9. Drivers
9 Drivers
This section provides a brief overview on how to write efficient drivers.
It is assumed that you have a good understanding of drivers.
9.1 Drivers and Concurrency
The runtime system always takes a lock before running any code in a driver.
By default, that lock is at the driver level, that is, if several ports have been opened to the same driver, only code for one port at the same time can be running.
A driver can be configured to have one lock for each port instead.
If a driver is used in a functional way (that is, holds no state, but only does some heavy calculation and returns a result), several ports with registered names can be opened beforehand, and the port to be used can be chosen based on the scheduler ID as follows:
-define(PORT_NAMES(),
{some_driver_01, some_driver_02, some_driver_03, some_driver_04,
some_driver_05, some_driver_06, some_driver_07,
