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.\" Hey Emacs! This file is -*- nroff -*- source.
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.\" Copyright (C) 2008 Michael Kerrisk <tmk.manpages@gmail.com>
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.\" and Copyright 2003 Abhijit Menon-Sen <ams@wiw.org>
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.\" %%%LICENSE_START(VERBATIM)
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.\" Permission is granted to make and distribute verbatim copies of this
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.\" manual provided the copyright notice and this permission notice are
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.\" preserved on all copies.
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.\" Formatted or processed versions of this manual, if unaccompanied by
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.\" the source, must acknowledge the copyright and authors of this work.
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.\" 2004-05-31, added tgkill, ahu, aeb
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.\" 2008-01-15 mtk -- rewote DESCRIPTION
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.\" 2008-01-15 mtk -- rewrote DESCRIPTION
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.TH TKILL 2 2012-07-13 "Linux" "Linux Programmer's Manual"
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can only be used to send a signal to a process (i.e., thread group)
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can be used to send a signal only to a process (i.e., thread group)
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as a whole, and the signal will be delivered to an arbitrary
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thread within that process.)
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is an obsolete predecessor to
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It only allows the target thread ID to be specified,
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It allows only the target thread ID to be specified,
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which may result in the wrong thread being signaled if a thread
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terminates and its thread ID is recycled.
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Avoid using this system call.
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.\" FIXME: Maybe say something about the following:
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.\" http://sourceware.org/bugzilla/show_bug.cgi?id=12889
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.\" Rich Felker <bugdal@aerifal.cx>
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.\" There is a race condition in pthread_kill: it is possible that,
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.\" between the time pthread_kill reads the pid/tid from the target
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.\" thread descriptor and the time it makes the tgkill syscall,
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.\" the target thread terminates and the same tid gets assigned
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.\" to a new thread in the same process.
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.\" (The tgkill syscall was designed to eliminate a similar race
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.\" condition in tkill, but it only succeeded in eliminating races
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.\" where the tid gets reused in a different process, and does not
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.\" help if the same tid gets assigned to a new thread in the
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.\" The only solution I can see is to introduce a mutex that ensures
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.\" that a thread cannot exit while pthread_kill is being called on it.
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.\" Note that in most real-world situations, like almost all race
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.\" conditions, this one will be extremely rare. To make it
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.\" measurable, one could exhaust all but 1-2 available pid values,
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.\" possibly by lowering the max pid parameter in /proc, forcing
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.\" the same tid to be reused rapidly.
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These are the raw system call interfaces, meant for internal
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thread library use.
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On success, zero is returned.
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On error, \-1 is returned, and \fIerrno\fP
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is set appropriately.
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Glibc does not provide wrappers for these system calls; call them using
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.BR rt_sigqueueinfo (2)
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This page is part of release 3.44 of the Linux
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This page is part of release 3.51 of the Linux
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A description of the project,
added
removed
man2/tkill.2
