control CPU usage

[kakarukeys]

On Sep 20, 6:24 pm, Dave Angel <da... at ieee.org> wrote:
> Jiang Fung Wong wrote:
> > Dear All,
>
> > Thank you for the information. I think I've some idea what the problem is
> > about after seeing the replies.
>
> > More information about my system and my script
>
> > PIII 1Ghz, 512MB RAM, Windows XP SP3
>
> > The script monitors global input using PyHook,
> > and calculates on the information collected from the events to output some
> > numbers. Based on the numbers, the script then performs some automation
> > using SendKeys module.
>
> > here is the memory usage:
> > firefox.exe, 69MB, 109MB
> > svchost.exe, 26MB, 17MB
> > pythonw.exe, 22MB, 17MB
> > searchindexer.exe, 16MB, 19MB
>
> > My first guess is that the script calculated for too long time after
> > receiving an event before propagating it to the default handler, resulting
> > the system to be non-responsive. I will try to implement the calculation
> > part in another thread.
> > Then the separate will have 100% CPU usage, hope the task scheduling of
> > Windows works in my favour.
>
> (You top-posted this message, putting the whole stream out of order.  So
> I deleted the history.)
>
> All my assumptions about your environment are now invalid.  You don't
> have a CPU-bound application, you have a Windows application with event
> loop.  Further, you're using SendKeys to generate a keystroke to the
> other process.  So there are many things that could be affecting your
> latency, and all my previous guesses are useless.
>
> Adding threads to your application will probably slow the system down
> much more.  You need to find out what your present problem is before
> complicating it.
>
> You haven't really described the problem.  You say the system is
> unresponsive, but you made it that way by creating a global hook;  a
> notoriously inefficient mechanism.  That global hook inserts code into
> every process in the system, and you've got a pretty low-end environment
> to begin with.  So what's the real problem, and how severe is it?  And
> how will you measure improvement?  The Task manager numbers are probably
> irrelevant.
>
> My first question is whether the pyHook event is calling the SendKeys
> function directly (after your "lengthy" calculation) or whether there
> are other events firing off  in between.  If it's all being done in the
> one event, then measure its time, and gather some statistics (min time,
> max time, average...).  The task manager has far too simplistic
> visibility to be useful for this purpose.
>
> What else is this application doing when it's waiting for a pyHook
> call?  Whose event loop implementation are you using?  And the program
> you're trying to control -- is there perhaps another way in?
>
> DaveA

Hi,

Sorry I wasn't sure how to use Google groups to post a msg to the
newsgroup, I used Gmail to write my previous reply. What you and the
other guy have provided me isn't useless. Now I understand the non-
responsiveness may not be caused by high CPU usage, as the OS, be it
Windows or Linux, has a way to prioritize the tasks. This is a vital
clue to me.

By "not responsive", I mean, for some time, the mouse pointer is not
moving smoothly, to such extent that I can't do anything with the
mouse. It's like playing a multi-player game on a connection with a
lot of lag. It's not caused by global hook, because it happens under
certain condition, i.e. when fpa.ProcessEvent(word) is computing.

I included my main script for your reference. Comments:
(1) The automation method tc.Auto() is slow, but it doesn't cause any
problem, because the user would wait for the automation to finish,
before he continues to do something.

(2) all other methods invoked are fast, except fpa.ProcessEvent(word)
(this information is obtained from profiling). It is this method that
causes 100% CPU usage. I'm planning to move this method to a separate
thread, so that OnEvent(event) can finish executing, while the
separate thread goes on to finish its calculation. Is this a good
idea?

import pyHook
import TypingAnalyzer
import GUI

def OnEvent(event):
	if hasattr(event, "Key") and event.Ascii == 9 and event.Key == "Tab"
and event.Injected == 0 and event.Alt == 0:
		tc.Auto()
		return False
	else:
		recognized = rk.ProcessEvent(event)
		if recognized:
			tc.MatchChar(recognized)
			paragraph = rc.ProcessEvent(recognized)
			if paragraph:
				for word in paragraph:
					fpa.ProcessEvent(word)

		return True

hm = pyHook.HookManager()
hm.MouseAllButtonsDown = OnEvent
hm.KeyDown = OnEvent
hm.HookMouse()
hm.HookKeyboard()

rk = TypingAnalyzer.ReadKey()
rc = TypingAnalyzer.ReadChar()
fpa =  TypingAnalyzer.Analysis()
tc = TypingAnalyzer.Automation(fpa)

if __name__ == '__main__':
	app = GUI.AWAApp()
	app.MainLoop()

Thank you for your attention.