Spring RTS Engine

This is what I get if I print the frame number in GameFrame: Frame 1 is skipped. Other mods I've tested don't have this issue (The Cursed, S44, ZK).

They can have this issue if there is a gadget that gets removed. I think that might be the reason here, too.

See http://springrts.com/mantis/view.php?id=1907

The problem has been known for a while. It's not only a
problem with the lua event handling, it's also present in
the C++ EventHandler.

For BZFlag, I rewrote both the C++ and lua event
handling to use lists instead of arrays. List iterators
are unaffected by insertions and deletions of other
iterators. The lua event list code is actually faster than
the code that SpringRTS is currently using (the lua list
implementation is surprising fast compared to array
iteration, and the BZFlag lua event handling code doesn't
have to do named function lookups).

trepan wrote:the BZFlag lua event handling code doesn't
have to do named function lookups

How?
I thought Lua doesn't support `pointers` to lua_objects (note even a LUA_REGISTRYINDEX is a table lookup).

PS: I am working on the gadget-/widget handlers atm,
so the lua side will get fixed soon enough.

jK wrote:

trepan wrote:the BZFlag lua event handling code doesn't
have to do named function lookups

Instead of doing a widget["func_name"] lookup for each
function call, the functions are registered into the ordered
event lists.

simplified iteration example:

As you can see from the last commit date,
this hasn't been touched in a while. As a
matter of fact, almost all BZFlag development
has ceased 8^)

EventClientList.h
http://bzflag.svn.sourceforge.net/viewv ... iew=markup

trepan wrote:

jK wrote:

trepan wrote:the BZFlag lua event handling code doesn't
have to do named function lookups

Instead of doing a widget["func_name"] lookup for each
function call, the functions are registered into the ordered
event lists.

simplified iteration example:

Code: Select all

local node = eventlist.start
while (node) do
  node.func(...)
  node = node.next
end

ah,
I thought you were still talking about the engine eventhandler.

One thing to note about the EventClientList.h example
is the "purify()" function (if anyone wants to take a shot
at fixing the C++ code). The reason for purify() is to
avoid problems when an EventClient is removed while
the list iterator pointing to it is active (being used to run
code).

One trick to solving this problem is shown in the following
header file (look for the CallbackList<F>::doIterate() method):
http://bzflag.svn.sourceforge.net/viewv ... iew=markup

That's seemed clunky to me, so instead I setup a dummy
EventClient instance, and replaced the EventClient pointer
in the list with the dummy instance (which has member
functions that don't do anything). A 'purify' flag is set on any
EventClientList with a removal, and you just have to clean
out the dummy instance pointers every once in a while.

quantum wrote:Bug report: gadget handler skips frames

Frame 1 is skipped.

I encountered this problem as well. lurker wrote me a gadget handler patch to fix this. See my "hotfixes.lua" gadget (in KP for instance). Eh, I actually even have released a BA version with this fix: http://springrts.com/phpbb/viewtopic.php?f=44&t=24034