Need some help with this...

[Bane]

grauzone Wrote:

> Bane wrote:
> > Following code will freeze app on std.gc.fullCollect(), when sqlite3_close() in destructor is called. If destructor is called manualy, everything goes ok.
> > 
> > Is it a bug, and if is, with what? It behaves same on winxp64 and centos5.2 using dmd 1.30 and sqlite 3.6.5 or 3.6.19 statically import lib. Libraries are tested so I do not suspect problem lies in them (they are compiled with dmc/gcc using full threading support).
> 
> It's not your fault, it's a well known bug. The following is what happens:
> 
> - in thread 1, a C function (e.g. malloc()) enters an internal lock
> - while thread 1 holds the lock, thread 2 triggers a D garbage 
> collection cycle
> - thread 2 pauses all threads forcibly, including thread 1
> - thread 2 collects some objects and calls finalizers on it
> - your finalizer calls a C function, which tries to enter the same lock 
> that is held by thread 1
> - but thread 1 has been paused
> - the GC won't resume the other threads until your function returns, and 
> you have a deadlock
> 
> As a solution, switch to D2 or Tango. These resume all suspended threads 
> before running the finalizers.

Thank you, grauzone. That clears it. Switching to D2 or Tango is a bit overkill as existing codebase is big and fairly tested (not including this issue :).

 I assume this happens pretty rarely, because I haven't noticed this bug so far. Manual delete seems to be workaround, so it is not a critical issue.

Thanks again :) Love D.