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zhuhjay 22e48d9558 build(www): 添加 Drone CI 流水线配置 
- 新增 .drone.yml 文件用于定义 CI/CD 流程
- 配置了基于 Docker 的部署步骤
- 设置了工作区和卷映射以支持持久化数据
- 添加了构建准备阶段和 Docker 部署阶段
- 定义了环境变量和代理设置
- 配置了 artifacts 目录的处理逻辑
- 添加了 timezone 映射以确保时间同步
- 设置了 docker.sock 映射以支持 Docker in Docker
2025-11-01 13:36:00 +08:00

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中使用的就是大名鼎鼎的 "),t("code",[s._v("Service Provider Interface (SPI)")])]),s._v(" "),t("ul",[t("li",[t("p",[s._v("约定如下，在 jar 包的 "),t("code",[s._v("META-INF/services")]),s._v(" 包下，以接口全限定名名为文件，文件内容是实现类名称（就像 "),t("code",[s._v("SpringBoot")]),s._v(" 中使用的 "),t("code",[s._v("spring.factories")]),s._v(" 文件）")]),s._v(" "),t("img",{staticStyle:{zoom:"50%"},attrs:{src:"/jvm/1670493540488.png",alt:"1670493540488"}})])]),s._v(" "),t("p",[s._v("之后就可以使用以下 ServiceLoader 加载器来加载信息")]),s._v(" "),t("div",{staticClass:"language-java line-numbers-mode"},[t("pre",{pre:!0,attrs:{class:"language-java"}},[t("code",[t("span",{pre:!0,attrs:{class:"token class-name"}},[s._v("ServiceLoader")]),t("span",{pre:!0,attrs:{class:"token generics"}},[t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("<")]),t("span",{pre:!0,attrs:{class:"token class-name"}},[s._v("Driver")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(">")])]),s._v(" loadedDrivers "),t("span",{pre:!0,attrs:{class:"token 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doSum 的方法内联，测试结果如下（每秒吞吐量，分数越高的更好）")]),s._v(" "),t("div",{staticClass:"language- line-numbers-mode"},[t("pre",{pre:!0,attrs:{class:"language-text"}},[t("code",[s._v("Benchmark Mode Cnt Score Error Units\nBenchmark1.test1 thrpt 5 3109424.624 ± 253596.436 ops/s\nBenchmark1.test2 thrpt 5 3354988.133 ± 91779.242 ops/s\nBenchmark1.test3 thrpt 5 3192089.287 ± 811172.283 ops/s\n")])]),s._v(" "),t("div",{staticClass:"line-numbers-wrapper"},[t("span",{staticClass:"line-number"},[s._v("1")]),t("br"),t("span",{staticClass:"line-number"},[s._v("2")]),t("br"),t("span",{staticClass:"line-number"},[s._v("3")]),t("br"),t("span",{staticClass:"line-number"},[s._v("4")]),t("br")])]),t("p",[s._v("接下来禁用 doSum 方法内联")]),s._v(" "),t("div",{staticClass:"language-java line-numbers-mode"},[t("pre",{pre:!0,attrs:{class:"language-java"}},[t("code",[t("span",{pre:!0,attrs:{class:"token annotation punctuation"}},[s._v("@CompilerControl")]),t("span",{pre:!0,attrs:{class:"token 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x"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(";")]),s._v("\n"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("}")]),s._v("\n")])]),s._v(" "),t("div",{staticClass:"line-numbers-wrapper"},[t("span",{staticClass:"line-number"},[s._v("1")]),t("br"),t("span",{staticClass:"line-number"},[s._v("2")]),t("br"),t("span",{staticClass:"line-number"},[s._v("3")]),t("br"),t("span",{staticClass:"line-number"},[s._v("4")]),t("br")])]),t("p",[s._v("此时测试结果如下，跟以上结果对比，发现吞吐量小了10倍左右")]),s._v(" "),t("div",{staticClass:"language- line-numbers-mode"},[t("pre",{pre:!0,attrs:{class:"language-text"}},[t("code",[s._v("Benchmark Mode Cnt Score Error Units\nBenchmark1.test1 thrpt 5 357337.402 ± 131498.372 ops/s\nBenchmark1.test2 thrpt 5 394812.201 ± 434387.776 ops/s\nBenchmark1.test3 thrpt 5 377967.137 ± 377008.086 ops/s\n")])]),s._v(" "),t("div",{staticClass:"line-numbers-wrapper"},[t("span",{staticClass:"line-number"},[s._v("1")]),t("br"),t("span",{staticClass:"line-number"},[s._v("2")]),t("br"),t("span",{staticClass:"line-number"},[s._v("3")]),t("br"),t("span",{staticClass:"line-number"},[s._v("4")]),t("br")])]),t("p",[s._v("分析：")]),s._v(" "),t("p",[s._v("在刚才的示例中，doSum 