#format rst
==================================
Performance Enhancements Resources
==================================

Jython benchmarks (from PyPy's suite): http://freya.cs.uiuc.edu/~njriley/benchmark.html

Plots of microbenchmarks (also from PyPy): http://freya.cs.uiuc.edu/~njriley/plots.html

Ideas
=====

jbaker & thobe's JavaOne '08 talk: `Jython Implementing Dynamic Language Features For The Java Ecosystem`_

Allocation/GC Expense
---------------------
Our algorithms are not always the problem, sometimes it's memory {de}allocations that slow you down

* dicts/stringmap

PyStringMap/PyDictionary pay a penalty on allocation now that they're backed by ConcurrentHashMap. We could probably tweak the ConcurrentHashMap initialCapacity, concurrentLevel to reduce this cost


* Frames

Frames are allocated for every Python method call, which is a GC expense. CPython (and JRuby?) recycle frame objects. Reducing the number of fields on the frame can also help (but this likely isn't possible)

Advanced Compiler
-----------------

Modules to rewrite in Java
--------------------------
* _heapq
* select
* socket
* unicodedata

iterlen support
---------------
Adds a length hint to various objects, mainly for smarter allocation during map and list. See test_iterlen

.. _`Jython Implementing Dynamic Language Features For The Java Ecosystem`: http://developers.sun.com/learning/javaoneonline/2008/pdf/TS-6039.pdf?cid=925321