15507a2aeSRuslan Ermilov.\" Copyright (c) 2005 David Xu <[email protected]> 2b1e515a3SDavid Xu.\" All rights reserved. 3e84ece6bSDavid Xu.\" 4e84ece6bSDavid Xu.\" Redistribution and use in source and binary forms, with or without 5e84ece6bSDavid Xu.\" modification, are permitted provided that the following conditions 6e84ece6bSDavid Xu.\" are met: 7e84ece6bSDavid Xu.\" 1. Redistributions of source code must retain the above copyright 8e84ece6bSDavid Xu.\" notice(s), this list of conditions and the following disclaimer as 9e84ece6bSDavid Xu.\" the first lines of this file unmodified other than the possible 10e84ece6bSDavid Xu.\" addition of one or more copyright notices. 11e84ece6bSDavid Xu.\" 2. Redistributions in binary form must reproduce the above copyright 12e84ece6bSDavid Xu.\" notice(s), this list of conditions and the following disclaimer in 13e84ece6bSDavid Xu.\" the documentation and/or other materials provided with the 14e84ece6bSDavid Xu.\" distribution. 15e84ece6bSDavid Xu.\" 16e84ece6bSDavid Xu.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY 17e84ece6bSDavid Xu.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18e84ece6bSDavid Xu.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19e84ece6bSDavid Xu.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE 20e84ece6bSDavid Xu.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21e84ece6bSDavid Xu.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22e84ece6bSDavid Xu.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 23e84ece6bSDavid Xu.\" BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 24e84ece6bSDavid Xu.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 25e84ece6bSDavid Xu.\" OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 26e84ece6bSDavid Xu.\" EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27e84ece6bSDavid Xu.\" 28e84ece6bSDavid Xu.\" $FreeBSD$ 29e84ece6bSDavid Xu.\" 305507a2aeSRuslan Ermilov.Dd November 11, 2005 31e84ece6bSDavid Xu.Dt SIGQUEUE 2 32e84ece6bSDavid Xu.Os 33e84ece6bSDavid Xu.Sh NAME 34e84ece6bSDavid Xu.Nm sigqueue 355507a2aeSRuslan Ermilov.Nd "queue a signal to a process (REALTIME)" 36e84ece6bSDavid Xu.Sh LIBRARY 37e84ece6bSDavid Xu.Lb libc 38e84ece6bSDavid Xu.Sh SYNOPSIS 39e84ece6bSDavid Xu.In signal.h 40e84ece6bSDavid Xu.Ft int 41e84ece6bSDavid Xu.Fn sigqueue "pid_t pid" "int signo" "const union sigval value" 42e84ece6bSDavid Xu.Sh DESCRIPTION 43e84ece6bSDavid XuThe 44e84ece6bSDavid Xu.Fn sigqueue 455507a2aeSRuslan Ermilovsystem call causes the signal specified by 46e84ece6bSDavid Xu.Fa signo 47e84ece6bSDavid Xuto be sent with the value specified by 48e84ece6bSDavid Xu.Fa value 49e84ece6bSDavid Xuto the process specified by 50e84ece6bSDavid Xu.Fa pid . 51e84ece6bSDavid XuIf 52e84ece6bSDavid Xu.Fa signo 53e84ece6bSDavid Xuis zero (the null signal), error checking is performed but 545507a2aeSRuslan Ermilovno signal is actually sent. 555507a2aeSRuslan ErmilovThe null signal can be used to check the 565507a2aeSRuslan Ermilovvalidity of PID. 57e84ece6bSDavid Xu.Pp 58e84ece6bSDavid XuThe conditions required for a process to have permission to queue a 59e84ece6bSDavid Xusignal to another process are the same as for the 605507a2aeSRuslan Ermilov.Xr kill 2 615507a2aeSRuslan Ermilovsystem call. 62e84ece6bSDavid XuThe 63e84ece6bSDavid Xu.Fn sigqueue 645507a2aeSRuslan Ermilovsystem call queues a signal to a single process specified by the 655507a2aeSRuslan Ermilov.Fa pid 665507a2aeSRuslan Ermilovargument. 