1. On Windows this works well as file and device locking is mandatory. Moreover, the default is to create an exclusive lock when opening an I/O channel to a device. So, by default other threads and processes cannot concurrently access the device. On Linux and OS X, file and device locking is 100% advisory. Any number of threads and processes can open an I/O channel to the same device and concurrently write or read from it.
2. Several years ago, I actually wrote the necessary Python code for the Eggbot Control extension to do coordinated device locking. However, I never got around to wiring it in. If someone is interested, here it is,
