>>Download of Image to hardware >>When a set request is received by the agent to download an image to hardware >>a function call is made to download. >>Within this download function I have the mutex to lock to prevent multiple >>requests to download and then I spawn a thread that downloads the image to >>the hardware device. Once complete the lock is disabled. The thread >>resources are removed once the thread exits.
This is what I sent out yesterday. Yes your both correct. The main thread however is blocked as stated in the above text. Thanks, Garyc ----- Original Message ----- From: "Robert Story (Users)" <[EMAIL PROTECTED]> Cc: "Gary Clark" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Thursday, October 28, 2004 8:06 AM Subject: Re: Sending traps in another thread > On Thu, 28 Oct 2004 09:39:43 +0100 Dave wrote: > DS> Robert> Ok, lets see if I got this right. You have the main agent thread, > DS> Robert> and two worker threads. The worker threads don't do any SNMP other > DS> Robert> than to call send_v2trap. Is that right? > DS> > DS> Gary> Yep you got it. > DS> > DS> Urk! I'm not sure that's safe. > DS> > DS> As far as I remember, doesn't the 'send_trap_vars' mechanism use the > DS> same (non-thread-safe) set of APIs as the incoming request handling? > DS> I'd expect this to suffer from problems between generating traps > DS> and receiving incoming requests. > DS> > DS> In order for that to work safely, wouldn't it be necessary to rework > DS> the 'send_trap_vars' code to use the SSI approach instead? > DS> > DS> All of the locking that you talk about sounds to be aimed at a different > DS> area of potential conflict. I'm not at all sure that you're protected > DS> against races within the SNMP library itself. > > Dave's right. If you were using the mutexes such that only one thread at a time > was doing SNMP, you'd probably be ok. But if the main thread isn't blocked > while the worker thread is doing it's trap thing, and you get an incoming > request to the main thread, you've got two threads accessing the same data. > > The odds of getting a request while sending/processing traps may be low, but > when it does happen, it could cause problems. > > -- > Robert Story; NET-SNMP Junkie <http://www.net-snmp.org/> > <irc://irc.freenode.net/#net-snmp> > Archive: <http://sourceforge.net/mailarchive/forum.php?forum=net-snmp-users> > > You are lost in a twisty maze of little standards, all different. > > > ------------------------------------------------------- > This SF.Net email is sponsored by: > Sybase ASE Linux Express Edition - download now for FREE > LinuxWorld Reader's Choice Award Winner for best database on Linux. > http://ads.osdn.com/?ad_id=5588&alloc_id=12065&op=click > _______________________________________________ > 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 ------------------------------------------------------- This SF.Net email is sponsored by: Sybase ASE Linux Express Edition - download now for FREE LinuxWorld Reader's Choice Award Winner for best database on Linux. http://ads.osdn.com/?ad_id=5588&alloc_id=12065&op=click _______________________________________________ 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
