LUMIERA.clone/tests/library/linked-elements-test.cpp
Ichthyostega 856d8a3b51 Library: allow to reverse intrusive single linked list
Looks like we'll actually retain and use this low-level solution
in cases where we just can not afford heap allocations but need
to keep polymorphic objects close to one another in memory.

Since single linked lists are filled by prepending, it is rather
common to need the reversed order of elements for traversal,
which can be achieved in linear time.

And while we're here, we can modernise the templated emplacement functions
2023-04-20 18:53:17 +02:00

515 lines
15 KiB
C++

/*
LinkedElements(Test) - verify the intrusive single linked list template
Copyright (C) Lumiera.org
2012, Hermann Vosseler <Ichthyostega@web.de>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
* *****************************************************/
/** @file linked-elements-test.cpp
** unit test \ref LinkedElements_test
*/
#include "lib/test/run.hpp"
#include "lib/test/test-helper.hpp"
#include "lib/util.hpp"
#include "lib/allocation-cluster.hpp"
#include "lib/linked-elements.hpp"
#include "lib/test/testdummy.hpp"
#include "lib/iter-source.hpp"
#include <memory>
namespace lib {
namespace test{
namespace error = lumiera::error;
using util::isnil;
using util::isSameObject;
using lumiera::error::LERR_(ITER_EXHAUST);
namespace { // test data...
LUMIERA_ERROR_DEFINE(PROVOKED_FAILURE, "provoked failure");
const uint NUM_ELEMENTS = 500;
int exception_trigger = -1;
inline void __triggerErrorAt(int i) { exception_trigger = i; }
inline void __triggerError_reset() { exception_trigger =-1; }
/**
* Test-Element, supporting intrusive linked list storage.
* Also tracks ctor/dtor calls by virtue of the Dummy baseclass.
*/
struct Nummy
: Dummy
{
Nummy* next;
Nummy()
: Dummy()
, next{0}
{ }
explicit
Nummy (int i)
: Dummy{i}
, next{0}
{
if (i == exception_trigger)
throw error::Fatal("simulated error", LERR_(PROVOKED_FAILURE));
}
};
/**
* to demonstrate holding subclasses
*/
template<uint I>
struct Num
: Nummy
{
void* storage[I]; // note size depends on template parameter
Num (int i=0, int j=0, int k=0)
: Nummy(I+i+j+k)
{ }
};
/**
* Helper to produce a pre-determined series
* of objects to populate a LinkedElements list.
* @note just happily heap allocating new instances
* and handing them out. The LinkedElements list
* will take ownership of them and care for
* clean de-allocation.
*/
class NummyGenerator
: public IterSource<Nummy>
{
uint maxNum_;
virtual Pos
firstResult()
{
return new Nummy(1);
}
virtual void
nextResult(Pos& num)
{
uint current = num->getVal();
if (maxNum_ <= current)
num = 0;
else
num = new Nummy(current+1);
}
public:
NummyGenerator (uint maxElms)
: maxNum_(maxElms)
{ }
};
/** Iterator-Frontend to generate this series of objects */
class Populator
: public NummyGenerator::iterator
{
public:
explicit
Populator (uint numElms)
: NummyGenerator::iterator (
NummyGenerator::build (new NummyGenerator(numElms)))
{ }
};
inline uint
sum (uint n)
{
return n*(n+1) / 2;
}
}//(End) subversive test data
/// default case: ownership for heap allocated nodes
using List = LinkedElements<Nummy>;
/// managing existing node elements without taking ownership
using ListNotOwner = LinkedElements<Nummy, linked_elements::NoOwnership>;
/// creating nodes in-place, using a custom allocator for creation and disposal
using ListCustomAllocated = LinkedElements<Nummy, linked_elements::UseAllocationCluster>;
/****************************************************************//**
* @test cover our custom single linked list template,
* in combination with Lumiera Forward Iterators
* and the usage of a custom allocator.
