FIX: GP Fault in Multi-Threaded DB-Library Program
  
PSS ID Number: Q105751
Article last modified on 01-24-1995
 
4.20 | 4.20
 
OS/2 | WINDOWS
 

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The information in this article applies to:
 
 - Microsoft SQL Server Programmer's Toolkit, version 4.2
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BUG# 9531 (4.20.00)
 
SYMPTOMS
========
 
When calling DB-Library from multiple threads of execution within a client
application, a general protection fault (GP fault) occurs. This happens
despite serialization of DB-Library calls involving global variables as
documented in the Microsoft SQL Server "Programmer's Reference for C."
 
CAUSE
=====
 
Interactions between threads executing several different DB-Library
functions can result in a situation leading to an infinite recursion and
GP fault. This is most likely to occur when multiple threads are executing
dbuse() and dbcursoropen() simultaneously.
 
WORKAROUND
==========
 
Access to the following functions should be serialized with a single
synchronization object:
 
   dbcursoropen()
   dbopen()
   dbuse()
   dbmsghandle()
   dberrhandle()
 
STATUS
======
 
Microsoft has confirmed this to be a problem in DB-Library version 4.20.00.
This problem was corrected in DB-Library version 4.21.00. For more
information, contact your primary support provider.
 
Additional reference words: 4.20.00 DB-Lib cursor cursors multi threads
KBCategory: kbprg
KBSubCategory: SSrvDB_Lib SSrvProg
 
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Copyright Microsoft Corporation 1995.
