我看到一个死锁std::mutex
时,互斥体可从被锁定DllMain()
下面是表现出对问题我最小的DLL测试用例。 我的实际代码执行互斥锁,因为它使用的也是正常功能时可用外初始化成员函数。
我认为这个问题是调度之间的僵局中的调用堆栈看到main()
线程和其他线程(可能)由调度催生。 僵局似乎之前发生main()
被实际执行。
我将不胜感激任何意见,以如何解决/解决死锁。
简单的DLL:
static void testFunc()
{
std::mutex mtx;
mtx.lock();
mtx.unlock();
}
BOOL APIENTRY DllMain( HMODULE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved
)
{
switch (ul_reason_for_call)
{
case DLL_PROCESS_ATTACH:
testFunc ();
break;
case DLL_THREAD_ATTACH:
testFunc ();
break;
case DLL_THREAD_DETACH:
case DLL_PROCESS_DETACH:
break;
}
return TRUE;
}
在僵局的点也有在这个过程中两个线程:
Not Flagged > 6408 0 Main Thread Main Thread msvcr110d.dll!Concurrency::details::SchedulerBase::SchedulerBase Normal
Not Flagged 7600 0 Worker Thread ntdll.dll!_TppWaiterpThread@4() ntdll.dll!_NtDelayExecution@8 Normal
下面是调用栈main()
线程:
ntdll.dll!_NtWaitForKeyedEvent@16() Unknown
ntdll.dll!_TppWaitpSet@16() Unknown
ntdll.dll!_TppSetWaitInterrupt@12() Unknown
ntdll.dll!_RtlRegisterWait@24() Unknown
kernel32.dll!_RegisterWaitForSingleObject@24() Unknown
> msvcr110d.dll!Concurrency::details::SchedulerBase::SchedulerBase(const Concurrency::SchedulerPolicy & policy) Line 152 C++
msvcr110d.dll!Concurrency::details::ThreadScheduler::ThreadScheduler(const Concurrency::SchedulerPolicy & policy) Line 26 C++
msvcr110d.dll!Concurrency::details::ThreadScheduler::Create(const Concurrency::SchedulerPolicy & policy) Line 34 C++
msvcr110d.dll!Concurrency::details::SchedulerBase::CreateWithoutInitializing(const Concurrency::SchedulerPolicy & policy) Line 276 C++
msvcr110d.dll!Concurrency::details::SchedulerBase::GetDefaultScheduler() Line 650 C++
msvcr110d.dll!Concurrency::details::SchedulerBase::CreateContextFromDefaultScheduler() Line 567 C++
msvcr110d.dll!Concurrency::details::SchedulerBase::CurrentContext() Line 399 C++
msvcr110d.dll!Concurrency::details::LockQueueNode::LockQueueNode(unsigned int timeout) Line 616 C++
msvcr110d.dll!Concurrency::critical_section::lock() Line 1017 C++
msvcp110d.dll!mtx_do_lock(_Mtx_internal_imp_t * * mtx, const xtime * target) Line 65 C++
msvcp110d.dll!_Mtx_lock(_Mtx_internal_imp_t * * mtx) Line 144 C++
ConsoleApplicationDll.dll!std::_Mtx_lockX(_Mtx_internal_imp_t * * _Mtx) Line 68 C++
ConsoleApplicationDll.dll!std::_Mutex_base::lock() Line 43 C++
ConsoleApplicationDll.dll!testFunc() Line 16 C++
ConsoleApplicationDll.dll!DllMain(HINSTANCE__ * hModule, unsigned long ul_reason_for_call, void * lpReserved) Line 29 C++
ConsoleApplicationDll.dll!__DllMainCRTStartup(void * hDllHandle, unsigned long dwReason, void * lpreserved) Line 508 C
ConsoleApplicationDll.dll!_DllMainCRTStartup(void * hDllHandle, unsigned long dwReason, void * lpreserved) Line 472 C
ntdll.dll!_LdrpCallInitRoutine@16() Unknown
ntdll.dll!_LdrpRunInitializeRoutines@4() Unknown
ntdll.dll!_LdrpInitializeProcess@8() Unknown
ntdll.dll!__LdrpInitialize@8() Unknown
ntdll.dll!_LdrInitializeThunk@8() Unknown
第二个线程调用堆栈短:
> ntdll.dll!_NtDelayExecution@8() Unknown
ntdll.dll!__LdrpInitialize@8() Unknown
ntdll.dll!_LdrInitializeThunk@8() Unknown
编辑1:
WinDbg中证明了它是装载机锁的问题:
PRIMARY_PROBLEM_CLASS: APPLICATION_HANG_HungIn_LoaderLock