life is a race

Author: gunjan5

day07-goroutines-channels-1/goroutines.go

@@ -6,10 +6,14 @@ import (
   "time"
 )
 
+func init() {
+	
+	runtime.GOMAXPROCS(runtime.NumCPU())
+}
 
 func sayMyName(name string){
 	for i:=0; i<5; i++ {
-		runtime.Gosched()
+		runtime.Gosched() //Gosched yields the processor, allowing other goroutines to run. It does not suspend the current goroutine, so execution resumes automatically.
 		fmt.Println("Oh na na what's my name? ", name)
 		time.Sleep(100*time.Millisecond) //doing some fake work here... please wait ZzzZzzZzzz
 	}
@@ -18,7 +22,6 @@ func sayMyName(name string){
 
 func main() {
 
-	runtime.GOMAXPROCS(runtime.NumCPU())
 
 	fmt.Println("You've got", runtime.NumCPU() , " CPU cores yo!")
 
@@ -32,7 +35,7 @@ func main() {
 
 	go sayMyName("bbbbbbbbbb")
 
-	var input string
-	fmt.Scanln(&input)
+	// var input string
+	// fmt.Scanln(&input)
 	fmt.Println("ok dude! the show is over, go home and eat a potato")
 }

day07-goroutines-channels-1/race.go

@@ -0,0 +1,41 @@
+package main
+
+import (
+	"fmt"
+	"sync"
+	"runtime"
+	"time"
+	"math/rand"
+)
+
+
+
+func init() {
+	runtime.GOMAXPROCS(runtime.NumCPU())
+}
+
+
+
+var globalcounter int
+var	wg sync.WaitGroup
+
+func main() {
+	wg.Add(2)
+	go incr("Red")
+	go incr("Blue")
+	wg.Wait()
+	fmt.Println("Final counter:", globalcounter, "instead of 100")
+}
+
+func incr(s string) {
+	for i := 0; i < 50; i++ {
+		x:=globalcounter
+		x++
+		time.Sleep(time.Duration(rand.Intn(2))*time.Millisecond)
+		globalcounter = x
+		fmt.Println(s, i, "counter:", globalcounter)
+	}
+	wg.Done()
+}
+
+