and the Laws of Physics
Vending machine
Queuing people
Processor
Threads
1 + 2 + 3 + 4
1 + 2 + 3 + 4 (1 + 2) + (3 + 4) 3 + 7 10
It doesn't matter
1 + 2 + 3 + 4 (1 + 2) + 3 + 4 (3 + 3) + 4 6 + 4 10
Stream(1) .repeat .debug() .take(3) .compile .toList
Stream.eval(IO.pure(1)) .repeat .debug() .take(3) .compile .toList .unsafeRunSync()
Stream(1) .repeat .debug() .take(3) .compile .drain
Stream.eval(IO.pure(1)) .repeat .debug() .take(3) .compile .drain .unsafeRunSync()
1 1 1 1
1 1 1
IO.println("Hello") >> IO.println("world")
If B happened, it happened after A
Enforced by IO
val program = IO.println("Hello") >> IO.println("world") val fiber = program.start fiber >>= (_.cancel)
val program = Resource.make(IO.println("Hello")) { _ => IO.println("world") } resource.use { program => val fiber = program.start fiber >>= (_.cancel) }
 If A happens, B must happen
Enforced with resources
Essential Effects, Adam Rosien
Essential Effects (book), Adam Rosien
Concurrency with Cats Effect, Michael Pilquist
Tackling concurrency bugs with TLA+, Hillel Wayne
How we program multicores, Joe Armstrong
Mindmap of this presentation
By Zainab Ali
