39 lines
1.0 KiB
Groff
39 lines
1.0 KiB
Groff
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.\" Copyright (C) 2022 Jens Axboe <axboe@kernel.dk>
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.\"
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.\" SPDX-License-Identifier: LGPL-2.0-or-later
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.\"
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.TH io_uring_peek_cqe 3 "March 12, 2022" "liburing-2.2" "liburing Manual"
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.SH NAME
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io_uring_peek_cqe \- check if an io_uring completion event is available
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.SH SYNOPSIS
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.nf
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.B #include <liburing.h>
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.PP
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.BI "int io_uring_peek_cqe(struct io_uring *" ring ","
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.BI " struct io_uring_cqe **" cqe_ptr ");"
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.fi
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.SH DESCRIPTION
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.PP
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The
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.BR io_uring_peek_cqe (3)
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function returns an IO completion from the queue belonging to the
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.I ring
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param, if one is readily available. On successful return,
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.I cqe_ptr
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param is filled with a valid CQE entry.
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This function does not enter the kernel to wait for an event, an event
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is only returned if it's already available in the CQ ring.
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.SH RETURN VALUE
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On success
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.BR io_uring_peek_cqe (3)
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returns
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.B 0
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and the cqe_ptr parameter is filled in. On failure it returns
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.BR -EAGAIN .
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.SH SEE ALSO
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.BR io_uring_submit (3),
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.BR io_uring_wait_cqes (3),
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.BR io_uring_wait_cqe (3)
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