NWLogLogicalRecord
Logs a logical record in a log table
#include <nwfile.h>
or
#include <nwcalls.h>
N_EXTERN_LIBRARY(NWCCODE)NWLogLogicalRecord (
NWCONN_HANDLE conn,
const nstr8 N_FAR *logRecName,
nuint8 lockFlags,
nuint16 timeOut);
uses calwin32
Function NWLogLogicalRecord
(conn : NWCONN_HANDLE;
const logRecName : pnstr8;
lockFlags : nuint8;
timeOut : nuint16
) : NWCCODE;
These are common return values; see Return Values (NDK: Connection, Message, and NCP Extensions) for more information.
A logical record is simply a name (string) registered with the NetWare server. The name (as with a semaphore) can then be locked or unlocked by applications and can be used as an inter-application locking mechanism.
NOTE:Locking or unlocking a logical record does not physically lock or unlock those resources associated with the logical record; only the applications using the record know about such an association.
When lockFlags is set to option one or three, the NetWare server attempts to lock the logical record for the length of time specified by timeOut. timeOut is specified in 1/18 second units.
lockFlags ’ values are the following:
0 = Log only 1 = Log and lock exclusive 3 = Log and lock shareable
timeOut is specified in units of 1/18 second (0 = no wait).
Normally, a set of files or records is logged and then locked as a set. However, a single file or record can also be locked when it is placed in the log table. The release functions, NWReleaseLogicalRecord and NWReleaseLogicalRecordSet, are used to unlock a lock (or set of locks). The clear functions, NWClearLogicalRecord and NWClearLogicalRecordSet, are used to unlock and remove a lock (or set of locks) from the log table.
To avoid deadlock, request those resources needing to be locked by making an entry in the File Log Table at the NetWare server. Once the log table is complete, NWLogLogicalRecord attempts to lock those records. Locking works only if all records in the table are available. If some of the logged resources cannot be locked, the lock fails and none of the resources are locked.
NWLogLogicalRecord cannot lock files already logged and exclusively locked by other applications.