I think we do not want to make any assumptions about runtime of any tasks since this would not work well with task that have variable runtime.
If you need to do heavy calculations since browser APIs have evolved a lot you should be using web workers anyway. On Wed, Jan 14, 2015 at 11:57 AM, Richard Wallis <[email protected]> wrote: > At the moment, incremental scheduler runs a repeating task in a while loop > that checks if its duration has exceeded 16ms and then returns control to > the browser. > > If you assume that an incrementally scheduled task will tend to run in > about the same time as it did before then you can get about a 10% speed up > by counting the number of times the task ran during the last duration loop > and then running the task that many times at the start (and skipping the > duration check). > > On chrome a task that calculated the fibonacci sequence managed to > calculate about 450000 numbers in a second with the current scheduler and > about 500000 numbers in the same time with my new one below. > > And a realworld task that parses xml dropped from taking about 50 seconds > each run to 42 seconds. > > Of course if the incrementally scheduled task tends to take a longer and > longer time to complete on each run the oprimization might cause issues so > maybe we need to create a new kind of task scheduler specifically for tasks > that tend to complete their runs in a similar timeframe. > > I'm looking for critiscim of the code below, (and maybe someone to take > ownership of this and do a PR to gerrit on my behalf) > > In SchedulerImpl replace the current runRepeatingTasks method with this: > (lastLoopCount is a private int field); > > /** > * Execute a list of Tasks that hold RepeatingCommands. > * > * @return A replacement array that is possibly a shorter copy of > <code>tasks</code> > */ > private JsArray<Task> runRepeatingTasks(JsArray<Task> tasks) { > assert tasks != null : "tasks"; > > int length = tasks.length(); > if (length == 0) { > return null; > } > > boolean canceledSomeTasks = false; > > Duration duration = createDuration(); > int loopCount = 0; > outer: while (duration.elapsedMillis() < TIME_SLICE) { > > if (length == 1) { > while (lastLoopCount-- > 0 ) { > if (!tasks.get(0).executeRepeating()) { > tasks.set(0, null); > canceledSomeTasks = true; > break outer; > } > loopCount += 1; > } > } > boolean executedSomeTask = false; > for (int i = 0; i < length; i++) { > assert tasks.length() == length : "Working array length changed " > + tasks.length() + " != " > + length; > Task t = tasks.get(i); > if (t == null) { > continue; > } > executedSomeTask = true; > > assert t.isRepeating() : "Found a non-repeating Task"; > > if (!t.executeRepeating()) { > tasks.set(i, null); > canceledSomeTasks = true; > } > loopCount += 1; > } > if (!executedSomeTask) { > // no work left to do, break to avoid busy waiting until > TIME_SLICE is reached > break; > } > } > if (length == 1) { > lastLoopCount = loopCount; > } > > if (canceledSomeTasks) { > lastLoopCount = 0; > JsArray<Task> newTasks = createQueue(); > // Remove tombstones > for (int i = 0; i < length; i++) { > if (tasks.get(i) != null) { > newTasks.push(tasks.get(i)); > } > } > assert newTasks.length() < length; > return newTasks.length() == 0 ? null : newTasks; > } else { > return tasks; > } > } > > -- > You received this message because you are subscribed to the Google Groups > "GWT Contributors" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/google-web-toolkit-contributors/80297aa7-c49a-4e3b-b70a-554bfaef52f0%40googlegroups.com > <https://groups.google.com/d/msgid/google-web-toolkit-contributors/80297aa7-c49a-4e3b-b70a-554bfaef52f0%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- Google Germany GmbH *Dienerstr. 12* *80331 München* Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg Geschäftsführer: Graham Law, Katherine Stephens -- You received this message because you are subscribed to the Google Groups "GWT Contributors" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/google-web-toolkit-contributors/CALLujipuOFMxCnLjdM_FER4n3-eAHPEWUQGf3AZENR_ezq255A%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
