);
+
+int add_atexit_unit(ExitCallbackList &callbacks, const AtExitUnit &unit);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_STDLIB_EXIT_HANDLER_H