Helen,
The processors switching between 100% from CPU 1 to CPU 2, etc... are
probably happening based on how the Linux kernel handles multiple
processors.  The CPU selection happens on a much lower level than what I'm
doing in Python.  However, there is obviously a problem with OpenShot maxing
out at 100% CPU.

Can you recreate this behavior using the new version you installed with .DEB
files?

On Thu, Jul 23, 2009 at 5:57 PM, Helen McCall <email address hidden>wrote:

> Wow! This test with the system monitor has woken me up from my tired
> state.
>
> The video files are all on a "projects" partition on one of my internal
> harddrives (SATA2). I ran the subsequent tests with only OpenShot,
> System Monitor, and Evolution running.
>
> I monitored first: The clip freezing in the viewport, but leaving
> Openshot still working in all other respects.
>
> Prior to this viewport freeze, all processors had their loads reasonably
> evenly spread with activity in the middle ranges for all of them.
>
> When the viewport froze, one processor went up to 100% and just stayed
> there like it was in a never ending loop. The other two processors went
> down to a low level of load around 10% or lower. Any activity like
> moving the timeline curser or opening a dialogue window caused the two
> low level processors to increase their activity a little.
>
> The only thing I found which changed this situation was to open a
> file-selection dialogue for importing a clip. This caused the 100%
> processor to swap with one of the other processors, so that a different
> processor was stuck at 100%, and the original high load processor was
> now one of the pair of low load processors!
>
> Second test: Openshot freezing completely on opening the project I sent
> you. This did the same thing and caused one processor (#2) to go to
> 100%, and the other two (#1 & #3) to go to very low load.
>
> I couldn't use the Openshot file-selection dialogue, so I opened gedit.
> no activity on that or on the terminal window affected the state of this
> #2 100% processor, except opening the file dialogue on gedit caused #2
> to go low level, and #1 to switch to 100%! I tried this a few times and
> it always caused a different processor to go to 100%. After leaving one
> processor running for a few minutes at 100%, the opening of a
> file-selection dialogue didn't switch the processors any more. Leaving
> that processor permanently at 100%
>
> On killing OpenShot with a "Force Quit", the 100% processor immediately
> dropped down to low level and joined the other two so I had then all
> three processors in a balanced load at low level.
>
> Therefore I would surmise that freezing of the viewport or the whole of
> OpenShot both are caused by a never ending loop as some process is
> waiting for a result from a sub process which has probably died, and the
> waiting is not being timed out.
>
> Women's intuition suggests to me either: that one of the MLT functions
> has a bug where it fails to return an error code when failing. Or else
> some function in the Python code is failing to test for the error return
> from a function, and is just looping and calling until it gets what it
> considers to be a valid return value (which never comes)
>
>  A clue to where this might be is that any call to the Gnome
> file-selection dialogue, causes that looping process to be re-spawned on
> a different processor. (Wow! This takes me back nearly 20 years to when
> I was learning to program Transputer arrays in the Occam2 language!)
>
> At soem point in all of this, some process related to the file selection
> is timing out but leaving the looping process as an orphan and so then
> it never switches until the application is killed and all related
> processes are sent the kill signal. Therefore the orphan process is
> still open to signals like KILL. (sig something, I can't remember all
> the signal codes anymore)
>
> I hope this helps.
>
> Helen
>
>
> On Thu, 2009-07-23 at 21:11 +0000, Jonathan Thomas wrote:
> > Helen, are your media files located on your primary harddrive?  or an
> > external harddrive?  Also, please check your "System Monitor", and see
> > what the CPU is doing while OpenShot is hanging.   And, as a side note,
> > see how many "Python" processes are running on your computer.  There
> > should only be a few.  Thanks!
> >
>
>
>