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Diffstat (limited to 'man/io_uring_prep_sendmsg.3')
| -rw-r--r-- | man/io_uring_prep_sendmsg.3 | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/man/io_uring_prep_sendmsg.3 b/man/io_uring_prep_sendmsg.3 new file mode 100644 index 0000000..bc81d91 --- /dev/null +++ b/man/io_uring_prep_sendmsg.3 @@ -0,0 +1,69 @@ +.\" Copyright (C) 2022 Jens Axboe <axboe@kernel.dk> +.\" +.\" SPDX-License-Identifier: LGPL-2.0-or-later +.\" +.TH io_uring_prep_sendmsg 3 "March 12, 2022" "liburing-2.2" "liburing Manual" +.SH NAME +io_uring_prep_sendmsg \- prepare a sendmsg request +.SH SYNOPSIS +.nf +.B #include <sys/types.h> +.B #include <sys/socket.h> +.B #include <liburing.h> +.PP +.BI "void io_uring_prep_sendmsg(struct io_uring_sqe *" sqe "," +.BI " int " fd "," +.BI " const struct msghdr *" msg "," +.BI " unsigned " flags ");" +.fi +.SH DESCRIPTION +.PP +The +.BR io_uring_prep_sendmsg (3) +function prepares a sendmsg request. The submission queue entry +.I sqe +is setup to use the file descriptor +.I fd +to start sending the data indicated by +.I msg +with the +.BR sendmsg (2) +defined flags in the +.I flags +argument. + +This function prepares an async +.BR sendmsg (2) +request. See that man page for details. + +.SH RETURN VALUE +None +.SH ERRORS +The CQE +.I 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 +.B -1 +on failure and set +.I errno +to the actual error value, io_uring never uses +.IR errno . +Instead it returns the negated +.I errno +directly in the CQE +.I res +field. +.SH NOTES +As with any request that passes in data in a struct, that data must remain +valid until the request has been successfully submitted. It need not remain +valid until completion. Once a request has been submitted, the in-kernel +state is stable. Very early kernels (5.4 and earlier) required state to be +stable until the completion occurred. Applications can test for this +behavior by inspecting the +.B IORING_FEAT_SUBMIT_STABLE +flag passed back from +.BR io_uring_queue_init_params (3). +.SH SEE ALSO +.BR io_uring_get_sqe (3), +.BR io_uring_submit (3), +.BR sendmsg (2) |