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<title>操作系统－第二章</title>
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<td width="100%" align="center" height="53" colspan="2"><font size="5" face="黑体" color="#FFFFFF"><font LANG="ZH-CN">第二章</font>
进程的描述与控制</font></td>
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<p style="TEXT-ALIGN: center" align="center"><font color="#FFFFFF"><span lang="EN-US" style="mso-bidi-font-size: 10.0pt"><a href="#ch21"><span style="mso-bidi-font-size: 10.0pt">2.1
前驱图和程序执行</span></a></span></font></p>
<p style="TEXT-ALIGN: center" align="center"><font color="#FFFFFF"><span lang="EN-US" style="mso-bidi-font-size: 10.0pt"><a href="#ch22">2.2
进程的描述</a></span></font></p>
<p ALIGN="center" style="text-align: center"><font color="#FFFFFF"><span lang="EN-US" style="mso-bidi-font-size: 10.0pt"><a href="#ch23"><span style="mso-bidi-font-size: 10.0pt">2.3
进程控制</span></a></span></font>
<p style="TEXT-ALIGN: center" align="center"><font color="#FFFFFF"><span lang="EN-US" style="mso-bidi-font-size: 10.0pt"><a href="#ch24"><span style="mso-bidi-font-size: 10.0pt">2.4
线程的基本概念</span></a></span><span lang="EN-US" style="mso-bidi-font-size: 10.0pt"><o:p>
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<td width="18%" align="center" height="39"><font LANG="ZH-CN" color="#FFFFFF">作业：</font></td>
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<p align="left"><font color="#FFFFFF"><font LANG="ZH-CN"> </font></font></td>
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<td width="114%" align="center" height="39" colspan="2"><a href="index.htm"><font color="#FFFFFF">返回<<</font></a></td>
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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="ch21"></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">1
</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'">前驱图和程序执行</span><span lang="EN-US" style="FONT-SIZE: 14pt; mso-bidi-font-size: 10.0pt"><o:p>
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<p style="MARGIN-LEFT: 18pt; TEXT-INDENT: -18pt; tab-stops: list 18.0pt; mso-list: l1 level1 lfo2"><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'">前驱图的定义。</span><span lang="EN-US">(</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">略</span><span lang="EN-US">)</span></font></p>
<p style="MARGIN-LEFT: 18pt; TEXT-INDENT: -18pt; tab-stops: list 18.0pt; mso-list: l1 level1 lfo2"><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'">程序顺序执行</span></font></p>
<p><font color="#FFFFFF"><span style="mso-spacerun: yes" lang="EN-US">
</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">⑴程序顺序执行概念</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">⑵程序顺序执行的特征：顺序性、封闭性、可再现性</font></span></p>
<p style="MARGIN-LEFT: 18pt"><font color="#FFFFFF"><span style="mso-spacerun: yes" lang="EN-US">
</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">封闭性：所谓封闭性是指程序一旦开始执行，其执行过程不受任何外界因素影响。</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"> 顺序性：当程序在处理机上执行时，处理机的操作严格按照程序所规定的顺序执行。</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"> 确定性：其程序执行结果与执行速度、时间的无关性。</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">可再现性：指程序对一组数据的重复执行必得到相同的结果。</font></span></p>
<p style="MARGIN-LEFT: 18pt; TEXT-INDENT: -18pt; tab-stops: list 18.0pt; mso-list: l1 level1 lfo2"><font color="#FFFFFF"><span lang="EN-US">3．</span><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</span></font></p>
<p><font color="#FFFFFF"><span style="mso-spacerun: yes" lang="EN-US">
</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">⑴程序并发执行</span></font></p>
<p><font color="#FFFFFF"><span style="mso-spacerun: yes" lang="EN-US">
</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">使一个程序分成若干个可同时执行的程序模块的方法成为并发程序设计，能够并发执行的程序成为并发程序。</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">⑵程序顺序执行的特征：间断性、失去封闭性、不可再现性（举例说明）</font></span></p>
<p style="MARGIN-LEFT: 18pt; TEXT-INDENT: -18pt; tab-stops: list 18.0pt; mso-list: l1 level1 lfo2"><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'">并发程序与顺序程序的比较</span></font><span style="mso-spacerun: yes" lang="EN-US"><font color="#FFFFFF"> </font></span></p>
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<td style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: windowtext 0.5pt solid; 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">顺序程序</font></span></td>
<td style="BORDER-RIGHT: medium none; PADDING-RIGHT: 5.4pt; BORDER-TOP: windowtext 0.5pt solid; 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">并发程序</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: 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">并发执行</font></span></td>
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