talloc null context thread safe ?
turboult at easynet.fr
Tue Nov 7 08:50:33 GMT 2006
thanks for all your answers.
tridge at samba.org a Ã©critÂ :
> > If so, my concern is with the allocation of "top-level" contexts i.e. when
> > using a NULL parent. When using the "talloc_enable_leak_report",
> I understand
> > that the NULL context is in fact a hidden "null context" global
> variable, so
> > allocating anything from the NULL context (e.g. tmp_ctx =
> talloc_new (NULL))
> > is no longer thread safe.
> that's right. It doesn't affect Samba,
out of curiosity, why doesn't it affect Samba ? no threads, or not
> but it is something that should
> concern threaded programs.
may be for the time being it is possible to add a small paragraph in
For example :
talloc itself does not deal with threads. It is thread-safe (assuming
the underlying "malloc" is), as long as each thread uses different
If two threads uses the same context then they need to synchronise in
order to be safe.
In particular, when using talloc_enable_leak_report(), giving directly
NULL as a parent context implicitly refers to a hidden "null context"
global variable, so this should not be used in a multi-threaded
environment without proper synchronisation.
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