1 /* Copyright (c) 2015, Google Inc.
2  *
3  * Permission to use, copy, modify, and/or distribute this software for any
4  * purpose with or without fee is hereby granted, provided that the above
5  * copyright notice and this permission notice appear in all copies.
6  *
7  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
8  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
10  * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
12  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
13  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
14 
15 #include "internal.h"
16 
17 #include <stdlib.h>
18 
19 #include <openssl/type_check.h>
20 
21 
22 #if !defined(OPENSSL_C11_ATOMIC)
23 
24 OPENSSL_COMPILE_ASSERT((CRYPTO_refcount_t)-1 == CRYPTO_REFCOUNT_MAX,
25                        CRYPTO_REFCOUNT_MAX_is_incorrect);
26 
27 static struct CRYPTO_STATIC_MUTEX g_refcount_lock = CRYPTO_STATIC_MUTEX_INIT;
28 
CRYPTO_refcount_inc(CRYPTO_refcount_t * count)29 void CRYPTO_refcount_inc(CRYPTO_refcount_t *count) {
30   CRYPTO_STATIC_MUTEX_lock_write(&g_refcount_lock);
31   if (*count < CRYPTO_REFCOUNT_MAX) {
32     (*count)++;
33   }
34   CRYPTO_STATIC_MUTEX_unlock(&g_refcount_lock);
35 }
36 
CRYPTO_refcount_dec_and_test_zero(CRYPTO_refcount_t * count)37 int CRYPTO_refcount_dec_and_test_zero(CRYPTO_refcount_t *count) {
38   int ret;
39 
40   CRYPTO_STATIC_MUTEX_lock_write(&g_refcount_lock);
41   if (*count == 0) {
42     abort();
43   }
44   if (*count < CRYPTO_REFCOUNT_MAX) {
45     (*count)--;
46   }
47   ret = (*count == 0);
48   CRYPTO_STATIC_MUTEX_unlock(&g_refcount_lock);
49 
50   return ret;
51 }
52 
53 #endif  /* OPENSSL_C11_ATOMIC */
54