Copyright (c) 2015 Mark Johnston <markj@FreeBSD.org>
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
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2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
$FreeBSD$
.Dd November 7, 2015 .Dt PHOLD 9 .Os .Sh NAME .Nm PHOLD .Nd hold a process .Sh SYNOPSIS n sys/proc.h .Fn PHOLD "struct proc *p" .Fn _PHOLD "struct proc *p" .Fn PRELE "struct proc *p" .Fn _PRELE "struct proc *p" .Fn PROC_ASSERT_HELD "struct proc *p" .Fn PROC_ASSERT_NOT_HELD "struct proc *p" .Sh DESCRIPTION The .Fn PHOLD macro increments the hold count of a process, and the .Fn PRELE macro decrements the hold count of a process.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
$FreeBSD$
.Dd November 7, 2015 .Dt PHOLD 9 .Os .Sh NAME .Nm PHOLD .Nd hold a process .Sh SYNOPSIS n sys/proc.h .Fn PHOLD "struct proc *p" .Fn _PHOLD "struct proc *p" .Fn PRELE "struct proc *p" .Fn _PRELE "struct proc *p" .Fn PROC_ASSERT_HELD "struct proc *p" .Fn PROC_ASSERT_NOT_HELD "struct proc *p" .Sh DESCRIPTION The .Fn PHOLD macro increments the hold count of a process, and the .Fn PRELE macro decrements the hold count of a process.
p If a process with a non-zero hold count attempts to exit, it will sleep until its hold count has reached zero before the kernel begins releasing resources associated with the process. Once a process has started exiting, it is invalid to increase its hold count. Thus, callers must not attempt to hold a process that has the .Dv P_WEXIT flag set. The VM daemon will not swap out the kernel stack of a thread belonging to a process with a non-zero hold count.
p The .Fn _PHOLD and .Fn _PRELE macros are identical to .Fn PHOLD and .Fn PRELE , except that they must be called with the process lock held. .Sh AUTHORS This manual page was written by .An Mark Johnston Aq Mt markj@FreeBSD.org .