[vlc-devel] Deadlock in freetype module

Rémi Denis-Courmont rem at videolan.org
Mon Aug 18 20:02:49 CEST 2008

Le lundi 18 août 2008 20:57:11 Laurent Aimar, vous avez écrit :
>  What this mess try to do:
>  - it creates a *unique* fontconfig for all instance of freetype.
>  - this fontconfig will be created in its own thread on the first freetype
> module creation (it can take a really long times).
>  - this fontconfig will be destroyed on the last freetype module release.
>  - the freetype module will use the fontconfig as soon as available, but it
> can still work without it (a bit degraded that's all).

My point is, var_AcquireMutex() is meant to create PROCESS-wide locks, for use 
with thread-unsafe library calls, especially library init/deinit functions.

The FreeType module is creating one fontconfig instance per LibVLC instance. 
which can be more than one per process. Of course, sharing a lock is always 
possible, but inefficient at best (the Qt4 vout does this for lack of better 

Rémi Denis-Courmont

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