我尝试注册一个名为MixCenter.dll的COM dll。我发现它所依赖的所有dll。首次执行DllMain时，它会冻结并且永远不会返回。似乎是一个僵局，但我没有调用任何LoadLibrary，并且它从未执行到DllMain。还有其他原因吗？这是DllMain的样子:
BOOL APIENTRY DllMain(HANDLE hModule, DWORD ul_reason_for_call, LPVOID lpReserved)
{
switch(ul_reason_for_call)
{
case DLL_PROCESS_ATTACH:
g_hinstDLL = hModule;
LOG(INFO) <<"--------------Begin Logging--------------";
return DllEntryPoint((HINSTANCE)hModule, ul_reason_for_call, lpReserved);
case DLL_THREAD_ATTACH:
break;
case DLL_THREAD_DETACH:
break;
case DLL_PROCESS_DETACH:
LOG(INFO) << "--------------End Logging--------------";
break;
}
return true;
}
我使用Dependency Walker记录了整个执行过程，该日志的重要部分是:
LoadLibraryExW("MixCenter.dll", 0x00000000, LOAD_WITH_ALTERED_SEARCH_PATH) called from "REGSVR32.EXE" at address 0x003920FF by thread 1.
Loaded "MIXCENTER.DLL" at address 0x10000000 by thread 1. Successfully hooked module.
Loaded "MSVCR80.DLL" at address 0x6F250000 by thread 1. Successfully hooked module.
Loaded "D3D9.DLL" at address 0x6C130000 by thread 1. Successfully hooked module.
Loaded "D3D8THK.DLL" at address 0x73490000 by thread 1. Successfully hooked module.
Loaded "D3DX9_40.DLL" at address 0x69B00000 by thread 1. Successfully hooked module.
Loaded "MSVCP80.DLL" at address 0x71430000 by thread 1. Successfully hooked module.
DllMain(0x6F250000, DLL_PROCESS_ATTACH, 0x00000000) in "MSVCR80.DLL" called by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "FlsAlloc") called from "MSVCR80.DLL" at address 0x6F253001 and returned 0x75CE8731 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "FlsGetValue") called from "MSVCR80.DLL" at address 0x6F25300E and returned 0x75CE0DC7 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "FlsSetValue") called from "MSVCR80.DLL" at address 0x6F25301B and returned 0x75CE2904 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "FlsFree") called from "MSVCR80.DLL" at address 0x6F253028 and returned 0x75CE2AD7 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "EncodePointer") called from "MSVCR80.DLL" at address 0x6F252BBC and returned 0x77603275 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "EncodePointer") called from "MSVCR80.DLL" at address 0x6F252BBC and returned 0x77603275 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "EncodePointer") called from "MSVCR80.DLL" at address 0x6F252BBC and returned 0x77603275 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "EncodePointer") called from "MSVCR80.DLL" at address 0x6F252BBC and returned 0x77603275 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "EncodePointer") called from "MSVCR80.DLL" at address 0x6F252BBC and returned 0x77603275 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "EncodePointer") called from "MSVCR80.DLL" at address 0x6F252BBC and returned 0x77603275 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "EncodePointer") called from "MSVCR80.DLL" at address 0x6F252BBC and returned 0x77603275 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "DecodePointer") called from "MSVCR80.DLL" at address 0x6F252C33 and returned 0x775FF050 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "InitializeCriticalSectionAndSpinCount") called from "MSVCR80.DLL" at address 0x6F259668 and returned 0x75CE0D2B by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "EncodePointer") called from "MSVCR80.DLL" at address 0x6F252BBC and returned 0x77603275 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "DecodePointer") called from "MSVCR80.DLL" at address 0x6F252C33 and returned 0x775FF050 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "DecodePointer") called from "MSVCR80.DLL" at address 0x6F252C33 and returned 0x775FF050 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "DecodePointer") called from "MSVCR80.DLL" at address 0x6F252C33 and returned 0x775FF050 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "DecodePointer") called from "MSVCR80.DLL" at address 0x6F252C33 and returned 0x775FF050 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "DecodePointer") called from "MSVCR80.DLL" at address 0x6F252C33 and returned 0x775FF050 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "DecodePointer") called from "MSVCR80.DLL" at address 0x6F252C33 and returned 0x775FF050 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "DecodePointer") called from "MSVCR80.DLL" at address 0x6F252C33 and returned 0x775FF050 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "DecodePointer") called from "MSVCR80.DLL" at address 0x6F252C33 and returned 0x775FF050 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "DecodePointer") called from "MSVCR80.DLL" at address 0x6F252C33 and returned 0x775FF050 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "DecodePointer") called from "MSVCR80.DLL" at address 0x6F252C33 and returned 0x775FF050 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "DecodePointer") called from "MSVCR80.DLL" at address 0x6F252C33 and returned 0x775FF050 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "DecodePointer") called from "MSVCR80.DLL" at address 0x6F252C33 and returned 0x775FF050 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "DecodePointer") called from "MSVCR80.DLL" at address 0x6F252C33 and returned 0x775FF050 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "DecodePointer") called from "MSVCR80.DLL" at address 0x6F252C33 and returned 0x775FF050 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "DecodePointer") called from "MSVCR80.DLL" at address 0x6F252C33 and returned 0x775FF050 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "EncodePointer") called from "MSVCR80.DLL" at address 0x6F252D3A and returned 0x77603275 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "DecodePointer") called from "MSVCR80.DLL" at address 0x6F252D4A and returned 0x775FF050 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "IsProcessorFeaturePresent") called from "MSVCR80.DLL" at address 0x6F26A967 and returned 0x75CE0DD4 by thread 1.
