[Indigo]<Cedar>TEdit>TEditLocksPrivateImpl.mesa!3

TEditLocksPrivateImpl.mesa Edited by Paxton on October 11, 1982 10:27 am

DIRECTORY

TEditLocks,

TEditLocksPrivate,

TextNode,

NodeProps;

TEditLocksPrivateImpl: CEDAR MONITOR

IMPORTS NodeProps, TextNode

EXPORTS TEditLocksPrivate = BEGIN OPEN TEditLocks, TEditLocksPrivate;

lastRoot: TextNode.Ref;

lastLock: LockRef;

GetLock: PUBLIC ENTRY PROC [root: TextNode.Ref] RETURNS [lock: LockRef] = {

ENABLE UNWIND => NULL;

IF root = NIL THEN RETURN [NIL];

IF root = lastRoot THEN RETURN [lastLock];

lastRoot ← root;

lock ← lastLock ← NARROW[NodeProps.GetProp[root, $DocumentLock]];

IF lastLock # NIL THEN RETURN;

lock ← lastLock ← TextNode.pZone.NEW[LockRecord];

NodeProps.PutProp[root, $DocumentLock, lock];

};

NodeProps.Register[$DocumentLock, NodeProps.NullRead, NodeProps.NullWrite, NodeProps.NullCopy];

Don't copy document lock or big trouble.

END..