【GoLang】golang context channel 详解

代码示例：

package main

import (
"fmt"
"time"

"golang.org/x/net/context"
)

func main() {
//    ctx, cancelFunc := context.WithDeadline(context.Background(), time.Now().Add(time.Second*5))
ctx, cancelFunc := context.WithTimeout(context.Background(), time.Second*5)
ctx = context.WithValue(ctx, "Test", "123456")
//    defer cancelFunc()

if t, ok := ctx.Deadline(); ok {
fmt.Println(time.Now())
fmt.Println(t.String())
}
go func(ctx context.Context) {
fmt.Println(ctx.Value("Test"))
for {
select {
case <-ctx.Done():
fmt.Println(ctx.Err())
return
//            default:
//                continue
}
}
}(ctx)
//    if ctx.Err() == nil {
//        fmt.Println("Sleep 10 seconds...")
//        time.Sleep(time.Second * 10)
//    }
//    if ctx.Err() != nil {
//        fmt.Println("Alredy exit...")
//    }
time.Sleep(time.Second * 3)
cancelFunc()
//    for {
//        if ctx.Err() != nil {
//            fmt.Println("gracefully exit...")
//            break
//        }
//    }
}

go程序包源码解读——golang.org/x/net/context:
http://m.blog.csdn.net/article/details?id=49100433
Go语言并发模型：像Unix Pipe那样使用channel:
https://segmentfault.com/a/1190000006261218
golang判断短chan channel是否关闭:
http://www.dotcoo.com/golang-channel-is-closed
如何安全关闭channel：
http://www.golangtc.com/t/53d8a5e1320b5252650000f0
channel小技巧： http://www.jb51.net/article/68909.htm
使用Golang的Context管理上下文: http://blog.csdn.net/u014029783/article/details/53782864
Go语言并发模型：使用 context: https://segmentfault.com/a/1190000006744213
golang x/net/context包笔记: http://blog.csdn.net/sryan/article/details/51969129
golang-context使用方式: http://www.tuicool.com/articles/ENnyYvR
Golang 1.7.3 Context 简单用法.类似sync.WaitGroup: http://blog.csdn.net/fyxichen/article/details/52104549
golang中context包解读: http://www.tuicool.com/articles/n6rInyn
Go语言并发模型：使用 context: http://www.tuicool.com/articles/3ieeuay