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BIO_SOCKET_WAIT(3ossl) OpenSSL BIO_SOCKET_WAIT(3ossl)
NAME
BIO_socket_wait, BIO_wait, BIO_do_connect_retry - BIO connection
utility functions
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