{"id":207661,"date":"2025-07-08T11:48:47","date_gmt":"2025-07-08T03:48:47","guid":{"rendered":"https:\/\/server.hk\/cnblog\/207661\/"},"modified":"2025-07-08T11:48:47","modified_gmt":"2025-07-08T03:48:47","slug":"go-%e5%87%bd%e6%95%b0%e4%b8%ad%e5%85%b7%e6%9c%89%e5%91%bd%e5%90%8d%e8%bf%94%e5%9b%9e%e5%80%bc%e7%9a%84%e6%95%b0%e6%8d%ae%e7%ab%9e%e4%ba%89%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/207661\/","title":{"rendered":"Go \u51fd\u6570\u4e2d\u5177\u6709\u547d\u540d\u8fd4\u56de\u503c\u7684\u6570\u636e\u7ade\u4e89\uff1f"},"content":{"rendered":"

<\/b> <\/p>\n

\u5f53\u524d\u4f4d\u7f6e\uff1a ><\/span> ><\/span> ><\/span> ><\/span> Go \u51fd\u6570\u4e2d\u5177\u6709\u547d\u540d\u8fd4\u56de\u503c\u7684\u6570\u636e\u7ade\u4e89\uff1f<\/span><\/p>\n

\u6765\u6e90\uff1astackoverflow<\/span>
\n2024-04-24 13:18:34<\/span>
\n<\/i>0\u6d4f\u89c8<\/span>
\n<\/i>\u6536\u85cf<\/span> <\/p>\n

\u5927\u5bb6\u597d\uff0c\u4eca\u5929\u672c\u4eba\u7ed9\u5927\u5bb6\u5e26\u6765\u6587\u7ae0\u300aGo \u51fd\u6570\u4e2d\u5177\u6709\u547d\u540d\u8fd4\u56de\u503c\u7684\u6570\u636e\u7ade\u4e89\uff1f\u300b<\/span>\uff0c\u6587\u4e2d\u5185\u5bb9\u4e3b\u8981\u6d89\u53ca\u5230<\/span><\/span>\uff0c\u5982\u679c\u4f60\u5bf9Golang<\/span>\u65b9\u9762\u7684\u77e5\u8bc6\u70b9\u611f\u5174\u8da3\uff0c\u90a3\u5c31\u8bf7\u5404\u4f4d\u670b\u53cb\u7ee7\u7eed\u770b\u4e0b\u53bb\u5427~\u5e0c\u671b\u80fd\u771f\u6b63\u5e2e\u5230\u4f60\u4eec\uff0c\u8c22\u8c22\uff01<\/p>\n

\u95ee\u9898\u5185\u5bb9
\n <\/p>\n

\u95ee\u9898<\/h1>\n

\u8fd4\u56de\u65b0\u9519\u8bef baz<\/code> \u65f6\uff0c\u4ee5\u4e0b\u4ee3\u7801\u4e2d qux()<\/code> \u5199\u5165 err<\/code> \u4e4b\u95f4\u662f\u5426\u5b58\u5728\u4e0d\u660e\u663e\u7684\u6570\u636e\u4e89\u7528\uff1f go \u5bf9\u6307\u5b9a\u8fd4\u56de\u503c\u7684\u5185\u90e8\u5904\u7406\u662f\u5426\u53ef\u80fd\u5c06\u65b0\u53d8\u91cf\u7684\u663e\u5f0f\u8fd4\u56de\u89c6\u4e3a\u5bf9\u6307\u5b9a\u8fd4\u56de\u503c\u7684\u4e8b\u5b9e\u4e0a\u7684\u8d4b\u503c\uff0c\u4ece\u800c\u5141\u8bb8\u6b64\u5904\u51fa\u73b0\u6570\u636e\u7ade\u4e89\uff1f<\/p>\n

