{"id":10008391,"date":"2024-02-23T15:33:39","date_gmt":"2024-02-23T07:33:39","guid":{"rendered":"https:\/\/blog.itmax.cn\/?p=10008391"},"modified":"2024-02-23T15:33:39","modified_gmt":"2024-02-23T07:33:39","slug":"%e9%80%9a%e4%bf%97%e6%98%93%e6%87%82%e5%89%96%e6%9e%90go-channel%ef%bc%9a%e7%90%86%e8%a7%a3%e5%b9%b6%e5%8f%91%e9%80%9a%e4%bf%a1%e7%9a%84%e6%a0%b8%e5%bf%83%e6%9c%ba%e5%88%b6","status":"publish","type":"post","link":"https:\/\/itmax.cn\/?p=10008391","title":{"rendered":"\u901a\u4fd7\u6613\u61c2\u5256\u6790Go Channel\uff1a\u7406\u89e3\u5e76\u53d1\u901a\u4fe1\u7684\u6838\u5fc3\u673a\u5236"},"content":{"rendered":"

\u672c\u6587\u6765\u81ea Go\u5c31\u4e1a\u8bad\u7ec3\u8425<\/a> \u5c0f\u97ec\u540c\u5b66\u7684\u6295\u7a3f\u3002<\/p>\n

\u4e5f\u5f3a\u70c8\u5b89\u5229\u5927\u5bb6\u591a\u5199\u535a\u5ba2\uff0c\u4e0d\u4ec5\u80fd\u5012\u903c\u81ea\u5df1\u5b66\u4e60\u603b\u7ed3\uff0c\u4e5f\u80fd\u4f5c\u4e3a\u7b80\u5386\u7684\u52a0\u5206\u9879\uff0c\u63d0\u9ad8\u6c42\u804c\u9762\u8bd5\u7684\u7ade\u4e89\u529b\u3002<\/strong><\/p>\n

\u4f60\u60f3\u60f3\u770b\uff1a\u9762\u8bd5\u5b98\u770b\u5230\u4f60\u7b80\u5386\u4e2d\u7684\u535a\u5ba2\u4e3b\u9875\u6709\u51e0\u5341\u7bc7\u6587\u7ae0\uff0c\u51e0\u5343\u7c89\u4e1d\u662f\u4ec0\u4e48\u611f\u89c9\u3002\u8981\u6bd4\u4f60\u7a7a\u6d1e\u6d1e\u7684\u5199\u4e00\u53e5\u201c\u70ed\u7231\u6280\u672f\u201d\u5f3a\u592a\u591a\u5566\uff01<\/strong><\/p>\n

\u6b63\u6587<\/h2>\n

\u6211\u4eec\u5728\u5b66\u4e60\u4e0e\u4f7f\u7528Go\u8bed\u8a00\u7684\u8fc7\u7a0b\u4e2d\uff0c\u5bf9channel<\/code>\u5e76\u4e0d\u964c\u751f\uff0cchannel<\/code>\u662fGo\u8bed\u8a00\u4e0e\u4f17\u4e0d\u540c\u7684\u7279\u6027\u4e4b\u4e00\uff0c\u4e5f\u662f\u975e\u5e38\u91cd\u8981\u7684\u4e00\u73af\uff0c\u6df1\u5165\u7406\u89e3Channel<\/code>\uff0c\u76f8\u4fe1\u80fd\u591f\u5728\u4f7f\u7528\u7684\u65f6\u5019\u66f4\u52a0\u7684\u5f97\u5fc3\u5e94\u624b\u3002<\/p>\n

\u4e00\u3001Channel\u57fa\u672c\u7528\u6cd5<\/h3>\n

1\u3001channel\u7c7b\u522b<\/h4>\n

channel<\/code>\u5728\u7c7b\u578b\u4e0a\uff0c\u53ef\u4ee5\u5206\u4e3a\u4e24\u79cd\uff1a
+\u00a0\u53cc\u5411channel<\/strong>\uff1a\u65e2\u80fd\u63a5\u6536\u53c8\u80fd\u53d1\u9001\u7684channel<\/code>
+\u00a0\u5355\u5411channel<\/strong>\uff1a\u53ea\u80fd\u53d1\u9001\u6216\u53ea\u80fd\u63a5\u6536\u7684channel<\/code>\uff0c\u5373\u5355\u5411channel<\/code>\u53ef\u4ee5\u4e3a\u5206\u4e3a\uff1a
\u00a0\u00a0\u00a0\u00a0+\u00a0\u53ea\u5199channel<\/code>
\u00a0\u00a0\u00a0\u00a0+\u00a0\u53ea\u8bfbchannel<\/code> <\/p>\n

\u58f0\u660e\u5e76\u521d\u59cb\u5316\u5982\u4e0b\u5982\u4e0b\uff1a<\/p>\n

func main() {  \n\u00a0\u00a0\u00a0\u00a0\/\/ \u58f0\u660e\u5e76\u521d\u59cb\u5316  \n\u00a0\u00a0\u00a0\u00a0var ch chan string = make(chan string) \/\/ \u53cc\u5411channel  \n\u00a0\u00a0\u00a0\u00a0var readCh <-chan string = make(<-chan string) \/\/ \u53ea\u8bfbchannel  \n\u00a0\u00a0\u00a0\u00a0var writeCh chan<- string = make(chan<- string) \/\/ \u53ea\u5199channel  \n}  <\/code><\/pre>\n
\u4e0a\u8ff0\u5b9a\u4e49\u4e2d\uff0c<-<\/code>\u8868\u793a\u5355\u5411\u7684channel<\/code>\u3002\u5982\u679c\u7bad\u5934\u6307\u5411chan<\/code>\uff0c\u5c31\u8868\u793a\u53ea\u5199channel<\/code>\uff0c\u53ef\u4ee5\u5f80chan<\/code>\u91cc\u8fb9\u5199\u5165\u6570\u636e\uff1b\u5982\u679c\u7bad\u5934\u8fdc\u79bbchan<\/code>\uff0c\u5219\u8868\u793a\u4e3a\u53ea\u8bfbchannel<\/code>\uff0c\u53ef\u4ee5\u4ecechan<\/code>\u8bfb\u6570\u636e\u3002  <\/p>\n
\u5728\u5b9a\u4e49channel\u65f6\uff0c\u53ef\u4ee5\u5b9a\u4e49\u4efb\u610f\u7c7b\u578b\u7684channel\uff0c\u56e0\u6b64\u4e5f\u540c\u6837\u53ef\u4ee5\u5b9a\u4e49chan\u7c7b\u578b\u7684channel\u3002\u4f8b\u5982\uff1a<\/p>\n
a := make(chan<- chan int)\u00a0\u00a0\u00a0\/\/ \u5b9a\u4e49\u7c7b\u578b\u4e3a chan int \u7684\u5199channel  \nb := make(chan<- <-chan int) \/\/ \u5b9a\u4e49\u7c7b\u578b\u4e3a <-chan int \u7684\u5199channel  \nc := make(<-chan <-chan int) \/\/ \u5b9a\u4e49\u7c7b\u578b\u4e3a <-chan int \u7684\u8bfbchannel  \nd := make(chan (<-chan int)) \/\/ \u5b9a\u4e49\u7c7b\u578b\u4e3a (<-chan int) \u7684\u8bfbchannel  <\/code><\/pre>\n
\u5f53channel<\/code>\u672a\u521d\u59cb\u5316\u65f6\uff0c\u5176\u96f6\u503c\u4e3anil<\/code><\/strong>\u3002nil \u662f chan \u7684\u96f6\u503c\uff0c\u662f\u4e00\u79cd\u7279\u6b8a\u7684 chan\uff0c\u5bf9\u503c\u662f nil \u7684 chan \u7684\u53d1\u9001\u63a5\u6536\u8c03\u7528\u8005\u603b\u662f\u4f1a\u963b\u585e\u3002<\/strong><\/p>\n
func main() {  \n\u00a0\u00a0\u00a0\u00a0var ch chan string  \n\u00a0\u00a0\u00a0\u00a0fmt.Println(ch) \/\/ <nil>  \n}  <\/code><\/pre>\n
\u901a\u8fc7make<\/code>\u6211\u4eec\u53ef\u4ee5\u521d\u59cb\u5316\u4e00\u4e2achannel\uff0c\u5e76\u4e14\u53ef\u4ee5\u8bbe\u7f6e\u5176\u5bb9\u91cf\u7684\u5927\u5c0f\uff0c\u5982\u4e0b\u521d\u59cb\u5316\u4e86\u4e00\u4e2a\u7c7b\u578b\u4e3astring<\/code>\uff0c\u5176\u5bb9\u91cf\u5927\u5c0f\u4e3a512<\/code>\u7684channel<\/code>\uff1a<\/p>\n
var ch chan string = make(chan string, 512)  <\/code><\/pre>\n
\u5f53\u521d\u59cb\u5316\u5b9a\u4e49\u4e86channel<\/code>\u7684\u5bb9\u91cf\uff0c\u5219\u8fd9\u6837\u7684channel<\/code>\u53eb\u505abuffered chan<\/code>\uff0c\u5373\u6709\u7f13\u51b2channel<\/code><\/strong>\u3002\u5982\u679c\u6ca1\u6709\u8bbe\u7f6e\u5bb9\u91cf\uff0cchannel<\/code>\u7684\u5bb9\u91cf\u4e3a0\uff0c\u8fd9\u6837\u7684channel<\/code>\u53eb\u505aunbuffered chan<\/code>\uff0c\u5373\u65e0\u7f13\u51b2channel<\/code><\/strong>\u3002  <\/p>\n
\u6709\u7f13\u51b2channel<\/code>\u4e2d\uff0c\u5982\u679cchannel<\/code>\u4e2d\u8fd8\u6709\u6570\u636e\uff0c\u5219\u4ece\u8fd9\u4e2achannel<\/code>\u63a5\u6536\u6570\u636e\u65f6\u4e0d\u4f1a\u88ab\u963b\u585e\u3002\u5982\u679cchannel<\/code>\u7684\u5bb9\u91cf\u8fd8\u672a\u6ee1\uff0c\u90a3\u4e48\u5411\u8fd9\u4e2achannel<\/code>\u53d1\u9001\u6570\u636e\u4e5f\u4e0d\u4f1a\u88ab\u963b\u585e\uff0c\u53cd\u4e4b\u5219\u4f1a\u88ab\u963b\u585e\u3002  <\/p>\n
\u65e0\u7f13\u51b2channel<\/code>\u5219\u53ea\u6709\u5f53\u8bfb\u5199\u64cd\u4f5c\u90fd\u51c6\u5907\u597d\u540e\uff0c\u624d\u4e0d\u4f1a\u963b\u585e\uff0c\u8fd9\u4e5f\u662funbuffered chan<\/code>\u5728\u4f7f\u7528\u8fc7\u7a0b\u4e2d\u975e\u5e38\u9700\u8981\u6ce8\u610f\u7684\u4e00\u70b9\uff0c\u5426\u5219\u53ef\u80fd\u4f1a\u51fa\u73b0\u5e38\u89c1\u7684bug\u3002  <\/p>\n
channel\u7684\u5e38\u89c1\u64cd\u4f5c\uff1a<\/strong>  <\/p>\n
1.\u00a0\u53d1\u9001\u6570\u636e  <\/p>\n
\u5f80channel\u53d1\u9001\u4e00\u4e2a\u6570\u636e\u4f7f\u7528ch <-<\/code><\/p>\n
func main() {  \n\u00a0\u00a0\u00a0\u00a0var ch chan int = make(chan int, 512)  \n\u00a0\u00a0\u00a0\u00a0ch <- 2000  \n}  <\/code><\/pre>\n