*/
class LinkedElements_test : public Test
{
virtual void
run (Arg)
{
simpleUsage();
iterating();
reverseList();
verify_nonOwnership();
verify_ExceptionSafety();
populate_by_iterator();
verify_RAII_safety();
verify_customAllocator();
}
void
simpleUsage()
{
CHECK (0 == Dummy::checksum());
{
List elements;
CHECK (isnil (elements));
CHECK (0 == elements.size());
CHECK (0 == Dummy::checksum());
elements.emplace<Nummy>(1);
elements.emplace<Nummy>(2);
elements.emplace<Nummy>(3);
elements.emplace<Nummy>(4);
elements.emplace<Nummy>(5);
CHECK (!isnil (elements));
CHECK (5 == elements.size());
CHECK (0 != Dummy::checksum());
CHECK (Dummy::checksum() == elements[0].getVal()
+ elements[1].getVal()
+ elements[2].getVal()
+ elements[3].getVal()
+ elements[4].getVal());
elements.clear();
CHECK (isnil (elements));
CHECK (0 == elements.size());
CHECK (0 == Dummy::checksum());
elements.emplace<Nummy>();
elements.emplace<Nummy>();
elements.emplace<Nummy>();
CHECK (3 == elements.size());
CHECK (0 != Dummy::checksum());
}
CHECK (0 == Dummy::checksum());
}
void
iterating()
{
CHECK (0 == Dummy::checksum());
{
List elements;
for (uint i=1; i<=NUM_ELEMENTS; ++i)
elements.emplace<Nummy>(i);
// since elements where pushed,
// they should appear in reversed order
int check=NUM_ELEMENTS;
List::iterator ii = elements.begin();
while (ii)
{
CHECK (check == ii->getVal());
CHECK (check == ii->acc(+5) - 5);
--check;
++ii;
}
CHECK (0 == check);
// Test the const iterator
List const& const_elm (elements);
check = NUM_ELEMENTS;
List::const_iterator cii = const_elm.begin();
while (cii)
{
CHECK (check == cii->getVal());
--check;
++cii;
}
CHECK (0 == check);
// Verify correct behaviour of iteration end
CHECK (! (elements.end()));
CHECK (isnil (elements.end()));
VERIFY_ERROR (ITER_EXHAUST, *elements.end() );
VERIFY_ERROR (ITER_EXHAUST, ++elements.end() );
CHECK (ii == elements.end());
CHECK (ii == List::iterator());
CHECK (cii == elements.end());
CHECK (cii == List::const_iterator());
VERIFY_ERROR (ITER_EXHAUST, ++ii );
VERIFY_ERROR (ITER_EXHAUST, ++cii );
}
CHECK (0 == Dummy::checksum());
}
void
reverseList()
{
CHECK (0 == Dummy::checksum());
{
List list;
CHECK (isnil (list));
list.reverse();
CHECK (isnil (list));
CHECK (0 == Dummy::checksum());
list.emplace<Nummy>(1);
CHECK (not isnil (list));
CHECK (1 == list[0].getVal());
CHECK (1 == Dummy::checksum());
list.reverse();
CHECK (1 == Dummy::checksum());
CHECK (1 == list[0].getVal());
CHECK (not isnil (list));
list.emplace<Nummy>(2);
CHECK (not isnil (list));
CHECK (2 == list.size());
CHECK (2 == list[0].getVal());
CHECK (2+1 == Dummy::checksum());
list.reverse();
CHECK (1+2 == Dummy::checksum());
CHECK (1 == list[0].getVal());
CHECK (2 == list.size());
list.emplace<Nummy>(3);
CHECK (3 == list.size());
CHECK (3 == list.top().getVal());
CHECK (3+1+2 == Dummy::checksum());
list.reverse();
CHECK (2 == list[0].getVal());
CHECK (1 == list[1].getVal());
CHECK (3 == list[2].getVal());
List::iterator ii = list.begin();
CHECK (2 == ii->getVal());
++ii;
CHECK (1 == ii->getVal());
++ii;
CHECK (3 == ii->getVal());
++ii;
CHECK (isnil (ii));
CHECK (2+1+3 == Dummy::checksum());
list.emplace<Nummy>(4);
CHECK (4 == list.top().getVal());
CHECK (3 == list[3].getVal());
list.reverse();
CHECK (3 == list[0].getVal());
CHECK (1 == list[1].getVal());
CHECK (2 == list[2].getVal());
CHECK (4 == list[3].getVal());
CHECK (3+1+2+4 == Dummy::checksum());
}
CHECK (0 == Dummy::checksum());
}
/** @test add some node elements to the LinkedElements list
* but without taking ownership or performing any
* memory management. This usage pattern is helpful
* when the node elements are already managed elsewhere.
