ETW (Event Tracing for Windows)

ETW is a tracing facility that allows a user to log events to a file or buffer. An overview of ETW can be found here. The basic architecture includes an Provider, Controller, and a Consumer. The controller defines and controls a capture session. This includes what providers are in the as well as starting and stopping the session. The provider, specified using a GUID (Globally Unique Identifier), logs events to a series of buffers. The Consumer receives messages either from a buffer or a file and processes them in chronological order.

This module is an entirely Python-based ctypes wrapper around the Win32 APIs necessary for for controlling ETW sessions and processing message data. The module is very flexible and can set pre or post capture filters.

Usage

To use this module import etw and create an instance of the ETW class by passing in a list of ProviderInfo instances for the provider(s) you wish to capture data from. To process data returned from ETW you will need to specify a callback.

import etw


def some_func():
    # define capture provider info
    providers = [etw.ProviderInfo('Some Provider', etw.GUID("{11111111-1111-1111-1111-111111111111}"))]

    # create instance of ETW and start capture
    with etw.ETW(providers=providers, event_callback=etw.on_event_callback):
        # run capture
        etw.run('etw')

Below is an example using the module to perform a capture using a custom callback.

import time
import etw


def some_func():
    # define capture provider info
    providers = [etw.ProviderInfo('Some Provider', etw.GUID("{11111111-1111-1111-1111-111111111111}"))]
    # create instance of ETW class
    job = etw.ETW(providers=providers, event_callback=lambda x: print(x))
    # start capture
    job.start()

    # wait some time
    time.sleep(5)

    # stop capture
    job.stop()

Subclassing is another handy way to define ETW capture classes.

import time
import etw


class MyETW(etw.ETW):

    def __init__(self, event_callback):
        # define capture provider info
        providers = [etw.ProviderInfo('Some Provider', etw.GUID("{11111111-1111-1111-1111-111111111111}"))]
        super().__init__(providers=providers, event_callback=event_callback)

    def start(self):
        # do pre-capture setup
        self.do_capture_setup()
        super().start()

    def stop(self):
        super().stop()
        # do post-capture teardown
        self.do_capture_teardown()

    def do_capture_setup(self):
        # do whatever setup for capture here
        pass

    def do_capture_teardown(self):
        # do whatever for capture teardown here
        pass


def my_capture():
    # instantiate class
    capture = MyETW(lambda x: print(x))
    # start capture
    capture.start()
    # wait some time to capture data
    time.sleep(5)
    # stop capture
    capture.stop()

For more examples see examples.