fun-with-routines

How to run locally

docker build -t fwr .
docker run --name test --rm fwr

Run tests

(after building the image)

docker run -it fwr go test -v github.com/keremgocen/fun-with-routines

Notes on my approach

Both problem functions are modified to enable unit testing on them.

Problem1

A taskCount int should be provided to the function problem1() to determine the number of random values to be printed.

A jobs channel then gets populated with job ids (ie. from 1 to 100) and go routines use this channel to coordinate. If a value is present in the channel, a random value is printed. This works as expected despite the number of go routines spawned or the size of loop in them.

For testing problem1(), generated values are written into a separate channel that is being read by the main process synchronously. It's length is then compared with the expected value in problem1_test.go.

Problem2

A taskCount int should be provided to the function problem2() as well. The task details of printing a random value to stdout is represented by a struct;

type task struct {
	id int // task id
	slot int // go routine slot running the task
	loop int // inner loop count inside the go routine
	num float32 // the number generated by the task 
}

Same as in problem1, jobs channels for go routines are populated with task ids and the tasks channel is passed in to fan-in results in the main process.

For testing problem2(), a time.Tick channel is used to limit the rate main process is reading the results from tasks channel. One result is read every second and the timestamp is recorded. Then in problem2_test.go timestamps are compared for consecutive tasks and the difference is expected to be between 0.9 and 1.1 seconds.