|
<h1 style="font-family:'-apple-system', 'SF UI Text', Arial, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', sans-serif, SimHei, SimSun;background-color:rgb(255,255,255);">进程控制块</h1><div style="color:rgb(51,51,51);font-family:'-apple-system', 'SF UI Text', Arial, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', sans-serif, SimHei, SimSun;font-size:14px;background-color:rgb(255,255,255);"><h4>百科名片</h4><div><div><div>进程控制块的作用是使一个在<a data-token="d3f628d56d980ff34ceb02a6ec8c8a40" href="http://baike.baidu.com/view/1189611.htm" rel="nofollow">多道程序</a>环境下不能独立运行的程序(含数据),成为一个能独立运行的基本单位,一个能与其它进程并发执行的进程。或者说,OS是根据PCB来对并发执行的进程进行控制和管理的。PCB通常是系统内存占用区中的一个连续存区,它存放着<a data-token="4fad9b842af221a9a2afa98e3b5bcada" href="http://baike.baidu.com/view/880.htm" rel="nofollow">操作系统</a>用于描述进程情况及控制进程运行所需的全部信息,它使一个在<a data-token="d3f628d56d980ff34ceb02a6ec8c8a40" href="http://baike.baidu.com/view/1189611.htm" rel="nofollow">多道程序</a>环境下不能独立运行的程序成为一个能独立运行的基本单位,一个能与其他进程并发执行的进程。</div></div></div></div><div style="color:rgb(51,51,51);font-family:'-apple-system', 'SF UI Text', Arial, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', sans-serif, SimHei, SimSun;font-size:14px;background-color:rgb(255,255,255);width:233px;"><p>目录</p><dl><dd><a data-token="ef043f6c53608fdc577246dfa6bf3279" href="http://baike.baidu.com/view/396362.htm#1" name="STAT_ONCLICK_UNSUBMIT_CATALOG" rel="nofollow">进程控制块的基本内容</a></dd><dd><a data-token="a36f931592ed0132e54643cfa260c70b" href="http://baike.baidu.com/view/396362.htm#2" rel="nofollow">实例</a></dd><dd>展开</dd></dl><dl style="width:158px;"><dd><a data-token="ef043f6c53608fdc577246dfa6bf3279" href="http://baike.baidu.com/view/396362.htm#1" rel="nofollow">进程控制块的基本内容</a></dd><dd><a data-token="a36f931592ed0132e54643cfa260c70b" href="http://baike.baidu.com/view/396362.htm#2" rel="nofollow">实例</a></dd><dd>展开</dd></dl></div><h2 style="font-family:'-apple-system', 'SF UI Text', Arial, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', sans-serif, SimHei, SimSun;background-color:rgb(255,255,255);"><a name="t1"></a><a name="1"></a><a name="sub396362_1"></a><span>进程控制块的基本内容</span></h2><h3 style="font-family:'-apple-system', 'SF UI Text', Arial, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', sans-serif, SimHei, SimSun;background-color:rgb(255,255,255);"><a name="t2"></a><a name="1_1"></a><a name="sub396362_1_1"></a><span>概述:</span></h3><div style="color:rgb(51,51,51);font-family:'-apple-system', 'SF UI Text', Arial, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', sans-serif, SimHei, SimSun;font-size:14px;background-color:rgb(255,255,255);">进程控制块(PCB)(系统为了管理进程设置的一个专门的数据结构,用它来记录进程的外部特征,描述进程的运动变化过程。系统利用PCB来控制和管理进程,所以PCB是系统感知进程存在的唯一标志。进程与PCB是一 一对应的)</div><h3 style="font-family:'-apple-system', 'SF UI Text', Arial, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', sans-serif, SimHei, SimSun;background-color:rgb(255,255,255);"><a name="t3"></a><a name="1_2"></a><a name="sub396362_1_2"></a><span>应用:</span></h3><div style="color:rgb(51,51,51);font-family:'-apple-system', 'SF UI Text', Arial, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', sans-serif, SimHei, SimSun;font-size:14px;background-color:rgb(255,255,255);">在不同的<a data-token="4fad9b842af221a9a2afa98e3b5bcada" href="http://baike.baidu.com/view/880.htm" rel="nofollow">操作系统</a>中对进程的控制和管理机制不同,PCB中的信息多少也不一样,通常PCB应包含如下一些信息。</div><div style="color:rgb(51,51,51);font-family:'-apple-system', 'SF UI Text', Arial, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', sans-serif, SimHei, SimSun;font-size:14px;background-color:rgb(255,255,255);">1、进程<a data-token="d069c75d3fbf512bd3a1d1b444d02368" href="http://baike.baidu.com/view/390932.htm" rel="nofollow">标识符</a>name:</div><div style="color:rgb(51,51,51);font-family:'-apple-system', 'SF UI Text', Arial, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', sans-serif, SimHei, SimSun;font-size:14px;background-color:rgb(255,255,255);">每个进程都必须有一个唯一的<a data-token="d069c75d3fbf512bd3a1d1b444d02368" href="http://baike.baidu.com/view/390932.htm" rel="nofollow">标识符</a>,可以是字符串,也可以是一个数字。</div><div style="color:rgb(51,51,51);font-family:'-apple-system', 'SF UI Text', Arial, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', sans-serif, SimHei, SimSun;font-size:14px;background-color:rgb(255,255,255);">2、进程当前状态 status:</div><div style="color:rgb(51,51,51);font-family:'-apple-system', 'SF UI Text', Arial, ' |
|