Currently I'm working on an application on my RPi which will be monitoring a set of GPIOs in real-time where the exact time when the GPIO turns HIGH is crucial for my application.
How the time is being dealt with on the RPi with the Arch Linux OS; is it synchronized towards a UDP NTP Time Server? If that's the case, is it being updated continuously in a background thread/daemon like other Linux installations? Or is it perhaps updated each time a call to get the time is made?
Because two events might occur on two (or more) GPIOs simultaneously I need to implement the fastest solution possible to get the real-time functionality.
The actual date is not important when the specific event happens; instead, the exact time relative to the other events is. The data recorded will be shown in a graph where the spacing between the events should be as exact as possible.
How is time handled on the RPi with Arch Linux, and how accurate is it in a multi-threaded environment?