[unixODBC-support] Core dump issue from UnixODBC on AIX platform

Nick Gorham nick.gorham at easysoft.com
Mon Nov 5 14:49:40 GMT 2007


Hassan Shaik wrote:

>Hi Nick,
>
>Thanks for your quick response. 
>
>1. Can you please point me to the ftp location from where I can download
>UnixODBC 2.2.13pre? When it will be released officially?
>  
>
ftp://ftp.easysoft.com/pub/unixODBC/unixODBC-2.2.13pre.tar.gz

No date for release yet.

>2. I have gone through some of the discussions in easysoft support email
>aliases. In one thread, its recommended to set "Threading = 0" in
>odbcinst.ini file. I have gone through the below notes in __handles.c
>file. Can you please more elaborate on when to use these levels? Does
>trying "Threading = 0" will help? Pls clarify.
>
>/*
> * use just one mutex for all the lists, this avoids any issues
> * with deadlocks, the performance issue should be minimal, if it
> * turns out to be a problem, we can readdress this
> *
> * We also have a mutex to protect the connection pooling code
> *
> * If compiled with thread support the DM allows four different
> * thread strategies
> *
> * Level 0 - Only the DM internal structures are protected
> * the driver is assumed to take care of it's self
> *
> * Level 1 - The driver is protected down to the statement level
> * each statement will be protected, and the same for the connect
> * level for connect functions, note that descriptors are considered
> * equal to statements when it comes to thread protection.
> *
> * Level 2 - The driver is protected at the connection level. only
> * one thread can be in a particular driver at one time
> *
> * Level 3 - The driver is protected at the env level, only one thing
> * at a time.
> *
> * By default the driver open connections with a lock level of 3,
> * this can be changed by adding the line
> *
> * Threading = N
> *
> * to the driver entry in odbcinst.ini, where N is the locking level
> * (0-3)
> *
> */
>
>Appreciate your help on this.
>  
>
The comments you posted explain the use of the flag. If your driver 
isn't thread safe use something otyher than 0, if it is, then 0 is fine. 
You didn't mention what driver you were using. As you seem to be 
reporting a problem with the driver managers own thread handling, the 
Threading level should have no effect.

-- 
Nick Gorham
Easysoft Limited
http://www.easysoft.com, http://www.unixODBC.org




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