func foo(baz time.duration) (bar *bar, err error) {\n    done := make(chan struct{})\n    \n    go func() {\n        bar, err = qux()\n        close(done)\n    }()\n\n    select {\n    case <-done:\n        return\n    case <-time.after(baz):\n        return nil, errors.new(\"baz\")\n    }\n}\n<\/pre>\n
\u8fd9\u5bf9\u6211\u6765\u8bf4\u6ca1\u6709\u4efb\u4f55\u610f\u4e49\uff0c\u56e0\u4e3a\u6211\u5e0c\u671b\u4e0a\u9762\u4ee3\u7801\u4e2d\u7684 errors.new()<\/code> \u7684\u7ed3\u679c\u5e94\u8be5\u5206\u914d\u5230\u4e0e\u9884\u521d\u59cb\u5316\u7684 err<\/code> \u4e0d\u540c\u7684\u5730\u5740\u3002\u7136\u800c\uff0c\u6211\u6709\u7406\u7531\u6000\u7591\u8fd9\u6b63\u662f\u53d1\u751f\u5728\u6211\u8eab\u4e0a\u7684\u4e8b\u60c5\u3002<\/p>\n
\u80cc\u666f<\/h1>\n
\u6211\u4eec\u7684\u4e00\u9879\u670d\u52a1\u6bcf\u79d2\u5728\u96c6\u7fa4\u4e2d\u7684\u591a\u4e2a pod \u4e0a\u6267\u884c\u4e0d\u5230 50 \u4e07\u4e2a http \u8bf7\u6c42\u3002\u5e73\u5747\u6bcf 5 \u4ebf\u5de6\u53f3\u7684\u8bf7\u6c42\u4e2d\uff0c\u6211\u4eec\u5728\u68c0\u67e5\u6807\u51c6\u5e93\u4e2d\u7684\u5305\u88c5\u9519\u8bef\u65f6\u4f1a\u53d1\u751f\u4e00\u6b21\u4e0d\u53ef\u6062\u590d\u7684\u6545\u969c\u6050\u614c\u3002\u5f53\u975e\u96f6\u6307\u9488\u6307\u5411\u9519\u8bef\u7684\u5185\u5b58\u5730\u5740\u65f6\uff0c\u901a\u5e38\u4f1a\u53d1\u751f\u8fd9\u79cd\u60c5\u51b5\uff0c\u8fd9\u8868\u660e\u5b58\u5728\u5e76\u53d1\u5199\u5165\u3002<\/p>\n
unexpected fault address 0x0\nfatal error: fault\n[signal sigsegv: segmentation violation code=0x80 addr=0x0 pc=0x40ebfa]\n\ngoroutine 7431988 [running]:\nruntime.throw(0x1bcf57c, 0x5)\n    \/usr\/local\/go\/src\/runtime\/panic.go:1116 +0x72 fp=0xc0026e8d38 sp=0xc0026e8d08 pc=0x43bef2\nruntime.sigpanic()\n    \/usr\/local\/go\/src\/runtime\/signal_unix.go:727 +0x405 fp=0xc0026e8d68 sp=0xc0026e8d38 pc=0x452805\nruntime.getitab(0x195cae0, 0xe93824548b483024, 0x1, 0x7f7fc8037af8)\n    \/usr\/local\/go\/src\/runtime\/iface.go:39 +0x3a fp=0xc0026e8db8 sp=0xc0026e8d68 pc=0x40ebfa\nruntime.asserti2i2(0x195cae0, 0xdcd388, 0x0, 0x7f7fc8037af8, 0xc018808a20, 0xc012bbaa01)\n    \/usr\/local\/go\/src\/runtime\/iface.go:472 +0x6a fp=0xc0026e8de8 sp=0xc0026e8db8 pc=0x41004a\nerrors.is(0x1dd3f20, 0xc0120b6780, 0x1dd2a60, 0xc00003c1c0, 0xc019510c60)\n    \/usr\/local\/go\/src\/runtime\/wrap.go:49 +0xd8 fp=0xc0026e8e50 sp=0xc0026e8de8 pc=0xaacbf8<\/pre>\n
\u6211\u4eec\u8fd0\u884c\u7684\u4ee3\u7801\u770b\u8d77\u6765\u6216\u591a\u6216\u5c11\u50cf\u8fd9\u6837\uff1a<\/p>\n
