adding documentation around goroutines

Author: symonk

README.md

@@ -35,6 +35,7 @@ all the examples `Run` functions sequentially in line with the table of contents
 * [21 - Struct Embedding](structembedding/main.go)
 * [22 - Generics](generics/main.go)
 * [23 - Errors](errors/main.go)
+* [24 - Goroutines](goroutines/main.go)
 * [34 - Timers](timers/main.go)
 * [35 - Tickers](tickers/main.go)
 * [36 - Worker Pools](workerpools/main.go)

goroutines/main.go

@@ -0,0 +1,46 @@
+package goroutines
+
+import (
+	"fmt"
+	"sync"
+	"time"
+)
+
+/*
+A `goroutine` is a lightweight thread of execution.
+*/
+func Run() {
+	synchroniseExample()
+	asynchronousExample()
+	waitForManyGoroutines()
+}
+
+func Goro(from string) {
+	for i := 0; i < 3; i++ {
+		fmt.Println(from, ":", i)
+	}
+}
+
+// Important to note: This is non blocking and will *not* wait for Goro to finish before exiting.
+func asynchronousExample() {
+	go Goro("Hello")
+}
+
+func synchroniseExample() {
+	Goro("foo")
+}
+
+func waitForManyGoroutines() {
+	var wg sync.WaitGroup
+	amount := 100
+	wg.Add(amount)
+	for i := 0; i < amount; i++ {
+		go func() {
+			time.Sleep(1 * time.Second)
+			wg.Done()
+		}()
+	}
+
+	wg.Wait() // Wait for all goroutines to finish
+	fmt.Printf("Waited for %d goroutines to complete\n", amount)
+}

main.go

@@ -11,6 +11,7 @@ import (
 	"github.com/symonk/learning-golang/forloop"
 	"github.com/symonk/learning-golang/functions"
 	"github.com/symonk/learning-golang/generics"
+	"github.com/symonk/learning-golang/goroutines"
 	"github.com/symonk/learning-golang/helloworld"
 	"github.com/symonk/learning-golang/ifelse"
 	"github.com/symonk/learning-golang/interfaces"
@@ -82,5 +83,6 @@ func buildMap() map[string]func() {
 	fnMap["structembedding"] = structembedding.Run
 	fnMap["generics"] = generics.Run
 	fnMap["errors"] = errors.Run
+	fnMap["goroutines"] = goroutines.Run
 	return fnMap
 }