\u4e0a\u8ff0\u7684ch<\/code>\u53ef\u4ee5\u662fchan int<\/code>\u7c7b\u578b\uff0c\u4e5f\u53ef\u4ee5\u662f\u5355\u5411chan <-int<\/code>\u3002  <\/p>\n
2.\u00a0\u63a5\u6536\u6570\u636e  <\/p>\n
\u4ecechannel\u63a5\u6536\u4e00\u6761\u6570\u636e\u53ef\u4ee5\u4f7f\u7528<-ch<\/code><\/p>\n
func main() {  \n\u00a0\u00a0\u00a0\u00a0var ch chan int = make(chan int, 512)  \n\u00a0\u00a0\u00a0\u00a0ch <- 2000 \/\/ \u53d1\u9001\u6570\u636e  \n  \n\u00a0\u00a0\u00a0\u00a0data := <-ch \/\/ \u63a5\u6536\u6570\u636e  \n\u00a0\u00a0\u00a0\u00a0fmt.Println(data) \/\/ 2000  \n}  <\/code><\/pre>\n
ch \u7c7b\u578b\u662f\u00a0chan T<\/code>\uff0c\u4e5f\u53ef\u4ee5\u662f\u5355\u5411<-chan T<\/code>  <\/p>\n
\u5728\u63a5\u6536\u6570\u636e\u65f6\uff0c\u53ef\u4ee5\u8fd4\u56de\u4e24\u4e2a\u8fd4\u56de\u503c\u3002\u7b2c\u4e00\u4e2a\u8fd4\u56de\u503c\u8fd4\u56dechannel<\/code>\u4e2d\u7684\u5143\u7d20\uff0c\u7b2c\u4e8c\u4e2a\u8fd4\u56de\u503c\u4e3abool<\/code>\u7c7b\u578b<\/strong>\uff0c\u8868\u793a\u662f\u5426\u6210\u529f\u5730\u4ecechannel<\/code>\u4e2d\u8bfb\u53d6\u5230\u4e00\u4e2a\u503c\u3002  <\/p>\n
\u5982\u679c\u7b2c\u4e8c\u4e2a\u53c2\u6570\u662ffalse<\/code>\uff0c\u5219\u8868\u793achannel<\/code>\u5df2\u7ecf\u88abclose<\/code>\u800c\u4e14channel<\/code>\u4e2d\u6ca1\u6709\u7f13\u5b58\u7684\u6570\u636e<\/strong>\uff0c\u8fd9\u4e2a\u65f6\u5019\u7b2c\u4e00\u4e2a\u503c\u8fd4\u56de\u7684\u662f\u96f6\u503c\u3002<\/p>\n
func main() {  \n\u00a0\u00a0\u00a0\u00a0var ch chan int = make(chan int, 512)  \n\u00a0\u00a0\u00a0\u00a0ch <- 2000 \/\/ \u53d1\u9001\u6570\u636e  \n  \n\u00a0\u00a0\u00a0\u00a0data1, ok1 := <-ch \/\/ \u63a5\u6536\u6570\u636e  \n\u00a0\u00a0\u00a0\u00a0fmt.Printf("data1 = %d, ok1 = %t\/n", data1, ok1) \/\/ data1 = 2000, ok1 = true  \n\u00a0\u00a0\u00a0\u00a0close(ch)\u00a0\u00a0\/\/ \u5173\u95edchannel  \n\u00a0\u00a0\u00a0\u00a0data2, ok2 := <-ch\u00a0\u00a0\/\/ \u63a5\u6536\u6570\u636e  \n\u00a0\u00a0\u00a0\u00a0fmt.Printf("data2 = %d, ok2 = %t", data2, ok2) \/\/ data2 = 0, ok2 = false  \n}  <\/code><\/pre>\n
\u6240\u4ee5\uff0c\u5982\u679c\u4ecechannel<\/code>\u8bfb\u53d6\u5230\u4e00\u4e2a\u96f6\u503c\uff0c\u53ef\u80fd\u662f\u53d1\u9001\u64cd\u4f5c\u771f\u6b63\u53d1\u9001\u7684\u96f6\u503c\uff0c\u4e5f\u53ef\u80fd\u662fclosed<\/code>\u5173\u95edchannel<\/code>\u5e76\u4e14channel<\/code>\u6ca1\u6709\u7f13\u5b58\u5143\u7d20\u4ea7\u751f\u7684\u96f6\u503c\uff0c\u8fd9\u662f\u9700\u8981\u6ce8\u610f\u5224\u522b\u7684\u4e00\u4e2a\u70b9\u3002  <\/p>\n
3.\u00a0\u5176\u4ed6\u64cd\u4f5c  <\/p>\n
Go\u5185\u5efa\u7684\u51fd\u6570close<\/code>\u3001cap<\/code>\u3001len<\/code>\u90fd\u53ef\u4ee5\u5bf9chan<\/code>\u7c7b\u578b\u8fdb\u884c\u64cd\u4f5c\u3002  
+\u00a0close<\/code>\uff1a\u5173\u95edchannel\u3002  
+\u00a0cap<\/code>\uff1a\u8fd4\u56dechannel\u7684\u5bb9\u91cf\u3002  
+\u00a0len<\/code>\uff1a\u8fd4\u56dechannel\u7f13\u5b58\u4e2d\u8fd8\u672a\u88ab\u53d6\u8d70\u7684\u5143\u7d20\u6570\u91cf\u3002<\/p>\n
func main() {  \n\u00a0\u00a0\u00a0\u00a0var ch chan int = make(chan int, 512)  \n\u00a0\u00a0\u00a0\u00a0ch <- 100  \n\u00a0\u00a0\u00a0\u00a0ch <- 200  \n\u00a0\u00a0\u00a0\u00a0fmt.Println("ch len:", len(ch)) \/\/ ch len: 2  \n\u00a0\u00a0\u00a0\u00a0fmt.Println("ch cap:", cap(ch)) \/\/ ch cap: 512  \n}  <\/code><\/pre>\n
\u53d1\u9001\u64cd\u4f5c<\/strong>\u4e0e\u63a5\u6536\u64cd\u4f5c<\/strong>\u53ef\u4ee5\u4f5c\u4e3aselect<\/code>\u8bed\u53e5\u4e2d\u7684case clause<\/code>\uff0c\u4f8b\u5982\uff1a<\/p>\n
func main() {  \n\u00a0\u00a0\u00a0\u00a0var ch = make(chan int, 512)  \n\u00a0\u00a0\u00a0\u00a0for i := 0; i < 10; i++ {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0select {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0case ch <- i:  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0case v := <-ch:  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0fmt.Println(v)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0}  \n}  <\/code><\/pre>\n
for-range<\/code>\u8bed\u53e5\u540c\u6837\u53ef\u4ee5\u5728chan<\/code>\u4e2d\u4f7f\u7528\uff0c\u4f8b\u5982\uff1a<\/p>\n
func main() {  \n\u00a0\u00a0\u00a0\u00a0var ch = make(chan int, 512)  \n\u00a0\u00a0\u00a0\u00a0ch <- 100  \n\u00a0\u00a0\u00a0\u00a0ch <- 200  \n\u00a0\u00a0\u00a0\u00a0ch <- 300  \n\u00a0\u00a0\u00a0\u00a0for v := range ch {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0fmt.Println(v)  \n\u00a0\u00a0\u00a0\u00a0}  \n}  \n  \n\/\/ \u6267\u884c\u7ed3\u679c  \n100  \n200  \n300  <\/code><\/pre>\n
2\u3001select\u4ecb\u7ecd<\/h4>\n
\u5728Go\u8bed\u8a00\u4e2d\uff0cselect<\/code>\u8bed\u53e5\u7528\u4e8e\u76d1\u63a7\u4e00\u7ec4case<\/code>\u8bed\u53e5\uff0c\u6839\u636e\u7279\u5b9a\u7684\u6761\u4ef6\u6267\u884c\u76f8\u5bf9\u5e94\u7684case<\/code>\u8bed\u53e5\u6216default<\/code>\u8bed\u53e5\uff0c\u4e0eswitch<\/code>\u7c7b\u4f3c\uff0c\u4f46\u4e0d\u540c\u4e4b\u5904\u5728\u4e8eselect<\/code>\u8bed\u53e5\u4e2d\u6240\u6709case<\/code>\u4e2d\u7684\u8868\u8fbe\u5f0f\u90fd\u5fc5\u987b\u662fchannel<\/code>\u7684\u53d1\u9001\u6216\u63a5\u6536\u64cd\u4f5c\u3002select<\/code>\u4f7f\u7528\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
select {  \ncase <-ch1:  \n\u00a0\u00a0\u00a0\u00a0fmt.Println("ch1")  \ncase ch2 <- 1:  \n\u00a0\u00a0\u00a0\u00a0fmt.Println("ch2")  \n}  <\/code><\/pre>\n
\u4e0a\u8ff0\u4ee3\u7801\u4e2d\uff0cselect<\/code>\u5173\u952e\u5b57\u8ba9\u5f53\u524dgoroutine<\/code>\u540c\u65f6\u7b49\u5f85ch1<\/code>\u00a0\u7684\u53ef\u8bfb\u548cch2<\/code>\u7684\u53ef\u5199\uff0c\u5728\u6ee1\u8db3\u4efb\u610f\u4e00\u4e2acase<\/code>\u5206\u652f\u4e4b\u524d\uff0cselect<\/code>\u00a0\u4f1a\u4e00\u76f4\u963b\u585e\u4e0b\u53bb\uff0c\u76f4\u5230\u5176\u4e2d\u7684\u4e00\u4e2a\u00a0channel<\/code>\u00a0\u8f6c\u4e3a\u5c31\u7eea\u72b6\u6001\u65f6\u6267\u884c\u5bf9\u5e94case<\/code>\u5206\u652f\u7684\u4ee3\u7801\u3002\u5982\u679c\u591a\u4e2achannel<\/code>\u540c\u65f6\u5c31\u7eea\u7684\u8bdd\u5219\u968f\u673a\u9009\u62e9\u4e00\u4e2acase<\/code>\u6267\u884c\u3002  <\/p>\n
\u5f53\u4f7f\u7528\u7a7aselect<\/code>\u65f6\uff0c\u7a7a\u7684\u00a0select<\/code>\u00a0\u8bed\u53e5\u4f1a\u76f4\u63a5\u963b\u585e\u5f53\u524d\u7684goroutine<\/code>\uff0c\u4f7f\u5f97\u8be5goroutine<\/code>\u8fdb\u5165\u65e0\u6cd5\u88ab\u5524\u9192\u7684\u6c38\u4e45\u4f11\u7720\u72b6\u6001\u3002\u7a7aselect<\/code>\uff0c\u5373select<\/code>\u5185\u4e0d\u5305\u542b\u4efb\u4f55case<\/code>\u3002<\/p>\n
select{  \n\u00a0\u00a0  \n}  <\/code><\/pre>\n
\u53e6\u5916\u5f53select<\/code>\u8bed\u53e5\u5185\u53ea\u6709\u4e00\u4e2acase<\/code>\u5206\u652f\u65f6\uff0c\u5982\u679c\u8be5case<\/code>\u5206\u652f\u4e0d\u6ee1\u8db3\uff0c\u90a3\u4e48\u5f53\u524dselect<\/code>\u5c31\u53d8\u6210\u4e86\u4e00\u4e2a\u963b\u585e\u7684channel<\/code>\u8bfb\/\u5199\u64cd\u4f5c\u3002<\/p>\n
