Memory leak in artiq_gui

[cjbe]

Using Artiq 1.0rc2 on Ubuntu 15.10, with the examples/master device_db, and the kc705-clock gateware, artiq_gui leaks memory.

Over 1000 minutes, the RSS linearly increased from 87 MB to 1500 MB.

I don't think this is a regression - I believe I have seen this issue in earlier versions of artiq_gui.

[sbourdeauducq]

Were you running something in particular or is the memory consumption increasing while nothing is happening?

[cjbe]

I was not running anything. I just started the master, ctrlmgr, and gui, and monitored the memory usage

[sbourdeauducq]

Were there any logging messages emitted by e.g. ctlmgr?

[cjbe]

No logging messages were emitted

[jordens]

Reproduced. Comes in chunks of about 6MB and valgrind doesn't see it. It's probably not strictly a "leak" then.

[sbourdeauducq]

Python has some functions to print the state of the GC (number of live objects, etc.). What do they say if you call them regularly with a timer?

[jordens]

http://mg.pov.lt/objgraph.py

[jordens]

10 Qtimers, 10 functions, 10 tuples, and 30 cells per second.

[jordens]

probably harvimt/quamash#62

[jordens]

was quamash.
@sbourdeauducq or @whitequark could you please copy the package over?

[sbourdeauducq]

Already there.

[jordens]

There is a bunch of Exception ignored in: Exception ignored in: pairs with the new quamash one for each applet. https://bugs.python.org/issue22836