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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:40:15 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:40:15 +0000 |
commit | 399644e47874bff147afb19c89228901ac39340e (patch) | |
tree | 1c4c0b733f4c16b5783b41bebb19194a9ef62ad1 /man2/io_getevents.2 | |
parent | Initial commit. (diff) | |
download | manpages-399644e47874bff147afb19c89228901ac39340e.tar.xz manpages-399644e47874bff147afb19c89228901ac39340e.zip |
Adding upstream version 6.05.01.upstream/6.05.01
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'man2/io_getevents.2')
-rw-r--r-- | man2/io_getevents.2 | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/man2/io_getevents.2 b/man2/io_getevents.2 new file mode 100644 index 0000000..3cf506c --- /dev/null +++ b/man2/io_getevents.2 @@ -0,0 +1,137 @@ +.\" Copyright (C) 2003 Free Software Foundation, Inc. +.\" +.\" SPDX-License-Identifier: GPL-1.0-or-later +.\" +.TH io_getevents 2 2023-03-30 "Linux man-pages 6.05.01" +.SH NAME +io_getevents \- read asynchronous I/O events from the completion queue +.SH LIBRARY +Standard C library +.RI ( libc ", " \-lc ) +.PP +Alternatively, Asynchronous I/O library +.RI ( libaio ", " \-laio ); +see VERSIONS. +.SH SYNOPSIS +.nf +.BR "#include <linux/aio_abi.h>" " /* Definition of " *io_* " types */" +.BR "#include <sys/syscall.h>" " /* Definition of " SYS_* " constants */" +.B #include <unistd.h> +.PP +.BI "int syscall(SYS_io_getevents, aio_context_t " ctx_id , +.BI " long " min_nr ", long " nr ", struct io_event *" events , +.BI " struct timespec *" timeout ); +.fi +.PP +.IR Note : +glibc provides no wrapper for +.BR io_getevents (), +necessitating the use of +.BR syscall (2). +.SH DESCRIPTION +.IR Note : +this page describes the raw Linux system call interface. +The wrapper function provided by +.I libaio +uses a different type for the +.I ctx_id +argument. +See VERSIONS. +.PP +The +.BR io_getevents () +system call +attempts to read at least \fImin_nr\fP events and +up to \fInr\fP events from the completion queue of the AIO context +specified by \fIctx_id\fP. +.PP +The \fItimeout\fP argument specifies the amount of time to wait for events, +and is specified as a relative timeout in a +.BR timespec (3) +structure. +.PP +The specified time will be rounded up to the system clock granularity +and is guaranteed not to expire early. +.PP +Specifying +.I timeout +as NULL means block indefinitely until at least +.I min_nr +events have been obtained. +.SH RETURN VALUE +On success, +.BR io_getevents () +returns the number of events read. +This may be 0, or a value less than +.IR min_nr , +if the +.I timeout +expired. +It may also be a nonzero value less than +.IR min_nr , +if the call was interrupted by a signal handler. +.PP +For the failure return, see VERSIONS. +.SH ERRORS +.TP +.B EFAULT +Either \fIevents\fP or \fItimeout\fP is an invalid pointer. +.TP +.B EINTR +Interrupted by a signal handler; see +.BR signal (7). +.TP +.B EINVAL +\fIctx_id\fP is invalid. +\fImin_nr\fP is out of range or \fInr\fP is +out of range. +.TP +.B ENOSYS +.BR io_getevents () +is not implemented on this architecture. +.SH VERSIONS +You probably want to use the +.BR io_getevents () +wrapper function provided by +.\" http://git.fedorahosted.org/git/?p=libaio.git +.IR libaio . +.PP +Note that the +.I libaio +wrapper function uses a different type +.RI ( io_context_t ) +.\" But glibc is confused, since <libaio.h> uses 'io_context_t' to declare +.\" the system call. +for the +.I ctx_id +argument. +Note also that the +.I libaio +wrapper does not follow the usual C library conventions for indicating errors: +on error it returns a negated error number +(the negative of one of the values listed in ERRORS). +If the system call is invoked via +.BR syscall (2), +then the return value follows the usual conventions for +indicating an error: \-1, with +.I errno +set to a (positive) value that indicates the error. +.SH STANDARDS +Linux. +.SH HISTORY +Linux 2.5. +.SH BUGS +An invalid +.I ctx_id +may cause a segmentation fault instead of generating the error +.BR EINVAL . +.SH SEE ALSO +.BR io_cancel (2), +.BR io_destroy (2), +.BR io_setup (2), +.BR io_submit (2), +.BR timespec (3), +.BR aio (7), +.BR time (7) +.\" .SH AUTHOR +.\" Kent Yoder. |