Re: Garbage Collection

[Diego Fernandes Nehab <diego@...>]

Hi,

> I wish to ensure that all handles are closed and all memory
> is deallocated when lua_close is called. I also want the
> lua garbage collection to close any loose statement(cursor)
> handles. However, I dont want statement handles closed when
> I am fetching data from them.

This is something I was about to start working with. What you need is to
keep  a reference  to  the  statement in  every  cursor  created by  it.
Probably the  best solution  is to do  it within the  C code.  There was
supposed to be code in LuaSQL to do this.

> Finally, the following two C code fragments are used in luaSQL,
> which approach is better?

I prefer the lua_newuserdata. Lua itself  frees the memory in that case.
All you need to  do is clean up whatever objects  you initialized in the
memory space returned by the function.

> lua_pushusertag(L, conn, env->conn_tag);
> cursor->conn = lua_ref(L, 1);
> /* gc method closes handle, does  lua_unref(L, cursor->conn);
> and presumably relies on gc to clean up the cursor userdata */

See the  code above?  The reference ensures  that the  connection object
will not be GCed before the cursor object is GCed. Is this not working?

Best regards,
Diego.