Bizarre problem with panel and E

[Daniel Burrows <Daniel_Burrows brown edu>]

  I just ran into a problem when starting Enlightenment that has me completely
puzzled.  What I did to trigger it is this: I started E, waited for my theme
(E-Mac) to load, and clicked on the panel menu.  I then (quickly, relevant??)
moved the mouse pointer up the panel, intending to start the Control Panel.
By the time I got to System, however, everything had frozen up.  That is, both
the panel and E stopped responding (although I could still move the mouse).  I
didn't have other programs open so I don't know what they would have done.

  Here's the bizrre twist, though:  after clicking around a bit and waiting for
about 30 seconds to see if they did something on their own, I switched to a
virtual console and (assuming that the problem had occured due to the panel
grabbing the mouse) did 'strace -p `pidof panel`' to see what happened.  For a
moment, I saw it blocked in a read(), but almost immediately the screen
filled with hundreds of system calls--and then it went to regularly polling.
Going back to X, I discovered that my panel was now active.  I then decided
to pop up an Eterm to see what I could see, but nothing visibly happened when
I hit the Eterm button.  I hit it again just to be sure, waited--and then tried
to get a background menu.  Nothing.  I switched back to a console, strace'd
E, and got the same result as with the panel.

  So having described this odyssy to you, I have two questions:

  a) Why did E and the panel freeze up like that?
  b) Why did strace()'ing them unfreeze them? (I've had other occasions where
    this happened but this was the most blatant)  Some obscure UNIX semantic
    I'm unaware of?

  Daniel Burrows
-- 
  The universe, they said, depended for its operation on the balance of four
forces which they identified as charm, persuasion, uncertainty and
bloody-mindedness.  Thus it was that the sun and the moon orbited the Disc
because they were persuaded not to fall down, but didn't actually fly away
because of uncertainty...
  Some druids suggested that there were certain flaws with this theory, but
senior druids explained very pointedly that there was indeed room for informed
argument, the cut and thrust of exciting scientific debate, and basically
it lay on top of the next solstice bonfire.

     -- Terry Pratchett on Discworld religion, _The Light Fantastic_