select {  \ncase <-ch1:  \n\u00a0\u00a0\u00a0\u00a0fmt.Println("ch1")  \n}  <\/code><\/pre>\n
\u4e0a\u8ff0select<\/code>\u4e2d\uff0c\u5f53ch1<\/code>\u53ef\u8bfb\u65f6\uff0c\u4f1a\u6267\u884c\u6253\u5370\u64cd\u4f5c\uff0c\u53cd\u4e4b\u5219\u963b\u585e\u5f53\u524dgoroutine<\/code>\u3002  <\/p>\n
\u5f53select<\/code>\u8bed\u53e5\u5185\u5305\u542bdefault<\/code>\u5206\u652f\u65f6\uff0c\u5982\u679cselect<\/code>\u5185\u7684\u6240\u6709case<\/code>\u90fd\u4e0d\u6ee1\u8db3\uff0c\u5219\u4f1a\u6267\u884cdefault<\/code>\u5206\u652f\u7684\u903b\u8f91\uff0c\u7528\u4e8e\u5f53\u5176\u4ed6case<\/code>\u90fd\u4e0d\u6ee1\u8db3\u65f6\u6267\u884c\u4e00\u4e9b\u9ed8\u8ba4\u64cd\u4f5c\u3002<\/p>\n
select {  \ncase <-ch1:  \n\u00a0\u00a0\u00a0\u00a0fmt.Println("ch1")  \ncase ch2 <- 1:  \n\u00a0\u00a0\u00a0\u00a0fmt.Println("ch2")  \ndefault:  \n\u00a0\u00a0\u00a0\u00a0fmt.Println("default")  \n}  <\/code><\/pre>\n
\u4e0a\u8ff0\u4ee3\u7801\u4e2d\uff0c\u5f53ch1<\/code>\u53ef\u8bfb\u6216ch2<\/code>\u53ef\u5199\u65f6\uff0c\u4f1a\u6267\u884c\u76f8\u5e94\u7684\u6253\u5370\u64cd\u4f5c\uff0c\u5426\u5219\u5c31\u6267\u884cdefault<\/code>\u8bed\u53e5\u4e2d\u7684\u4ee3\u7801\uff0c\u76f8\u5f53\u4e8e\u4e00\u4e2a\u975e\u963b\u585e\u7684channel<\/code>\u8bfb\u53d6\u64cd\u4f5c\u3002  <\/p>\n
select<\/code>\u7684\u4f7f\u7528\u53ef\u4ee5\u603b\u7ed3\u4e3a\uff1a  <\/p>\n
+\u00a0select<\/code>\u4e0d\u5b58\u5728\u4efb\u4f55\u7684case<\/code>\u4e14\u6ca1\u6709default<\/code>\u5206\u652f\uff1a\u6c38\u4e45\u963b\u585e\u5f53\u524d goroutine\uff1b  
+\u00a0select<\/code>\u53ea\u5b58\u5728\u4e00\u4e2acase<\/code>\u4e14\u6ca1\u6709default<\/code>\u5206\u652f\uff1a\u963b\u585e\u7684\u53d1\u9001\/\u63a5\u6536\uff1b  
+\u00a0select<\/code>\u5b58\u5728\u591a\u4e2acase<\/code>\uff1a\u968f\u673a\u9009\u62e9\u4e00\u4e2a\u6ee1\u8db3\u6761\u4ef6\u7684case<\/code>\u6267\u884c\uff1b  
+\u00a0select<\/code>\u5b58\u5728default<\/code>\uff0c\u5176\u4ed6case<\/code>\u90fd\u4e0d\u6ee1\u8db3\u65f6\uff1a\u6267\u884cdefault<\/code>\u8bed\u53e5\u4e2d\u7684\u4ee3\u7801\uff1b<\/p>\n
\u4e8c\u3001Channel\u5b9e\u73b0\u539f\u7406<\/h3>\n
\u4ece\u4ee3\u7801\u7684\u89d2\u5ea6\u5256\u6790channel<\/code>\u7684\u5b9e\u73b0\uff0c\u80fd\u591f\u8ba9\u6211\u4eec\u66f4\u597d\u7684\u53bb\u4f7f\u7528channel<\/code>\u3002  <\/p>\n
\u6211\u4eec\u53ef\u4ee5\u4ecechan<\/code>\u7c7b\u578b\u7684\u6570\u636e\u7ed3\u6784\u3001\u521d\u59cb\u5316\u4ee5\u53ca\u4e09\u4e2a\u64cd\u4f5c\u53d1\u9001\u3001\u63a5\u6536\u548c\u5173\u95ed\u8fd9\u51e0\u4e2a\u65b9\u9762\u6765\u4e86\u89e3channel<\/code>\u3002<\/p>\n
1\u3001chan\u6570\u636e\u7ed3\u6784<\/h4>\n
chan\u7c7b\u578b\u7684\u6570\u636e\u7ed3\u6784\u5b9a\u4e49\u4f4d\u4e8eruntime.hchan<\/a>\uff0c\u5176\u7ed3\u6784\u4f53\u5b9a\u4e49\u5982\u4e0b\uff1a<\/p>\n
type hchan struct {  \n\u00a0\u00a0\u00a0\u00a0qcount\u00a0\u00a0\u00a0uint\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/ total data in the queue  \n\u00a0\u00a0\u00a0\u00a0dataqsiz uint\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/ size of the circular queue  \n\u00a0\u00a0\u00a0\u00a0buf\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0unsafe.Pointer \/\/ points to an array of dataqsiz elements  \n\u00a0\u00a0\u00a0\u00a0elemsize uint16  \n\u00a0\u00a0\u00a0\u00a0closed\u00a0\u00a0\u00a0uint32  \n\u00a0\u00a0\u00a0\u00a0elemtype *_type \/\/ element type  \n\u00a0\u00a0\u00a0\u00a0sendx\u00a0\u00a0\u00a0\u00a0uint\u00a0\u00a0\u00a0\/\/ send index  \n\u00a0\u00a0\u00a0\u00a0recvx\u00a0\u00a0\u00a0\u00a0uint\u00a0\u00a0\u00a0\/\/ receive index  \n\u00a0\u00a0\u00a0\u00a0recvq\u00a0\u00a0\u00a0\u00a0waitq\u00a0\u00a0\/\/ list of recv waiters  \n\u00a0\u00a0\u00a0\u00a0sendq\u00a0\u00a0\u00a0\u00a0waitq\u00a0\u00a0\/\/ list of send waiters  \n  \n\u00a0\u00a0\u00a0\u00a0\/\/ lock protects all fields in hchan, as well as several  \n\u00a0\u00a0\u00a0\u00a0\/\/ fields in sudogs blocked on this channel.  \n\u00a0\u00a0\u00a0\u00a0\/\/  \n\u00a0\u00a0\u00a0\u00a0\/\/ Do not change another G's status while holding this lock  \n\u00a0\u00a0\u00a0\u00a0\/\/ (in particular, do not ready a G), as this can deadlock  \n\u00a0\u00a0\u00a0\u00a0\/\/ with stack shrinking.  \n\u00a0\u00a0\u00a0\u00a0lock mutex  \n}  <\/code><\/pre>\n
\u89e3\u91ca\u4e00\u4e0b\u4e0a\u8ff0\u5404\u4e2a\u5b57\u6bb5\u7684\u610f\u4e49\uff1a  <\/p>\n
+\u00a0qcount<\/code>\uff1a\u8868\u793achan<\/code>\u4e2d\u5df2\u7ecf\u63a5\u6536\u5230\u7684\u6570\u636e\u4e14\u8fd8\u672a\u88ab\u53d6\u8d70\u7684\u5143\u7d20\u4e2a\u6570\u3002\u5185\u5efa\u51fd\u6570len<\/code>\u53ef\u4ee5\u8fd4\u56de\u8fd9\u4e2a\u5b57\u6bb5\u7684\u503c\u3002  
+\u00a0datasiz<\/code>\uff1a\u5faa\u73af\u961f\u5217\u7684\u5927\u5c0f\u3002chan<\/code>\u5728\u5b9e\u73b0\u4e0a\u4f7f\u7528\u4e00\u4e2a\u5faa\u73af\u961f\u5217\u6765\u5b58\u653e\u5143\u7d20\u7684\u4e2a\u6570\uff0c\u5faa\u73af\u961f\u5217\u9002\u7528\u4e8e\u751f\u4ea7\u8005-\u6d88\u8d39\u8005\u7684\u573a\u666f\u3002  
+\u00a0buf<\/code>\uff1a\u5b58\u653e\u5143\u7d20\u7684\u5faa\u73af\u961f\u5217buffer<\/code>\uff0cbuf<\/code>\u00a0\u5b57\u6bb5\u662f\u4e00\u4e2a\u6307\u5411\u961f\u5217\u7f13\u51b2\u533a\u7684\u6307\u9488\uff0c\u5373\u6307\u5411\u4e00\u4e2adataqsiz<\/code>\u5143\u7d20\u7684\u6570\u7ec4\u3002buf<\/code>\u00a0\u5b57\u6bb5\u662f\u4f7f\u7528\u00a0unsafe.Pointer<\/code>\u00a0\u7c7b\u578b\u6765\u8868\u793a\u961f\u5217\u7f13\u51b2\u533a\u7684\u8d77\u59cb\u5730\u5740\u3002unsafe.Pointer<\/code>\u662f\u4e00\u79cd\u7279\u6b8a\u7684\u6307\u9488\u7c7b\u578b\uff0c\u5b83\u53ef\u4ee5\u7528\u4e8e\u6307\u5411\u4efb\u4f55\u7c7b\u578b\u7684\u6570\u636e\u3002\u7531\u4e8e\u961f\u5217\u7f13\u51b2\u533a\u7684\u7c7b\u578b\u662f\u52a8\u6001\u5206\u914d\u7684\uff0c\u6240\u4ee5\u4e0d\u80fd\u76f4\u63a5\u4f7f\u7528\u67d0\u4e2a\u5177\u4f53\u7c7b\u578b\u7684\u6307\u9488\u6765\u8868\u793a\u3002  
+\u00a0elemtype<\/code>\u3001elemsize<\/code>\uff1aelemtype<\/code>\u8868\u793achan\u4e2d\u5143\u7d20\u7684\u6570\u636e\u7c7b\u578b\uff0celemsize<\/code>\u8868\u793a\u5176\u5927\u5c0f\u3002\u5f53chan\u5b9a\u4e49\u540e\uff0c\u5b83\u7684\u5143\u7d20\u7c7b\u578b\u662f\u56fa\u5b9a\u7684\uff0c\u5373\u666e\u901a\u7c7b\u578b\u6216\u8005\u6307\u9488\u7c7b\u578b\uff0c\u56e0\u6b64\u5143\u7d20\u5927\u5c0f\u4e5f\u662f\u56fa\u5b9a\u7684\u3002  
+\u00a0sendx<\/code>\uff1a\u5904\u7406\u53d1\u9001\u6570\u636e\u64cd\u4f5c\u7684\u6307\u9488\u5728buf\u961f\u5217\u4e2d\u7684\u4f4d\u7f6e\u3002\u5f53channel\u63a5\u6536\u5230\u4e86\u65b0\u7684\u6570\u636e\u65f6\uff0c\u8be5\u6307\u9488\u5c31\u4f1a\u52a0\u4e0aelemsize<\/code>\uff0c\u79fb\u52a8\u5230\u4e0b\u4e00\u4e2a\u4f4d\u7f6e\u3002buf<\/code>\u00a0\u7684\u603b\u5927\u5c0f\u662felemsize<\/code>\u7684\u6574\u6570\u500d\u4e14buf<\/code>\u662f\u4e00\u4e2a\u5faa\u73af\u5217\u8868\u3002  