67e84ece6bSDavid Xu.Pp 685507a2aeSRuslan ErmilovThe 695507a2aeSRuslan Ermilov.Fn sigqueue 705507a2aeSRuslan Ermilovsystem call returns immediately. 715507a2aeSRuslan ErmilovIf the resources were 72e84ece6bSDavid Xuavailable to queue the signal, the signal will be queued and sent to 73e84ece6bSDavid Xuthe receiving process. 74e84ece6bSDavid Xu.Pp 75e84ece6bSDavid XuIf the value of 76e84ece6bSDavid Xu.Fa pid 77e84ece6bSDavid Xucauses 78e84ece6bSDavid Xu.Fa signo 79e84ece6bSDavid Xuto be generated for the sending process, and if 80e84ece6bSDavid Xu.Fa signo 81e84ece6bSDavid Xuis not blocked for the calling thread and if no other thread has 82e84ece6bSDavid Xu.Fa signo 83e84ece6bSDavid Xuunblocked or is waiting in a 84e84ece6bSDavid Xu.Fn sigwait 855507a2aeSRuslan Ermilovsystem call for 86b71ec5beSDavid Xu.Fa signo , 87b71ec5beSDavid Xueither 88e84ece6bSDavid Xu.Fa signo 89e84ece6bSDavid Xuor at least the pending, unblocked signal will be delivered to the 905507a2aeSRuslan Ermilovcalling thread before 91e84ece6bSDavid Xu.Fn sigqueue 925507a2aeSRuslan Ermilovreturns. 935507a2aeSRuslan ErmilovShould any multiple pending signals in the range 945507a2aeSRuslan Ermilov.Dv SIGRTMIN 955507a2aeSRuslan Ermilovto 965507a2aeSRuslan Ermilov.Dv SIGRTMAX 975507a2aeSRuslan Ermilovbe selected for delivery, it is the lowest numbered 985507a2aeSRuslan Ermilovone. 995507a2aeSRuslan ErmilovThe selection order between realtime and non-realtime signals, or 100e84ece6bSDavid Xubetween multiple pending non-realtime signals, is unspecified. 101e84ece6bSDavid Xu.Sh RETURN VALUES 1025507a2aeSRuslan Ermilov.Rv -std 103e84ece6bSDavid Xu.Sh ERRORS 104e84ece6bSDavid XuThe 105e84ece6bSDavid Xu.Fn sigqueue 1065507a2aeSRuslan Ermilovsystem call 107e84ece6bSDavid Xuwill fail if: 108e84ece6bSDavid Xu.Bl -tag -width Er 109e84ece6bSDavid Xu.It Bq Er EAGAIN 1105507a2aeSRuslan ErmilovNo resources are available to queue the signal. 1115507a2aeSRuslan ErmilovThe process has already 1125507a2aeSRuslan Ermilovqueued 1135507a2aeSRuslan Ermilov.Brq Dv SIGQUEUE_MAX 1145507a2aeSRuslan Ermilovsignals that are still pending at the receiver(s), 115e84ece6bSDavid Xuor a system-wide resource limit has been exceeded. 116e84ece6bSDavid Xu.It Bq Er EINVAL 117e84ece6bSDavid XuThe value of the 118e84ece6bSDavid Xu.Fa signo 119e84ece6bSDavid Xuargument is an invalid or unsupported signal number. 120e84ece6bSDavid Xu.It Bq Er EEPERM 121e84ece6bSDavid XuThe process does not have the appropriate privilege to send the signal 122e84ece6bSDavid Xuto the receiving process. 123e84ece6bSDavid Xu.It Bq Er ESRCH 1245507a2aeSRuslan ErmilovThe process 1255507a2aeSRuslan Ermilov.Fa pid 1265507a2aeSRuslan Ermilovdoes not exist. 127e84ece6bSDavid Xu.El 128e84ece6bSDavid Xu.Sh SEE ALSO 129e84ece6bSDavid Xu.Xr sigaction 2 , 130e84ece6bSDavid Xu.Xr sigpending 2 , 1315507a2aeSRuslan Ermilov.Xr sigqueue 2 , 132e84ece6bSDavid Xu.Xr sigsuspend 2 , 1335507a2aeSRuslan Ermilov.Xr sigtimedwait 2 , 1345507a2aeSRuslan Ermilov.Xr sigwait 2 , 1355507a2aeSRuslan Ermilov.Xr sigwaitinfo 2 , 136e84ece6bSDavid Xu.Xr pause 3 , 137e84ece6bSDavid Xu.Xr pthread_sigmask 3 138e84ece6bSDavid Xu.Sh STANDARDS 139e84ece6bSDavid XuThe 140e84ece6bSDavid Xu.Fn sigqueue 1415507a2aeSRuslan Ermilovsystem call conforms to 142*6f59c4c0SDavid Xu.St -p1003.1-2004 143*6f59c4c0SDavid Xu.Sh HISTORY 144*6f59c4c0SDavid XuSupport for POSIX realtime signal queue first appeared in 145*6f59c4c0SDavid Xu.Fx 7.0 . 146