DOCUMENT:Q102738  10-AUG-1993  [W_NT]
TITLE   :INF: File and Record Locking in Windows NT
PRODUCT :Windows NT
PROD/VER:3.10
OPER/SYS:WINDOWS
KEYWORDS:

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The information in this article applies to:
 
 - Microsoft Windows NT operating system, version 3.1
 - Microsoft Windows NT Advanced Server, version 3.1
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SUMMARY
=======
 
Microsoft Windows NT version 3.1 can support file and record locking
using appropriate Win32 application programming interfaces (APIs).
File sharing with these capabilities can be achieved via Windows NT
server message block (SMB) file sharing protocol extensions.
 
MORE INFORMATION
================
 
File, record, and field locking are essential for applications that
require sharing a file by multiple users who may be entering data
concurrently. In Windows NT, this may be achieved by using Win32 APIs.
 
 - LockFile - Locks a region in an open file. Locking a region with
   this API denies all other processes read and write access to the
   specified region.
 
 - LockFileEx - Locks a byte range within an open file for shared or
   exclusive access. This API allows read access if shared lock is
   specified but denies write access.
 
If the specified file is at a remote location, the file and record
locking can be handled by one of the SMB.
 
 - LOCKING_ANDX_SHARED_LOCK - Locks a byte range within the specified
   file for shared or exclusive access.
 
Reference(s):
 
1. NT LAN Manager SMB File Sharing Protocol Extensions by
   Chuck Lenzmeir and Manny Weiser.
2. Microsoft Win32 Programmer's Reference, Volume 4 page 103.
 
Additional reference words: 3.10 file locking
KBCategory:
KBSubCategry: NETSRV

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