On Wednesday, 19 August 2015 at 14:45:31 UTC, Steven
Schveighoffer wrote:
In the case where the pointer changes, you are in trouble. The
original memory is now free, which means it can be overwritten
by something else (either the C heap or some other thread that
reallocates it). Then if your GC runs *before* you have added
the new memory, it may collect the now-no-longer-referred-to
data. It's no different than your original situation.
I actually think the case where the pointer changes is worse.
Yes I made the same observation in the meantime.
Also, I note that others have said one can call GC.collect from
another thread, which is true. One could call GC.enable as
well. If you have concerns of this happening (i.e. you don't
control all the code, and think your code may coexist with
something that calls GC.collect), the likely correct mechanism
is to take the GC global lock while doing your operation. I'm
not sure if you can do that via the current API, you may have
to add such a feature.
Yes I figured as much. The entire purpose of this thraed was to
point out that you can not safely forward a realloc to the GC.
Unfortunately its not a option not to use realloc as I'm binding
some code I don't have control over. To summarize the entire
issue and a possible solutions I created the following ticket:
https://issues.dlang.org/show_bug.cgi?id=14934
Kind Regards
Benjamin Thaut
