SSL_get_rpoll_descriptor, SSL_get_wpoll_descriptor, SSL_net_read_desired, SSL_net_write_desired - obtain

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       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>.

3.5.0                                              2025-06-04                     SSL_GET_RPOLL_DESCRIPTOR(3SSL)

       The functions SSL_get_rpoll_descriptor() and SSL_get_wpoll_descriptor() can be used to determine when an
       SSL object which represents a QUIC connection can perform useful network I/O, so that an application
       using a QUIC connection SSL object in nonblocking mode can determine when it should call
       SSL_handle_events().

       On success, these functions output poll descriptors. For more information on poll descriptors, see
       BIO_get_rpoll_descriptor(3).

       The functions SSL_net_read_desired() and SSL_net_write_desired() return 1 or 0 depending on whether the
       SSL object is currently interested in receiving data from the network and/or writing data to the network
       respectively.  If an SSL object is not interested in reading data from the network at the current time,
       SSL_net_read_desired() will return 0; likewise, if an SSL object is not interested in writing data to the
       network at the current time, SSL_net_write_desired() will return 0.

       The intention is that an application using QUIC in nonblocking mode can use these calls, in conjunction
       with SSL_get_event_timeout(3) to wait for network I/O conditions which allow the SSL object to perform
       useful work. When such a condition arises, SSL_handle_events(3) should be called.

       In particular, the expected usage is as follows:

       •   SSL_handle_events()  should  be  called whenever the timeout returned by SSL_get_event_timeout(3) (if
           any) expires

       •   If the last call to SSL_net_read_desired() returned 1, SSL_handle_events() should be called  whenever
           the poll descriptor output by SSL_get_rpoll_descriptor() becomes readable.

       •   If the last call to SSL_net_write_desired() returned 1, SSL_handle_events() should be called whenever
           the poll descriptor output by SSL_get_wpoll_descriptor() becomes writable.

       The  return  values  of  the  SSL_net_read_desired()  and SSL_net_write_desired() functions may change in
       response to any call to  the  SSL  object  other  than  SSL_net_read_desired(),  SSL_net_write_desired(),
       SSL_get_rpoll_descriptor(), SSL_get_wpoll_descriptor() and SSL_get_event_timeout().

       On  non-QUIC SSL objects, calls to SSL_get_rpoll_descriptor() and SSL_get_wpoll_descriptor() function the
       same as calls to BIO_get_rpoll_descriptor() and BIO_get_wpoll_descriptor() on  the  respective  read  and
       write BIOs configured on the SSL object.

       On non-QUIC SSL objects, calls to SSL_net_read_desired() and SSL_net_write_desired() function identically
       to calls to SSL_want_read() and SSL_want_write() respectively.

       The      SSL_get_rpoll_descriptor(),      SSL_get_wpoll_descriptor(),      SSL_net_read_desired()     and
       SSL_net_write_desired() functions were added in OpenSSL 3.2.

       SSL_get_rpoll_descriptor, SSL_get_wpoll_descriptor, SSL_net_read_desired, SSL_net_write_desired - obtain
       information which can be used to determine when network I/O can be performed

       These functions return 1 on success and 0 on failure.

SSL_handle_events(3), SSL_get_event_timeout(3), ssl(7)

        #include <openssl/ssl.h>

        int SSL_get_rpoll_descriptor(SSL *s, BIO_POLL_DESCRIPTOR *desc);
        int SSL_get_wpoll_descriptor(SSL *s, BIO_POLL_DESCRIPTOR *desc);
        int SSL_net_read_desired(SSL *s);
        int SSL_net_write_desired(SSL *s);