+\u00a0recvx<\/code>\uff1a\u5904\u7406\u63a5\u6536\u6570\u636e\u64cd\u4f5c\u7684\u6307\u9488\u5728buf<\/code>\u961f\u5217\u4e2d\u7684\u4f4d\u7f6e\u3002\u5f53\u4ecebuf\u4e2d\u53d6\u51fa\u6570\u636e\uff0c\u6b64\u6307\u9488\u4f1a\u79fb\u52a8\u5230\u4e0b\u4e00\u4e2a\u4f4d\u7f6e\u3002  
+\u00a0recvq<\/code>\uff1a\u5f53\u63a5\u6536\u64cd\u4f5c\u53d1\u73b0channel<\/code>\u4e2d\u6ca1\u6709\u6570\u636e\u53ef\u8bfb\u65f6\uff0c\u4f1a\u88ab\u5219\u8272\uff0c\u6b64\u65f6\u4f1a\u88ab\u52a0\u5165\u5230recvq<\/code>\u961f\u5217\u4e2d\u3002  
+\u00a0sendq<\/code>\uff1a\u5f53\u53d1\u9001\u64cd\u4f5c\u53d1\u73b0buf<\/code>\u961f\u5217\u5df2\u6ee1\u65f6\uff0c\u4f1a\u88ab\u8fdb\u884c\u963b\u585e\uff0c\u6b64\u65f6\u4f1a\u88ab\u52a0\u5165\u5230sendq<\/code>\u961f\u5217\u4e2d\u3002  <\/p>\n
<p align=center><img src="https:\/\/p9-juejin.byteimg.com\/tos-cn-i-k3u1fbpfcp\/ddc1b911e2ac40b9ad73bff9647e4dc0~tplv-k3u1fbpfcp-jj-mark:0:0:0:0:q75.image#?w=395&h=524&s=37043&e=png&b=fbf7f6" alt="image.png"\u00a0\u00a0\/><\/p><\/p>\n
2\u3001chan\u521d\u59cb\u5316<\/h4>\n
channel<\/code>\u5728\u8fdb\u884c\u521d\u59cb\u5316\u65f6\uff0cGo\u7f16\u8bd1\u5668\u4f1a\u6839\u636e\u662f\u5426\u4f20\u5165\u5bb9\u91cf\u7684\u5927\u5c0f\uff0c\u6765\u9009\u62e9\u8c03\u7528makechan64<\/code>\uff0c\u8fd8\u662fmakechan<\/code>\u3002makechan64<\/code>\u5728\u5b9e\u73b0\u4e0a\u5e95\u5c42\u8fd8\u662f\u8c03\u7528makechan<\/code>\u6765\u8fdb\u884c\u521d\u59cb\u5316\uff0cmakechan64<\/code>\u53ea\u662f\u5bf9size<\/code>\u505a\u4e86\u68c0\u67e5\u3002  <\/p>\n
makechan<\/code>\u51fd\u6570\u6839\u636echan<\/code>\u7684\u5bb9\u91cf\u7684\u5927\u5c0f\u548c\u5143\u7d20\u7684\u7c7b\u578b\u4e0d\u540c\uff0c\u521d\u59cb\u5316\u4e0d\u540c\u7684\u5b58\u50a8\u7a7a\u95f4\u3002\u7701\u7565\u4e00\u4e9b\u68c0\u67e5\u4ee3\u7801\uff0cmakechan<\/code>\u51fd\u6570\u7684\u4e3b\u8981\u903b\u8f91\u5982\u4e0b\uff1a<\/p>\n
func makechan(t *chantype, size int) *hchan {  \n\u00a0\u00a0\u00a0\u00a0elem := t.elem  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0...  \n  \n\u00a0\u00a0\u00a0\u00a0mem, overflow := math.MulUintptr(elem.size, uintptr(size))  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0...  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0var c *hchan  \n\u00a0\u00a0\u00a0\u00a0switch {  \n\u00a0\u00a0\u00a0\u00a0case mem == 0:  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/ \u961f\u5217\u6216\u5143\u7d20\u5927\u5c0f\u4e3a\u96f6\uff0c\u4e0d\u5fc5\u521b\u5efabuf  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0c = (*hchan)(mallocgc(hchanSize, nil, true))  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0c.buf = c.raceaddr()  \n\u00a0\u00a0\u00a0\u00a0case elem.ptrdata == 0:  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/ \u5143\u7d20\u4e0d\u5305\u542b\u6307\u9488\uff0c\u5206\u914d\u4e00\u5757\u8fde\u7eed\u7684\u5185\u5b58\u7ed9hchan\u6570\u636e\u7ed3\u6784\u548cbuf  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/ hchan\u6570\u636e\u7ed3\u6784\u540e\u9762\u7d27\u63a5\u7740\u5c31\u662fbuf\uff0c\u5728\u4e00\u6b21\u8c03\u7528\u4e2d\u5206\u914dhchan\u548cbuf  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0c = (*hchan)(mallocgc(hchanSize+mem, nil, true))  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0c.buf = add(unsafe.Pointer(c), hchanSize)  \n\u00a0\u00a0\u00a0\u00a0default:  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/ \u5143\u7d20\u5305\u542b\u6307\u9488\uff0c\u5355\u72ec\u5206\u914dbuf  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0c = new(hchan)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0c.buf = mallocgc(mem, elem, true)  \n\u00a0\u00a0\u00a0\u00a0}  \n  \n\u00a0\u00a0\u00a0\u00a0\/\/ \u8bb0\u5f55\u5143\u7d20\u5927\u5c0f\u3001\u7c7b\u578b\u3001\u5bb9\u91cf  \n\u00a0\u00a0\u00a0\u00a0c.elemsize = uint16(elem.size)  \n\u00a0\u00a0\u00a0\u00a0c.elemtype = elem  \n\u00a0\u00a0\u00a0\u00a0c.dataqsiz = uint(size)  \n\u00a0\u00a0\u00a0\u00a0lockInit(&c.lock, lockRankHchan)  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0...  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0return c  \n}  <\/code><\/pre>\n
3\u3001send\u53d1\u9001\u64cd\u4f5c<\/h4>\n
Go\u5728\u7f16\u8bd1\u53d1\u9001\u6570\u636e\u7ed9channel<\/code>\u65f6\uff0c\u4f1a\u628a\u53d1\u9001\u64cd\u4f5csend<\/code>\u8f6c\u6362\u6210chansend1<\/code>\u51fd\u6570\uff0c\u800cchansend1<\/code>\u51fd\u6570\u4f1a\u8c03\u7528chansend<\/code>\u51fd\u6570\u3002<\/p>\n
func chansend1(c *hchan, elem unsafe.Pointer) {  \n\u00a0\u00a0\u00a0\u00a0chansend(c, elem, true, getcallerpc())  \n}  <\/code><\/pre>\n
\u6211\u4eec\u53ef\u4ee5\u6765\u5206\u6bb5\u5206\u6790chansend<\/code>\u51fd\u6570\u7684\u5b9e\u73b0\u903b\u8f91\u3002  <\/p>\n
\u7b2c\u4e00\u90e8\u5206:<\/strong>  <\/p>\n
\u4e3b\u8981\u662f\u5bf9chan<\/code>\u8fdb\u884c\u5224\u65ad\uff0c\u5224\u65adchan<\/code>\u662f\u5426\u4e3anil<\/code>\uff0c\u82e5\u4e3anil<\/code>\uff0c\u5219\u5224\u65ad\u662f\u5426\u9700\u8981\u5c06\u5f53\u524dgoroutine<\/code>\u8fdb\u884c\u963b\u585e\uff0c\u963b\u585e\u901a\u8fc7gopark<\/code>\u6765\u5bf9\u8c03\u7528\u8005goroutine park<\/code>(\u963b\u585e\u4f11\u7720)\u3002<\/p>\n
func chansend(c *hchan, ep unsafe.Pointer, block bool, callerpc uintptr) bool {  \n\u00a0\u00a0\u00a0\u00a0\/\/ \u7b2c\u4e00\u90e8\u5206  \n\u00a0\u00a0\u00a0\u00a0if c == nil { \/\/ \u5224\u65adchan\u662f\u5426\u4e3anil  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if !block { \/\/ \u5224\u65ad\u662f\u5426\u9700\u8981\u963b\u585e\u5f53\u524dgoroutine  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0return false  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/ \u8c03\u7528\u8fd9goroutine park\uff0c\u8fdb\u884c\u963b\u585e\u4f11\u7720  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0gopark(nil, nil, waitReasonChanSendNilChan, traceEvGoStop, 2)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0throw("unreachable")  \n\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0...  \n}  <\/code><\/pre>\n
\u7b2c\u4e8c\u90e8\u5206<\/strong>  <\/p>\n
\u7b2c\u4e8c\u90e8\u5206\u7684\u903b\u8f91\u5224\u65ad\u662f\u5f53\u4f60\u5f80\u4e00\u4e2a\u5bb9\u91cf\u5df2\u6ee1\u7684chan<\/code>\u5b9e\u4f8b\u53d1\u9001\u6570\u636e\uff0c\u4e14\u4e0d\u60f3\u5f53\u524d\u8c03\u7528\u7684goroutine<\/code>\u88ab\u963b\u585e\u65f6\uff08chan<\/code>\u672a\u88ab\u5173\u95ed\uff09\uff0c\u90a3\u4e48\u5904\u7406\u7684\u903b\u8f91\u662f\u76f4\u63a5\u8fd4\u56de\u3002<\/p>\n
