What steps will reproduce the problem?

Running the attached code fails with (roughly) 25 or more threads.

Eg. > python y.py 50 [] [yappi-err] context not found. [] [yappi-err] context not found. [] [yappi-err] context not found. [] [yappi-err] context not found. ...

What is the expected output? What do you see instead? > python y.py 5 name #n tsub ttot tavg ../python2.6/threading.py.init:5 20 0.000035 0.000035 0.000002 ..lib/python2.6/threading.py._note:6 20 0.000028 0.000028 0.000001 ..ython2.6/threading.py._is_owned:22 10 0.000044 0.000088 0.000009 ...

What version of the product are you using? On what operating system? Python 2.6.5, Ubuntu Linux, yappi-0.52.zip

Please provide any additional information below. A similar script using thread.start_new_thread() instead of inheriting from threading.Thread doesn't seem to have the problem.

Cannot see the included file y.py. Can you please re-send the attachment?

A copy of the problem with some example source code is at: http://www.mail-archive.com/python-list@python.org/msg306045.html

Not sure why the attachment didn't work. I've re-written the code out here:

import yappi import time import threading import sys

class MyThread(threading.Thread): def run(self): time.sleep(1)

n = int(sys.argv[1])

yappi.start() for i in range(0,n): c = MyThread() c.start() time.sleep(1) yappi.print_stats() yappi.stop()

Hello,

I think the problem is fixed. Can you also please confirm the problem is fixed in your setup and stat outputs are valid? You can find the development source here: https://bitbucket.org/sumerc/yappi/

Thanks,

This seems to work on the basic example above. However, when I run a heavily threaded application I'm getting lots of the following warnings printed out: [] [yappi-err] Context add failed. Already added?(0x21d98c0, 139712695199488) [] [yappi-err] Context add failed. Already added?(0x20df110, 139712720377600) [] [yappi-err] Context add failed. Already added?(0x251a360, 139712711984896) [] [yappi-err] Context add failed. Already added?(0x22b5080, 139712695199488)

It seems to complete successfully though.

Is this likely to be an issue or can they safely be ignored?

Very good inspection. This is an issue I expected. This can safely be ignored, however I need to make sure this error message only happens when a specific compile option is provided. Just to make sure, can you confirm the output is valid in the second example with heavy multithreaded app.?

it seems to be working fine now if I ignore the warnings. The statistics generated seem reasonable for the application as well. I was getting some strange timings but I think they're all to do with blocking IO cases (http://code.google.com/p/yappi/wiki/multithreaded_statistics) rather than an error being introduced by this patch.

Accurate timing statistics with heavy I/O bound multithreaded applications are currently not possible (as explained in the Wiki page you suggested.) But I am thinking to get help from OS for specific platforms on future versions of yappi for these situations. Anyway, thanks for your help, will release 0.53 ASAP.

fixed in v0.53.