|  | =pod | 
|  |  | 
|  | =head1 NAME | 
|  |  | 
|  | BIO_new, BIO_up_ref, BIO_free, BIO_vfree, BIO_free_all, | 
|  | BIO_set - BIO allocation and freeing functions | 
|  |  | 
|  | =head1 SYNOPSIS | 
|  |  | 
|  | #include <openssl/bio.h> | 
|  |  | 
|  | BIO *  BIO_new(const BIO_METHOD *type); | 
|  | int    BIO_set(BIO *a, const BIO_METHOD *type); | 
|  | int    BIO_up_ref(BIO *a); | 
|  | int    BIO_free(BIO *a); | 
|  | void   BIO_vfree(BIO *a); | 
|  | void   BIO_free_all(BIO *a); | 
|  |  | 
|  | =head1 DESCRIPTION | 
|  |  | 
|  | The BIO_new() function returns a new BIO using method B<type>. | 
|  |  | 
|  | BIO_up_ref() increments the reference count associated with the BIO object. | 
|  |  | 
|  | BIO_free() frees up a single BIO, BIO_vfree() also frees up a single BIO | 
|  | but it does not return a value. | 
|  | If B<a> is NULL nothing is done. | 
|  | Calling BIO_free() may also have some effect | 
|  | on the underlying I/O structure, for example it may close the file being | 
|  | referred to under certain circumstances. For more details see the individual | 
|  | BIO_METHOD descriptions. | 
|  |  | 
|  | BIO_free_all() frees up an entire BIO chain, it does not halt if an error | 
|  | occurs freeing up an individual BIO in the chain. | 
|  | If B<a> is NULL nothing is done. | 
|  |  | 
|  | =head1 RETURN VALUES | 
|  |  | 
|  | BIO_new() returns a newly created BIO or NULL if the call fails. | 
|  |  | 
|  | BIO_set(), BIO_up_ref() and BIO_free() return 1 for success and 0 for failure. | 
|  |  | 
|  | BIO_free_all() and BIO_vfree() do not return values. | 
|  |  | 
|  | =head1 NOTES | 
|  |  | 
|  | If BIO_free() is called on a BIO chain it will only free one BIO resulting | 
|  | in a memory leak. | 
|  |  | 
|  | Calling BIO_free_all() on a single BIO has the same effect as calling BIO_free() | 
|  | on it other than the discarded return value. | 
|  |  | 
|  | =head1 HISTORY | 
|  |  | 
|  | BIO_set() was removed in OpenSSL 1.1.0 as BIO type is now opaque. | 
|  |  | 
|  | =head1 EXAMPLE | 
|  |  | 
|  | Create a memory BIO: | 
|  |  | 
|  | BIO *mem = BIO_new(BIO_s_mem()); | 
|  |  | 
|  | =head1 COPYRIGHT | 
|  |  | 
|  | Copyright 2000-2016 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 | 
|  | L<https://www.openssl.org/source/license.html>. | 
|  |  | 
|  | =cut |