func chansend(c *hchan, ep unsafe.Pointer, block bool, callerpc uintptr) bool {  \n\u00a0\u00a0\u00a0\u00a0...  \n\u00a0\u00a0\u00a0\u00a0\/\/ \u7b2c\u4e8c\u90e8\u5206  \n\u00a0\u00a0\u00a0\u00a0if !block && c.closed == 0 && full(c) {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0return false  \n\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0...  \n}  <\/code><\/pre>\n
\u7b2c\u4e09\u90e8\u5206<\/strong>  <\/p>\n
\u7b2c\u4e09\u90e8\u5206\u7684\u903b\u8f91\u5224\u65ad\u662f\u9996\u5148\u8fdb\u884c\u4e92\u65a5\u9501\u52a0\u9501\uff0c\u7136\u540e\u5224\u65ad\u5f53\u524dchan<\/code>\u662f\u5426\u5173\u95ed\uff0c\u5982\u679cchan<\/code>\u5df2\u7ecf\u88abclose<\/code>\u4e86\uff0c\u5219\u91ca\u653e\u4e92\u65a5\u9501\u5e76panic<\/code>\uff0c\u5373\u5bf9\u5df2\u5173\u95ed\u7684chan<\/code>\u53d1\u9001\u6570\u636e\u4f1apanic<\/code>\u3002<\/p>\n
func chansend(c *hchan, ep unsafe.Pointer, block bool, callerpc uintptr) bool {  \n\u00a0\u00a0\u00a0\u00a0...  \n\u00a0\u00a0\u00a0\u00a0\/\/ \u7b2c\u4e09\u90e8\u5206  \n\u00a0\u00a0\u00a0\u00a0lock(&c.lock) \/\/ \u5f00\u59cb\u52a0\u9501  \n  \n\u00a0\u00a0\u00a0\u00a0if c.closed != 0 { \/\/ \u5224\u65adchannel\u662f\u5426\u5173\u95ed  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0unlock(&c.lock)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0panic(plainError("send on closed channel"))  \n\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0...  \n}  <\/code><\/pre>\n
\u7b2c\u56db\u90e8\u5206<\/strong>  <\/p>\n
\u7b2c\u56db\u90e8\u5206\u7684\u903b\u8f91\u4e3b\u8981\u662f\u5224\u65ad\u63a5\u6536\u961f\u5217\u4e2d\u662f\u5426\u6709\u6b63\u5728\u7b49\u5f85\u7684\u63a5\u6536\u65b9receiver<\/code>\u3002\u5982\u679c\u5b58\u5728\u6b63\u5728\u7b49\u5f85\u7684receiver<\/code>\uff08\u8bf4\u660e\u6b64\u65f6buf<\/code>\u4e2d\u6ca1\u6709\u7f13\u5b58\u7684\u6570\u636e\uff09\uff0c\u5219\u5c06\u4ed6\u4ece\u63a5\u6536\u961f\u5217\u4e2d\u5f39\u51fa\uff0c\u76f4\u63a5\u5c06\u9700\u8981\u53d1\u9001\u5230channel<\/code>\u7684\u6570\u636e\u4ea4\u7ed9\u8fd9\u4e2areceiver<\/code>\uff0c\u800c\u65e0\u9700\u653e\u5165\u5230buf<\/code>\u4e2d\uff0c\u8ba9\u53d1\u9001\u64cd\u4f5c\u901f\u5ea6\u66f4\u5feb\u4e00\u4e9b\u3002<\/p>\n
func chansend(c *hchan, ep unsafe.Pointer, block bool, callerpc uintptr) bool {  \n\u00a0\u00a0\u00a0\u00a0...  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0\/\/ \u7b2c\u56db\u90e8\u5206  \n\u00a0\u00a0\u00a0\u00a0if sg := c.recvq.dequeue(); sg != nil {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/ \u627e\u5230\u4e86\u4e00\u4e2a\u6b63\u5728\u7b49\u5f85\u7684\u63a5\u6536\u8005\u3002\u6211\u4eec\u4f20\u9012\u6211\u4eec\u60f3\u8981\u53d1\u9001\u7684\u503c  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/ \u76f4\u63a5\u4f20\u9012\u7ed9receiver\u63a5\u6536\u8005\uff0c\u7ed5\u8fc7channel buf\u7f13\u5b58\u533a(\u5982\u679creceiver\u6709\u7684\u8bdd)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0send(c, sg, ep, func() { unlock(&c.lock) }, 3)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0return true  \n\u00a0\u00a0\u00a0\u00a0}  \n  \n\u00a0\u00a0\u00a0\u00a0...  \n}  <\/code><\/pre>\n
\u7b2c\u4e94\u90e8\u5206<\/strong>  <\/p>\n
\u5f53\u7b49\u5f85\u961f\u5217\u4e2d\u5e76\u6ca1\u6709\u6b63\u5728\u7b49\u5f85\u7684receiver<\/code>\uff0c\u5219\u8bf4\u660e\u5f53\u524dbuf<\/code>\u8fd8\u6ca1\u6709\u6ee1\uff0c\u6b64\u65f6\u5c06\u53d1\u9001\u7684\u6570\u636e\u653e\u5165\u5230buf<\/code>\u4e2d\u3002<\/p>\n
func chansend(c *hchan, ep unsafe.Pointer, block bool, callerpc uintptr) bool {  \n\u00a0\u00a0\u00a0\u00a0...  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0\/\/ \u7b2c\u4e94\u90e8\u5206  \n\u00a0\u00a0\u00a0\u00a0if c.qcount < c.dataqsiz { \/\/ \u5224\u65adbuf\u662f\u5426\u6ee1\u4e86  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/ channel buf\u8fd8\u6709\u53ef\u7528\u7684\u7a7a\u95f4. \u5c06\u53d1\u9001\u6570\u636e\u5165buf\u5faa\u73af\u961f\u5217.  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0qp := chanbuf(c, c.sendx)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if raceenabled {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0racenotify(c, c.sendx, nil)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0typedmemmove(c.elemtype, qp, ep)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0c.sendx++  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if c.sendx == c.dataqsiz {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0c.sendx = 0  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0c.qcount++  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0unlock(&c.lock)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0return true  \n\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0...  \n}  <\/code><\/pre>\n
\u7b2c\u516d\u90e8\u5206<\/strong>  <\/p>\n
\u5f53\u903b\u8f91\u8d70\u5230\u7b2c\u516d\u90e8\u5206\uff0c\u8bf4\u660e\u6b63\u5728\u5904\u7406buf<\/code>\u5df2\u6ee1\u7684\u60c5\u51b5\u3002\u5982\u679cbuf<\/code>\u5df2\u6ee1\uff0c\u5219\u53d1\u9001\u64cd\u4f5c\u7684goroutine<\/code>\u5c31\u4f1a\u52a0\u5165\u5230\u53d1\u9001\u8005\u7684\u7b49\u5f85\u961f\u5217\uff0c\u76f4\u5230\u88ab\u5524\u9192\u3002\u5f53goroutine<\/code>\u88ab\u5524\u9192\u65f6\uff0c\u6570\u636e\u6216\u8005\u88ab\u53d6\u8d70\u4e86\uff0c\u6216\u8005chan<\/code>\u5df2\u7ecf\u88ab\u5173\u95ed\u4e86\u3002<\/p>\n
func chansend(c *hchan, ep unsafe.Pointer, block bool, callerpc uintptr) bool {  \n\u00a0\u00a0\u00a0\u00a0...  \n\u00a0\u00a0\u00a0\u00a0\/\/ \u7b2c\u516d\u90e8\u5206  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0\/\/ chansend1\u51fd\u6570\u8c03\u7528\u4e0d\u4f1a\u8fdb\u5165if\u5757\u91cc\uff0c\u56e0\u4e3achansend1\u7684block=true  \n\u00a0\u00a0\u00a0\u00a0if !block {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0unlock(&c.lock)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0return false  \n\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0...  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0c.sendq.enqueue(mysg) \/\/ \u52a0\u5165\u53d1\u9001\u961f\u5217  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0...  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0gopark(chanparkcommit, unsafe.Pointer(&c.lock), waitReasonChanSend, traceEvGoBlockSend, 2) \/\/ \u963b\u585e  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0...  \n}  <\/code><\/pre>\n
4\u3001recv\u63a5\u6536\u64cd\u4f5c<\/h4>\n
