操作系统-Linux命令2301_78772942ZIPsdfdfg3wer.zip 349.06KB 立即下载资源文件列表:ZIP sdfdfg3wer.zip 大约有1个文件 sdfdfg3wer.pdf 363.89KB 资源介绍: 操作系统_Linux命令 <link href="/image.php?url=https://csdnimg.cn/release/download_crawler_static/css/base.min.css" rel="stylesheet"/><link href="/image.php?url=https://csdnimg.cn/release/download_crawler_static/css/fancy.min.css" rel="stylesheet"/><link href="/image.php?url=https://csdnimg.cn/release/download_crawler_static/89623180/raw.css" rel="stylesheet"/><div id="sidebar" style="display: none"><div id="outline"></div></div><div class="pf w0 h0" data-page-no="1" id="pf1"><div class="pc pc1 w0 h0"><img alt="" class="bi x0 y0 w1 h1" src="/image.php?url=https://csdnimg.cn/release/download_crawler_static/89623180/bg1.jpg"/><div class="c x0 y1 w2 h0"><div class="t m0 x1 h2 y2 ff1 fs0 fc0 sc0 ls0 ws0">操作系统<span class="ff2"> </span></div><div class="t m0 x1 h3 y3 ff2 fs1 fc0 sc0 ls1 ws0">1.<span class="ff3 ls0"> <span class="_ _0"></span><span class="ff1">进程与线程的区别<span class="ff2"> </span></span></span></div><div class="t m0 x1 h4 y4 ff4 fs2 fc0 sc0 ls0 ws0">进程:指系统正在运行的一个应用程序;程序一旦运行就是进程;进程是系统资源分</div><div class="t m0 x1 h4 y5 ff4 fs2 fc0 sc0 ls0 ws0">配的最小单位。<span class="ff5"> </span></div><div class="t m0 x1 h4 y6 ff4 fs2 fc0 sc0 ls0 ws0">线程:<span class="ff1">线程是操作系统调度的最小单元</span>。进程是系统执行的最小单位。一个进程在其</div><div class="t m0 x1 h4 y7 ff4 fs2 fc0 sc0 ls0 ws0">执行的过程中可以产生多个线程。<span class="ff5"> </span></div><div class="t m0 x1 h4 y8 ff4 fs2 fc0 sc0 ls0 ws0">线程是进程的一个实体,比进程更小的独立运行基本单位。<span class="ff5"> </span></div><div class="t m0 x1 h4 y9 ff4 fs2 fc0 sc0 ls0 ws0">一个程序下至少有一个进程,一个进程下至少有一个线程,一个进程下也可以有多个</div><div class="t m0 x1 h4 ya ff4 fs2 fc0 sc0 ls0 ws0">线程来增加程序的执行速度。<span class="ff5"> </span></div><div class="t m0 x1 h4 yb ff1 fs2 fc0 sc0 ls0 ws0">进程和进程之间的资源无法共享,线程和线程之间的资源可以共享<span class="ff4">。<span class="ff5"> </span></span></div><div class="t m0 x1 h3 yc ff2 fs1 fc0 sc0 ls1 ws0">2.<span class="ff3 ls0"> <span class="_ _0"></span><span class="ff1">进程间的通信方式<span class="ff2"> </span></span></span></div><div class="t m0 x1 h4 yd ff1 fs2 fc0 sc0 ls0 ws0">管道<span class="ff2 ls2"> </span>有名管道<span class="ff2"> </span>信号量<span class="ff2 ls3"> </span>消息队列<span class="ff2"> </span>共享内存<span class="ff2"> </span>套接字<span class="ff5"> </span></div><div class="t m0 x1 h4 ye ff4 fs2 fc0 sc0 ls0 ws0">管道:一个管道只能一个进程写,另一个进程读。一个进程写完后,另一个进程才能</div><div class="t m0 x1 h4 yf ff4 fs2 fc0 sc0 ls0 ws0">读。效率低。<span class="ff5"> </span></div><div class="t m0 x1 h4 y10 ff4 fs2 fc0 sc0 ls0 ws0">信号量:计数器,信号量用于实现进程间的互斥与同步<span class="ff5"> </span></div><div class="t m0 x1 h4 y11 ff4 fs2 fc0 sc0 ls0 ws0">消息队列:往消息队列写入数据就可以正常返回,效率高。<span class="ff5"> </span></div><div class="t m0 x1 h4 y12 ff4 fs2 fc0 sc0 ls0 ws0">共享内存:指两个或多个进程共享一个给定的存储区。<span class="ff5"> </span></div><div class="t m0 x1 h3 y13 ff2 fs1 fc0 sc0 ls1 ws0">3.<span class="ff3 ls0"> <span class="_ _0"></span><span class="ff1">线程间的通信方式<span class="ff2"> </span></span></span></div><div class="t m0 x1 h4 y14 ff4 fs2 fc0 sc0 ls0 ws0">全局变量<span class="ff5"> </span></div><div class="t m0 x1 h4 y15 ff4 fs2 fc0 sc0 ls0 ws0">消息队列<span class="ff5"> </span></div><div class="t m0 x1 h3 y16 ff2 fs1 fc0 sc0 ls1 ws0">4.