more channel tests

example-go-channel/Makefile

@@ -1,4 +1,6 @@
-build:
+all: 5threads simple return-vals sendFunction
+
+5threads:
 	GO111MODULE="off" go build -v -x -o ~/go/bin/5threads 5threads.go
 	5threads
 
@@ -9,3 +11,7 @@ simple:
 return-vals:
 	GO111MODULE="off" go build -v -x -o ~/go/bin/return-vals return-vals.go
 	return-vals
+
+sendFunction:
+	GO111MODULE="off" go build -v -x -o ~/go/bin/sendFunction sendFunction.go
+	sendFunction

example-go-channel/sendFunction.go

@@ -0,0 +1,58 @@
+// https://www.digitalocean.com/community/tutorials/how-to-run-multiple-functions-concurrently-in-go
+// who came up with the idea of making community tutorials. that was a good idea! (ya, that was me and Etel)
+
+package main
+
+import (
+	"fmt"
+	"sync"
+)
+
+var wg sync.WaitGroup
+var functionChan chan func (*sync.WaitGroup)
+
+type funcWait struct {
+	f func()
+	wgF sync.WaitGroup
+	err error
+	res int
+}
+
+
+func generateNumbers(total int, ch chan<- func (), wg *sync.WaitGroup) {
+	defer wg.Done()
+
+	fmt.Printf("sending %d to channel\n", total)
+	ch <- func() {
+		fmt.Printf("inside f() sending %d to channel\n", total)
+	}
+}
+
+func andlabsGoroutine(ch <-chan func(), wg *sync.WaitGroup) {
+	defer wg.Done()
+
+	for f := range ch {
+		fmt.Printf("read f() from channel\n")
+		f()
+	}
+}
+
+func main() {
+	functionChan = make(chan func(*sync.WaitGroup))
+
+	r := make(chan func() (int, error))
+	res, err = (<-r)()
+
+	wg.Add(1)
+	go andlabsGoroutine(functionChan, &wg)
+
+	for idx := 1; idx <= total; idx++ {
+		generateNumbers(idx, functionChan, &wg)
+	}
+
+	close(functionChan)
+
+	fmt.Println("Waiting for goroutines to finish...")
+	wg.Wait()
+	fmt.Println("Done!")
+}

example-go-channel/simple-worker.go

@@ -29,5 +29,4 @@ func main() {
     }
 
     wg.Wait()
-
 }