xref: /freebsd/crypto/openssl/include/internal/thread_once.h (revision 0957b409a90fd597c1e9124cbaf3edd2b488f4ac)
1 /*
2  * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the OpenSSL license (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 #include <openssl/crypto.h>
11 
12 #define DEFINE_RUN_ONCE(init)                   \
13     static int init(void);                     \
14     int init##_ossl_ret_ = 0;                   \
15     void init##_ossl_(void)                     \
16     {                                           \
17         init##_ossl_ret_ = init();              \
18     }                                           \
19     static int init(void)
20 #define DECLARE_RUN_ONCE(init)                  \
21     extern int init##_ossl_ret_;                \
22     void init##_ossl_(void);
23 
24 #define DEFINE_RUN_ONCE_STATIC(init)            \
25     static int init(void);                     \
26     static int init##_ossl_ret_ = 0;            \
27     static void init##_ossl_(void)              \
28     {                                           \
29         init##_ossl_ret_ = init();              \
30     }                                           \
31     static int init(void)
32 
33 /*
34  * RUN_ONCE - use CRYPTO_THREAD_run_once, and check if the init succeeded
35  * @once: pointer to static object of type CRYPTO_ONCE
36  * @init: function name that was previously given to DEFINE_RUN_ONCE,
37  *        DEFINE_RUN_ONCE_STATIC or DECLARE_RUN_ONCE.  This function
38  *        must return 1 for success or 0 for failure.
39  *
40  * The return value is 1 on success (*) or 0 in case of error.
41  *
42  * (*) by convention, since the init function must return 1 on success.
43  */
44 #define RUN_ONCE(once, init)                                            \
45     (CRYPTO_THREAD_run_once(once, init##_ossl_) ? init##_ossl_ret_ : 0)
46