Minor Description
We have a standlone VC++ application and we added logging using the log4cxx0.10.0 version.
The application will initiate a thread (for some time consuming operation) and if it takes more than threshold time then the main thread will kill the thread using TerminateThread method.
The child thread function also has some logging prints.Log4CXX configured with rolling file appender of 1 MB size of 5 backup copies.
Logging is working fine in most of the scenarios. But in some scenarios main thread logging function call is hanging after killing the child thread and hence the entire application is in hanging state.
Subsequent instances of the application is also hanging. We took the full crash dumps of the application and analyzed using the WinDbg.
Here is the call stack of the application
00 ntdll!NtWaitForSingleObject+0xa
01 ntdll!RtlpWaitOnCriticalSection+0xe8
02 ntdll!RtlEnterCriticalSection+0xd1
03 log4cxx!log4cxx::filter::DenyAllFilter::decide+0x194
04 log4cxx!log4cxx::helpers::synchronized::synchronized+0x31
05 log4cxx!log4cxx::Logger::callAppenders+0x81
06 log4cxx!log4cxx::Logger::forcedLog+0xe5
07 Test!CXX_LOG(int LOG_TYPE = 0n2, char * format = 0x00000001`3f2a2ad8 "Main thread pint...")+0x463 [d:\test\saf\test.cpp @ 2360]
08 test!TestFunction(int argc = 0n3, char ** argv = 0x00000001`3f2ae880, int level = 0n1)+0x586 [d:\test\saf\test.cpp @ 1634]
09 test!main(int argc = 0n4, char ** argv = 0x00000000`00282920)+0x1820 [d:\test\saf\test.cpp @ 2309]
0a test!__tmainCRTStartup(void)+0x13b [f:\dd\vctools\crt_bld\self_64_amd64\crt\src\crt0.c @ 278]
0b kernel32!BaseThreadInitThunk+0xd
0c ntdll!RtlUserThreadStart+0x1d
and subsequent applications hangs for locking the file and call stack of the instance as follows
ntdll!ZwLockFile+0xa
KERNELBASE!LockFileEx+0xb2
kernel32!LockFileEx+0x1b
log4cxx!log4cxx::filter::DenyAllFilter::decide+0x2a89
log4cxx!log4cxx::helpers::DatagramPacket::setData+0x559c
log4cxx!log4cxx::helpers::FileOutputStream::write+0x82
log4cxx!log4cxx::rolling::RollingFileAppenderSkeleton::getTriggeringPolicy+0x1ca
log4cxx!log4cxx::helpers::OutputStreamWriter::write+0xbe
log4cxx!log4cxx::WriterAppender::subAppend+0x7c
log4cxx!log4cxx::rolling::RollingFileAppenderSkeleton::subAppend+0xd0
log4cxx!log4cxx::WriterAppender::append+0x31
log4cxx!log4cxx::AppenderSkeleton::doAppend+0x293
log4cxx!log4cxx::helpers::AppenderAttachableImpl::appendLoopOnAppenders+0x40
log4cxx!log4cxx::Logger::callAppenders+0xa3
log4cxx!log4cxx::Logger::forcedLog+0xe5
test!CXX_LOG(int LOG_TYPE = 0n2, char * format = 0x00000001`3f2a3868 "Starting the application")+0x463
test!main(int argc = 0n4, char ** argv = 0x00000000`00162920)+0x1806
test!__tmainCRTStartup(void)+0x13b
kernel32!BaseThreadInitThunk+0xd
ntdll!RtlUserThreadStart+0x21
We have checked the function 'decide' and it has nothing to do with locking. it is just returning some constant value.
I have read that LOG4CXX is thread safe. This issue is not occurring frequently and hence we didn't have the steps to reproduce in consistent way.
Is it anything needs to be addressed when we killing the child thread??