Benchmarking Python syscalls vs. exceptions vs. funcalls and such

bench.py

#!/usr/bin/env python

import benchmark
import ctypes
import ctypes.util
import os

DEVZERO = open('/dev/zero', 'r')
DEVZERO_FILENO = DEVZERO.fileno()

CTYPES_READ = ctypes.CDLL(ctypes.util.find_library('c'), use_errno=True).read
CTYPES_BUFFER = ctypes.create_string_buffer(64)


def returns_a_value():
    return 1


def raises_ioerror():
    raise IOError(12, "oops")


class BenchmarkFlowControl(benchmark.Benchmark):
    def a_method(self):
        return 123

    def test_exception(self):
        try:
            raises_ioerror()
        except IOError:
            pass
                
    def test_funcall(self):
        if returns_a_value() == 1:
            pass
        else:
            return "blah blah doesn't happen"
                
    def test_method(self):
        if self.a_method == 123:
            pass
        else:
            return "blah blah doesn't happen"

    def test_syscall_via_libc_ctypes(self):
        CTYPES_READ(DEVZERO_FILENO, CTYPES_BUFFER, 2)

    def test_syscall_via_python(self):
        os.read(DEVZERO_FILENO, 1)
        

if __name__ == '__main__':
    benchmark.main(each=100000)

Benchmark results

~$ python bench.py

Benchmark Report
================

BenchmarkFlowControl
--------------------

              name | rank |  runs |      mean |        sd | timesBaseline
-------------------|------|-------|-----------|-----------|--------------
           funcall |    1 | 1e+05 | 5.054e-06 | 1.028e-05 |           1.0
            method |    2 | 1e+05 | 5.496e-06 |  1.28e-05 |  1.0875915267
syscall via python |    3 | 1e+05 | 6.723e-06 | 1.123e-05 | 1.33035478392
  syscall via libc |    4 | 1e+05 | 8.254e-06 | 9.457e-06 | 1.63330675599
         exception |    5 | 1e+05 | 8.858e-06 | 1.065e-05 | 1.75288261936

Each of the above 500000 runs were run in random, non-consecutive order by
`benchmark` v0.1.5 (http://jspi.es/benchmark) with Python 2.7.3
Linux-3.13.0-37-generic-x86_64 on 2014-11-03 18:46:55.