Essentially, --predictable turns off anything in V8 that is known to cause changes in behavior from one run to the next: multiple thread usage (it restricts V8 to using *just one thread*, no background threads at all), the random number generator in Math.random(), and anything else we could think of (which I can't think of right now ;-) ). It is intended for debugging flaky problems (by making them reproducible), but sometimes it has the side effect of hiding flaky problems...
On Sun, Sep 24, 2017 at 8:52 PM, Brandon Jonson <brandon.e.jon...@gmail.com> wrote: > Hello All! > > I have V8 embedded in a multi threaded app. The app uses locker/unlocker > and all seems to work just fine in those regards (no locker errors or full > on app crashes). I do have an edge case though I thought I'd get some input > on. If I basically pound the isolate (utilizing locker of course) from > multiple threads v8 will eventually FREEZE on a resolve and never respond. > Below is the line it freezes on... > > resolver->Resolve(String::NewFromUtf8(isolate, msg)); > > It doesn't crash the app...it just won't ever move on from that line of > code, waiting for V8. It's as if V8 decided to just not respond anymore but > I'm not seeing any indication of an error. Also if I change this to an > actual function call it will do the same thing (so not necessarily Promise > related). > > The crazy thing is that when I add the --predictable flag that issue goes > away. I understand they replaced set_max_available_threads, allowing the > Platform to handle the work and that this --predictable flag basically > forces the Platform to use one thread for background processes (I think). > My assumption the freeze is occurring because of too many threads? > > Anyway I was hoping somebody a hell of a lot smarter than me could explain > what this flag is changing and what fresh hell did I open myself up to by > enabling it. > > Thank You! > > -- > -- > v8-users mailing list > v8-users@googlegroups.com > http://groups.google.com/group/v8-users > --- > You received this message because you are subscribed to the Google Groups > "v8-users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to v8-users+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups "v8-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