<span class="ff3 ls0"> <span class="_ _0"></span><span class="ff1">线程同步的方式<span class="ff2"> </span></span></span></div></div></div><div class="pi" data-data='{"ctm":[1.612022,0.000000,0.000000,1.612022,0.000000,0.000000]}'></div></div><div id="pf2" class="pf w0 h0" data-page-no="2"><div class="pc pc2 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="/image.php?url=https://csdnimg.cn/release/download_crawler_static/89623180/bg2.jpg"><div class="c x0 y1 w2 h0"><div class="t m0 x1 h4 y17 ff4 fs2 fc0 sc0 ls0 ws0">线程<span class="_ _0"></span>同<span class="_ _0"></span>步是<span class="_ _0"></span>两<span class="_ _0"></span>个或<span class="_ _0"></span>多个<span class="_ _0"></span>共<span class="_ _0"></span>享关<span class="_ _0"></span>键资<span class="_ _0"></span>源<span class="_ _0"></span>的线<span class="_ _0"></span>程<span class="_ _0"></span>的并<span class="_ _0"></span>发执<span class="_ _0"></span>行。<span class="_ _0"></span>应<span class="_ _0"></span>该同<span class="_ _0"></span>步<span class="_ _0"></span>线程<span class="_ _0"></span>以避<span class="_ _0"></span>免<span class="_ _0"></span>关键<span class="_ _0"></span>的</div><div class="t m0 x1 h4 y18 ff4 fs2 fc0 sc0 ls0 ws0">资源使用冲突。操作系统一般有下面三种线程同步的方式:<span class="ff5"> </span></div><div class="t m0 x1 h4 y19 ff4 fs2 fc0 sc0 ls0 ws0">●<span class="ff6"> <span class="_ _1"> </span><span class="ff1 ls4">互斥量</span><span class="ff2">(Mutex)<span class="_ _0"></span></span></span>:<span class="_ _0"></span>采用<span class="_ _0"></span>互<span class="_ _0"></span>斥<span class="_ _0"></span>对<span class="_ _0"></span>象<span class="_ _0"></span>机<span class="_ _0"></span>制<span class="_ _0"></span>,<span class="_ _0"></span>只<span class="_ _0"></span>有<span class="_ _0"></span>拥<span class="_ _0"></span>有<span class="_ _0"></span>互<span class="_ _0"></span>斥<span class="_ _0"></span>对<span class="_ _0"></span>象<span class="_ _0"></span>的<span class="_ _0"></span>线<span class="_ _0"></span>程<span class="_ _0"></span>才<span class="_ _0"></span>有<span class="_ _0"></span>访<span class="_ _0"></span>问<span class="_ _0"></span>公<span class="_ _0"></span>共<span class="_ _0"></span>资</div><div class="t m0 x1 h4 y1a ff4 fs2 fc0 sc0 ls0 ws0">源的<span class="_ _0"></span>权<span class="_ _0"></span>限。<span class="_ _0"></span>因为<span class="_ _0"></span>互<span class="_ _0"></span>斥对象<span class="_ _0"></span>只<span class="_ _0"></span>有<span class="_ _0"></span>一个<span class="_ _0"></span>,所<span class="_ _0"></span>以可<span class="_ _0"></span>以保<span class="_ _0"></span>证<span class="_ _0"></span>公共<span class="_ _0"></span>资源<span class="_ _0"></span>不会<span class="_ _0"></span>被<span class="_ _0"></span>多个<span class="_ _0"></span>线程<span class="_ _0"></span>同时<span class="_ _0"></span>访问<span class="_ _0"></span>。</div><div class="t m0 x1 h4 y1b ff4 fs2 fc0 sc0 ls0 ws0">比如<span class="ff5"> Java </span>中的<span class="ff5"> synchronized </span>关键词和各种<span class="ff5"> Lock </span>都是这种机制。