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BIO_socket_wait(3)                  OpenSSL                 BIO_socket_wait(3)



NAME
       BIO_socket_wait, BIO_wait, BIO_do_connect_retry - BIO connection
       utility functions

LIBRARY
       libcrypto, -lcrypto

SYNOPSIS
        #include <openssl/bio.h>

        #ifndef OPENSSL_NO_SOCK
        int BIO_socket_wait(int fd, int for_read, time_t max_time);
        #endif
        int BIO_wait(BIO *bio, time_t max_time, unsigned int nap_milliseconds);
        int BIO_do_connect_retry(BIO *bio, int timeout, int nap_milliseconds);

DESCRIPTION
       BIO_socket_wait() waits on the socket fd for reading if for_read is not
       0, else for writing, at most until max_time.  It succeeds immediately
       if max_time == 0 (which means no timeout given).

       BIO_wait() waits at most until max_time on the given (typically socket-
       based) bio, for reading if bio is supposed to read, else for writing.
       It is used by BIO_do_connect_retry() and can be used together
       BIO_read(3).  It succeeds immediately if max_time == 0 (which means no
       timeout given).  If sockets are not available it supports polling by
       succeeding after sleeping at most the given nap_milliseconds in order
       to avoid a tight busy loop.  Via nap_milliseconds the caller determines
       the polling granularity.

       BIO_do_connect_retry() connects via the given bio.  It retries
       BIO_do_connect() as far as needed to reach a definite outcome, i.e.,
       connection succeeded, timeout has been reached, or an error occurred.
       For nonblocking and potentially even non-socket BIOs it polls every
       nap_milliseconds and sleeps in between using BIO_wait().  If
       nap_milliseconds is < 0 then a default value of 100 ms is used.  If the
       timeout parameter is > 0 this indicates the maximum number of seconds
       to wait until the connection is established or a definite error
       occurred.  A value of 0 enables waiting indefinitely (i.e, no timeout),
       while a value < 0 means that BIO_do_connect() is tried only once.  The
       function may, directly or indirectly, invoke ERR_clear_error().

RETURN VALUES
       BIO_socket_wait(), BIO_wait(), and BIO_do_connect_retry() return -1 on
       error, 0 on timeout, and 1 on success.

SEE ALSO
       BIO_do_connect(3), BIO_read(3)

HISTORY
       BIO_socket_wait(), BIO_wait(), and BIO_do_connect_retry() were added in
       OpenSSL 3.0.

COPYRIGHT
       Copyright 2019-2020 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the Apache License 2.0 (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>.



3.0.12                            2023-05-07                BIO_socket_wait(3)