方法是否内联会影响 elements 成员变量读取的优化：")]),s._v(" "),t("p",[s._v("如果 doSum 方法内联了，刚才的 test1 方法会被优化成下面的样子（伪代码）：")]),s._v(" "),t("div",{staticClass:"language-java line-numbers-mode"},[t("pre",{pre:!0,attrs:{class:"language-java"}},[t("code",[t("span",{pre:!0,attrs:{class:"token annotation punctuation"}},[s._v("@Benchmark")]),s._v("\n"),t("span",{pre:!0,attrs:{class:"token keyword"}},[s._v("public")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token keyword"}},[s._v("void")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token function"}},[s._v("test1")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("(")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(")")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("{")]),s._v("\n "),t("span",{pre:!0,attrs:{class:"token comment"}},[s._v("// elements 首次读取会缓存起来 -> int[] local（机器码级别缓存，后续就不需要再访问 elements 成员变量了）")]),s._v("\n "),t("span",{pre:!0,attrs:{class:"token keyword"}},[s._v("for")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("(")]),t("span",{pre:!0,attrs:{class:"token keyword"}},[s._v("int")]),s._v(" i "),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v("=")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token number"}},[s._v("0")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(";")]),s._v(" i "),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v("<")]),s._v(" elements"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(".")]),s._v("length"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(";")]),s._v(" i"),t("span",{pre:!0,attrs:{class:"token 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"),t("div",{staticClass:"line-numbers-wrapper"},[t("span",{staticClass:"line-number"},[s._v("1")]),t("br"),t("span",{staticClass:"line-number"},[s._v("2")]),t("br"),t("span",{staticClass:"line-number"},[s._v("3")]),t("br"),t("span",{staticClass:"line-number"},[s._v("4")]),t("br"),t("span",{staticClass:"line-number"},[s._v("5")]),t("br"),t("span",{staticClass:"line-number"},[s._v("6")]),t("br"),t("span",{staticClass:"line-number"},[s._v("7")]),t("br")])]),t("p",[s._v("可以节省 1999 次 Field 读取操作")]),s._v(" "),t("p",[s._v("但如果 doSum 方法没有内联，则不会进行上面的优化")]),s._v(" "),t("blockquote",[t("p",[s._v("练习：在内联情况下将 elements 添加 volatile 修饰符会发生什么？")]),s._v(" "),t("p",[s._v("运行结果如下，发现方法一的吞吐量大大降低了")]),s._v(" "),t("div",{staticClass:"language- line-numbers-mode"},[t("pre",{pre:!0,attrs:{class:"language-text"}},[t("code",[s._v("Benchmark Mode Cnt Score Error Units\nBenchmark1.test1 thrpt 5 660532.339 ± 41637.563 ops/s\nBenchmark1.test2 thrpt 5 3356062.311 ± 32060.956 ops/s\nBenchmark1.test3 thrpt 5 3359952.483 ± 30073.397 ops/s\n")])]),s._v(" "),t("div",{staticClass:"line-numbers-wrapper"},[t("span",{staticClass:"line-number"},[s._v("1")]),t("br"),t("span",{staticClass:"line-number"},[s._v("2")]),t("br"),t("span",{staticClass:"line-number"},[s._v("3")]),t("br"),t("span",{staticClass:"line-number"},[s._v("4")]),t("br")])])]),s._v(" "),t("blockquote",[t("p",[t("strong",[s._v("Tip")]),s._v(":")]),s._v(" "),t("p",[s._v("这三种方法分别进行了优化")]),s._v(" "),t("ol",[t("li",[s._v("如果没有关闭方法内联，则虚拟机将自动进行优化")]),s._v(" "),t("li",[s._v("使用了局部变量，避免多次向成员变量进行访问，进行了手动优化")]),s._v(" "),t("li",[s._v("foreach 语法糖编译结果与 2 相同，也属于编译器优化")])]),s._v(" "),t("p",[t("strong",[s._v("注意")]),s._v("：若要对这种类似的进行优化，可以考虑多使用局部变量。")])]),s._v(" "),t("h3",{attrs:{id:"_3-2-反射优化"}},[t("a",{staticClass:"header-anchor",attrs:{href:"#_3-2-反射优化"}},[s._v("#")]),s._v(" 3.2 反射优化")]),s._v(" "),t("p",[s._v("运行以下反射代码，进行代码执行分析")]),s._v(" "),t("div",{staticClass:"language-java 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