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- (window.webpackJsonp=window.webpackJsonp||[]).push([[59],{349:function(t,s,a){"use strict";a.r(s);var n=a(14),r=Object(n.a)({},(function(){var t=this,s=t._self._c;return s("ContentSlotsDistributor",{attrs:{"slot-key":t.$parent.slotKey}},[s("h1",{attrs:{id:"非抢占式最短作业优先算法"}},[s("a",{staticClass:"header-anchor",attrs:{href:"#非抢占式最短作业优先算法"}},[t._v("#")]),t._v(" 非抢占式最短作业优先算法")]),t._v(" "),s("h2",{attrs:{id:"调度策略与算法原理"}},[s("a",{staticClass:"header-anchor",attrs:{href:"#调度策略与算法原理"}},[t._v("#")]),t._v(" 调度策略与算法原理")]),t._v(" "),s("p",[t._v("\tSJF（Shortest Job First，最短作业优先）是一种进程调度策略，它选择执行时间最短的进程来优先执行。在SJF调度策略下，操作系统会根据进程的执行时间长度来决定调度顺序，短作业将被优先执行。")]),t._v(" "),s("p",[t._v("基本原则和策略：")]),t._v(" "),s("ol",[s("li",[t._v("作业长度：SJF调度策略假设我们可以预测每个进程的执行时间。因此，每个进程都被分配了一个执行时间长度。")]),t._v(" "),s("li",[t._v("最短作业优先：在就绪队列中，选择具有最短执行时间的进程来执行。这意味着进程的执行时间越短，越容易获得CPU的执行机会。")]),t._v(" "),s("li",[t._v("非抢占式调度：一旦进程开始执行，它将一直运行到完成，除非它自愿释放CPU或阻塞。")]),t._v(" "),s("li",[t._v("先来先服务：当多个进程具有相同的执行时间时，采用先到先服务（FIFO）原则，即按照进程到达的顺序来决定执行顺序。")])]),t._v(" "),s("p",[t._v("\tSJF调度策略旨在减少平均等待时间，因为短作业往往能够更快地完成并释放CPU资源，从而提高系统的吞吐量和响应时间。然而，SJF调度策略需要提前了解每个进程的执行时间，而在实际情况中，通常无法准确预测进程的执行时间。因此，SJF调度策略往往用作一种参考，而非实际应用的主要调度算法。")]),t._v(" "),s("p",[t._v("\t扩展：抢占式最短作业优先算法是：最短完成时间优先（Shortest Time to Complet First）调度策略。")]),t._v(" "),s("h2",{attrs:{id:"实验步骤"}},[s("a",{staticClass:"header-anchor",attrs:{href:"#实验步骤"}},[t._v("#")]),t._v(" 实验步骤")]),t._v(" "),s("p",[t._v("\t接上文，在这里继续完成调度算法的实现")]),t._v(" "),s("p",[t._v("\t你只需要实现一个SJF算法类，然后实现schedule函数，比如下面的方法：")]),t._v(" "),s("div",{staticClass:"language-cpp extra-class"},[s("pre",{pre:!0,attrs:{class:"language-cpp"}},[s("code",[s("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("bool")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token function"}},[t._v("compareByBurstTime")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),s("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("const")]),t._v(" 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