io_uring_prep_socket(3) — Linux manual page


io_uring_prep_socket(3)      liburing Manual     io_uring_prep_socket(3)

NAME         top

       io_uring_prep_socket - prepare a socket creation request

SYNOPSIS         top

       #include <sys/socket.h>
       #include <liburing.h>

       void io_uring_prep_socket(struct io_uring_sqe *sqe,
                                 int domain,
                                 int type,
                                 int protocol,
                                 unsigned int flags);

       void io_uring_prep_socket_direct(struct io_uring_sqe *sqe,
                                        int domain,
                                        int type,
                                        int protocol,
                                        unsigned int file_index,
                                        unsigned int flags);

       void io_uring_prep_socket_direct_alloc(struct io_uring_sqe *sqe,
                                        int domain,
                                        int type,
                                        int protocol,
                                        unsigned int flags);

DESCRIPTION         top

       The io_uring_prep_socket(3) function prepares a socket creation
       request. The submission queue entry sqe is setup to use the
       communication domain defined by domain and use the communication
       type defined by type and the protocol set by protocol.  The flags
       argument are currently unused.

       The io_uring_prep_socket_direct(3) helper works just like
       io_uring_prep_socket(3), except it maps the socket to a direct
       descriptor rather than return a normal file descriptor. The
       file_index argument should be set to the slot that should be used
       for this socket.

       The io_uring_prep_socket_direct_alloc(3) helper works just like
       io_uring_prep_socket_direct(3), except it allocates a new direct
       descriptor rather than pass a free slot in. It is equivalent to
       using io_uring_prep_socket_direct(3) with IORING_FILE_INDEX_ALLOC
       as the file_index .  Upon completion, the res field of the CQE
       will return the direct slot that was allocated for the socket.

       If the direct variants are used, the application must first have
       registered a file table using io_uring_register_files(3) of the
       appropriate size. Once registered, a direct socket request may
       use any entry in that table, as long as it is within the size of
       the registered table.  If a specified entry already contains a
       file, the file will first be removed from the table and closed.
       It's consistent with the behavior of updating an existing file
       with io_uring_register_files_update(3).

       For a direct descriptor socket request, the file_index argument
       can be set to IORING_FILE_INDEX_ALLOC, In this case a free entry
       in io_uring file table will be used automatically and the file
       index will be returned as CQE res.  -ENFILE is otherwise returned
       if there is no free entries in the io_uring file table.

       These functions prepare an async socket(2) request. See that man
       page for details.

RETURN VALUE         top


ERRORS         top

       The CQE res field will contain the result of the operation. See
       the related man page for details on possible values. Note that
       where synchronous system calls will return -1 on failure and set
       errno to the actual error value, io_uring never uses errno.
       Instead it returns the negated errno directly in the CQE res

SEE ALSO         top

       io_uring_get_sqe(3), io_uring_submit(3), socket(2)

COLOPHON         top

       This page is part of the liburing (A library for io_uring)
       project.  Information about the project can be found at 
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       this manual page, send it to  This page
       was obtained from the project's upstream Git repository
       ⟨⟩ on 2024-06-14.  (At that
       time, the date of the most recent commit that was found in the
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liburing-2.2                  May 27, 2022       io_uring_prep_socket(3)

Pages that refer to this page: io_uring_prep_socket(3)io_uring_prep_socket_direct(3)io_uring_prep_socket_direct_alloc(3)