[Debtags-devel] Any Idea why this fails?

[Benjamin Mesing]

Hello

> Uhm... multiple times as in:
>   while (1)
>   {
>          Tagcoll::InputMerger<int, string> merger;
>          Tagcoll::TagcollBuilder collBuilder(*(new Tagcoll::HandleMaker<string>()));
>          // load the database into the collBuilder and change it to handles
>          Debtags::TagDB::outputSystem(collBuilder, false);
>   }
This does definetely work (at least doing it twice).

> or multiple times as in:
>   while (1)
>   {
>     exec in new thread {
>          Tagcoll::InputMerger<int, string> merger;
>          Tagcoll::TagcollBuilder collBuilder(*(new Tagcoll::HandleMaker<string>()));
>          // load the database into the collBuilder and change it to handles
>          Debtags::TagDB::outputSystem(collBuilder, false);
>     }
>   }
> ?
For the failing case I am not completely sure as I work with the QT
which is multithreaded. But I think it happens from a single thread. The
request is triggered asynchron (by user interaction) which might come
from another thread. I do not know above about QT internals and threads
to be sure of it.

I would have hoped that the failing only in the latest version would
have hinted towards the problem.

> Design note: now that we have autodebtag I was considering moving
> expansion of derived tags into autodebtag, and just loading the system
> database "as is".  This would really help efficiency: for example, you
> could mmap the file, or add an index pointing to where the tags for a
> given package are in the text file.  
Hmm.. I never cared for such low level stuff as mmap and was scared by
it from libapt, but I am sure you will provide a nice object oriented
interface for it :-)
But I would really like this as this would also trim down the memory
usage.

Greetings Ben