Condition

Author: naeemaei

15-Concurrency/06-Cond/example1.go

@@ -0,0 +1,47 @@
+package main
+
+import (
+"log"
+"sync"
+"time"
+)
+
+var myList = []int{}
+var done = false
+
+func read(name string, c *sync.Cond) {
+defer c.L.Unlock()
+c.L.Lock()
+if !done {
+c.Wait()
+}
+log.Println(name, "starts reading")
+}
+
+func write(id int, c *sync.Cond) {
+log.Println(id, "starts writing")
+time.Sleep(time.Second)
+c.L.Lock()
+myList = append(myList, id)
+if len(myList) == 100 {
+done = true
+c.Broadcast()
+log.Println(id, "wakes all")
+}
+c.L.Unlock()
+}
+
+func RunExample1() {
+cond := sync.NewCond(&sync.Mutex{})
+
+go read("reader1", cond)
+go read("reader2", cond)
+go read("reader3", cond)
+for i := 0; i < 1000; i++ {
+write(i, cond)
+}
+
+time.Sleep(time.Second * 3)
+}
+
+//

15-Concurrency/06-Cond/go.mod

@@ -0,0 +1,3 @@
+module condExample
+
+go 1.18

15-Concurrency/06-Cond/main.go

@@ -0,0 +1,45 @@
+package main
+
+import (
+"sync"
+"time"
+)
+
+var userList = []int{}
+var ready = false
+
+func main() {
+
+condition := sync.NewCond(&sync.Mutex{})
+
+for i := 0; i < 1000; i++ {
+go NewRequest(i, condition)
+}
+
+time.Sleep(time.Second * 5)
+
+}
+
+func NewRequest(userId int, condition *sync.Cond) {
+Checking(userId, condition)
+condition.L.Lock()
+defer condition.L.Unlock()
+for !ready {
+condition.Wait()
+}
+println("User ", userId, "start streaming") //
+}
+
+func Checking(userId int, condition *sync.Cond) {
+println(userId, "waiting for start streaming")
+time.Sleep(time.Millisecond * 50)
+condition.L.Lock()
+defer condition.L.Unlock()
+userList = append(userList, userId)
+if len(userList) == 55 {
+ready = true
+condition.Broadcast()
+println("User ", userId, "waiting end")
+}
+
+}