=pod =head1 NAME SSL_waiting_for_async, SSL_get_all_async_fds, SSL_get_changed_async_fds - manage asynchronous operations =head1 SYNOPSIS =for comment multiple includes #include #include int SSL_waiting_for_async(SSL *s); int SSL_get_all_async_fds(SSL *s, OSSL_ASYNC_FD *fd, size_t *numfds); int SSL_get_changed_async_fds(SSL *s, OSSL_ASYNC_FD *addfd, size_t *numaddfds, OSSL_ASYNC_FD *delfd, size_t *numdelfds); =head1 DESCRIPTION SSL_waiting_for_async() determines whether an SSL connection is currently waiting for asynchronous operations to complete (see the SSL_MODE_ASYNC mode in L). SSL_get_all_async_fds() returns a list of file descriptor which can be used in a call to select() or poll() to determine whether the current asynchronous operation has completed or not. A completed operation will result in data appearing as "read ready" on the file descriptor (no actual data should be read from the file descriptor). This function should only be called if the SSL object is currently waiting for asynchronous work to complete (i.e. SSL_ERROR_WANT_ASYNC has been received - see L). Typically the list will only contain one file descriptor. However if multiple asynchronous capable engines are in use then more than one is possible. The number of file descriptors returned is stored in B<*numfds> and the file descriptors themselves are in B<*fds>. The B parameter may be NULL in which case no file descriptors are returned but B<*numfds> is still populated. It is the callers responsibility to ensure sufficient memory is allocated at B<*fds> so typically this function is called twice (once with a NULL B parameter and once without). SSL_get_changed_async_fds() returns a list of the asynchronous file descriptors that have been added and a list that have been deleted since the last SSL_ERROR_WANT_ASYNC was received (or since the SSL object was created if no SSL_ERROR_WANT_ASYNC has been received). Similar to SSL_get_all_async_fds() it is the callers responsibility to ensure that B<*addfd> and B<*delfd> have sufficient memory allocated, although they may be NULL. The number of added fds and the number of deleted fds are stored in B<*numaddfds> and B<*numdelfds> respectively. =head1 RETURN VALUES SSL_waiting_for_async() will return 1 if the current SSL operation is waiting for an async operation to complete and 0 otherwise. SSL_get_all_async_fds() and SSL_get_changed_async_fds() return 1 on success or 0 on error. =head1 NOTES On Windows platforms the openssl/async.h header is dependent on some of the types customarily made available by including windows.h. The application developer is likely to require control over when the latter is included, commonly as one of the first included headers. Therefore it is defined as an application developer's responsibility to include windows.h prior to async.h. =head1 SEE ALSO L, L =head1 HISTORY SSL_waiting_for_async(), SSL_get_all_async_fds() and SSL_get_changed_async_fds() were first added to OpenSSL 1.1.0. =head1 COPYRIGHT Copyright 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. =cut