On Monday, October 12, 2015 at 1:59:59 AM UTC-4, Yakir Gagnon wrote: > > One important piece of information is the integration time (similar to the > shutter speed in a camera): after I set the integration time the > spectrometer start sampling the spectra at that frequency. When I try to > retrieve the intensities it will spit them out only when one cycle ends. > This means that when I try to run the function that retrieves the > intensities it can take anything from 0 to integration-time seconds. > > Here's the weird thing: > When I run my code the REPL becomes non-responsive for integration-time > seconds, so if I try to type some text, the letters get typed in only one > letter at an integration-time (note that CPU usage is less than 3%)... But, > if I replace the function that retrieves the intensities with some mock > function that `sleep`s for a random amount of time and returns a (equally > long) vector of random floats, the REPL jitter is gone..! >
Julia I/O functions, and functions like sleep(t), use the libuv library for asynchronous cooperative multitasking. That means that when one task is waiting on I/O, another task (e.g. the REPL) can wake up if there is something for it to do. However, Python I/O does not use libuv, so when the Python I/O task is waiting to finish reading something then it just blocks, and nothing else in Julia can run.
