From: sgf <sgf.dma@gmail.com>
Date: Thu, 2 Jun 2022 15:37:59 +0000 (+0300)
Subject: new(go): More code from "Go concurrency patterns" video.
X-Git-Url: https://gitweb.sgf-dma.tk/?a=commitdiff_plain;h=302997f030e018e734da1cde74c65e2653ef56cb;p=go.git

new(go): More code from "Go concurrency patterns" video.
---

diff --git a/go-concurrency-patterns/conc1.go b/go-concurrency-patterns/conc1.go
index 80373ba..2738bee 100644
--- a/go-concurrency-patterns/conc1.go
+++ b/go-concurrency-patterns/conc1.go
@@ -135,8 +135,130 @@ func main41() {
     fmt.Println("You're boring. I'm leaving.")
 }
 
+func main5() {
+    c := boring("Joe")
+    for {
+        select {
+        case s := <-c:
+            fmt.Println(s)
+        case <-time.After(2200 * time.Millisecond):
+            fmt.Println("You're too slow.")
+            return
+        }
+    }
+}
+
+func main6() {
+    c := boring("Joe")
+    timeout := time.After(7 * time.Second)
+    for {
+        select {
+        case s := <-c:
+            fmt.Println(s)
+        case <-timeout:
+            fmt.Println("You talk too much.")
+            return
+        }
+    }
+}
+
+func boring7(msg string, quit chan bool) <- chan string {
+    c := make(chan string)
+    go func() {
+        for i := 0; ; i++ {
+            r := rand.Intn(3e3)
+            select {
+            case c <- fmt.Sprintf("%s %d (%d)", msg, i, r):
+            case <-quit:
+                return
+            }
+            time.Sleep(time.Duration(r) * time.Millisecond)
+        }
+    }()
+    return c
+}
+
+func main7() {
+    quit := make(chan bool)
+    c := boring7("Joe", quit)
+    r := rand.Intn(10)
+    fmt.Printf("Expecting %v values\n", r + 1)
+    for i := r; i >= 0; i-- {
+        fmt.Printf("%q\n", <-c)
+    }
+    quit <-true
+    fmt.Println("You're boring. I'm leaving.")
+}
+
+func cleanup() {
+    fmt.Println("Cleanup")
+}
+
+func boring8(msg string, quit chan string) <- chan string {
+    c := make(chan string)
+    go func() {
+        for i := 0; ; i++ {
+            r := rand.Intn(3e3)
+            select {
+            case c <- fmt.Sprintf("%s %d (%d)", msg, i, r):
+            case <-quit:
+                cleanup()
+                quit <- "See you!"
+                return
+            }
+            time.Sleep(time.Duration(r) * time.Millisecond)
+        }
+    }()
+    return c
+}
+
+func main8() {
+    quit := make(chan string)
+    c := boring8("Joe", quit)
+    r := rand.Intn(10)
+    fmt.Printf("Expecting %v values\n", r + 1)
+    for i := r; i >= 0; i-- {
+        fmt.Printf("%q\n", <-c)
+    }
+    quit <- "Bye!"
+    fmt.Printf("Joe says: %q\n", <-quit)
+}
+
+func f(left, right chan int) {
+    left <- 1 + <-right
+}
+
+func main9() {
+    const n = 10000
+    leftmost := make(chan int)
+    right := leftmost
+    left := leftmost
+    for i := 0; i < n; i++ {
+        right = make(chan int)
+        go f(left, right)
+        left = right
+    }
+    go func(c chan int) { c <- 1 }(right)
+    fmt.Println(<-leftmost)
+}
+
+// Build a chain in reverse direction.
+func main91() {
+    const n = 10000
+    rightmost := make(chan int)
+    right := rightmost
+    var left chan int
+    for i := 0; i < n; i++ {
+        left = make(chan int)
+        go f(left, right)
+        right = left
+    }
+    go func(c chan int) { c <- 1 }(rightmost)
+    fmt.Println(<-left)
+}
+
 func main() {
     rand.Seed(time.Now().Unix())
 
-    main4()
+    main9()
 }