1nbd_aio_peek_command_completed(3) LIBNBD nbd_aio_peek_command_completed(3)
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6 nbd_aio_peek_command_completed - check if any command has completed
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9 #include <libnbd.h>
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11 int64_t nbd_aio_peek_command_completed (struct nbd_handle *h);
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14 Return the unique positive 64 bit cookie of the first non-retired but
15 completed command, 0 if there are in-flight commands but none of them
16 are awaiting retirement, or "-1" on error including when there are no
17 in-flight commands. Any cookie returned by this function must still be
18 passed to nbd_aio_command_completed(3) to actually retire the command
19 and learn whether the command was successful.
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22 This call returns a 64 bit signed integer ≥ 0.
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25 On error "-1" is returned.
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27 Refer to "ERROR HANDLING" in libnbd(3) for how to get further details
28 of the error.
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31 This function first appeared in libnbd 1.0.
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33 If you need to test if this function is available at compile time check
34 if the following macro is defined:
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36 #define LIBNBD_HAVE_NBD_AIO_PEEK_COMMAND_COMPLETED 1
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39 nbd_aio_command_completed(3), nbd_create(3), libnbd(3).
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42 Eric Blake
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44 Richard W.M. Jones
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47 Copyright (C) 2019 Red Hat Inc.
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50 This library is free software; you can redistribute it and/or modify it
51 under the terms of the GNU Lesser General Public License as published
52 by the Free Software Foundation; either version 2 of the License, or
53 (at your option) any later version.
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55 This library is distributed in the hope that it will be useful, but
56 WITHOUT ANY WARRANTY; without even the implied warranty of
57 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
58 Lesser General Public License for more details.
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60 You should have received a copy of the GNU Lesser General Public
61 License along with this library; if not, write to the Free Software
62 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
63 02110-1301 USA
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67libnbd-1.3.7 2020-04-23 nbd_aio_peek_command_completed(3)