線程本地存儲（TLS）使同一進程的多個線程能夠使用由TlsAlloc函數分配的索引來存儲和檢索線程本地的值。在此示例中，在進程啟動時分配索引。當每個線程啟動時，它會分配一個動態內存塊，并使用TlsSetValue函數在TLS槽中存儲指向此內存的指針。CommonFunc函數使用TlsGetValue函數來訪問與調用線程本地的索引相關聯的數據。在每個線程終止之前，它會釋放其動態內存。在進程終止之前，它會調用TlsFree來釋放索引。

#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); 
}

相關話題

在動態鏈接庫中使用線程本地存儲