| kqueue.2 (275900) | kqueue.2 (281454) |
|---|---|
| 1.\" Copyright (c) 2000 Jonathan Lemon 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. --- 8 unchanged lines hidden (view full) --- 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" | 1.\" Copyright (c) 2000 Jonathan Lemon 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. --- 8 unchanged lines hidden (view full) --- 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" |
| 25.\" $FreeBSD: stable/10/lib/libc/sys/kqueue.2 275900 2014-12-18 11:36:14Z kib $ | 25.\" $FreeBSD: stable/10/lib/libc/sys/kqueue.2 281454 2015-04-12 06:52:43Z kib $ |
| 26.\" | 26.\" |
| 27.Dd July 18, 2014 | 27.Dd March 29, 2015 |
| 28.Dt KQUEUE 2 29.Os 30.Sh NAME 31.Nm kqueue , 32.Nm kevent 33.Nd kernel event notification mechanism 34.Sh LIBRARY 35.Lb libc 36.Sh SYNOPSIS 37.In sys/types.h 38.In sys/event.h 39.In sys/time.h 40.Ft int 41.Fn kqueue "void" 42.Ft int 43.Fn kevent "int kq" "const struct kevent *changelist" "int nchanges" "struct kevent *eventlist" "int nevents" "const struct timespec *timeout" | 28.Dt KQUEUE 2 29.Os 30.Sh NAME 31.Nm kqueue , 32.Nm kevent 33.Nd kernel event notification mechanism 34.Sh LIBRARY 35.Lb libc 36.Sh SYNOPSIS 37.In sys/types.h 38.In sys/event.h 39.In sys/time.h 40.Ft int 41.Fn kqueue "void" 42.Ft int 43.Fn kevent "int kq" "const struct kevent *changelist" "int nchanges" "struct kevent *eventlist" "int nevents" "const struct timespec *timeout" |
| 44.Fn EV_SET "&kev" ident filter flags fflags data udata | 44.Fn EV_SET "kev" ident filter flags fflags data udata |
| 45.Sh DESCRIPTION 46The 47.Fn kqueue 48system call 49provides a generic method of notifying the user when an event 50happens or a condition holds, based on the results of small 51pieces of kernel code termed filters. 52A kevent is identified by the (ident, filter) pair; there may only --- 474 unchanged lines hidden (view full) --- 527.It Dv NOTE_TRIGGER 528Cause the event to be triggered. 529.El 530.Pp 531On return, 532.Va fflags 533contains the users defined flags in the lower 24 bits. 534.El | 45.Sh DESCRIPTION 46The 47.Fn kqueue 48system call 49provides a generic method of notifying the user when an event 50happens or a condition holds, based on the results of small 51pieces of kernel code termed filters. 52A kevent is identified by the (ident, filter) pair; there may only --- 474 unchanged lines hidden (view full) --- 527.It Dv NOTE_TRIGGER 528Cause the event to be triggered. 529.El 530.Pp 531On return, 532.Va fflags 533contains the users defined flags in the lower 24 bits. 534.El |
| 535.Sh CANCELLATION BEHAVIOUR 536If 537.Fa nevents 538is non-zero, i.e. the function is potentially blocking, the call 539is a cancellation point. 540Otherwise, i.e. if 541.Fa nevents 542is zero, the call is not cancellable. 543Cancellation can only occur before any changes are made to the kqueue, 544or when the call was blocked and no changes to the queue were requested. |
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| 535.Sh RETURN VALUES 536The 537.Fn kqueue 538system call 539creates a new kernel event queue and returns a file descriptor. 540If there was an error creating the kernel event queue, a value of -1 is 541returned and errno set. 542.Pp --- 47 unchanged lines hidden (view full) --- 590There was an error reading or writing the 591.Va kevent 592structure. 593.It Bq Er EBADF 594The specified descriptor is invalid. 595.It Bq Er EINTR 596A signal was delivered before the timeout expired and before any 597events were placed on the kqueue for return. | 545.Sh RETURN VALUES 546The 547.Fn kqueue 548system call 549creates a new kernel event queue and returns a file descriptor. 550If there was an error creating the kernel event queue, a value of -1 is 551returned and errno set. 552.Pp --- 47 unchanged lines hidden (view full) --- 600There was an error reading or writing the 601.Va kevent 602structure. 603.It Bq Er EBADF 604The specified descriptor is invalid. 605.It Bq Er EINTR 606A signal was delivered before the timeout expired and before any 607events were placed on the kqueue for return. |
| 608.It Bq Er EINTR 609A cancellation request was delivered to the thread, but not yet handled. |
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| 598.It Bq Er EINVAL 599The specified time limit or filter is invalid. 600.It Bq Er ENOENT 601The event could not be found to be modified or deleted. 602.It Bq Er ENOMEM 603No memory was available to register the event 604or, in the special case of a timer, the maximum number of 605timers has been exceeded. 606This maximum is configurable via the 607.Va kern.kq_calloutmax 608sysctl. 609.It Bq Er ESRCH 610The specified process to attach to does not exist. 611.El | 610.It Bq Er EINVAL 611The specified time limit or filter is invalid. 612.It Bq Er ENOENT 613The event could not be found to be modified or deleted. 614.It Bq Er ENOMEM 615No memory was available to register the event 616or, in the special case of a timer, the maximum number of 617timers has been exceeded. 618This maximum is configurable via the 619.Va kern.kq_calloutmax 620sysctl. 621.It Bq Er ESRCH 622The specified process to attach to does not exist. 623.El |
| 624.Pp 625When 626.Fn kevent 627call fails with 628.Er EINTR 629error, all changes in the 630.Fa changelist 631have been applied. |
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| 612.Sh SEE ALSO 613.Xr aio_error 2 , 614.Xr aio_read 2 , 615.Xr aio_return 2 , 616.Xr poll 2 , 617.Xr read 2 , 618.Xr select 2 , 619.Xr sigaction 2 , 620.Xr write 2 , | 632.Sh SEE ALSO 633.Xr aio_error 2 , 634.Xr aio_read 2 , 635.Xr aio_return 2 , 636.Xr poll 2 , 637.Xr read 2 , 638.Xr select 2 , 639.Xr sigaction 2 , 640.Xr write 2 , |
| 641.Xr pthread_setcancelstate 3 , |
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| 621.Xr signal 3 622.Sh HISTORY 623The 624.Fn kqueue 625and 626.Fn kevent 627system calls first appeared in 628.Fx 4.1 . 629.Sh AUTHORS 630The 631.Fn kqueue 632system and this manual page were written by 633.An Jonathan Lemon Aq jlemon@FreeBSD.org . 634.Sh BUGS 635The 636.Fa timeout 637value is limited to 24 hours; longer timeouts will be silently 638reinterpreted as 24 hours. | 642.Xr signal 3 643.Sh HISTORY 644The 645.Fn kqueue 646and 647.Fn kevent 648system calls first appeared in 649.Fx 4.1 . 650.Sh AUTHORS 651The 652.Fn kqueue 653system and this manual page were written by 654.An Jonathan Lemon Aq jlemon@FreeBSD.org . 655.Sh BUGS 656The 657.Fa timeout 658value is limited to 24 hours; longer timeouts will be silently 659reinterpreted as 24 hours. |