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Welcome to the fbLockUDF wiki!

Firebird Lock UDF is a UDF module for windows server which can obtain a server wide lock for a maximum of a specified amount of seconds.

Especially useful if you require unique access to resources for a short period of time.

Locks are not connection or transaction specific, and there is no security available for who can obtain or release a lock.

External Function Definitions

DECLARE EXTERNAL FUNCTION fb_ServerLockGet CSTRING(100), INTEGER
RETURNS INTEGER BY VALUE
ENTRY_POINT 'fbServerLockGet'
MODULE_NAME 'fbLockUdf';

DECLARE EXTERNAL FUNCTION fb_ServerLockRel CSTRING(100)
RETURNS INTEGER BY VALUE
ENTRY_POINT 'fbServerLockRel'
MODULE_NAME 'fbLockUdf';

Restrictions

Maximum of 10 locks per database instance. Maximum lock wait of 2000 milliseconds fbServerLockGet

fbServerLockGet

Obtains a server wide lock

Parameters

• CSTRING(100) - Unique string to identify the lock INTEGER - Number of seconds the lock can remain active

Return Value - INTEGER

• 0 - Lock Obtained
• 1 - Maximum Lock Count Exceeded
• 2 - Lock Already Exists
• 3 - Invalid Lock Handle
• 4 - Access Denied
• 5 - Time Out waiting to obtain a lock
• 6 - Invalid Lock Name
• 7 - Invalid Parameter
• 8 - Invalid Age (Must be between 0 and 1440 seconds)
• 9 - Lock not Found
• 999 - General Error

fbServerLockRel

fbServerLockRel releases a server wide lock

Parameters

• CSTRING(100) - Unique string to identify the lock

Return Value - INTEGER

• 0 - Lock Released
• 3 - Invalid Lock Handle
• 4 - Access Denied
• 5 - Time Out waiting to obtain a lock
• 6 - Invalid Lock Name
• 9 - Lock not Found
• 999 - General Error

Source code is available via Git Hub https://github.com/k3ldar/fbLockUDF

Features

• 32 and 64 bit versions.
• Free for personal, commercial and all other uses.
• Source code available.
• Unlimited Updates/Patches
• Open Source - Released under Initial Developers Public Licence