Man page - io_uring_sqe_set_data(3)

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Manual

io_uring_sqe_set_data

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
SEE ALSO

NAME

io_uring_sqe_set_data - set user data for submission queue event

SYNOPSIS

#include <liburing.h>

void io_uring_sqe_set_data(struct io_uring_sqe * sqe ,
void *
user_data );
void io_uring_sqe_set_data64(struct io_uring_sqe *
sqe ,
__u64
data );

DESCRIPTION

The io_uring_sqe_set_data (3) function stores a user_data pointer with the submission queue entry sqe .

The io_uring_sqe_set_data64 (3) function stores a 64-bit data value with the submission queue entry sqe .

After the caller has requested a submission queue entry (SQE) with io_uring_get_sqe (3) , they can associate a data pointer or value with the SQE. Once the completion arrives, the function io_uring_cqe_get_data (3) or io_uring_cqe_get_data64 (3) can be called to retrieve the data pointer or value associated with the submitted request.

Note that if neither of these functions are called, or the user_data field in the sqe isn’t set manually either, then the field may contain a value from a previous use of this sqe. If an application relies on always having a valid user_data value present, it must always assign one to each sqe.

RETURN VALUE

None

SEE ALSO

io_uring_get_sqe (3), io_uring_cqe_get_data (3)