chore: checkpoint before Python removal

vendor/aws-lc-sys/aws-lc/crypto/refcount_lock.c

@@ -0,0 +1,42 @@
+// Copyright (c) 2015, Google Inc.
+// SPDX-License-Identifier: ISC
+
+#include "internal.h"
+
+#include <stdlib.h>
+
+#include <openssl/type_check.h>
+
+
+#if !defined(OPENSSL_C11_ATOMIC) && !defined(OPENSSL_WINDOWS_ATOMIC)
+
+OPENSSL_STATIC_ASSERT((CRYPTO_refcount_t)-1 == CRYPTO_REFCOUNT_MAX,
+                      CRYPTO_REFCOUNT_MAX_is_incorrect)
+
+static struct CRYPTO_STATIC_MUTEX g_refcount_lock = CRYPTO_STATIC_MUTEX_INIT;
+
+void CRYPTO_refcount_inc(CRYPTO_refcount_t *count) {
+  CRYPTO_STATIC_MUTEX_lock_write(&g_refcount_lock);
+  if (*count < CRYPTO_REFCOUNT_MAX) {
+    (*count)++;
+  }
+  CRYPTO_STATIC_MUTEX_unlock_write(&g_refcount_lock);
+}
+
+int CRYPTO_refcount_dec_and_test_zero(CRYPTO_refcount_t *count) {
+  int ret;
+
+  CRYPTO_STATIC_MUTEX_lock_write(&g_refcount_lock);
+  if (*count == 0) {
+    abort();
+  }
+  if (*count < CRYPTO_REFCOUNT_MAX) {
+    (*count)--;
+  }
+  ret = (*count == 0);
+  CRYPTO_STATIC_MUTEX_unlock_write(&g_refcount_lock);
+
+  return ret;
+}
+
+#endif  // !OPENSSL_C11_ATOMIC && !OPENSSL_WINDOWS_ATOMICS