<span class="ff5"> </span></div><div class="t m0 x1 h4 y1c ff4 fs2 fc0 sc0 ls0 ws0">●<span class="ff6"> <span class="_ _1"> </span><span class="ff1">信号量<span class="ff2">(Semaphore)<span class="ff5"> <span class="_ _2"></span></span></span></span></span>:它允许同一时刻多个线程访问同一资源,但是需要控制同</div><div class="t m0 x1 h4 y1d ff4 fs2 fc0 sc0 ls0 ws0">一时刻访问此资源的最大线程数量。<span class="ff5"> </span></div><div class="t m0 x1 h4 y1e ff4 fs2 fc0 sc0 ls0 ws0">●<span class="ff6"> <span class="_ _1"> </span><span class="ff1">事件<span class="ff2">(Event)<span class="ff5"> <span class="_ _3"></span>:Wait/Notify</span></span></span></span>:通过通知操作的方式来保持多线程同步,还可以方便</div><div class="t m0 x1 h4 y1f ff4 fs2 fc0 sc0 ls0 ws0">的实现多线程优先级的比较操作。<span class="ff5"> </span></div><div class="t m0 x1 h3 y20 ff2 fs1 fc0 sc0 ls1 ws0">5.<span class="ff3 ls0"> <span class="_ _0"></span><span class="ff1">线程的状态<span class="ff2"> </span></span></span></div><div class="t m0 x1 h4 y21 ff5 fs2 fc0 sc0 ls0 ws0">NEW <span class="ff4">新建状态:线程被创建出来但没有被调用</span> <span class="fc1">start()</span><span class="ff4">。</span> </div><div class="t m0 x1 h4 y22 ff5 fs2 fc0 sc0 ls0 ws0">RUNNABLE <span class="ff4">就绪</span>(<span class="ff4">可运行状态</span>)<span class="ff4">:线程被调用了</span> <span class="fc1">start()</span><span class="ff4">,等待运行的状态。</span> </div><div class="t m0 x1 h4 y23 ff5 fs2 fc0 sc0 ls0 ws0">Running<span class="ff4">:运行状态,就绪状态的线程被<span class="_"> </span></span>cpu<span class="_ _4"> </span><span class="ff4">调度后,执行程序代码</span> </div><div class="t m0 x1 h4 y24 ff5 fs2 fc0 sc0 ls0 ws0">BLOCKED <span class="ff4">阻塞状态:需要等待锁释放。</span> </div><div class="t m0 x1 h4 y25 ff5 fs2 fc0 sc0 ls0 ws0">WAITING <span class="_ _3"></span><span class="ff4">持<span class="_ _0"></span>续等<span class="_ _0"></span>待<span class="_ _0"></span>状<span class="_ _0"></span>态<span class="_ _0"></span>:<span class="_ _0"></span>表<span class="_ _0"></span>示<span class="_ _0"></span>该<span class="_ _0"></span>线程<span class="_ _0"></span>需<span class="_ _0"></span>要<span class="_ _0"></span>等<span class="_ _0"></span>待<span class="_ _0"></span>其<span class="_ _0"></span>他<span class="_ _0"></span>线<span class="_ _0"></span>程做<span class="_ _0"></span>出<span class="_ _0"></span>一<span class="_ _0"></span>些<span class="_ _0"></span>特<span class="_ _0"></span>定动<span class="_ _0"></span>作<span class="_ _0"></span>(<span class="_ _0"></span>通<span class="_ _0"></span>知或</span></div><div class="t m0 x1 h4 y26 ff4 fs2 fc0 sc0 ls0 ws0">中断)。如通过<span class="_"> </span><span class="ff5">wait()</span>方法进行等待的线程等待一个<span class="ff5"> no<span class="_ _0"></span>tify()</span>或者<span class="ff5"> notifyAll()</span>方法,通</div><div class="t m0 x1 h4 y27 ff4 fs2 fc0 sc0 ls0 ws0">过<span class="ff5"> join()</span>方法进行等待的线程等待目标线程运行结束而唤醒。<span class="ff5"> </span></div><div class="t m0 x1 h4 y28 ff5 fs2 fc0 sc0 ls0 ws0">TIMED_WAITING <span class="_ _3"></span><span class="ff4">超时等<span class="_ _0"></span>待状态<span class="_ _0"></span>:<span class="ls5">可以在指定的时间后自行返回而不是像<span class="_ _0"></span></span></span> <span class="_ _3"></span>WAITING </div><div class="t m0 x1 h4 y29 ff4 fs2 fc0 sc0 ls0 ws0">那样一直等待。