Re: [Wesnoth-dev] possible game_events cleanup

[David White]

Yann Dirson wrote:

> The thing that strikes me much in game_events is that
> game_events::manager is not a class, but a struct, whose ctor and dtor
> deal with variables in the anonymous namespace, instead of using
> object members.  The whole thing therefor looks a bit non-reentrant -
> is there a particular reason.  Could it be that there was a start of a
> move to a full-fledged game_events::manager class, which has not been
> completed yet ?
>  
This idiom is actually used fairly often in Wesnoth, and it's a 
legitimate one imho.

The variables aren't members of the manager class because that doesn't 
make logical sense -- they are completely private to the module and the 
manager doesn't manipulate them other than setting them up and 
destroying them when things are done. The manager is simply an 
exception-safe implementation of the C-style module_init() and 
module_deinit() idiom.

If re-entrance is desired (and I can understand an argument for it 
always being wanted), then we can simply add a boolean flag to tell if a 
manager object is already active, and to make the manager do nothing if 
a manager is already active. See network::manager for an example of 
this. Other than possible adding of support for re-entrance, I don't see 
any reason to change the fundamental functionality of game_events::manager.

David