Go Channels

Transcript

1. Channels 101 Sinan Ulker github.com/unicod3 twitter.com/unicod3
2. What is Concurrency? ◆ Ability of a computer to deal with multiple things at once. ◆ A way to structure software. ◆ Enables parallelism.
3. What is not Concurrency? Parallelism
4. Process, Thread, Heap, Stack
5. Concurrency in GO: Goroutines ➔ use ‘go’ keyword to create goroutines ➔ It's not a thread. ➔ Very cheap compared to threads
6. Goroutines vs Threads • managed by go runtime and has no hardware dependencies. • have 2KB of stack size; can grow up dynamically if needed by using heap storage • uses channels to communicate with other • Threads are managed by kernel and has hardware dependencies. • Threads generally have fixed stack size of 1-2MB • There is no easy communication between threads, inter-thread communication
7. Goroutines https://play.golang.org/p/4gNR8QivtX3
8. Channels • Provides a type safe connection between goroutines • Unbuffered Channels • Buffered Channels
9. Channel Blocking https://play.golang.org/p/DsLVudZ2CEz
10. Channel Blocking https://play.golang.org/p/DGp6YrPHMAg
11. Buffered Channels https://play.golang.org/p/tKgkQ10mbkW
12. Channels: Range https://play.golang.org/p/L_B70u0Pzbg Blocks until receive a value
13. Channels: Select https://play.golang.org/p/-u339fXjHno
14. Further Reading • https://www.youtube.com/watch?v=f6kdp27TYZs (Google I/O 2012 - Go Concurrency Patterns) • https://medium.com/rungo/achieving-concurrency-in-go-3f84cbf870ca • https://medium.com/@trevor4e/learning-gos-concurrency-through-illustrations-8c4aff603b3 • https://dougrichardson.org/2016/01/23/go-memory-allocations.html • https://stackoverflow.com/questions/25795131/do-golang-channels-maintain-order