\u4ecechannel<\/code>\u4e2d\u63a5\u6536\u6570\u636e\u65f6\uff0cGo\u4f1a\u5c06\u4ee3\u7801\u8f6c\u6362\u6210chanrecv1<\/code>\u51fd\u6570\u3002\u5982\u679c\u9700\u8981\u8fd4\u56de\u4e24\u4e2a\u8fd4\u56de\u503c\uff0c\u5219\u4f1a\u8f6c\u6362\u6210chanrecv2<\/code>\uff0cchanrecv1<\/code>\u51fd\u6570\u548cchanrecv2<\/code>\u90fd\u4f1a\u8c03\u7528chanrecv<\/code>\u51fd\u6570\u3002chanrecv1<\/code>\u548cchanrecv2<\/code>\u4f20\u5165\u7684\u00a0block<\/code>\u53c2\u6570\u7684\u503c\u662ftrue<\/code>\uff0c\u4e24\u79cd\u8c03\u7528\u90fd\u662f\u963b\u585e\u65b9\u5f0f\uff0c\u56e0\u6b64\u5728\u5206\u6790chanrecv<\/code>\u51fd\u6570\u7684\u5b9e\u73b0\u65f6\uff0c\u53ef\u4ee5\u4e0d\u8003\u8651\u00a0block=false<\/code>\u7684\u60c5\u51b5\u3002<\/p>\n
\/\/ \u4ece\u5df2\u7f16\u8bd1\u4ee3\u7801\u4e2d\u8fdb\u5165 <-c \u7684\u5165\u53e3\u70b9  \nfunc chanrecv1(c *hchan, elem unsafe.Pointer) {  \n\u00a0\u00a0\u00a0\u00a0chanrecv(c, elem, true)  \n}  \n  \nfunc chanrecv2(c *hchan, elem unsafe.Pointer) (received bool) {  \n\u00a0\u00a0\u00a0\u00a0_, received = chanrecv(c, elem, true)  \n\u00a0\u00a0\u00a0\u00a0return  \n}  <\/code><\/pre>\n
\u540c\u6837\uff0c\u7701\u7565\u4e00\u4e9b\u68c0\u67e5\u7c7b\u7684\u4ee3\u7801\uff0c\u6211\u4eec\u4e5f\u53ef\u4ee5\u5206\u6bb5\u5206\u6790chanrecv<\/code>\u51fd\u6570\u7684\u903b\u8f91\u3002  <\/p>\n
\u7b2c\u4e00\u90e8\u5206<\/strong>  <\/p>\n
\u7b2c\u4e00\u90e8\u5206\u4e3b\u8981\u5224\u65ad\u5f53\u524d\u8fdb\u884c\u63a5\u6536\u64cd\u4f5c\u7684chan<\/code>\u5b9e\u4f8b\u662f\u5426\u4e3anil<\/code>\uff0c\u82e5\u4e3anil<\/code>\uff0c\u5219\u4ecenil chan<\/code>\u4e2d\u63a5\u6536\u6570\u636e\u7684\u8c03\u7528\u8fd9goroutine<\/code>\u4f1a\u88ab\u963b\u585e\u3002<\/p>\n
func chanrecv(c *hchan, ep unsafe.Pointer, block bool) (selected, received bool) {  \n\u00a0\u00a0\u00a0\u00a0...  \n\u00a0\u00a0\u00a0\u00a0\/\/ \u7b2c\u4e00\u90e8\u5206  \n\u00a0\u00a0\u00a0\u00a0if c == nil { \/\/ \u5224\u65adchan\u662f\u5426\u4e3anil  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if !block { \/\/ \u662f\u5426\u963b\u585e\uff0c\u9ed8\u8ba4\u4e3ablock=true  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0return  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/ \u8fdb\u884c\u963b\u585e  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0gopark(nil, nil, waitReasonChanReceiveNilChan, traceEvGoStop, 2)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0throw("unreachable")  \n\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0...  \n}  <\/code><\/pre>\n
\u7b2c\u4e8c\u90e8\u5206<\/strong>  
\u8fd9\u4e00\u90e8\u5206\u53ea\u8981\u662f\u8003\u8651block=false<\/code>\u4e14c<\/code>\u4e3a\u7a7a\u7684\u60c5\u51b5\uff0cblock=false<\/code>\u7684\u60c5\u51b5\u6211\u4eec\u53ef\u4ee5\u4e0d\u505a\u8003\u8651\u3002<\/p>\n
func chanrecv(c *hchan, ep unsafe.Pointer, block bool) (selected, received bool) {  \n\u00a0\u00a0\u00a0\u00a0...  \n\u00a0\u00a0\u00a0\u00a0\/\/ \u68c0\u67e5\u672a\u83b7\u5f97\u9501\u7684\u5931\u8d25\u975e\u963b\u585e\u64cd\u4f5c\u3002  \n\u00a0\u00a0\u00a0\u00a0if !block && empty(c) {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0...  \n\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0...  \n}  <\/code><\/pre>\n
\u7b2c\u4e09\u90e8\u5206<\/strong>  <\/p>\n
\u7b2c\u4e09\u90e8\u5206\u7684\u903b\u8f91\u4e3a\u5224\u65ad\u5f53\u524dchan<\/code>\u662f\u5426\u88ab\u5173\u95ed\uff0c\u82e5\u5f53\u524dchan<\/code>\u5df2\u7ecf\u88abclose<\/code>\u4e86\uff0c\u5e76\u4e14\u7f13\u5b58\u961f\u5217\u4e2d\u6ca1\u6709\u7f13\u51b2\u7684\u5143\u7d20\u65f6\uff0c\u8fd4\u56detrue<\/code>\u3001false<\/code>\u3002<\/p>\n
func chanrecv(c *hchan, ep unsafe.Pointer, block bool) (selected, received bool) {  \n  \n\u00a0\u00a0\u00a0\u00a0...  \n\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0lock(&c.lock) \/\/ \u52a0\u9501\uff0c\u8fd4\u56de\u65f6\u91ca\u653e\u9501  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0\/\/ \u7b2c\u4e09\u90e8\u5206  \n\u00a0\u00a0\u00a0\u00a0if c.closed != 0 { \/\/ \u5f53chan\u5df2\u88ab\u5173\u95ed\u65f6  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if c.qcount == 0 { \/\/ \u4e14 buf\u533a \u6ca1\u6709\u7f13\u5b58\u7684\u6570\u636e\u4e86  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0...  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0unlock(&c.lock) \/\/ \u89e3\u9501  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if ep != nil {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0typedmemclr(c.elemtype, ep)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0return true, false  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0}\u00a0  \n\u00a0\u00a0\u00a0\u00a0...  \n}  <\/code><\/pre>\n
\u7b2c\u56db\u90e8\u5206<\/strong>  <\/p>\n
\u7b2c\u56db\u90e8\u5206\u662f\u5904\u7406\u901a\u9053\u672a\u5173\u95ed\u4e14buf<\/code>\u7f13\u5b58\u961f\u5217\u5df2\u6ee1\u7684\u60c5\u51b5\u3002\u53ea\u6709\u5f53\u7f13\u5b58\u961f\u5217\u5df2\u6ee1\u65f6\uff0c\u624d\u80fd\u591f\u4ece\u53d1\u9001\u7b49\u5f85\u961f\u5217\u83b7\u53d6\u5230sender<\/code>\u3002\u82e5\u5f53\u524d\u7684chan<\/code>\u4e3aunbuffer<\/code>\u7684chan<\/code>\uff0c\u5373\u65e0\u7f13\u51b2\u533achannel<\/code>\u65f6\uff0c\u5219\u76f4\u63a5\u5c06sender<\/code>\u7684\u53d1\u9001\u6570\u636e\u4f20\u9012\u7ed9receiver<\/code>\u3002\u5426\u5219\u5c31\u4ece\u7f13\u5b58\u961f\u5217\u7684\u5934\u90e8\u8bfb\u53d6\u4e00\u4e2a\u5143\u7d20\u503c\uff0c\u5e76\u5c06\u83b7\u53d6\u7684sender<\/code>\u643a\u5e26\u7684\u503c\u52a0\u5165\u5230buf<\/code>\u5faa\u73af\u961f\u5217\u7684\u5c3e\u90e8\u3002<\/p>\n
func chanrecv(c *hchan, ep unsafe.Pointer, block bool) (selected, received bool) {  \n\u00a0\u00a0\u00a0\u00a0...  \n\u00a0\u00a0\u00a0\u00a0if c.closed != 0 { \/\/ \u5f53chan\u5df2\u88ab\u5173\u95ed\u65f6  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0} else { \/\/ \u7b2c\u56db\u90e8\u5206\uff0c\u901a\u9053\u672a\u5173\u95ed  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/ \u5982\u679csendq\u961f\u5217\u4e2d\u6709\u7b49\u5f85\u53d1\u9001\u7684sender  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if sg := c.sendq.dequeue(); sg != nil {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/ \u5b58\u5728\u6b63\u5728\u7b49\u5f85\u7684sender\uff0c\u5982\u679c\u7f13\u5b58\u533a\u7684\u5bb9\u91cf\u4e3a0\u5219\u76f4\u63a5\u5c06\u53d1\u9001\u65b9\u7684\u503c\u4f20\u9012\u7ed9\u63a5\u6536\u65b9  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/ \u53cd\u4e4b\uff0c\u5219\u4ece\u7f13\u5b58\u961f\u5217\u7684\u5934\u90e8\u83b7\u53d6\u6570\u636e\uff0c\u5e76\u5c06\u83b7\u53d6\u7684sender\u7684\u53d1\u9001\u503c\u52a0\u5165\u5230\u7f13\u5b58\u961f\u5217\u5c3e\u90e8  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0recv(c, sg, ep, func() { unlock(&c.lock) }, 3)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0return true, true  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0...  \n}  <\/code><\/pre>\n
