tools.rst

Useful Development Tools

Memory Profiling

GObject Instance Count Leak Check

Requires a development (only available in debug mode) version of glib. Jhbuild recommended.

jhbuild shell
GOBJECT_DEBUG=instance-count GTK_DEBUG=interactive ./quodlibet.py

• In the GTK+ Inspector switch to the "Statistics" tab
• Sort by "Cumulative" and press the "Next" multimedia key to quickly switch songs.
• If something in the "Cumulative" column steadily increases we have a leak.

Performance Profiling

cProfile

• https://docs.python.org/2/library/profile.html
• bundled with python

python -m cProfile -s [sort_order] quodlibet.py > cprof.txt

where sort_order can one of the following: calls, cumulative, file, line, module, name, nfl, pcalls, stdname, time

Example output:

885311 function calls (866204 primitive calls) in 12.110 seconds

Ordered by: cumulative time

ncalls tottime percall cumtime percall filename:lineno(function)

1 0.002 0.002 12.112 12.112 quodlibet.py:11(<module>) 1 0.007 0.007 12.026 12.026 quodlibet.py:25(main)

19392/13067 0.151 0.000 4.342 0.000 __init__.py:639(__get__)

1 0.003 0.003 4.232 4.232 quodlibetwindow.py:121(__init__) 1 0.000 0.000 4.029 4.029 quodlibetwindow.py:549(select_browser) 1 0.002 0.002 4.022 4.022 albums.py:346(__init__) ... ...

SnakeViz

• https://jiffyclub.github.io/snakeviz/
• pip install snakeviz

python -m cProfile -o prof.out quodlibet.py
snakeviz prof.out

Run Snake

• http://www.vrplumber.com/programming/runsnakerun/
• package runsnakerun in debian Wheezy

python -m cProfile -o prof.out quodlibet.py
runsnake  prof.out

Example: https://www.google.at/search?q=runsnakerun&tbm=isch

Gprof2Dot

• https://github.com/jrfonseca/gprof2dot

python -m cProfile -o output.pstats ./quodlibet.py
gprof2dot.py -f pstats output.pstats | dot -Tpng -o output.png

Line Profiler

• https://github.com/rkern/line_profiler

# wrap all functions of interest with the @profile decorator
./kernprof.py  -l ./quodlibet.py # creates quodlibet.py.lprof
python line_profiler.py quodlibet.py.lprof > prof.txt

Example output:

Timer unit: 1e-06 s

File: test.py
Function: a at line 2
Total time: 0.001528 s

Line #      Hits         Time  Per Hit   % Time  Line Contents
==============================================================
     2                                           @profile
     3                                           def a():
     4         1          134    134.0      8.8      print "hello"
     5         1           12     12.0      0.8      b = []
     6       101          628      6.2     41.1      for i in xrange(100):
     7       100          696      7.0     45.5          b.append(i)
     8         1           58     58.0      3.8      print "world"

strace

• https://linux.die.net/man/1/strace

strace -c ./quodlibet.py

Example output:

time     seconds  usecs/call     calls    errors syscall

------ ----------- ----------- --------- --------- ---------------- 81.64 0.013274 9 1444 178 read

7.04 0.001144 0 4041 3259 open 3.81 0.000619 11 54 getdents64 2.80 0.000456 0 1004 fstat64 1.84 0.000299 0 2221 1688 stat64

...

IOProfiler

• https://code.google.com/archive/p/ioapps/wikis/ioprofiler.wiki
• strace GUI
• Shows read/write to files (how many reads/writes per file, which parts of the files were affected)

strace -q -a1 -s0 -f -tttT -oOUT_FILE -e trace=file,desc,process,socket ./quodlibet.py
ioreplay -c -f OUT_FILE -o OUT_FILE.bin
ioprofiler.py
# open OUT_FILE.bin

Example: https://code.google.com/archive/p/ioapps/wikis/IOProfilerScreenshots.wiki