openssl/include/internal/thread_once.h
Richard Levitte 37b8f1e21c Clarify what RUN_ONCE returns
RUN_ONCE really just returns 0 on failure or whatever the init
function returned.  By convention, however, the init function must
return 0 on failure and 1 on success.  This needed to be clarified.

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2225)
2017-01-13 13:10:21 +01:00

46 lines
1.8 KiB
C

/*
* Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <openssl/crypto.h>
#define DEFINE_RUN_ONCE(init) \
static int init(void); \
int init##_ossl_ret_ = 0; \
void init##_ossl_(void) \
{ \
init##_ossl_ret_ = init(); \
} \
static int init(void)
#define DECLARE_RUN_ONCE(init) \
extern int init##_ossl_ret_; \
void init##_ossl_(void);
#define DEFINE_RUN_ONCE_STATIC(init) \
static int init(void); \
static int init##_ossl_ret_ = 0; \
static void init##_ossl_(void) \
{ \
init##_ossl_ret_ = init(); \
} \
static int init(void)
/*
* RUN_ONCE - use CRYPTO_THREAD_run_once, and check if the init succeeded
* @once: pointer to static object of type CRYPTO_ONCE
* @init: function name that was previously given to DEFINE_RUN_ONCE,
* DEFINE_RUN_ONCE_STATIC or DECLARE_RUN_ONCE. This function
* must return 1 for success or 0 for failure.
*
* The return value is 1 on success (*) or 0 in case of error.
*
* (*) by convention, since the init function must return 1 on success.
*/
#define RUN_ONCE(once, init) \
(CRYPTO_THREAD_run_once(once, init##_ossl_) ? init##_ossl_ret_ : 0)