This allows completely avoiding the call overhead if there
are none. The downside is that the event object now has to
be a userdata with lots of metamethods.
- This context requires core suspend lock and asserts it in a few places.
- Special 'event' objects are introduced. They can be invoked as
functions, in which case they iterate all their fields and call
them as functions. Errors are printed and consumed.
- When a plugin is opened by the core context, events registered in
a special array are linked to it. The system is organized so as to
avoid even trying to pass the event to lua if the module isn't loaded.
- To ensure reload safety functions have to be wrapped. Every call
checks the loaded state and locks a mutex in Plugin. If the plugin
is unloaded, calling its functions throws a lua error. Therefore,
plugins may not create closures or export yieldable functions.
- The set of function argument and return types supported by
LuaWrapper is severely limited when compared to being compiled
inside the main library.
Currently supported types: numbers, bool, std::string, df::foo,
df::foo*, std::vector<bool>, std::vector<df::foo*>.
- To facilitate postponing initialization until after all plugins
have been loaded, the core sends a SC_CORE_INITIALIZED event.
- As an example, the burrows plugin now exports its functions.
This is an incompatible change to the plugin ABI.
The Console is not thread-safe unless used indirectly
via color_ostream_proxy, so everything should use their
per-thread stream.