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'\"
'\" The contents of this file are subject to the AOLserver Public License
'\" Version 1.1 (the "License"); you may not use this file except in
'\" compliance with the License. You may obtain a copy of the License at
'\" http://aolserver.com/.
'\"
'\" Software distributed under the License is distributed on an "AS IS"
'\" basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
'\" the License for the specific language governing rights and limitations
'\" under the License.
'\"
'\" The Original Code is AOLserver Code and related documentation
'\" distributed by AOL.
'\"
'\" The Initial Developer of the Original Code is America Online,
'\" Inc. Portions created by AOL are Copyright (C) 1999 America Online,
'\" Inc. All Rights Reserved.
'\"
'\" Alternatively, the contents of this file may be used under the terms
'\" of the GNU General Public License (the "GPL"), in which case the
'\" provisions of GPL are applicable instead of those above. If you wish
'\" to allow use of your version of this file only under the terms of the
'\" GPL and not to allow others to use your version of this file under the
'\" License, indicate your decision by deleting the provisions above and
'\" replace them with the notice and other provisions required by the GPL.
'\" If you do not delete the provisions above, a recipient may use your
'\" version of this file under either the License or the GPL.
'\"
'\"
'\" $Header: /cvsroot/aolserver/aolserver/doc/Ns_Master.3,v 1.5 2003/04/10 22:00:45 shmooved Exp $
'\"
'\"
.so man.macros
.TH Ns_Master 3 4.0 AOLserver "AOLserver Library Procedures"
.BS
'\" Note: do not modify the .SH NAME line immediately below!
.SH NAME
Ns_MasterLock, Ns_MasterUnlock \- Enter and leave the single master critical section lock
.SH SYNOPSIS
.nf
\fB#include "ns.h"\fR
.sp
void
\fBNs_MasterLock\fR(\fIvoid\fR)
.sp
void
\fBNs_MasterUnlock\fR(\fIvoid\fR)
.BE
.SH DESCRIPTION
.PP
The single master critical section lock is used throughout the core
server to protect portions of code from being run by more than one
thread at a time. These are convenience functions which actually make
calls to \fBNs_CsEnter\fR and \fBNs_CsLeave\fR to perform the locking
and unlocking function.
You should not use these functions in your modules. To protect
critical sections in your modules you should create and initialize
your own named locks, then wrap your critical sections with calls to
\fBNs_CsEnter\fR and \fBNs_CsLeave\fR.
.TP
\fBNs_MasterLock\fR()
Enter the single master lock. The thread that holds this lock is
guaranteed exclusive access to the section of code that follows the
call to \fBNs_MasterLock\fR. Other threads that attempt to enter the
master critical section while another thread owns the master lock will
block until the owning thread releases the master lock.
Be extremely careful with code you place within the master critical
section. If the thread that owns the master lock blocks for any reason
while in the master critical section, other threads that need to enter
that section of code will block until the master lock is released.
.TP
\fBNs_MasterUnlock\fR()
Leave the single master critical section. The thread that owns the
lock must release it after the critical section of code has completed
so that other threads may execute the critical section code.
.SH "SEE ALSO"
nsd(1), info(n), Ns_CsEnter(3), Ns_CsLeave(3)
.SH KEYWORDS
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