Dear java2d members, FYI: I now have a working patched java2d pisces that performs better: no memory waste (99%) and performance increased on complex operations (dashed ...); patch / benchmark in progress ...
Does J2DBench have a regression test mode ? i.e. capture screenshots (with few shapes) to compare them between different runs (image comparison pixel by pixel) Besides, I found an important bug in pisces Stroker / Dasher: it does not use the clip region given to PiscesRenderingEngine.getAATileGenerator(clip). In Aspro2, I can zoom on jFreeChart plots a lot and it draws shapes (rectangle or lines with dashed lines) then the dasher emits segments out of the visible area (millions in case of a important zoom) and the application hangs a for while (5s to minutes). I would like to determine the shape part (line or any complex shape) that is inside the clip and avoid useless segments (Stroker / Dasher). Does somebody have any idea ? or know java2d.pisces code enough to help me ? Laurent 2013/3/26 Laurent Bourgès <bourges.laur...@gmail.com> > Dear all, > > First I joined recently the openJDK contributors, and I plan to fix java2D > pisces code in my spare time. > > I have a full time job on Aspro2: http://www.jmmc.fr/aspro; it is an > application to prepare astronomical observations at VLTI / CHARA and is > very used in our community (200 users): it provides scientific computations > (observability, model images using complex numbers ...) and zoomable plots > thanks to jFreeChart. > > Aspro2 is known to be very efficient (computation parallelization) and I > am often doing profiling using netbeans profiler or visualVM. > > To fix huge memory usages by java2d.pisces, I started implementing an > efficient ArrayCache (int[] and float[]) (in thread local to concurrency > problems): > - arrays in sizes between 10 and 10000 (more small arrays used than big > ones) > - resizing support (Arrays.copyOf) without wasting arrays > - reentrance i.e. many arrays are used at the same time (java2D Pisces > stroke / dash creates many segments to render) > - GC / Heap friendly ie support cache eviction and avoid consuming too > much memory > > I know object pooling is known to be not efficient with recent VM (GC is > better) but I think it is counter productive to create so many int[] arrays > in java2d.pisces and let the GC remove such wasted memory. > > Does someone have implemented such (open source) array cache (core-libs) ? > Opinions are welcome (but avoid "trolls"). > > Moreover, sun.java2d.pisces.Helpers.widenArray() performs a lot of array > resizing / copy (Arrays.copyOf) that I want to avoid mostly: > // These use a hardcoded factor of 2 for increasing sizes. Perhaps this > // should be provided as an argument. > static float[] widenArray(float[] in, final int cursize, final int > numToAdd) { > if (in.length >= cursize + numToAdd) { > return in; > } > return Arrays.copyOf(in, 2 * (cursize + numToAdd)); > } > > static int[] widenArray(int[] in, final int cursize, final int > numToAdd) { > if (in.length >= cursize + numToAdd) { > return in; > } > return Arrays.copyOf(in, 2 * (cursize + numToAdd)); > } > > Thanks to Peter Levart, I use its microbench tool ( > https://github.com/plevart/micro-bench/tree/v2) to benchmark ArrayCache > operations... and J2DBench to test java2d performances > > ... > > PS: java.awt.geom.Path2D has also memory allocation issues: > void needRoom(boolean needMove, int newCoords) { > if (needMove && numTypes == 0) { > throw new IllegalPathStateException("missing initial > moveto "+ > "in path definition"); > } > int size = pointTypes.length; > if (numTypes >= size) { > int grow = size; > if (grow > EXPAND_MAX) { > grow = EXPAND_MAX; > } > pointTypes = Arrays.copyOf(pointTypes, size+grow); > } > size = floatCoords.length; > if (numCoords + newCoords > size) { > int grow = size; > if (grow > EXPAND_MAX * 2) { > grow = EXPAND_MAX * 2; > } > if (grow < newCoords) { > grow = newCoords; > } > floatCoords = Arrays.copyOf(floatCoords, size+grow); > } > } > > Best regards, > Laurent >
