Executeinmainthreadwithresult Doesn't Like Being Repeatedly Called?

[rjpieke]

I'm finding that this script will, in the best case, output nothing and, in the worst case, crash Maya. If I change the 1000 to 100, however, it works perfectly.

CODE
import threading
import maya

def sumItUp() :

  maya.utils.executeInMainThreadWithResult( 'x = 0' )

  for i in range( 1000 ) :
    maya.utils.executeInMainThreadWithResult( 'x = x + %d' % ( i ) )

  maya.utils.executeInMainThreadWithResult( 'print x' )

threading.Thread( target=sumItUp, args=() ).start()

I realise this script is absolutely useless, but it's a lot easier to read than the practical PyQt application I was writing that suffers from the same sort or problem

Any ideas?

Cheers!

[daniel-faust]

There is no workaround. Marshalling data between threads is an expensive operation and if you bomb the main thread with lots of data then Maya will come to a point where it can't take care of itself anymore. The only way out is to get a faster pc that can keep up with the incoming mel execution requests. It's basically a DoS attack.

---

one thing can be done (I don't know the python code for this) is the following

for i in range( 1000 ) {
maya.utils.executeInMainThreadWithResult( 'x = x + %d' % ( i ) )
sleep(10~100millisecons)
}

[rjpieke]

Ah nuts ... that's what I was afraid of. I guess we'll just write a wrapper here:

CODE
import maya
import time
def hopefullyMaybePossiblySafeExecuteInMainTheadWithResult( cmd ) :
  time.sleep( 0.01 )
  return maya.executeInMainThreadWithResult( cmd )

[joojaa]

Well actually you shouldnt do it like that; instead you should. Send if possible cumulative update each so and so seconds. Because you need to let may have tine to refresh. Otherwise you might end up scheduling maya loong into the future. You hve to remebetr maya makes the hard job not you, so its your job to not run maya to its death.

So what you end up doing is syncing the current state of the gui and maya. Now the real bad downside of executeInMainThreadWithResult is that maya reserves the right to update its own stuff before yours. This means you may have problems updadting stuff during animation runtime for example. Which is fine for maya but not necceserily for you trying to do a gui on top of maya (wich offcourse is something you should try to avoid at all cost use mel for that if mel is not enough then maybe make a new mel gui item butr i dont suggest that either).