如<span class="_"> </span><span class="ff5">sleep(3000)</span>方法。<span class="ff5"> </span></div><div class="t m0 x1 h4 y2a ff5 fs2 fc0 sc0 ls0 ws0">TERMINATED <span class="ff4">终止状态:表示该线程已经运行完毕。</span> </div><div class="t m0 x1 h3 y2b ff2 fs1 fc0 sc0 ls1 ws0">6.<span class="ff3 ls0"> <span class="_ _0"></span><span class="ff1">进程的调度方法<span class="ff2"> </span></span></span></div><div class="t m0 x1 h4 y2c ff4 fs2 fc0 sc0 ls0 ws0">为了确定首先执行哪个进程以及最后执行哪个进程以实现最大<span class="ff5"> CPU </span>利用率,计算机</div><div class="t m0 x1 h4 y2d ff4 fs2 fc0 sc0 ls0 ws0">科学家已经定义了一些算法,它们是:<span class="ff5"> </span></div></div></div><div class="pi" data-data='{"ctm":[1.612022,0.000000,0.000000,1.612022,0.000000,0.000000]}'></div></div><div id="pf3" class="pf w0 h0" data-page-no="3"><div class="pc pc3 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="/image.php?url=https://csdnimg.cn/release/download_crawler_static/89623180/bg3.jpg"><div class="c x0 y1 w2 h0"><div class="t m0 x1 h4 y2e ff4 fs2 fc0 sc0 ls0 ws0">●<span class="ff6"> <span class="_ _1"> </span><span class="ff1 ls6">先到先服务</span><span class="ff2">(FCFS)<span class="ff1">调<span class="_ _0"></span>度算<span class="_ _0"></span>法<span class="_ _0"></span><span class="ff5"> <span class="_ _3"> </span><span class="ls7">: <span class="_ _3"> </span></span></span></span></span></span>从<span class="_ _0"></span>就<span class="_ _0"></span>绪队<span class="_ _0"></span>列中<span class="_ _0"></span>选<span class="_ _0"></span>择<span class="_ _0"></span>一个<span class="_ _0"></span>最先<span class="_ _0"></span>进<span class="_ _0"></span>入该<span class="_ _0"></span>队<span class="_ _0"></span>列的<span class="_ _0"></span>进<span class="_ _0"></span>程为<span class="_ _0"></span>之</div><div class="t m0 x1 h4 y18 ff4 fs2 fc0 sc0 ls0 ws0">分配资源,使它立即执行并一直执行到完成或发生某事件而被阻塞放弃占用<span class="ff5"> CPU </span>时再</div><div class="t m0 x1 h4 y2f ff4 fs2 fc0 sc0 ls0 ws0">重新调度。<span class="ff5"> </span></div><div class="t m0 x1 h4 y30 ff4 fs2 fc0 sc0 ls0 ws0">●<span class="ff6"> <span class="_ _1"> </span><span class="ff1 ls5">短作业优先</span><span class="ff2">(SJF)<span class="ff1 ls5">的调度算法</span><span class="ff5"> <span class="_ _3"> </span><span class="ls7">: <span class="_ _3"> </span></span></span></span></span>从<span class="_ _0"></span>就绪队<span class="_ _0"></span>列中选<span class="_ _0"></span>出一个<span class="_ _0"></span>估计运<span class="_ _0"></span>行时间<span class="_ _0"></span>最短的<span class="_ _0"></span>进程为</div><div class="t m0 x1 h4 y1b ff4 fs2 fc0 sc0 ls0 ws0">之分配资源,使它立即执行并一直执行到完成或发生某事件而被阻塞放弃占用<span class="ff5"> CPU </span>时</div><div class="t m0 x1 h4 y31 ff4 fs2 fc0 sc0 ls0 ws0">再重新调度。<span class="ff5"> </span></div><div class="t m0 x1 h4 y32 ff4 fs2 fc0 sc0 ls0 ws0">●<span class="ff6"> <span class="_ _1"> </span><span class="ff1">时间片轮转调度算法<span class="ff5"> <span class="ls7">: <span class="_ _0"></span></span></span></span></span>时间片轮转调度是一种最古老,最简单,最公平且使用最广</div><div class="t m0 x1 h4 y33 ff4 fs2 fc0 sc0 ls0 ws0">的算法,又称<span class="ff5"> <span class="_ _3"></span>RR(Round <span class="_ _3"> </span>robin)</span>调度。