ofstream (standard C++ file output) not working

[slavik262]

Right, so if it is called before fopen() in the same thread, why would there be a race condition?

I think we're having some kind of communication disconnect. Sorry.

[jhersh]

Originally Posted by slavik262

Right, so if it is called before fopen() in the same thread, why would there be a race condition?

You would not. The situation described above (or how I read it anyway) was that you were not calling Priv_SetWriteFileAllowed, and that it sometimes worked. I was suggesting that there are other tasks that may be calling it that would allow the write to work sometimes and not others.

If what you are saying is that you are calling it in the same task before the fopen and it still only works some of the time, then I don't have a good theory for you. Let me know if this is the case and I'll try to look into it a bit more.

-Joe

[byteit101]

A race condition would make sense, originally, I had the write in the simple template constructor, later i put it in the auto. I will test out the race condition today. My plan:
write to file in entry point function before anything else
write to file in robot constructor
write to file in robot auto after 10 second wait

they will be tested 10 times without priv_set..., and 10 times with priv_set...
I will report back later

[byteit101]

Hmm, I am not seeing any blocked attempts to write; Every test was successful, without the priv_set... Sometimes it took up to 10 seconds to find it over FTP, but every test was successful

[jhersh]

Originally Posted by byteit101

Sometimes it took up to 10 seconds to find it over FTP, but every test was successful

Make sure your FTP client is not caching the directory listing. What client are you using?

[byteit101]

Originally Posted by jhersh

Make sure your FTP client is not caching the directory listing. What client are you using?

FileZilla

[jhersh]

Originally Posted by byteit101

FileZilla

Hmm... should be fine as long as you refresh and are connected. Have you tried putting prints to go along with your writes to get some idea of when the write happened vs. when you see the file on the FTP server?

[byteit101]

no, but I think it might be the code is slow (I only immediatly looked at the folder for a few test), you hit Run kernel task and it downloads, (I was measuring from that point), it calls the entry point function, and inits everything before creating the file

[davidalln]

We finally got our log working consistently (although not as sophisticated as 3132's Logger, it's a foundation in which stuff can be added on). It looks like the race condition problems listed above were the culprit. The key is not to completely overwhelm it with added lines in the main loop.

We have wrapped it in a class if anyone's interested: http://gist.github.com/296373