1BIO_SOCKET_WAIT(3ossl)              OpenSSL             BIO_SOCKET_WAIT(3ossl)
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NAME

6       BIO_socket_wait, BIO_wait, BIO_do_connect_retry - BIO connection
7       utility functions
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SYNOPSIS

10        #include <openssl/bio.h>
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12        #ifndef OPENSSL_NO_SOCK
13        int BIO_socket_wait(int fd, int for_read, time_t max_time);
14        #endif
15        int BIO_wait(BIO *bio, time_t max_time, unsigned int nap_milliseconds);
16        int BIO_do_connect_retry(BIO *bio, int timeout, int nap_milliseconds);
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DESCRIPTION

19       BIO_socket_wait() waits on the socket fd for reading if for_read is not
20       0, else for writing, at most until max_time.  It succeeds immediately
21       if max_time == 0 (which means no timeout given).
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23       BIO_wait() waits at most until max_time on the given (typically socket-
24       based) bio, for reading if bio is supposed to read, else for writing.
25       It is used by BIO_do_connect_retry() and can be used together
26       BIO_read(3).  It succeeds immediately if max_time == 0 (which means no
27       timeout given).  If sockets are not available it supports polling by
28       succeeding after sleeping at most the given nap_milliseconds in order
29       to avoid a tight busy loop.  Via nap_milliseconds the caller determines
30       the polling granularity.
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32       BIO_do_connect_retry() connects via the given bio.  It retries
33       BIO_do_connect() as far as needed to reach a definite outcome, i.e.,
34       connection succeeded, timeout has been reached, or an error occurred.
35       For nonblocking and potentially even non-socket BIOs it polls every
36       nap_milliseconds and sleeps in between using BIO_wait().  If
37       nap_milliseconds is < 0 then a default value of 100 ms is used.  If the
38       timeout parameter is > 0 this indicates the maximum number of seconds
39       to wait until the connection is established or a definite error
40       occurred.  A value of 0 enables waiting indefinitely (i.e, no timeout),
41       while a value < 0 means that BIO_do_connect() is tried only once.  The
42       function may, directly or indirectly, invoke ERR_clear_error().
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RETURN VALUES

45       BIO_socket_wait(), BIO_wait(), and BIO_do_connect_retry() return -1 on
46       error, 0 on timeout, and 1 on success.
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SEE ALSO

49       BIO_do_connect(3), BIO_read(3)
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HISTORY

52       BIO_socket_wait(), BIO_wait(), and BIO_do_connect_retry() were added in
53       OpenSSL 3.0.
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56       Copyright 2019-2020 The OpenSSL Project Authors. All Rights Reserved.
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58       Licensed under the Apache License 2.0 (the "License").  You may not use
59       this file except in compliance with the License.  You can obtain a copy
60       in the file LICENSE in the source distribution or at
61       <https://www.openssl.org/source/license.html>.
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653.1.1                             2023-08-31            BIO_SOCKET_WAIT(3ossl)
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