线程本地存储（TLS）使同一进程的多个线程能够使用由TlsAlloc函数分配的索引来存储和检索线程本地的值。在此示例中，在进程启动时分配索引。当每个线程启动时，它会分配一个动态内存块，并使用TlsSetValue函数在TLS槽中存储指向此内存的指针。CommonFunc函数使用TlsGetValue函数来访问与调用线程本地的索引相关联的数据。在每个线程终止之前，它会释放其动态内存。在进程终止之前，它会调用TlsFree来释放索引。

#include <windows.h> 
#include <stdio.h> #define THREADCOUNT 4 
DWORD dwTlsIndex; VOID ErrorExit(LPSTR); VOID CommonFunc(VOID) 
{ LPVOID lpvData; // Retrieve a data pointer for the current thread. lpvData = TlsGetValue(dwTlsIndex); if ((lpvData == 0) && (GetLastError() != ERROR_SUCCESS)) ErrorExit("TlsGetValue error"); // Use the data stored for the current thread. printf("common: thread %d: lpvData=%lx\n", GetCurrentThreadId(), lpvData); Sleep(5000); 
} DWORD WINAPI ThreadFunc(VOID) 
{ LPVOID lpvData; // Initialize the TLS index for this thread. lpvData = (LPVOID) LocalAlloc(LPTR, 256); if (! TlsSetValue(dwTlsIndex, lpvData)) ErrorExit("TlsSetValue error"); printf("thread %d: lpvData=%lx\n", GetCurrentThreadId(), lpvData); CommonFunc(); // Release the dynamic memory before the thread returns. lpvData = TlsGetValue(dwTlsIndex); if (lpvData != 0) LocalFree((HLOCAL) lpvData); return 0; 
} int main(VOID) 
{ DWORD IDThread; HANDLE hThread[THREADCOUNT]; int i; // Allocate a TLS index. if ((dwTlsIndex = TlsAlloc()) == TLS_OUT_OF_INDEXES) ErrorExit("TlsAlloc failed"); // Create multiple threads. for (i = 0; i < THREADCOUNT; i++) { hThread[i] = CreateThread(NULL, // default security attributes 0,                           // use default stack size (LPTHREAD_START_ROUTINE) ThreadFunc, // thread function NULL,                    // no thread function argument 0,                       // use default creation flags &IDThread);              // returns thread identifier // Check the return value for success. if (hThread[i] == NULL) ErrorExit("CreateThread error\n"); } for (i = 0; i < THREADCOUNT; i++) WaitForSingleObject(hThread[i], INFINITE); TlsFree(dwTlsIndex);return 0; 
} VOID ErrorExit (LPSTR lpszMessage) 
{ fprintf(stderr, "%s\n", lpszMessage); ExitProcess(0); 
}

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在动态链接库中使用线程本地存储