\u6211\u4eec\u4f7f\u7528 WaitGroup \u6765\u89e3\u51b3\u5f53\u524d\u534f\u7a0b\u5206\u7ec4\u540c\u6b65\u7684\u95ee\u9898\uff0c\u5b83\u5f88\u597d\u5730\u5b9e\u73b0\u4e86\u4efb\u52a1\u540c\u6b65\uff0c\u4f46\u662f\u5374\u65e0\u6cd5\u8fd4\u56de\u9519\u8bef\u3002\u5f53\u4e00\u7ec4\u534f\u7a0b\u4e2d\u7684\u67d0\u4e00\u4e2a\u534f\u7a0b\u51fa\u9519\u65f6\uff0c\u6211\u4eec\u662f\u65e0\u6cd5\u611f\u77e5\u5230\u7684\u3002\u4e3a\u4e86\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0c\u5b98\u65b9\u63d0\u4f9b\u4e86 errgroup\uff08golang.org\/x\/sync\/errgroup\uff09\u5305\uff0c\u5b83\u662f\u5bf9WaitGroup \u8fdb\u884c\u4e86\u5c01\u88c5\uff0c\u652f\u6301\u8fd4\u56de\u534f\u7a0b\u9047\u5230\u7684\u7b2c\u4e00\u4e2a\u9519\u8bef\u3002<\/p>\n
\u5728errgroup\u5305\u4e0b\u5b9a\u4e49\u4e86\u4e00\u4e2aGroup \u7ed3\u6784\u4f53\uff0c\u5b83\u5c31\u662f\u6211\u4eec\u8981\u4ecb\u7ecd\u7684ErrGroup\u5e76\u53d1\u539f\u8bed\uff0c\u5b9a\u4e49\u5982\u4e0b\uff1a<\/p>\n
\/\/ Group \u7b49\u5f85\u7ec4\u7ed3\u6784\u4f53\u5b9a\u4e49\ntype Group struct {\n cancel func() \/\/\u7528\u4e8e\u63a7\u5236\u9047\u5230err\u540e\u4e0d\u518d\u6267\u884c\u540e\u7eed\u51fd\u6570\n wg sync.WaitGroup \/\/\u7b49\u5f85\u6240\u6709g\u6267\u884c\u5b8c\u6bd5\n errOnce sync.Once \/\/\u4fdd\u8bc1\u53ea\u8bb0\u5f55\u7b2c\u4e00\u4e2aerr\n err error \/\/\u8bb0\u5f55\u9047\u5230\u7684\u7b2c\u4e00\u4e2aerr\n}\n<\/code><\/pre>\n\u5728\u4f7f\u7528ErrGroup\u65f6\uff0c\u8981\u7528\u5230\u4e09\u4e2a\u65b9\u6cd5\uff0c\u5206\u522b\u662fWithContext\u3001Go\u548cWait\u3002<\/p>\n
\/\/ WithContext \u6839\u636e\u4f20\u5165\u7684ctx\u8fd4\u56deGroup\u548c\u65b0\u7684ctx\n\/\/\u53ef\u4ee5\u7b80\u5355\u7406\u89e3\u6210\u662f\u4e00\u4e2a New \u65b9\u6cd5\uff0c\u8fd4\u56de Group \u7ed3\u6784\u4f53\u6307\u9488\uff0c\u7528\u4e8e\u8c03\u7528 Go \u548c Wait \u65b9\u6cd5\uff0c\n\/\/\u8fd9\u91cc\u9700\u8981\u6ce8\u610f\uff0c\u867d\u7136\u7b2c\u4e8c\u4e2a\u53c2\u6570\u8fd4\u56de ctx\uff0c\u4f46\u8fd9\u91cc\u5df2\u7ecf\u4e0d\u662f\u6211\u4eec\u4f20\u8fdb\u53bb\u7684 ctx \u4e86\uff0c\u662f\u901a\u8fc7 WithCancel\uff0c\u65b9\u6cd5\u751f\u6210\u4e86\u5168\u65b0\u7684 ctx\uff0c\u6240\u4ee5\u5927\u591a\u6570\u573a\u666f\u6211\u4eec\u5e76\u4e0d\u9700\u8981\u63a5\u53d7\u4e86\u7b2c\u4e8c\u4e2a\u8fd4\u56de\u53c2\u6570\u3002\n\/\/\u4e0d\u8fc7\u6709\u4e9b\u573a\u666f\u53ef\u4ee5\u901a\u8fc7\u8fd4\u56de\u7684 ctx.Done() \u6765\u76d1\u542c\u6bcf\u4e00\u4e2a goroutine \u7ed3\u675f\u3002\nfunc WithContext(ctx context.Context) (*Group, context.Context) {\n ctx, cancel := context.WithCancel(ctx)\n return &Group{cancel: cancel}, ctx\n}\n\n\n\/\/ Go \u542f\u52a8\u4e00\u4e2a\u65b0g\u6267\u884c\u7ed9\u5b9a\u65b9\u6cd5\n\/\/\u6267\u884c\u6211\u4eec\u81ea\u5b9a\u4e49\u7684\u65b9\u6cd5\uff0c\u4f46\u5fc5\u987b\u8fd4\u56de err\uff0c\u8fd9\u91cc\u6211\u4eec\u53d1\u73b0\u901a\u8fc7 sync.Once.Do \u65b9\u6cd5\uff0c\u7528\u6765\u4fdd\u8bc1\u53ea\u5c06\u7b2c\u4e00\u4e2a\u9047\u5230\u7684 err \u8bb0\u5f55\u5e76\u8fd4\u56de\u3002\nfunc (g *Group) Go(f func() error) {\n g.wg.Add(1)\n\n go func() {\n defer g.wg.Done()\n\n if err := f(); err != nil {\n g.errOnce.Do(func() {\n g.err = err\n if g.cancel != nil {\n g.cancel()\n }\n })\n }\n }()\n}\n\n\/\/ Wait \u7b49\u5f85\u6240\u6709g\u6267\u884c\u5b8c\u6bd5\uff0c\u6216\u5728\u67d0\u4e2ag\u6267\u884c\u5931\u8d25\u8fd4\u56de\u7b2c\u4e00\u4e2aerr\n\/\/\u901a\u8fc7 WaitGroup \u7b49\u5f85\u6240\u6709 goroutine \u7ed3\u675f\uff0c\u5e76\u8fd4\u56de\u9047\u5230\u7684\u7b2c\u4e00\u4e2a err\u3002\nfunc (g *Group) Wait() error {\n g.wg.Wait()\n if g.cancel != nil {\n g.cancel()\n }\n return g.err\n}\n<\/code><\/pre>\n\u4f7f\u7528\u793a\u4f8b\uff1a<\/p>\n
func main() {\n eg, ctx := errgroup.WithContext(context.Background())\n for i := 0; i < 100; i++ {\n i := i\n eg.Go(func() error {\n time.Sleep(2 * time.Second)\n select {\n case <-ctx.Done():\n fmt.Println(\"Canceled:\", i)\n return nil\n default:\n fmt.Println(\"End:\", i)\n return nil\n }})}\n if err := eg.Wait(); err != nil {\n log.Fatal(err)\n }\n}\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"\u6211\u4eec\u4f7f\u7528 WaitGroup \u6765\u89e3\u51b3\u5f53\u524d\u534f\u7a0b\u5206\u7ec4\u540c\u6b65\u7684\u95ee\u9898\uff0c\u5b83\u5f88\u597d\u5730\u5b9e\u73b0\u4e86\u4efb\u52a1\u540c\u6b65\uff0c\u4f46\u662f\u5374\u65e0\u6cd5\u8fd4\u56de\u9519\u8bef\u3002\u5f53\u4e00\u7ec4…<\/p>\n Read More<\/span> errGroup<\/span><\/a>","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"Layout":"","footnotes":""},"categories":[12],"tags":[],"class_list":["entry","author-suredandan","post-403","post","type-post","status-publish","format-standard","category-golang"],"views":1638,"_links":{"self":[{"href":"https:\/\/www.db2go.net\/index.php?rest_route=\/wp\/v2\/posts\/403","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.db2go.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.db2go.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.db2go.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.db2go.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=403"}],"version-history":[{"count":1,"href":"https:\/\/www.db2go.net\/index.php?rest_route=\/wp\/v2\/posts\/403\/revisions"}],"predecessor-version":[{"id":404,"href":"https:\/\/www.db2go.net\/index.php?rest_route=\/wp\/v2\/posts\/403\/revisions\/404"}],"wp:attachment":[{"href":"https:\/\/www.db2go.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=403"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.db2go.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=403"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.db2go.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=403"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}