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.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