每个进程被分配一个时间<span class="_ _0"></span>段,称作它的时间片,</div><div class="t m0 x1 h4 y1f ff4 fs2 fc0 sc0 ls0 ws0">即该进程允许运行的时间。<span class="ff5"> </span></div><div class="t m0 x1 h4 y34 ff4 fs2 fc0 sc0 ls0 ws0">●<span class="ff6"> <span class="_ _1"> </span><span class="ff1">多级反<span class="_ _0"></span>馈队列<span class="_ _0"></span>调度<span class="_ _0"></span>算法<span class="_ _0"></span><span class="ff5"> <span class="_ _3"> </span></span></span></span><span class="ls5">:前面介绍的几种进<span class="_ _0"></span>程调度的算法都有一定<span class="_ _0"></span>的局限性。如</span></div><div class="t m0 x1 h4 y35 ff1 fs2 fc0 sc0 ls0 ws0">短进程优先的调<span class="_ _0"></span>度算法,仅照<span class="_ _0"></span>顾了短进程而<span class="_ _0"></span>忽略了长进程<span class="_ _0"></span><span class="ff5"> <span class="_ _3"> </span><span class="ff4">。<span class="_ _0"></span>多级反馈队列调度<span class="_ _0"></span>算法既</span></span></div><div class="t m0 x1 h4 y36 ff4 fs2 fc0 sc0 ls0 ws0">能使<span class="_ _0"></span>高<span class="_ _0"></span>优先<span class="_ _0"></span>级<span class="_ _0"></span>的作<span class="_ _0"></span>业得<span class="_ _0"></span>到<span class="_ _0"></span>响应<span class="_ _0"></span>又能<span class="_ _0"></span>使<span class="_ _0"></span>短作<span class="_ _0"></span>业<span class="_ _0"></span>(进<span class="_ _0"></span>程)<span class="_ _0"></span>迅速<span class="_ _0"></span>完<span class="_ _0"></span>成。<span class="_ _0"></span>,<span class="_ _0"></span>因而<span class="_ _0"></span>它是<span class="_ _0"></span>目<span class="_ _0"></span>前<span class="_ _2"></span><span class="ff1 ls6">被公</span></div><div class="t m0 x1 h4 y37 ff1 fs2 fc0 sc0 ls0 ws0">认的一种较好的进程调度算法<span class="ff4">,<span class="ff5">UNIX </span>操作系统采取的便是这种调度算法。<span class="ff5"> </span></span></div><div class="t m0 x1 h4 y38 ff4 fs2 fc0 sc0 ls0 ws0">●<span class="ff6"> <span class="_ _1"> </span><span class="ff1">优先级调度<span class="ff5"> <span class="_ _3"></span></span></span></span>:<span class="ff5"> <span class="_ _5"></span></span>为每个流程分配优先级,首先执行具有最高优先级的进程,依此类</div><div class="t m0 x1 h4 y39 ff4 fs2 fc0 sc0 ls0 ws0">推。具<span class="_ _0"></span>有相同<span class="_ _0"></span>优先<span class="_ _0"></span>级的<span class="_ _0"></span>进程<span class="_ _0"></span>以<span class="_ _0"></span><span class="ff5"> <span class="_ _3"></span>FCFS <span class="_ _3"></span></span><span class="ls5">方式执行。可以根据内存要求<span class="_ _0"></span>,时间要求或任何</span></div><div class="t m0 x1 h4 y3a ff4 fs2 fc0 sc0 ls0 ws0">其他资源要求来确定优先级。<span class="ff5"> </span></div><div class="t m0 x1 h3 y3b ff2 fs1 fc0 sc0 ls1 ws0">7.