Optstrategy, preload and runonce relation

[momentum]

Hi,

I wonder why when runonce is False, then the data are not preloaded in optimization. I also wonder what happens when someone is using _nextforce = True instead. It seems to me that preloading will take place as the indicators that will call _disable_runonce are added afterwards.

Thanks

        iterstrats = itertools.product(*self.strats)
        if not self._dooptimize or self.p.maxcpus == 1:
            # If no optimmization is wished ... or 1 core is to be used
            # let's skip process "spawning"
            for iterstrat in iterstrats:
                runstrat = self.runstrategies(iterstrat)
                self.runstrats.append(runstrat)
                if self._dooptimize:
                    for cb in self.optcbs:
                        cb(runstrat)  # callback receives finished strategy
        else:
            if self.p.optdatas and self._dopreload and self._dorunonce:
                for data in self.datas:
                    data.reset()
                    if self._exactbars < 1:  # datas can be full length
                        data.extend(size=self.params.lookahead)
                    data._start()
                    if self._dopreload:
                        data.preload()

            pool = multiprocessing.Pool(self.p.maxcpus or None)
            for r in pool.imap(self, iterstrats):
                self.runstrats.append(r)
                for cb in self.optcbs:
                    cb(r)  # callback receives finished strategy

            pool.close()