📄 csdn_文档中心_关注内存 提高软件性能.htm
字号:
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">gc(</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">垃圾回收</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">)</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">问题</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">.<o:p></o:p></SPAN></FONT></P>
<P align=left class=MsoNormal
style="MARGIN: 0cm 0cm 0pt 18pt; TEXT-ALIGN: left; TEXT-INDENT: -18pt; mso-layout-grid-align: none; mso-list: l0 level1 lfo1; tab-stops: list 18.0pt"><FONT
color=#191b18><SPAN lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt; mso-fareast-font-family: 'Times New Roman'"><SPAN
style="mso-list: Ignore">2.<SPAN
style="FONT: 7pt 'Times New Roman'">
</SPAN></SPAN></SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">如何提高内存的使用效率</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">,</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">改善程序的性能</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt"><o:p></o:p></SPAN></FONT></P>
<P align=left class=MsoNormal
style="MARGIN: 0cm 0cm 0pt 18pt; TEXT-ALIGN: left; TEXT-INDENT: -18pt; mso-layout-grid-align: none; mso-list: l1 level1 lfo2; tab-stops: list 18.0pt"><FONT
color=#191b18><SPAN lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体"><SPAN
style="mso-list: Ignore">一.<SPAN
style="FONT: 7pt 'Times New Roman'">
</SPAN></SPAN></SPAN><SPAN lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">C++</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">中的</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">gc<o:p></o:p></SPAN></FONT></P>
<P align=left class=MsoNormal
style="MARGIN: 0cm 0cm 0pt 18pt; TEXT-ALIGN: left; mso-layout-grid-align: none"><FONT
color=#191b18><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">在</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">java,c#</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">中在创建对象的时候</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">,</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">你只需要调用</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">new,</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">而根本不需要去</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">delete.</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">因为这项工作交给由语言内嵌的机制实现了</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">.</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">当一个对象不用的时候</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">,</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">会由这种机制来实现垃圾收集</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">,</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">把资源归还给</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">os</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">的任务</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">.</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">而</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">c++</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">就没这么幸运了</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">.</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">你必须自己负责显示的条用</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">new,delete</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">来显示负责资源的分配和资源的回收</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">.</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">稍有不慎就会出现</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">memory
leak.memory leak</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">的严重性我就不说了</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">.</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">我想在这里实现的东西是想讲讲几种</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">gc</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">实现的思路</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">.</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">或者谈不上是垃圾回收吧</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">.</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">只是想做到象</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">java,c#</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">里面一样</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">,</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">只用显示调用</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">new,</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">而不用</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">delete,</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">在对象生命终结的时候会自动释放内存</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">.</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">我想用比较简单的代码来模拟这种思路</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">.<o:p></o:p></SPAN></FONT></P>
<P align=left class=MsoNormal
