ch2.htm

汤子瀛《操作系统》电子教案

            <td style="BORDER-RIGHT: medium none; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 122.4pt; PADDING-TOP: 0cm; BORDER-BOTTOM: medium none" vAlign="top" width="163" align="center"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">程序与执行对应</font></span></td>
            <td style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 0.5pt solid; WIDTH: 144pt; PADDING-TOP: 0cm; BORDER-BOTTOM: medium none" vAlign="top" width="192" align="center"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">一一对应</font></span></td>
            <td style="BORDER-RIGHT: medium none; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 159.6pt; PADDING-TOP: 0cm; BORDER-BOTTOM: medium none" vAlign="top" width="213" align="center"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">一个程序可对应多个执行</font></span></td>
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            <td style="BORDER-RIGHT: medium none; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 122.4pt; PADDING-TOP: 0cm; BORDER-BOTTOM: medium none" vAlign="top" width="163" align="center"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">封闭性</font></span></td>
            <td style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 0.5pt solid; WIDTH: 144pt; PADDING-TOP: 0cm; BORDER-BOTTOM: medium none" vAlign="top" width="192" align="center"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">独占资源，具有封闭性</font></span></td>
            <td style="BORDER-RIGHT: medium none; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 159.6pt; PADDING-TOP: 0cm; BORDER-BOTTOM: medium none" vAlign="top" width="213" align="center"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">共享资源，不具有封闭性</font></span></td>
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            <td style="BORDER-RIGHT: medium none; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 122.4pt; PADDING-TOP: 0cm; BORDER-BOTTOM: medium none" vAlign="top" width="163" align="center"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">确定性</font></span></td>
            <td style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 0.5pt solid; WIDTH: 144pt; PADDING-TOP: 0cm; BORDER-BOTTOM: medium none" vAlign="top" width="192" align="center"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">具有</font></span></td>
            <td style="BORDER-RIGHT: medium none; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 159.6pt; PADDING-TOP: 0cm; BORDER-BOTTOM: medium none" vAlign="top" width="213" align="center"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">无</font></span></td>
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            <td style="BORDER-RIGHT: medium none; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 122.4pt; PADDING-TOP: 0cm; BORDER-BOTTOM: medium none" vAlign="top" width="163" align="center"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">可再现性</font></span></td>
            <td style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 0.5pt solid; WIDTH: 144pt; PADDING-TOP: 0cm; BORDER-BOTTOM: medium none" vAlign="top" width="192" align="center"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">具有</font></span></td>
            <td style="BORDER-RIGHT: medium none; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 159.6pt; PADDING-TOP: 0cm; BORDER-BOTTOM: medium none" vAlign="top" width="213" align="center"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">无</font></span></td>
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            <td style="BORDER-RIGHT: medium none; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 122.4pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid" vAlign="top" width="163" align="center"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">程序间关系</font></span></td>
            <td style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 0.5pt solid; WIDTH: 144pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid" vAlign="top" width="192" align="center"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">无</font></span></td>
            <td style="BORDER-RIGHT: medium none; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 159.6pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid" vAlign="top" width="213" align="center"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">有间接制约或直接制约关系</font></span></td>
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      <p><span lang="EN-US"><font color="#FFFFFF">5．</font></span><font color="#FFFFFF"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">程序并发执行的条件（保持可再现性）</span></font></p>
      <p style="MARGIN-LEFT: 18pt"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">两段程序间无共享变量或对共享变量仅有读操作。</font></span></p>
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    <p style="TEXT-ALIGN: center" align="center"><font color="#FFFFFF"><span lang="EN-US" style="FONT-SIZE: 14pt; mso-bidi-font-size: 10.0pt"><a name="ch22"></a>2</span><span style="FONT-SIZE: 14pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">．</span><span lang="EN-US" style="FONT-SIZE: 14pt; mso-bidi-font-size: 10.0pt">2   
    </span><span style="FONT-SIZE: 14pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">进程的描述</span><span lang="EN-US" style="FONT-SIZE: 14pt; mso-bidi-font-size: 10.0pt"><o:p>
    </o:p>
    </span></font></p>
