We are observing 4-6 threads on Windows 7 x64 in the application which have 3 threads and behaves normally on any Windows (either 32 or 64 bit) prior Windows 7.
Process Explorer shows the following "unknown" thread:
ntdll.dll!EtwDeliverDataBlock+offset
after random interval the following threads appear:
ntdll.dll!TpCallbackIndependent+offset
ntdll.dll!TpCallbackIndependent+offset
after that application can't create thread (error code 8, hot enough space ...).
It seems to me that some system DLL creates ETW threads or something. Does anyone know what these threads for and how to manage them?