Plot updates cause heap to grow massively

So I’ve been working on updating plots from within the notebook and noticed that interaction really slows down after a lot of plot updates. I started profiling a little bit using the bokeh serve fourier_animated.py example on 0.12.3dev4 and found that the heap just keeps on growing, after about 30 seconds it had grown to 1 GB and the plot starts slowing down.

It seems something is not being garbage collected. After a bit of investigation I found that there are a lot of LinearMapper instances that accumulate:

and there also seem to be a lot of change events:

Here’s the heap allocation for the same example in 0.12.2:

Bokeh 0.12.3dev4 Chrome Version 53.0.2785.116 (64-bit) OS X 10.11.6

[mattpap]

@philippjfr, regarding testing this I started issue #5269.

[philippjfr]

Working well for me, the JS heap now hovers around 30-50 MB on the fourier_example even after running it for a while. Thanks for the quick fix!

+1 on adding automated testing for this somehow, because it’s easy to miss but really important.