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925d17f3 RL |
1 | /* |
2 | * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved. | |
3 | * | |
48f4ad77 | 4 | * Licensed under the Apache License 2.0 (the "License"). You may not use |
925d17f3 RL |
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 | ||
660a1e04 MC |
12 | /* |
13 | * DEFINE_RUN_ONCE: Define an initialiser function that should be run exactly | |
14 | * once. It takes no arguments and returns and int result (1 for success or | |
15 | * 0 for failure). Typical usage might be: | |
df443918 | 16 | * |
660a1e04 MC |
17 | * DEFINE_RUN_ONCE(myinitfunc) |
18 | * { | |
19 | * do_some_initialisation(); | |
20 | * if (init_is_successful()) | |
21 | * return 1; | |
22 | * | |
23 | * return 0; | |
24 | * } | |
25 | */ | |
925d17f3 RL |
26 | #define DEFINE_RUN_ONCE(init) \ |
27 | static int init(void); \ | |
28 | int init##_ossl_ret_ = 0; \ | |
29 | void init##_ossl_(void) \ | |
30 | { \ | |
31 | init##_ossl_ret_ = init(); \ | |
32 | } \ | |
33 | static int init(void) | |
660a1e04 MC |
34 | |
35 | /* | |
36 | * DECLARE_RUN_ONCE: Declare an initialiser function that should be run exactly | |
37 | * once that has been defined in another file via DEFINE_RUN_ONCE(). | |
38 | */ | |
925d17f3 RL |
39 | #define DECLARE_RUN_ONCE(init) \ |
40 | extern int init##_ossl_ret_; \ | |
41 | void init##_ossl_(void); | |
42 | ||
660a1e04 MC |
43 | /* |
44 | * DEFINE_RUN_ONCE_STATIC: Define an initialiser function that should be run | |
45 | * exactly once. This function will be declared as static within the file. It | |
46 | * takes no arguments and returns and int result (1 for success or 0 for | |
47 | * failure). Typical usage might be: | |
df443918 | 48 | * |
660a1e04 MC |
49 | * DEFINE_RUN_ONCE_STATIC(myinitfunc) |
50 | * { | |
51 | * do_some_initialisation(); | |
52 | * if (init_is_successful()) | |
53 | * return 1; | |
54 | * | |
55 | * return 0; | |
56 | * } | |
57 | */ | |
925d17f3 RL |
58 | #define DEFINE_RUN_ONCE_STATIC(init) \ |
59 | static int init(void); \ | |
60 | static int init##_ossl_ret_ = 0; \ | |
61 | static void init##_ossl_(void) \ | |
62 | { \ | |
63 | init##_ossl_ret_ = init(); \ | |
64 | } \ | |
65 | static int init(void) | |
66 | ||
660a1e04 MC |
67 | /* |
68 | * DEFINE_RUN_ONCE_STATIC_ALT: Define an alternative initialiser function. This | |
69 | * function will be declared as static within the file. It takes no arguments | |
70 | * and returns and int result (1 for success or 0 for failure). An alternative | |
71 | * initialiser function is expected to be associated with a primary initialiser | |
72 | * function defined via DEFINE_ONCE_STATIC where both functions use the same | |
73 | * CRYPTO_ONCE object to synchronise. Where an alternative initialiser function | |
74 | * is used only one of the primary or the alternative initialiser function will | |
75 | * ever be called - and that function will be called exactly once. Definitition | |
76 | * of an alternative initialiser function MUST occur AFTER the definition of the | |
df443918 SR |
77 | * primiary initialiser function. |
78 | * | |
660a1e04 | 79 | * Typical usage might be: |
df443918 | 80 | * |
660a1e04 MC |
81 | * DEFINE_RUN_ONCE_STATIC(myinitfunc) |
82 | * { | |
83 | * do_some_initialisation(); | |
84 | * if (init_is_successful()) | |
85 | * return 1; | |
86 | * | |
87 | * return 0; | |
88 | * } | |
df443918 | 89 | * |
660a1e04 MC |
90 | * DEFINE_RUN_ONCE_STATIC_ALT(myaltinitfunc, myinitfunc) |
91 | * { | |
92 | * do_some_alternative_initialisation(); | |
93 | * if (init_is_successful()) | |
94 | * return 1; | |
95 | * | |
96 | * return 0; | |
97 | * } | |
98 | */ | |
99 | #define DEFINE_RUN_ONCE_STATIC_ALT(initalt, init) \ | |
100 | static int initalt(void); \ | |
101 | static void initalt##_ossl_(void) \ | |
102 | { \ | |
103 | init##_ossl_ret_ = initalt(); \ | |
104 | } \ | |
105 | static int initalt(void) | |
106 | ||
925d17f3 RL |
107 | /* |
108 | * RUN_ONCE - use CRYPTO_THREAD_run_once, and check if the init succeeded | |
109 | * @once: pointer to static object of type CRYPTO_ONCE | |
110 | * @init: function name that was previously given to DEFINE_RUN_ONCE, | |
37b8f1e2 RL |
111 | * DEFINE_RUN_ONCE_STATIC or DECLARE_RUN_ONCE. This function |
112 | * must return 1 for success or 0 for failure. | |
925d17f3 | 113 | * |
37b8f1e2 RL |
114 | * The return value is 1 on success (*) or 0 in case of error. |
115 | * | |
116 | * (*) by convention, since the init function must return 1 on success. | |
925d17f3 RL |
117 | */ |
118 | #define RUN_ONCE(once, init) \ | |
119 | (CRYPTO_THREAD_run_once(once, init##_ossl_) ? init##_ossl_ret_ : 0) | |
660a1e04 MC |
120 | |
121 | /* | |
122 | * RUN_ONCE_ALT - use CRYPTO_THREAD_run_once, to run an alternative initialiser | |
123 | * function and check if that initialisation succeeded | |
124 | * @once: pointer to static object of type CRYPTO_ONCE | |
125 | * @initalt: alternative initialiser function name that was previously given to | |
126 | * DEFINE_RUN_ONCE_STATIC_ALT. This function must return 1 for | |
127 | * success or 0 for failure. | |
128 | * @init: primary initialiser function name that was previously given to | |
129 | * DEFINE_RUN_ONCE_STATIC. This function must return 1 for success or | |
130 | * 0 for failure. | |
131 | * | |
132 | * The return value is 1 on success (*) or 0 in case of error. | |
133 | * | |
134 | * (*) by convention, since the init function must return 1 on success. | |
135 | */ | |
136 | #define RUN_ONCE_ALT(once, initalt, init) \ | |
137 | (CRYPTO_THREAD_run_once(once, initalt##_ossl_) ? init##_ossl_ret_ : 0) |