shared memory read/write using threads Post: 302206749

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ns_masterlock

Ns_Master(3aolserver)					   AOLserver Library Procedures 				     Ns_Master(3aolserver)

__________________________________________________________________________________________________________________________________________________

NAME

       Ns_MasterLock, Ns_MasterUnlock - Enter and leave the single master critical section lock

SYNOPSIS

       #include "ns.h"

       void
       Ns_MasterLock(void)

       void
       Ns_MasterUnlock(void)
_________________________________________________________________

DESCRIPTION

       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 Ns_CsEnter and Ns_CsLeave to perform the locking and unlock-
       ing 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 Ns_CsEnter and Ns_CsLeave.

       Ns_MasterLock()

	      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	Ns_MasterLock.	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.

       Ns_MasterUnlock()

	      Leave the single master critical section. The thread that owns the lock must release it after the critical section of code has  com-
	      pleted so that other threads may execute the critical section code.

SEE ALSO

       nsd(1), info(n), Ns_CsEnter(3), Ns_CsLeave(3)

KEYWORDS

AOLserver								4.0						     Ns_Master(3aolserver)