style="MARGIN: 0cm 0cm 0pt 18pt; TEXT-ALIGN: left; mso-layout-grid-align: none"><FONT
color=#191b18><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">最经典的就是智能指针吧</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">.</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">或者我下面的思路有点象智能指针</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">.</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">呵呵</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">.</SPAN><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">不过是个简</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt"><o:p></o:p></SPAN></FONT></P>
<P align=left class=MsoNormal
style="MARGIN: 0cm 0cm 0pt 18pt; TEXT-ALIGN: left; mso-layout-grid-align: none"><FONT
color=#191b18><SPAN
style="COLOR: blue; FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt">化的了</SPAN><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">.<o:p></o:p></SPAN></FONT></P>
<P align=left class=MsoNormal
style="MARGIN: 0cm 0cm 0pt 18pt; TEXT-ALIGN: left; mso-layout-grid-align: none"><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt"><o:p><FONT
color=#191b18> </FONT></o:p></SPAN></P>
<P align=left class=MsoNormal
style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none"><SPAN
lang=EN-US
style="COLOR: black; FONT-SIZE: 12pt; mso-font-kerning: 0pt"><o:p> </o:p></SPAN></P>
<P align=left class=MsoNormal
style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none"><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">#include<</SPAN><SPAN
lang=EN-US
style="COLOR: black; FONT-SIZE: 12pt; mso-font-kerning: 0pt">iostream><o:p></o:p></SPAN></P>
<P align=left class=MsoNormal
style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none"><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">using</SPAN><SPAN
lang=EN-US
style="COLOR: black; FONT-SIZE: 12pt; mso-font-kerning: 0pt">
</SPAN><SPAN lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">namespace</SPAN><SPAN
lang=EN-US
style="COLOR: black; FONT-SIZE: 12pt; mso-font-kerning: 0pt">
</SPAN><SPAN lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">std</SPAN><SPAN
lang=EN-US
style="COLOR: black; FONT-SIZE: 12pt; mso-font-kerning: 0pt">;<o:p></o:p></SPAN></P>
<P align=left class=MsoNormal
style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none"><SPAN
lang=EN-US
style="COLOR: black; FONT-SIZE: 12pt; mso-font-kerning: 0pt"><o:p> </o:p></SPAN></P>
<P align=left class=MsoNormal
style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none"><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">class</SPAN><SPAN
lang=EN-US
style="COLOR: black; FONT-SIZE: 12pt; mso-font-kerning: 0pt">
smpPointer<o:p></o:p></SPAN></P>
<P align=left class=MsoNormal
style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none"><SPAN
lang=EN-US
style="COLOR: black; FONT-SIZE: 12pt; mso-font-kerning: 0pt">{<o:p></o:p></SPAN></P>
<P align=left class=MsoNormal
style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none"><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">public</SPAN><SPAN
lang=EN-US
style="COLOR: black; FONT-SIZE: 12pt; mso-font-kerning: 0pt">:<o:p></o:p></SPAN></P>
<P align=left class=MsoNormal
style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none"><SPAN
lang=EN-US
style="COLOR: black; FONT-SIZE: 12pt; mso-font-kerning: 0pt"><SPAN
style="mso-tab-count: 1">
</SPAN>smpPointer(</SPAN><SPAN lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">void</SPAN><SPAN
lang=EN-US
style="COLOR: black; FONT-SIZE: 12pt; mso-font-kerning: 0pt"> * p) {
_p = p;<o:p></o:p></SPAN></P>
<P align=left class=MsoNormal
style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none"><SPAN
lang=EN-US
style="COLOR: black; FONT-SIZE: 12pt; mso-font-kerning: 0pt"><SPAN
style="mso-tab-count: 1">
</SPAN>}<o:p></o:p></SPAN></P>
<P align=left class=MsoNormal
style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none"><SPAN
lang=EN-US
style="COLOR: black; FONT-SIZE: 12pt; mso-font-kerning: 0pt"><SPAN
style="mso-tab-count: 1">
</SPAN>~smpPointer() { </SPAN><SPAN lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">delete</SPAN><SPAN
lang=EN-US
style="COLOR: black; FONT-SIZE: 12pt; mso-font-kerning: 0pt">
_p;<o:p></o:p></SPAN></P>
<P align=left class=MsoNormal
style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none"><SPAN
lang=EN-US
style="COLOR: black; FONT-SIZE: 12pt; mso-font-kerning: 0pt"><SPAN
style="mso-tab-count: 1">
</SPAN>}<o:p></o:p></SPAN></P>
<P align=left class=MsoNormal
style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none"><SPAN
lang=EN-US
style="COLOR: blue; FONT-SIZE: 12pt; mso-font-kerning: 0pt">private</SPAN><SPAN
lang=EN-US
style="COLOR: black; FONT-SIZE: 12pt; mso-font-kerning: 0pt">:<o:p></o:p></SPAN></P>
<P align=left class=MsoNormal
style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none"><SPAN
lang=EN-US
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -