Re: [PATCH] More functions for dynamic storage engine plugins

[Jim Starkey]

Sergei Golubchik wrote:
> external_lock - both at the start and at the end.  If it's not called
> (the rules are currently more complex than I'd want them to be,
> unfortunately, but they do exist) then start_stmt() is called at the
> start and commit/rollback - at the end.
>   

If external_lock() and other functions were structured as virtual 
methods on, say, the THD object, they would work across a loadable 
library boundary.  The same is true for access functions defined to 
render the internal of THD opaque to loaded library.

The goal should be to eliminate all global references from a plugin into 
server functions and variables.  When the only cross talk between a 
plugin and the server is a singled exported entrypoint of the plugin and 
objects defined by abstract interfaces to the plugin, plugins will work 
on windows and be version-safe on ELF systems.