當DLL被加載時如何加載JVM，並且在卸載DLL時釋放它

Question

我正在開發一個調用jar來通過JNI完成大部分工作的dll。我怎樣才能創建DLL，使得它只在DLL加載時創建JVM一次，並在卸載DLL時釋放它？

Answer 1

提供一個DllMain函數，在此之後圖案：

BOOL WINAPI DllMain(
    HINSTANCE hinstDLL, // handle to DLL module 
    DWORD fdwReason,  // reason for calling function 
    LPVOID lpReserved)  // reserved 
{ 
    // Perform actions based on the reason for calling. 
    switch(fdwReason) 
    { 
     case DLL_PROCESS_ATTACH: 
      // Initialize once for each new process. 
      // Return FALSE to fail DLL load. 
      LOAD_JVM(); // <----------------------------------------- 
      break; 
     case DLL_THREAD_ATTACH: 
      // Do thread-specific initialization. 
      break; 
     case DLL_THREAD_DETACH: 
      // Do thread-specific cleanup. 
      break; 
     case DLL_PROCESS_DETACH: 
      // Perform any necessary cleanup. 
      UNLOAD_JVM(); // <----------------------------------------- 
      break; 
    } 
    // Successful DLL_PROCESS_ATTACH. 
    return TRUE; 
}