golang coroutine 的等待与死锁用法

package main
import (
 "fmt"
        "time"
)
func main() {
 go func1()
 go func2()
 select{}
}
func func1() {
       for{
     fmt.Println("here1")
            time.Sleep(10 * time.Minute)
        }
}
func func2() {
       for{
    fmt.Println("here2")
           time.Sleep(10 * time.Minute)
       }
}

package main
import (
 "fmt"
 //"time"
)
func main() {
 go func1()
 go func2()
 select {
 }
}
func func1() {
 fmt.Println("here1")
}
func func2() {
 fmt.Println("here2")
}

package main
import (
 "fmt"
)
var c = make(chan int, 2)
func main() {
 go func1()
 go func2()
 <-c
 <-c
 fmt.Println("ok")
}
func func1() {
 fmt.Println("here1")
 c <- 1
}
func func2() {
 fmt.Println("here2")
 c <- 1
}

  var wg sync.WaitGroup
    var urls = []string{
            "http://www.golang.org/",
            "http://www.google.com/",
            "http://www.somestupidname.com/",
    }
    for _, url := range urls {
            // Increment the WaitGroup counter.
            wg.Add(1)
            // Launch a goroutine to fetch the URL.
            go func(url string) {
                    // Decrement the counter when the goroutine completes.
                    defer wg.Done()
                    // Fetch the URL.
                    http.Get(url)
            }(url)
    }
    // Wait for all HTTP fetches to complete.
    wg.Wait()

func main() {
    q := make(chan int, 2)
    <-q
}

func main() {
    q := make(chan int, 2)
    select {
    case v := <-q:
        fmt.Println(v)
    default:
        fmt.Println("nothing in channel")
    }
}

func main() {
    q := make(chan int, 2)
    q <- 1
    q <- 2
    q <- 3
}

func main() {
    q := make(chan int, 2)
    q <- 1
    q <- 2
    select {
    case q <- 3:
        fmt.Println("ok")
    default:
        fmt.Println("wrong")
    }
}

func main() {
    q := make(chan int, 2)
    close(q)
    q <- 1
}

func main() {
    q := make(chan int, 3)
    q <- 1
    q <- 2
    q <- 3
    close(q)
    for v := range q {
        fmt.Println(v)
    }

package main
import "fmt"
func main() {
 c:=make(chan string)
 go func() {
  c<-"hello"
 }()
 fmt.Println(<-c)
}

package main
import "fmt"
func main() {
 c:=make(chan string)
 fmt.Println(<-c)
 go func() {
  c<-"hello"
 }()
}