ConcurrentModificationException when using LineAndPointRenderer and calling plot.clear()

[tjohnn]

• Description of the problem
  1. LineAndPointRenderer.cullPointsCache() checks if registry contains the current LineAndPointFormatter instance getPlot().getRegistry().contains(series, LineAndPointFormatter.class), the contains() implementation here runs a foreach loop on an internal arraylist in SeriesRegistry
  2. The same arraylist in 1 above is cleared when we call plot.clear()
  3. if at some we happen to call 1 & 2 above concurrently, then we get java.util.ConcurrentModificationException
• Version(s) of Androidplot being used 1.5.7
• A stacktrace if the issue is causing a crash

java.util.ConcurrentModificationException
        at java.util.ArrayList$Itr.next(ArrayList.java:860)
        at com.androidplot.SeriesRegistry.contains(SeriesRegistry.java:130)
        at com.androidplot.xy.LineAndPointRenderer.cullPointsCache(LineAndPointRenderer.java:125)
        at com.androidplot.xy.LineAndPointRenderer$1.onBeforeDraw(LineAndPointRenderer.java:54)
        at com.androidplot.Plot.notifyListenersBeforeDraw(Plot.java:607)
        at com.androidplot.xy.XYPlot.notifyListenersBeforeDraw(XYPlot.java:333)
        at com.androidplot.Plot.renderOnCanvas(Plot.java:881)
        at com.androidplot.Plot.lambda$startBackgroundRendering$0$Plot(Plot.java:440)
        at com.androidplot.Plot$$ExternalSyntheticLambda0.run(Unknown Source:2)
        at java.lang.Thread.run(Thread.java:920)

[halfhp]

For performance reasons, Androidplot does not leverage immutability to avoid concurrency issues. Instead, an interface is exposed to allow users to synchronize their usage with Androidplot's rendering cycles. See more here. In your case it's likely simpler to just synchronize your two calls externally.