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Entry  23 Oct 2008, Konstantin Olchanski, Bug Report, Inconsistent handling of odb and evet buffer timeouts 
    Reply  28 Oct 2008, Stefan Ritt, Bug Report, Inconsistent handling of odb and evet buffer timeouts 
Message ID: 517     Entry time: 28 Oct 2008     In reply to: 514
Author: Stefan Ritt 
Topic: Bug Report 
Subject: Inconsistent handling of odb and evet buffer timeouts 
> In midas.c there are several places where client last activity time stamps are checked against the 
> watchdog timeout and the clients are declared dead if they fail to update their activity time stamps. 
> ODB time stamps and data buffer time stamps appear to be handled in a similar manner.
> Most checks are done like this:
> now = ss_millitime();
> if (client->watchdog > 0      <----- check that the watchdog is enabled
>     && now > client->last_activity    <---- check for crazy time stamps from the future
>     && now - client->last_activity > client->watchdog_timeout)   <--- normal timeout
>         remove_client(client);
> But in a few places, the extra checks are missing:
> now = ss_millitime();
> if (now - client->last_activity > client->watchdog_timeout)
>         remove_client(client);
> Is this an oversight from when additional checks were added?
> Should I make all checks read like the first one?
> K.O.

This is on purpose. Inside cm_watchdog(), the system check for client->watchdog > 0. If the watchdog 
timeout is zero, the client is not removed. This feature is used if you debug a program. If you come to a 
breakpoint and sit there for a while, you might be declared dead and the application is removed from the 
ODB, meaning that you cannot continue debugging (on the next ODB access the application asserts). This 
can be avoided by setting the watchdog to zero, which is implemented in most applications by supplying 
"-d" on the command line. Now assume you debug a program, so you set the watchdog timeout to zero, but in 
the debugging session you decide to quit. Since the watchdog timeout is zero, you will never be removed 
from the ODB. Therefore, the code inside cm_cleanup() doe NOT check client->watchdog > 0. Therefore, a 
"cleanup" inside odbedit will even remove clients having the timeout set to zero. 

Now there might be more clever ways to accomplish that, but that's how it is implemented right now.
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