\u7b2c\u4e94\u90e8\u5206<\/strong>  <\/p>\n
\u7b2c\u4e94\u90e8\u5206\u7684\u4e3b\u8981\u903b\u8f91\u662f\u5904\u7406\u53d1\u9001\u961f\u5217\u4e2d\u6ca1\u6709\u7b49\u5f85\u7684sender<\/code>\u4e14buf<\/code>\u4e2d\u6709\u7f13\u5b58\u7684\u6570\u636e\u3002\u8be5\u6bb5\u903b\u8f91\u4e0e\u5916\u51fa\u7684\u4e92\u65a5\u9501\u5171\u7528\u4e00\u628a\u9501\uff0c\u56e0\u6b64\u4e0d\u5b58\u5728\u5e76\u53d1\u95ee\u9898\u3002\u5f53buf<\/code>\u7f13\u5b58\u533a\u6709\u7f13\u5b58\u5143\u7d20\u65f6\uff0c\u5219\u53d6\u51fa\u8be5\u5143\u7d20\u4f20\u9012\u7ed9receiver<\/code>\uff0c\u540c\u65f6\u79fb\u52a8\u63a5\u6536\u6307\u9488\u3002<\/p>\n
func chanrecv(c *hchan, ep unsafe.Pointer, block bool) (selected, received bool) {  \n\u00a0\u00a0\u00a0\u00a0...  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0\/\/ \u7b2c\u4e94\u90e8\u5206  \n\u00a0\u00a0\u00a0\u00a0if c.qcount > 0 { \/\/ \u53d1\u9001\u961f\u5217\u4e2d\u6ca1\u6709\u7b49\u5f85\u7684sender\uff0c\u4e14buf\u4e2d\u6709\u7f13\u5b58\u6570\u636e  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/ \u76f4\u63a5\u4ece\u7f13\u5b58\u961f\u5217\u4e2d\u83b7\u53d6\u6570\u636e  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0qp := chanbuf(c, c.recvx)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if raceenabled {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0racenotify(c, c.recvx, nil)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if ep != nil {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0typedmemmove(c.elemtype, ep, qp)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0typedmemclr(c.elemtype, qp)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0c.recvx++ \/\/ \u79fb\u52a8\u63a5\u6536\u6307\u9488  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if c.recvx == c.dataqsiz { \/\/ \u6307\u9488\u82e5\u5df2\u5230\u672b\u5c3e\u5219\u8fdb\u884c\u91cd\u7f6e(\u5faa\u73af\u961f\u5217)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0c.recvx = 0  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0c.qcount-- \/\/ \u83b7\u53d6\u6570\u636e\u540e\uff0cbuf\u7f13\u5b58\u533a\u5143\u7d20\u4e2a\u6570\u51cf\u4e00  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0unlock(&c.lock) \/\/ \u89e3\u9501  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0return true, true  \n\u00a0\u00a0\u00a0\u00a0}  \n  \n\u00a0\u00a0\u00a0\u00a0if !block { \/\/ block=true  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0unlock(&c.lock)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0return false, false  \n\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0...  \n}  <\/code><\/pre>\n
\u7b2c\u516d\u90e8\u5206<\/strong>  <\/p>\n
\u7b2c\u516d\u90e8\u5206\u7684\u903b\u8f91\u4e3b\u8981\u662f\u5904\u7406buf<\/code>\u7f13\u5b58\u533a\u4e2d\u6ca1\u6709\u7f13\u5b58\u6570\u636e\u7684\u60c5\u51b5\u3002\u5f53buf<\/code>\u7f13\u5b58\u533a\u6ca1\u6709\u7f13\u5b58\u6570\u636e\u65f6\uff0c\u90a3\u4e48\u5f53\u524d\u7684receiver<\/code>\u5c31\u4f1a\u88ab\u963b\u585e\uff0c\u76f4\u5230\u5b83\u4ecesender<\/code>\u4e2d\u63a5\u6536\u4e86\u6570\u636e\uff0c\u6216\u8005\u662fchan<\/code>\u88abclose<\/code>\uff0c\u624d\u4f1a\u8fd4\u56de\u3002<\/p>\n
func chanrecv(c *hchan, ep unsafe.Pointer, block bool) (selected, received bool) {  \n\u00a0\u00a0\u00a0\u00a0...  \n\u00a0\u00a0\u00a0\u00a0c.recvq.enqueue(mysg) \/\/ \u5c06\u5f53\u524d\u63a5\u6536\u64cd\u4f5c\u5165\u63a5\u6536\u961f\u5217  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0...  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0\/\/ \u8fdb\u884c\u963b\u585e\uff0c\u7b49\u5f85\u5524\u9192  \n\u00a0\u00a0\u00a0\u00a0gopark(chanparkcommit, unsafe.Pointer(&c.lock), waitReasonChanReceive, traceEvGoBlockRecv, 2)  \n\u00a0\u00a0\u00a0\u00a0...  \n}  <\/code><\/pre>\n
5\u3001close\u5173\u95ed<\/h4>\n
close<\/code>\u51fd\u6570\u4e3b\u8981\u7528\u4e8echannel<\/code>\u7684\u5173\u95ed\uff0cGo\u7f16\u8bd1\u5668\u4f1a\u66ff\u6362\u6210closechan<\/code>\u51fd\u6570\u7684\u8c03\u7528\u3002\u7701\u7565\u4e00\u4e9b\u68c0\u67e5\u4e0b\u7684\u4ee3\u7801\u540e\uff0cclosechan<\/code>\u51fd\u6570\u7684\u4e3b\u8981\u903b\u8f91\u5982\u4e0b\uff1a  
+\u00a0\u5982\u679c\u5f53\u524dchan<\/code>\u4e3anil<\/code>\uff0c\u5219\u76f4\u63a5panic<\/code>  
+\u00a0\u5982\u679c\u5f53\u524dchan<\/code>\u5df2\u5173\u95ed\uff0c\u518d\u6b21close<\/code>\u5219\u76f4\u63a5panic<\/code>  
+\u00a0\u5982\u679cchan<\/code>\u4e0d\u4e3anil<\/code>\uff0cchan<\/code>\u4e5f\u6ca1\u6709closed<\/code>\uff0c\u5c31\u628a\u7b49\u5f85\u961f\u5217\u4e2d\u7684 sender\uff08writer\uff09<\/code>\u548c\u00a0receiver\uff08reader\uff09<\/code>\u4ece\u961f\u5217\u4e2d\u5168\u90e8\u79fb\u9664\u5e76\u5524\u9192\u3002<\/p>\n
func closechan(c *hchan) {  \n\u00a0\u00a0\u00a0\u00a0if c == nil { \/\/ \u82e5\u5f53\u524dchan\u672anil\uff0c\u5219\u76f4\u63a5panic  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0panic(plainError("close of nil channel"))  \n\u00a0\u00a0\u00a0\u00a0}  \n  \n\u00a0\u00a0\u00a0\u00a0lock(&c.lock) \/\/ \u52a0\u9501  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0if c.closed != 0 { \/\/ \u82e5\u5f53\u524dchan\u5df2\u7ecf\u5173\u95ed\uff0c\u5219\u76f4\u63a5panic  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0unlock(&c.lock)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0panic(plainError("close of closed channel"))  \n\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0  \n\u00a0\u00a0\u00a0\u00a0...  \n  \n\u00a0\u00a0\u00a0\u00a0c.closed = 1 \/\/ \u8bbe\u7f6e\u5f53\u524dchannel\u7684\u72b6\u6001\u4e3a\u5df2\u5173\u95ed  \n  \n\u00a0\u00a0\u00a0\u00a0var glist gList  \n  \n\u00a0\u00a0\u00a0\u00a0\/\/ \u91ca\u653e\u63a5\u6536\u961f\u5217\u4e2d\u6240\u6709\u7684reader  \n\u00a0\u00a0\u00a0\u00a0for {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0sg := c.recvq.dequeue()  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if sg == nil {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0break  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if sg.elem != nil {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0typedmemclr(c.elemtype, sg.elem)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0sg.elem = nil  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if sg.releasetime != 0 {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0sg.releasetime = cputicks()  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0gp := sg.g  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0gp.param = unsafe.Pointer(sg)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0sg.success = false  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if raceenabled {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0raceacquireg(gp, c.raceaddr())  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0glist.push(gp)  \n\u00a0\u00a0\u00a0\u00a0}  \n  \n\u00a0\u00a0\u00a0\u00a0\/\/ \u91ca\u653e\u53d1\u9001\u961f\u5217\u4e2d\u6240\u6709\u7684writer (\u5b83\u4eec\u4f1apanic)  \n\u00a0\u00a0\u00a0\u00a0for {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0sg := c.sendq.dequeue()  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if sg == nil {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0break  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0sg.elem = nil  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if sg.releasetime != 0 {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0sg.releasetime = cputicks()  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0gp := sg.g  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0gp.param = unsafe.Pointer(sg)  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0sg.success = false  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if raceenabled {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0raceacquireg(gp, c.raceaddr())  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0glist.push(gp)  \n\u00a0\u00a0\u00a0\u00a0}  \n\u00a0\u00a0\u00a0\u00a0unlock(&c.lock)  \n  \n\u00a0\u00a0\u00a0\u00a0for !glist.empty() {  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0gp := glist.pop()  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0gp.schedlink = 0  \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0goready(gp, 3)  \n\u00a0\u00a0\u00a0\u00a0}  \n}  <\/code><\/pre>\n
\u4e09\u3001\u603b\u7ed3<\/h3>\n
\u901a\u8fc7\u5b66\u4e60channel<\/code>\u7684\u57fa\u672c\u4f7f\u7528\uff0c\u4e86\u89e3\u5176\u64cd\u4f5c\u80cc\u540e\u7684\u5b9e\u73b0\u539f\u7406\uff0c\u53ef\u4ee5\u5e2e\u52a9\u6211\u4eec\u66f4\u597d\u7684\u4f7f\u7528channel<\/code>\uff0c\u907f\u514d\u4e00\u4e9b\u64cd\u4f5c\u4e0d\u5f53\u800c\u5bfc\u81f4\u7684panic<\/code>\u6216\u8005\u8bf4\u662fbug<\/code>\uff0c\u8ba9\u6211\u4eec\u5728\u4f7f\u7528channel<\/code>\u65f6\u80fd\u591f\u66f4\u52a0\u7684\u5f97\u5fc3\u5e94\u624b\u3002  <\/p>\n
channel<\/code>\u7684\u503c\u548c\u72b6\u6001\u6709\u591a\u79cd\u60c5\u51b5\uff0c\u800c\u4e0d\u540c\u7684\u64cd\u4f5c\uff08send\u3001recv\u3001close\uff09<\/code>\u53c8\u53ef\u80fd\u5f97\u5230\u4e0d\u540c\u7684\u7ed3\u679c\uff0c\u8fd9\u662f\u4f7f\u7528\u00a0channel<\/code>\u00a0\u7c7b\u578b\u65f6\u9700\u8981\u7ecf\u5e38\u6ce8\u610f\u7684\u70b9\uff0c\u6211\u4eec\u53ef\u4ee5\u5c06\u4e0d\u540cchannel<\/code>\u503c\u4e0b\u7684\u4e0d\u540c\u64cd\u4f5c\u8fdb\u884c\u4e00\u4e2a\u603b\u7ed3\uff0c\u7279\u522b\u6ce8\u610f\u64cd\u4f5cchannel<\/code>\u65f6\u4f1a\u4ea7\u751fpanic<\/code>\u7684\u60c5\u51b5\uff0c\u5df2\u7ecf\u53ef\u80fd\u4f1a\u5bfc\u81f4\u7ebf\u7a0b\u963b\u585e\u7684\u60c5\u51b5<\/strong>\uff0c\u90fd\u662f\u6709\u53ef\u80fd\u5bfc\u81f4\u6b7b\u9501\u4e0egoroutine<\/code>\u6cc4\u6f0f\u7684\u7f6a\u9b41\u7978\u9996\u3002  <\/p>\n
| channel\u6267\u884c\u64cd\u4f5c\/channel\u72b6\u6001 | channel\u4e3anil | channel buf\u4e3a\u7a7a\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0| channel buf\u5df2\u6ee1\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0| channel buf\u672a\u6ee1\u4e14\u4e0d\u4e3a\u7a7a\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0| channel\u5df2\u5173\u95ed\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0|  
| ————————— | ———— | —————————— | —————————– | —————————– | ——————- |  
|\u00a0receive<\/code>\u63a5\u6536\u64cd\u4f5c\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0| \u963b\u585e\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0| \u963b\u585e\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0| \u8bfb\u53d6\u6570\u636e\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0| \u8bfb\u53d6\u6570\u636e\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0| \u8fd4\u56debuf\u4e2d\u7f13\u5b58\u7684\u6570\u636e |  
|\u00a0send<\/code>\u53d1\u9001\u64cd\u4f5c\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0| \u963b\u585e\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0| \u5199\u5165\u6570\u636e\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0| \u963b\u585e\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0| \u5199\u5165\u6570\u636e\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0|\u00a0panic<\/strong>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0|  
|\u00a0close<\/code>\u5173\u95ed\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0|\u00a0panic<\/strong>\u00a0\u00a0\u00a0\u00a0| \u5173\u95edchannel\uff0cbuf\u4e2d\u6ca1\u6709\u7f13\u5b58\u6570\u636e | \u5173\u95edchannel\uff0c\u4fdd\u7559\u5df2\u7f13\u5b58\u7684\u6570\u636e | \u5173\u95edchannel\uff0c\u4fdd\u7559\u5df2\u7f13\u5b58\u7684\u6570\u636e |\u00a0panic<\/strong><\/p>\n
\u53c8\u51fa\u6210\u7ee9\u5566<\/h3>\n
\u6211\u4eec\u53c8\u51fa\u6210\u7ee9\u5566\uff01\u5927\u5382Offer\u96c6\u9526\uff01\u9065\u9065\u9886\u5148\uff01<\/a><\/p>\n
\u8fd9\u4e9b\u670b\u53cb\u8d62\u9ebb\u4e86\uff01<\/a> <\/p>\n
\u8fd9\u662f\u4e00\u4e2a\u4e13\u6ce8\u7a0b\u5e8f\u5458\u5347\u804c\u52a0\u85aa\u306e\u77e5\u8bc6\u661f\u7403<\/a><\/p>\n
\u7b54\u7591\u89e3\u60d1<\/h3>\n
\u9700\u8981\u300c\u7b80\u5386\u4f18\u5316\u300d\u3001\u300c\u5c31\u4e1a\u8f85\u5bfc\u300d\u3001\u300c\u804c\u4e1a\u89c4\u5212\u300d\u7684\u670b\u53cb\u53ef\u4ee5\u8054\u7cfb\u6211\u3002<\/p>\n
\u52a0\u6211\u5fae\u4fe1\uff1awangzhongyang1993<\/strong><\/p>\n
\u5173\u6ce8\u6211\u7684\u540c\u540d\u516c\u4f17\u53f7\uff1a\u738b\u4e2d\u9633Go<\/a><\/p>\n
https:\/\/segmentfault.com\/a\/1190000044644615<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
\u672c\u6587\u6765\u81ea Go\u5c31\u4e1a\u8bad\u7ec3\u8425 \u5c0f\u97ec\u540c\u5b66\u7684\u6295\u7a3f\u3002 \u4e5f\u5f3a\u70c8\u5b89\u5229\u5927\u5bb6\u591a\u5199\u535a\u5ba2\uff0c\u4e0d\u4ec5\u80fd\u5012\u903c\u81ea\u5df1\u5b66\u4e60\u603b\u7ed3\uff0c\u4e5f\u80fd\u4f5c\u4e3a\u7b80\u5386\u7684\u52a0\u5206 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[4],"tags":[],"class_list":["post-10008391","post","type-post","status-publish","format-standard","hentry","category-share"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10008391","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10008391"}],"version-history":[{"count":0,"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10008391\/revisions"}],"wp:attachment":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10008391"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10008391"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10008391"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}