    <p style="MARGIN-LEFT: 18pt; TEXT-INDENT: -18pt; tab-stops: list 18.0pt; mso-list: l3 level1 lfo4"><font color="#FFFFFF"><span lang="EN-US">1．</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">进程的引入和定义</span></font></p>
    <p><font color="#FFFFFF"><span style="mso-spacerun: yes" lang="EN-US">&nbsp;   
    </span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">⑴进程引入的原因</span></font></p>
    <p style="MARGIN-LEFT: 18pt"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">进程：操作系统中最基本、最重要的概念</font></span></p>
    <p style="MARGIN-LEFT: 18pt"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">多道程序设计出现以后，为了刻划系统内部出现的情况，描述系统内部各作业的活动规律引入的。</font></span></p>
    <p style="MARGIN-LEFT: 18pt"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">多到系统的特点：并行性、程序间的制约、动态特征</font></span></p>
    <p style="MARGIN-LEFT: 18pt"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">程序是静态的，不能并行</font></span></p>
    <p><font color="#FFFFFF"><span style="mso-spacerun: yes" lang="EN-US">&nbsp;   
    </span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">⑵进程的定义</span></font></p>
    <p style="MARGIN-LEFT: 18pt"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">通用定义：（举例解释）</font></span></p>
    <p><font color="#FFFFFF"><span style="mso-spacerun: yes" lang="EN-US">&nbsp;   
    </span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">⑶进程的特征：动态性、并发性、独立性、异步性、结构特征</span></font></p>
    <p><font color="#FFFFFF"><span style="mso-spacerun: yes" lang="EN-US">&nbsp;&nbsp;</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">⑷进程和程序的区别与联系</span></font></p>
    <p style="TEXT-INDENT: 24pt"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">区别：进程是一动态概念，而程序则是一静态概念。程序是指令的有序集合，永远存在，进程强调的是执行，是程序在数据集上的一次执行，有创建有撤销，存在是暂时的；</font></span></p>
    <p style="TEXT-INDENT: 24pt"><font color="#FFFFFF"><span style="mso-spacerun: yes" lang="EN-US">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;   
    </span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">进程具有并发性，而程序没有；</span></font></p>
    <p style="TEXT-INDENT: 24pt"><font color="#FFFFFF"><span style="mso-spacerun: yes" lang="EN-US">&nbsp;   
    &nbsp;&nbsp;&nbsp;&nbsp;</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">进程是竞争计算机资源的基本单位，程序不是。</span></font></p>
    <p style="TEXT-INDENT: 24pt"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">联系：进程是程序在数据集上的一次执行；</font></span></p>
    <p style="TEXT-INDENT: 24pt"><font color="#FFFFFF"><span style="mso-spacerun: yes" lang="EN-US">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;   
    </span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">一个程序可对应多个进程，一个进程可包括多个程序。</span></font></p>
    <p style="MARGIN-LEFT: 18pt; TEXT-INDENT: -18pt; tab-stops: list 18.0pt; mso-list: l3 level1 lfo4"><font color="#FFFFFF"><span lang="EN-US">2．</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">进程的基本状态：</span></font></p>
    <p><font color="#FFFFFF"><span style="mso-spacerun: yes" lang="EN-US">&nbsp;   
    </span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">⑴进程的三种基本状态：（引入状态的原因）</span></font></p>
    <p style="TEXT-INDENT: 24pt"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">等待态：</font></span></p>
    <p style="TEXT-INDENT: 24pt"><font color="#FFFFFF"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">就绪态：</span><span style="mso-spacerun: yes" lang="EN-US">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span></font></p>
    <p style="TEXT-INDENT: 24pt"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">运行态：</font></span></p>
    <p style="TEXT-INDENT: 24pt"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font color="#FFFFFF">进程的状态不断发生变化，但任何时候都要处于某种状态。</font></span></p>
    <p><font color="#FFFFFF"><span style="mso-spacerun: yes" lang="EN-US">&nbsp;   
    </span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">⑵新状态和终止状态</span></font></p>
    <p><font color="#FFFFFF"><span style="mso-spacerun: yes" lang="EN-US">&nbsp;   
    </span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">⑶进程的状态转换：（进程状态转换图）</span></font></p>
    <p><span lang="EN-US"><font color="#FFFFFF">&nbsp;<o:p>
    </o:p>  
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    <p style="MARGIN-LEFT: 18pt; TEXT-INDENT: -18pt; tab-stops: list 18.0pt; mso-list: l3 level1 lfo4"><span lang="EN-US"><font color="#FFFFFF">3．</font></span><font color="#FFFFFF"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">进程的挂起状态：</span></font></p>
    <p><font color="#FFFFFF"><span style="mso-spacerun: yes" lang="EN-US">&nbsp;   
    </span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">⑴挂起状态的引入</span></font></p>
    <p><font color="#FFFFFF"><span style="mso-spacerun: yes" lang="EN-US">&nbsp;&nbsp;&nbsp;   
    </span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">终端用户的需要、父进程的需要、操作系统的需要、对换的需要、负荷调节的需要</span></font></p>
    <p><font color="#FFFFFF"><span style="mso-spacerun: yes" lang="EN-US">&nbsp;   
    </span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">⑵进程的状态转换：（进程状态转换图）</span></font></p>
    <p style="MARGIN-LEFT: 18pt; TEXT-INDENT: -18pt; tab-stops: list 18.0pt; mso-list: l3 level1 lfo4"><font color="#FFFFFF"><span lang="EN-US">4．</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">进程控制块（</span><span lang="EN-US">PCB</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">）</span></font></p>
    <p style="MARGIN-LEFT: 18pt"><font color="#FFFFFF"><span lang="EN-US">PCB</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">是用以记录进程有关信息的一块主存，由系统建立</span></font></p>