Add a script for benchmarking gevent.local

[skip ci]
Current numbers:

local_36_master
===============

getattr gevent: Mean +- std dev: 216 ns +- 6 ns
setattr gevent: Mean +- std dev: 215 ns +- 6 ns
getattr gevent sub: Mean +- std dev: 600 ns +- 19 ns
setattr gevent sub: Mean +- std dev: 591 ns +- 38 ns
getattr native: Mean +- std dev: 56.9 ns +- 4.1 ns
setattr native: Mean +- std dev: 84.3 ns +- 4.9 ns
getattr native sub: Mean +- std dev: 65.6 ns +- 5.3 ns
setattr native sub: Mean +- std dev: 76.2 ns +- 4.6 ns

local_27_master
===============

getattr gevent: Mean +- std dev: 177 ns +- 7 ns
setattr gevent: Mean +- std dev: 192 ns +- 6 ns
getattr gevent sub: Mean +- std dev: 501 ns +- 10 ns
setattr gevent sub: Mean +- std dev: 536 ns +- 25 ns
getattr native: Mean +- std dev: 93.8 ns +- 3.6 ns
setattr native: Mean +- std dev: 118 ns +- 6 ns
getattr native sub: Mean +- std dev: 102 ns +- 4 ns
setattr native sub: Mean +- std dev: 118 ns +- 8 ns

local_pypy_master
=================

getattr gevent: Mean +- std dev: 135 ns +- 6 ns
setattr gevent: Mean +- std dev: 126 ns +- 4 ns
getattr gevent sub: Mean +- std dev: 150 ns +- 4 ns
setattr gevent sub: Mean +- std dev: 153 ns +- 7 ns
getattr native: Mean +- std dev: 0.18 ns +- 0.00 ns
setattr native: Mean +- std dev: 0.18 ns +- 0.01 ns
getattr native sub: Mean +- std dev: 0.18 ns +- 0.01 ns
setattr native sub: Mean +- std dev: 0.19 ns +- 0.01 ns

src/greentest/bench_local.py

+# -*- coding: utf-8 -*-
+"""
+Benchmarks for thread locals.
+
+"""
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+import perf
+
+from gevent.local import local as glocal
+from threading import local as nlocal
+
+class GLocalSub(glocal):
+    pass
+
+class NativeSub(nlocal):
+    pass
+
+
+benchmarks = []
+
+
+def _populate(l):
+    for i in range(10):
+        setattr(l, 'attr' + str(i), i)
+
+
+def bench_getattr(loops, local):
+    t0 = perf.perf_counter()
+
+    for _ in range(loops):
+        # pylint:disable=pointless-statement
+        local.attr0
+        local.attr1
+        local.attr2
+        local.attr3
+        local.attr4
+        local.attr5
+        local.attr6
+        local.attr7
+        local.attr8
+        local.attr9
+
+    return perf.perf_counter() - t0
+
+def bench_setattr(loops, local):
+    t0 = perf.perf_counter()
+
+    for _ in range(loops):
+        local.attr0 = 0
+        local.attr1 = 1
+        local.attr2 = 2
+        local.attr3 = 3
+        local.attr4 = 4
+        local.attr5 = 5
+        local.attr6 = 6
+        local.attr7 = 7
+        local.attr8 = 8
+        local.attr9 = 9
+
+    return perf.perf_counter() - t0
+
+def main():
+    runner = perf.Runner()
+
+    for name, obj in (('gevent', glocal()),
+                      ('gevent sub', GLocalSub()),
+                      ('native', nlocal()),
+                      ('native sub', NativeSub())):
+        _populate(obj)
+
+        benchmarks.append(
+            runner.bench_time_func('getattr ' + name,
+                                   bench_getattr,
+                                   obj,
+                                   inner_loops=10))
+
+        benchmarks.append(
+            runner.bench_time_func('setattr ' + name,
+                                   bench_setattr,
+                                   obj,
+                                   inner_loops=10))
+
+
+if __name__ == '__main__':
+    main()