func (c *client) get(ctx context.context, query query) (results, error) {\n    b, err := c.fetchandlearn(ctx, query)\n    if errors.is(err, context.canceled) { \/\/ panic happens on this line\n        \/\/ ...\n    }\n\n    \/\/ ...\n}\n\nfunc (c *client) fetchandlearn(ctx context.context, query query) (response *http.response, err error) {\n    done := make(chan struct{})\n\n    go func() {\n        response, err = c.fetch(ctx, query)\n        close(done)\n    }()\n\n    select {\n    case <-done:\n        return\n    case <-clock.after(c.gettimeout(query)):\n        return nil, xerrors.new(\"timeout exceeded\")\n    }\n}\n<\/pre>\n
\u5728\u6beb\u65e0\u7ed3\u679c\u7684\u8c03\u8bd5\u4e4b\u540e\uff0c\u6211\u60f3\u77e5\u9053 go \u662f\u5426\u5728\u5e55\u540e\u505a\u4e86\u4e00\u4e9b\u4e0d\u76f4\u89c2\u7684\u4e8b\u60c5\uff0c\u56e0\u4e3a\u8fd9\u91cc\u4f7f\u7528\u4e86\u547d\u540d\u8fd4\u56de\u503c\u3002\u51ed\u501f\u8fd9\u79cd\u5fae\u5f31\u7684\u76f4\u89c9\uff0c\u6211\u53ea\u9700\u5220\u9664\u547d\u540d\u7684\u8fd4\u56de\u503c\u5e76\u58f0\u660e\u5355\u72ec\u7684 err \u53d8\u91cf\uff0c\u5c31\u89e3\u51b3\u4e86\u4e0d\u53ef\u6062\u590d\u7684\u6050\u614c\u95ee\u9898\u3002<\/p>\n
func (c *client) fetchAndLearn(ctx context.Context, query Query) (*http.Response, error) {\n    done := make(chan struct{})\n    var response *http.Response\n    var err error\n\n    go func() {\n        response, err = c.fetch(ctx, query)\n        close(done)\n    }()\n\n    select {\n    case <-done:\n        if err != nil {\n            return nil, xerrors.Errorf(\": %w\", err)\n        }\n        return response, nil\n    case <-clock.After(c.getTimeout(query)):\n        return nil, xerrors.New(\"timeout exceeded during request duration learning\")\n    }\n}\n<\/pre>\n
\u4f46\u8fd9\u5bf9\u6211\u6765\u8bf4\u4ecd\u7136\u6ca1\u6709\u591a\u5927\u610f\u4e49\uff0c\u5982\u679c\u6709\u4eba\u5bf9 go \u5185\u90e8\u5de5\u4f5c\u539f\u7406\u6709\u5f88\u597d\u7684\u4e86\u89e3\uff0c\u53ef\u4ee5\u8bc1\u5b9e\u6216\u5426\u8ba4\u6211\u7684\u6000\u7591\uff0c\u6211\u5c06\u975e\u5e38\u611f\u6fc0\u3002<\/p>\n
 <\/p>\n
\u89e3\u51b3\u65b9\u6848<\/h2>\n
 <\/p>\n
\u56de\u7b54<\/h1>\n
\u662f\u7684\uff0c\u547d\u540d\u8fd4\u56de\u51fd\u6570\u4e2d\u7684\u663e\u5f0f\u8fd4\u56de\u5c06\u6309\u7167 \u5199\u5165\u9884\u521d\u59cb\u5316\u7684\u547d\u540d\u7ed3\u679c\u3002<\/p>\n
\u80cc\u666f<\/h1>\n
\u5982\u679c\u60a8\u8fd0\u884c\u4ee5\u4e0b\u4ee3\u7801\uff0c\u60a8\u4f1a\u6ce8\u610f\u5230\uff0c\u5373\u4f7f\u5728 foo()<\/code> \u4e2d\uff0c\u9884\u521d\u59cb\u5316\u7684 val<\/code> \u5728\u521d\u59cb\u8d4b\u503c\u540e\u6c38\u8fdc\u4e0d\u4f1a\u76f4\u63a5\u64cd\u4f5c\uff0c\u4f46\u5b83\u4f1a\u5728\u8fd4\u56de val2<\/code> \u540e\u66f4\u6539\u5185\u5bb9\u3002<\/p>\n
