线程局部存储TLS

<a href="">Thread local storage</a> (TLS)统一进程的多个线程可以通过由TlsAlloc方法返回的索引值在线程自身的空间内存储和取回一个值。在以下这个例子里，索引值在进程开始时创建，当各个线程启动时，会各自申请一块动态内存并且将内存指针通过TlsSetValue方法存储到各自的TLS空间中（由先前的索引值标定）。CommonFunc方法使用TlsGetValue方法通过索引取得数据指针。在各个线程结束前，释放动态内存块。在进程结束见，调用TlsFree方法释放索引。 
<div>
 1
<img align="top" alt="" src="https://beijingoptbbs.oss-cn-beijing.aliyuncs.com/cs/5606289-cbef093dcc044b2793832001e2365e43.gif">
#include 
<
windows.h
>
 
 2
<img align="top" alt="" src="https://beijingoptbbs.oss-cn-beijing.aliyuncs.com/cs/5606289-cbef093dcc044b2793832001e2365e43.gif">#include 
<
stdio.h
>
 
 3
<img align="top" alt="" src="https://beijingoptbbs.oss-cn-beijing.aliyuncs.com/cs/5606289-cbef093dcc044b2793832001e2365e43.gif"> 
 4
<img align="top" alt="" src="https://beijingoptbbs.oss-cn-beijing.aliyuncs.com/cs/5606289-cbef093dcc044b2793832001e2365e43.gif">
#define
 THREADCOUNT 4 
 
 5
<img align="top" alt="" src="https://beijingoptbbs.oss-cn-beijing.aliyuncs.com/cs/5606289-cbef093dcc044b2793832001e2365e43.gif">DWORD dwTlsIndex; 
 6
<img align="top" alt="" src="https://beijingoptbbs.oss-cn-beijing.aliyuncs.com/cs/5606289-cbef093dcc044b2793832001e2365e43.gif"> 
 7
<img align="top" alt="" src="https://beijingoptbbs.oss-cn-beijing.aliyuncs.com/cs/5606289-cbef093dcc044b2793832001e2365e43.gif">VOID ErrorExit(LPSTR); 
 8
<img align="top" alt="" src="https://beijingoptbbs.oss-cn-beijing.aliyuncs.com/cs/5606289-cbef093dcc044b2793832001e2365e43.gif"> 
 9
<img align="top" alt="" src="https://beijingoptbbs.oss-cn-beijing.aliyuncs.com/cs/5606289-cbef093dcc044b2793832001e2365e43.gif">VOID CommonFunc(VOID) 
10
<img align="top" alt="" id="Codehighlighter1_137_513_Open_Image" src="https://beijingoptbbs.oss-cn-beijing.aliyuncs.com/cs/5606289-2f88ce130b654eb5dc6788e02dbcfc90.gif">
{ 11<img align="top" alt="" src="https://beijingoptbbs.oss-cn-beijing.aliyuncs.com/cs/5606289-df37983f39daa189b8c814e01a6a9011.gif"> LPVOID lpvData; 12<img align="top" alt="" src="https://beijingoptbbs.oss-cn-beijing.aliyuncs.com/cs/5606289-df37983f39daa189b8c814e01a6a9011.gif"> 13<img align="top" alt="" src="https://beijingoptbbs.oss-cn-beijing.aliyuncs.com/cs/5606289-df37983f39daa189b8c814e01a6a9011.gif">// Retrieve a data pointer for the current thread. 14<img align="top" alt="" src="https://beijingoptbbs.oss-cn-beijing.aliyuncs.com/cs/5606289-df37983f39daa189b8c814e01a6a9011.gif"> 15<img align="top" alt="" src="https://beijingoptbbs.oss-cn-beijing.aliyuncs.com/cs/5606289-df37983f39daa189b8c814e01a6a9011.gif"> lpvData = TlsGetValue(dwTlsIndex); 16<img align="top" alt="" src="https://beijingoptbbs.oss-cn-beijing.aliyuncs.com/cs/5606289-df37983f39daa189b8c814e01a6a9011.gif"> if ((lpvData == 0) && (GetLastError() != ERROR_SUCCESS)) 17<img align="top" alt="" src="https://beijingopt