Add stateful goroutines

statefulgoroutines/statefulgoroutines.go

@@ -0,0 +1,78 @@
+package statefulgoroutines
+
+import (
+	"fmt"
+	"math/rand"
+	"sync/atomic"
+	"time"
+)
+
+type readOp struct {
+	key  int
+	resp chan int
+}
+
+type writeOp struct {
+	key   int
+	value int
+	resp  chan int
+}
+
+func StatefulGoroutines() {
+	var readCounts, writeCounts atomic.Uint64
+
+	reads := make(chan readOp)
+	writes := make(chan writeOp)
+
+	go func() {
+		state := map[int]int{}
+
+		for {
+			select {
+			case r := <-reads:
+				r.resp <- state[r.key]
+			case w := <-writes:
+				state[w.key] = w.value
+				w.resp <- state[w.key]
+			}
+		}
+	}()
+
+	// Spawn goroutines to do reads
+	for range 100 {
+		go func() {
+			for {
+				r := readOp{
+					key:  rand.Intn(5),
+					resp: make(chan int),
+				}
+				reads <- r
+				<-r.resp
+				readCounts.Add(1)
+				time.Sleep(time.Millisecond)
+			}
+		}()
+	}
+
+	// Spawn goroutines to do writes
+	for range 10 {
+		go func() {
+			for {
+				w := writeOp{
+					key:   rand.Intn(5),
+					value: rand.Intn(100),
+					resp:  make(chan int),
+				}
+				writes <- w
+				<-w.resp
+				writeCounts.Add(1)
+				time.Sleep(time.Millisecond)
+			}
+		}()
+	}
+
+	time.Sleep(time.Second)
+
+	fmt.Printf("# of reads => %d\n", readCounts.Load())
+	fmt.Printf("# of writes => %d\n", writeCounts.Load())
+}