package main\n\nimport (\n    \"fmt\"\n    \"time\"\n)\n\nfunc main() {\n    val := foo()\n    fmt.Printf(\"Main: %+v\\n\", val.Bar) \/\/ explicit\n    time.Sleep(2 * time.Second)\n}\n\ntype Foo struct {\n    Bar string\n}\n\nfunc foo() (val *Foo) {\n    val = &Foo{Bar: \"named\"}\n    go func() {\n        time.Sleep(time.Second)\n        fmt.Printf(\"Goroutine: %+v\\n\", val.Bar) \/\/ explicit\n    }()\n\n    val2 := &Foo{Bar: \"explicit\"}\n\n    return val2\n}\n<\/pre>\n
\u53d1\u751f\u8fd9\u79cd\u60c5\u51b5\u662f\u56e0\u4e3a\u5728 go \u4e2d\uff0c\u6bcf\u4e2a\u51fd\u6570\u542f\u52a8\u65f6\u90fd\u4f1a\u521d\u59cb\u5316\u96f6\u503c\u8fd4\u56de\u53c2\u6570\u3002\u7136\u540e\uff0c\u5728\u8fd4\u56de\u65f6\uff0c\u6240\u6709\u8fd4\u56de\u503c\u90fd\u4f1a\u5206\u914d\u7ed9\u9884\u521d\u59cb\u5316\u7684\u503c\u3002\u5728\u6211\u4eec\u7684\u793a\u4f8b\u4e2d\uff0c\u8fd4\u56de\u65f6 val2<\/code> \u88ab\u5206\u914d\u7ed9 val<\/code>\uff0c\u7136\u540e\u7531\u51fd\u6570\u8fd4\u56de\u3002\u8fd9\u5e26\u6765\u4e86\u6570\u636e\u7ade\u4e89\u7684\u53ef\u80fd\u6027\uff0c\u56e0\u4e3a\u5373\u4f7f\u60a8\u5c06\u503c\u5206\u914d\u7ed9 val2<\/code>\uff0c\u5b83\u6700\u7ec8\u4e5f\u4f1a\u5206\u914d\u7ed9 val<\/code>\u3002<\/p>\n
\u6211\u552f\u4e00\u7684\u501f\u53e3\u662f\uff0c\u622a\u81f3\u64b0\u5199\u672c\u6587\u65f6\uff0c\u5b98\u65b9 \u6709\u70b9\u4e0d\u76f4\u89c2\uff0c\u56e0\u4e3a\u5b83\u8bf4\u547d\u540d\u7ed3\u679c\u5df2\u521d\u59cb\u5316\u5e76\u4e0e\u672a\u4fee\u9970\u7684\u8fd4\u56de\u7ed1\u5b9a<\/em>\uff0c\u8fd9\u9519\u8bef\u5730\u5047\u8bbe\u4e86\u663e\u5f0f\u56de\u62a5\u4e0d\u53d7\u7ea6\u675f<\/strong>\u3002\u611f\u8c22 \u80cc\u540e\u7684\u4e50\u4e8e\u52a9\u4eba\u7684\u4eba\u3002<\/p>\n
\u5230\u8fd9\u91cc\uff0c\u6211\u4eec\u4e5f\u5c31\u8bb2\u5b8c\u4e86\u300aGo \u51fd\u6570\u4e2d\u5177\u6709\u547d\u540d\u8fd4\u56de\u503c\u7684\u6570\u636e\u7ade\u4e89\uff1f\u300b\u7684\u5185\u5bb9\u4e86\u3002\u4e2a\u4eba\u8ba4\u4e3a\uff0c\u57fa\u7840\u77e5\u8bc6\u7684\u5b66\u4e60\u548c\u5de9\u56fa\uff0c\u662f\u4e3a\u4e86\u66f4\u597d\u7684\u5c06\u5176\u8fd0\u7528\u5230\u9879\u76ee\u4e2d\uff0c\u6b22\u8fce\u5173\u6ce8\u516c\u4f17\u53f7\uff0c\u5e26\u4f60\u4e86\u89e3\u66f4\u591a\u5173\u4e8e\u7684\u77e5\u8bc6\u70b9\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
\u5f53\u524d\u4f4d\u7f6e\uff1a > > ...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4925],"tags":[],"class_list":["post-207661","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/207661","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=207661"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/207661\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=207661"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=207661"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=207661"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}