Re: Plugins redux (was Re: [PATCHES] PL instrumentation

> Also, should we create an on_proc_exit() handler that would unload all
> dynamic libraries (specifically to call the _PG_fini() functions)? 

Yeah, I thought about that too, but I'm inclined not to do it;
it seems like just excess cycles.  The process is quitting anyway,
so the only reason this would be useful is if the library thinks it's
going to update external or shared state during _PG_fini ... and on
the whole that sounds like a bad idea.  Besides, if a library really
needs this it can add its own on_proc_exit handler.

 It seems a little dangerous for a dynamic library to register an on_proc_exit() handler.  If we ever add support for unloading a dynamic library, we'll have to add an unregister_on_proc_exit() too. Otherwise, a dynamic library might register a function pointer with on_proc_exit() and then leave a dangling pointer when it gets unloaded.

 Given that, I assume you don't feel the need to unload old shared libraries if the user (a superuser) removes an entry from backend_load_libraries, right?

 In fact, it looks _PG_fini() is only called if you *reload* a library, unless I'm missing something somwhere.


 --
   Korry Douglas    korryd@enterprisedb.com
   EnterpriseDB      http://www.enterprisedb.com