* @note we're still (intrusively) using the next pointer
* within the node elements. This means, that still
* a given node can't be member in multiple lists.
*/
void
verify_nonOwnership()
{
CHECK (0 == Dummy::checksum());
{
ListNotOwner elements;
CHECK (isnil (elements));
Num<22> n2;
Num<44> n4;
Num<66> n6;
CHECK (22+44+66 == Dummy::checksum());
elements.push(n2);
elements.push(n4);
elements.push(n6);
CHECK (!isnil (elements));
CHECK (3 == elements.size());
CHECK (22+44+66 == Dummy::checksum()); // not altered: we're referring the originals
CHECK (66 == elements[0].getVal());
CHECK (44 == elements[1].getVal());
CHECK (22 == elements[2].getVal());
CHECK (isSameObject(n2, elements[2]));
CHECK (isSameObject(n4, elements[1]));
CHECK (isSameObject(n6, elements[0]));
elements.clear();
CHECK (isnil (elements));
CHECK (22+44+66 == Dummy::checksum()); // referred elements unaffected
}
CHECK (0 == Dummy::checksum());
}
void
verify_ExceptionSafety()
{
CHECK (0 == Dummy::checksum());
{
List elements;
CHECK (isnil (elements));
__triggerErrorAt(3);
elements.emplace<Nummy>(1);
elements.emplace<Nummy>(2);
CHECK (1+2 == Dummy::checksum());
VERIFY_ERROR (PROVOKED_FAILURE, elements.emplace<Nummy>(3) );
CHECK (1+2 == Dummy::checksum());
CHECK (2 == elements.size());
CHECK (2 == elements[0].getVal());
CHECK (1 == elements[1].getVal());
elements.clear();
CHECK (0 == Dummy::checksum());
__triggerError_reset();
}
CHECK (0 == Dummy::checksum());
}
void
populate_by_iterator()
{
CHECK (0 == Dummy::checksum());
{
Populator yieldSomeElements(NUM_ELEMENTS);
List elements (yieldSomeElements);
CHECK (!isnil (elements));
CHECK (NUM_ELEMENTS == elements.size());
CHECK (sum(NUM_ELEMENTS) == Dummy::checksum());
int check=NUM_ELEMENTS;
List::iterator ii = elements.begin();
while (ii)
{
CHECK (check == ii->getVal());
--check;
++ii;
}
CHECK (0 == check);
}
CHECK (0 == Dummy::checksum());
}
/** @test to support using LinkedElements within RAII-style components,
* all the elements might be added in one sway, by pulling them
* from a Lumiera Forward Iterator. In case this is done in the
* ctor, any exception while doing so will trigger cleanup
* of all elements (and then failure of the ctor alltogether)
*/
void
verify_RAII_safety()
{
CHECK (0 == Dummy::checksum());
__triggerErrorAt(3);
Populator yieldSomeElements(NUM_ELEMENTS);
VERIFY_ERROR (PROVOKED_FAILURE, List elements(yieldSomeElements) );
CHECK (0 == Dummy::checksum());
__triggerError_reset();
}
void
verify_customAllocator()
{
CHECK (0 == Dummy::checksum());
{
AllocationCluster allocator;
ListCustomAllocated elements(allocator);
elements.emplace<Num<1>> (2);
elements.emplace<Num<3>> (4,5);
elements.emplace<Num<6>> (7,8,9);
CHECK (sum(9) == Dummy::checksum());
CHECK (3 == allocator.size());
CHECK (1 == allocator.count<Num<1>>());
CHECK (1 == allocator.count<Num<3>>());
CHECK (1 == allocator.count<Num<6>>());
CHECK (3 == elements.size());
CHECK (1+2 == elements[2].getVal());
CHECK (3+4+5 == elements[1].getVal());
CHECK (6+7+8+9 == elements[0].getVal());
elements.clear();
CHECK (3 == allocator.size());
CHECK (sum(9) == Dummy::checksum());
// note: elements won't be discarded unless
// the AllocationCluster goes out of scope
}
CHECK (0 == Dummy::checksum());
}
};
LAUNCHER (LinkedElements_test, "unit common");
}} // namespace lib::test