disable itimers during all-thread-synch?

_From [derek.br...@gmail.com](https://code.google.com/u/117968039472581148324/) on April 02, 2010 11:46:40_

when suspending the other threads we don't really want alarm signals
causing execution of DR code (and client code with PR 368737) in a thread
we think is at a safe spot and can't grab any DR locks or modify any DR
data structures. maybe it's best to disable itimers while a thread is
suspended?

_Original issue: http://code.google.com/p/dynamorio/issues/detail?id=282_