ALLEGRO_STATE man page
ALLEGRO_STATE — Allegro 5 API
typedef struct ALLEGRO_STATE ALLEGRO_STATE;
Opaque type which is passed to al_store_state(3)/al_restore_state(3).
The various state kept internally by Allegro can be displayed like this:
global active system driver current config per thread new bitmap params new display params active file interface errno current blending mode current display deferred drawing current target bitmap current transformation current projection transformation current clipping rectangle bitmap locking current shader
In general, the only real global state is the active system driver. All other global state is per-thread, so if your application has multiple separate threads they never will interfere with each other. (Except if there are objects accessed by multiple threads of course. Usually you want to minimize that though and for the remaining cases use synchronization primitives described in the threads section or events described in the events section to control inter-thread communication.)