GetProcAddress(0x75BC0000 [MSVCRT.DLL], "_set_error_mode") called from "MSVCR80.DLL" at address 0x6F254447 and returned 0x75BD4A3D by thread 1.
GetProcAddress(0x75BC0000 [MSVCRT.DLL], "?set_terminate@@YAP6AXXZP6AXXZ@Z") called from "MSVCR80.DLL" at address 0x6F254463 and returned 0x75BEEBB7 by thread 1.
GetProcAddress(0x75BC0000 [MSVCRT.DLL], "_get_terminate") called from "MSVCR80.DLL" at address 0x6F25447F and returned NULL by thread 1. Error: (127).
GetProcAddress(0x75C90000 [KERNEL32.DLL], "FindActCtxSectionStringW") called from "MSVCR80.DLL" at address 0x6F251DBE and returned 0x75CE18F9 by thread 1.
GetProcAddress(0x75C90000 [KERNEL32.DLL], "GetSystemWindowsDirectoryW") called from "MSVCR80.DLL" at address 0x6F251F1A and returned 0x75CE0E64 by thread 1.
DllMain(0x6F250000, DLL_PROCESS_ATTACH, 0x00000000) in "MSVCR80.DLL" returned 1 (0x1) by thread 1.
DllMain(0x73490000, DLL_PROCESS_ATTACH, 0x00000000) in "D3D8THK.DLL" called by thread 1.
DllMain(0x73490000, DLL_PROCESS_ATTACH, 0x00000000) in "D3D8THK.DLL" returned 1 (0x1) by thread 1.
DllMain(0x6C130000, DLL_PROCESS_ATTACH, 0x00000000) in "D3D9.DLL" called by thread 1.
DllMain(0x6C130000, DLL_PROCESS_ATTACH, 0x00000000) in "D3D9.DLL" returned 1 (0x1) by thread 1.
DllMain(0x69B00000, DLL_PROCESS_ATTACH, 0x00000000) in "D3DX9_40.DLL" called by thread 1.
DllMain(0x69B00000, DLL_PROCESS_ATTACH, 0x00000000) in "D3DX9_40.DLL" returned 1 (0x1) by thread 1.
DllMain(0x71430000, DLL_PROCESS_ATTACH, 0x00000000) in "MSVCP80.DLL" called by thread 1.
DllMain(0x71430000, DLL_PROCESS_ATTACH, 0x00000000) in "MSVCP80.DLL" returned 1 (0x1) by thread 1.
DllMain(0x10000000, DLL_PROCESS_ATTACH, 0x00000000) in "MIXCENTER.DLL" called by thread 1.
最佳答案
DllMain中有很多您不能做的事情。您不仅不能自己调用LoadLibrary，而且不能做任何会导致LoadLibrary被调用的事情，并且注册COM服务器听起来像在某个时候很容易就能完成LoadLibrary。
但这不是DllMain无法做到的程度。该列表很长而且很复杂，因此最好的做法是使用两阶段初始化方案，其中DllMain只是设置一个标志，然后DLL中的其他代码将执行复杂的初始化。此“其他代码”可能是与DLL一起使用的另一个线程，也可能只是调用DLL的主例程中调用的Init()函数。
关于c++ - DllMain卡住在注册COM dll时，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/5622759/