このコードはリンクするライブラリをマルチスレッド対応版にするだけで動くんだが何故だ？
DWORD WINAPI TestFunc(LPVOID ThreadData)
{
ThreadInfo &Info = *(ThreadInfo *)ThreadData;
std::string RetStr("result: "); const char *sep = ",";
char IDBuf[64]; sprintf(IDBuf, "Thread 0x%08X Info", GetCurrentThreadId());

WaitForSingleObject(Info.hMutex, INFINITE); Sleep(100); char *s = strtok(Info.TestStr, sep); ReleaseMutex(Info.hMutex);
while(s) {
RetStr += s; RetStr += " - ";
WaitForSingleObject(Info.hMutex, INFINITE); Sleep(100); s = strtok(NULL, sep); ReleaseMutex(Info.hMutex);
}
MessageBox(NULL, RetStr.c_str(), IDBuf, MB_OK);
return 0;
}
int main()
{
DWORD Thread1ID, Thread2ID; HANDLE hMutex = CreateMutex(NULL, TRUE, NULL);
ThreadInfo Info1 = { hMutex, "ab,cd,ef,gh" }, Info2 = { hMutex, "12,34,56,78" };
HANDLE hThread1 = CreateThread(NULL, 0, TestFunc, &Info1, 0, &Thread1ID);
HANDLE hThread2 = CreateThread(NULL, 0, TestFunc, &Info2, 0, &Thread2ID);
ReleaseMutex(hMutex);
WaitForSingleObject(hThread1, INFINITE); WaitForSingleObject(hThread2, INFINITE);
return 0;
}