[BUG] Memory leaks inside RCPs

[vovannikov]

Description

There are memory leaks in the new structure solver. The debug version of Trilinos clearly reveals it, see the attached log file. valgrind also detects them, see another log.

I looked at those location indicated by Trilinos, and it seems the leaks are related for those objects which get added to a shared ParametersList in multiple places. At least, the pattern preceding the appearances of this leaks is always the same: something gets plugged into an arbitrary branch of a large params list. I assume, there is a cycle dependency appearing somewhere. I could not identify the source of the problem with a glance look at the code since the hierarchy between the shared pointers is actually quite complicated + a lot of objects behaving like global variables. I can try to debug it a bit further.

valgrind --leak-check=full --log-file=valgrind.log \
    ~/development/4C-debug/4C ~/development/4C/tests/input_files/structure_new_nln_solver_singlestep_cube_linear.dat test1

valgrind.log
4c-log.txt

Steps to reproduce

1. Build debug version of Trilinos
2. Build debug version of 4C and link it against the debug version of Trilinos
3. Execute the command above

[amgebauer]

Thanks for reporting the issue. That reminds me of #63

[vovannikov]

Just another small remark, I think we should not abuse ParametersList for transferring objects all over the code, this is nasty. The pattern like this appears in multiple places:

4C/src/structure_new/src/utils/4C_structure_new_dbc.cpp

Lines 99 to 108 in 0c76853

	// get a mutable reference to the linear solver parameter list
	Teuchos::ParameterList& p_linsolver = const_cast<Teuchos::ParameterList&>(
	pnox.sublist("Direction").sublist("Newton").sublist("Linear Solver"));
	NOX::Nln::LinSystem::PrePostOperator::Map& prepostlinsystem_map =
	NOX::Nln::LinSystem::PrePostOp::get_map(p_linsolver);
	// create the new pre/post operator for the nox nln linear system
	Teuchos::RCP<NOX::Nln::Abstract::PrePostOperator> prepostdbc_ptr =
	Teuchos::make_rcp<NOX::Nln::LinSystem::PrePostOp::Dbc>(Teuchos::rcpFromRef(*this));
	// insert/replace the old pointer in the map
	prepostlinsystem_map[NOX::Nln::LinSystem::prepost_dbc] = prepostdbc_ptr;

[sebproell]

FYI, I have been trying to reduce the number of RCPs/shared_ptrs inside 4C for precisely this reason. And fully agree on the ParameterList thing. It's really meant for input and should not be used as dynamic container to make bad inheritance work, see #61.

[vovannikov]

Actually, the code example above is exactly a typical example that creates a cyclic dependency, we need just to a few more lines above to recognize it:

4C/src/structure_new/src/utils/4C_structure_new_dbc.cpp

Lines 94 to 109 in 0c76853

	const Teuchos::ParameterList& pnox = timint_ptr_->get_data_sdyn().get_nox_params();
	if (pnox.sublist("Direction").isSublist("Newton"))
	{
	if (pnox.sublist("Direction").sublist("Newton").isSublist("Linear Solver"))
	{
	// get a mutable reference to the linear solver parameter list
	Teuchos::ParameterList& p_linsolver = const_cast<Teuchos::ParameterList&>(
	pnox.sublist("Direction").sublist("Newton").sublist("Linear Solver"));
	NOX::Nln::LinSystem::PrePostOperator::Map& prepostlinsystem_map =
	NOX::Nln::LinSystem::PrePostOp::get_map(p_linsolver);
	// create the new pre/post operator for the nox nln linear system
	Teuchos::RCP<NOX::Nln::Abstract::PrePostOperator> prepostdbc_ptr =
	Teuchos::make_rcp<NOX::Nln::LinSystem::PrePostOp::Dbc>(Teuchos::rcpFromRef(*this));
	// insert/replace the old pointer in the map
	prepostlinsystem_map[NOX::Nln::LinSystem::prepost_dbc] = prepostdbc_ptr;
	}

timint_ptr_ is a shared pointer inside Solid::Dbc, it contains the ParametersList, to which we ultimately store the RCP to the this object itself.