Re: Net-SNMP 5.6.rc1 available for testing

22.12.2010 15:02, Bart Van Assche wrote:
> Hi Kirill,
>
> Sorry, but that still doesn't prove that the cause is in the Net-SNMP
> source code. As an example, adding threads without using proper
> synchronization constructs may introduce race conditions that do no harm
> with one version of the Net-SNMP source code but are harmless with
> another version. Have you already analyzed your code with a data race
> detector ?
>
> Another potential booby trap when working with threads are POSIX
> signals. Unless signals are blocked before any threads are created and
> unblocked by the thread that will handle them, signals can be delivered
> to any thread. That's another potential source of race conditions. For
> more information, see also
> http://pubs.opengroup.org/onlinepubs/009695399/functions/sigprocmask.html.
>
> Bart.

I wrote special test mib-module that starts thread like this:

void test_thread_function(void)
{
	while(1)
	{
		struct timeval timeout;
		timeout.tv_sec = 1;
		timeout.tv_usec = 0;
		select(0, NULL, NULL, NULL, &timeout);
		log_add(LOG_INFO, "I am still alive\n");
	}
}

Works ok in 5.4.2.1 and does not work in 5.5.
log_add function just writes string to the file and it is not used 
anywhere else. I can't see any possibilities for race conditions here.

And thanks for info on signals, I'll check it.

Kirill

------------------------------------------------------------------------------
Forrester recently released a report on the Return on Investment (ROI) of
Google Apps. They found a 300% ROI, 38%-56% cost savings, and break-even
within 7 months.  Over 3 million businesses have gone Google with Google Apps:
an online email calendar, and document program that's accessible from your 
browser. Read the Forrester report: http://p.sf.net/sfu/googleapps-sfnew
_______________________________________________
Net-snmp-users mailing list
[email protected]
Please see the following page to unsubscribe or change other options:
https://lists.sourceforge.net/lists/listinfo/net-snmp-users