<span class="ff3 ls0"> <span class="_ _0"></span><span class="ff1">多进程和多线程的区别<span class="ff2"> </span></span></span></div><div class="t m0 x1 h4 y28 ff4 fs2 fc0 sc0 ls0 ws0">进程<span class="_ _0"></span>是<span class="_ _0"></span>程序<span class="_ _0"></span>在<span class="_ _0"></span>计算<span class="_ _0"></span>机上<span class="_ _0"></span>的<span class="_ _0"></span>一次<span class="_ _0"></span>执行<span class="_ _0"></span>活<span class="_ _0"></span>动,<span class="_ _0"></span>即<span class="_ _0"></span>正在<span class="_ _0"></span>运行<span class="_ _0"></span>中的<span class="_ _0"></span>应<span class="_ _0"></span>用程<span class="_ _0"></span>序<span class="_ _0"></span>,通<span class="_ _0"></span>常称<span class="_ _0"></span>为<span class="_ _0"></span>进程<span class="_ _0"></span>。</div><div class="t m0 x1 h4 y29 ff4 fs2 fc0 sc0 ls0 ws0">每<span class="_ _0"></span>个<span class="_ _0"></span>进<span class="_ _0"></span>程<span class="_ _0"></span>都有<span class="_ _2"></span>自己<span class="_ _0"></span>独<span class="_ _0"></span>立<span class="_ _0"></span>的<span class="_ _0"></span>地<span class="_ _0"></span>址<span class="_ _0"></span>空<span class="_ _0"></span>间<span class="_ _0"></span><span class="ff5">(<span class="_ _0"></span></span>内<span class="_ _0"></span>存<span class="_ _0"></span>空<span class="_ _0"></span>间<span class="_ _0"></span><span class="ff5">)<span class="_ _0"></span></span>,<span class="_ _0"></span>每<span class="_ _0"></span>当<span class="_ _0"></span>用<span class="_ _0"></span>户<span class="_ _0"></span>启<span class="_ _0"></span>动<span class="_ _0"></span>一<span class="_ _0"></span>个<span class="_ _0"></span>进<span class="_ _0"></span>程<span class="_ _0"></span>时<span class="_ _0"></span>,操<span class="_ _0"></span>作<span class="_ _0"></span>系<span class="_ _0"></span>统</div><div class="t m0 x1 h4 y2a ff4 fs2 fc0 sc0 ls0 ws0">就会为该进程分配一个独立的内存空间,让应用程序在这个独立的内存空间中运行。<span class="ff5"> </span></div><div class="t m0 x1 h4 y3c ff4 fs2 fc0 sc0 ls0 ws0">在同<span class="_ _0"></span>一<span class="_ _0"></span>个时<span class="_ _0"></span>间里<span class="_ _0"></span>,<span class="_ _0"></span>同一个<span class="_ _0"></span>计<span class="_ _0"></span>算<span class="_ _0"></span>机系<span class="_ _0"></span>统中<span class="_ _0"></span>如果<span class="_ _0"></span>允许<span class="_ _0"></span>两<span class="_ _0"></span>个或<span class="_ _0"></span>两个<span class="_ _0"></span>以上<span class="_ _0"></span>的<span class="_ _0"></span>进程<span class="_ _0"></span>处于<span class="_ _0"></span>运行<span class="_ _0"></span>状态<span class="_ _0"></span>,</div><div class="t m0 x1 h4 y3d ff4 fs2 fc0 sc0 ls6 ws0">这便是<span class="ff1 ls0">多进<span class="_ _0"></span>程<span class="_ _0"></span><span class="ff4">,也<span class="_ _0"></span>称多<span class="_ _0"></span>任务<span class="_ _0"></span>。<span class="_ _0"></span>现代<span class="_ _0"></span>的<span class="_ _0"></span>操作<span class="_ _0"></span>系统<span class="_ _0"></span>几<span class="_ _0"></span>乎都<span class="_ _0"></span>是多<span class="_ _0"></span>任<span class="_ _0"></span>务操<span class="_ _0"></span>作<span class="_ _0"></span>系统<span class="_ _0"></span>,能<span class="_ _0"></span>够同<span class="_ _0"></span>时<span class="_ _0"></span>管</span></span></div><div class="t m0 x1 h4 y3e ff4 fs2 fc0 sc0 ls0 ws0">理多个进程的运行。<span class="ff5"> </span></div></div></div><div class="pi" data-data='{"ctm":[1.612022,0.000000,0.000000,1.612022,0.000000,0.000000]}'></div></div>