/* SeveralBuilder(Test) - building a limited fixed collection of elements Copyright (C) Lumiera.org 2008, Hermann Vosseler 2024, Hermann Vosseler 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 several-builder-test.cpp ** unit test \ref SeveralBuilder_test */ #include "lib/test/run.hpp" #include "lib/test/tracking-dummy.hpp" #include "lib/test/tracking-allocator.hpp" #include "lib/test/test-coll.hpp" #include "lib/test/test-helper.hpp" #include "lib/test/diagnostic-output.hpp"////////////////TODO #include "lib/iter-explorer.hpp" #include "lib/format-util.hpp" #include "lib/util.hpp" #include "lib/several-builder.hpp" #include #include using ::test::Test; using std::vector; using std::array; using std::rand; using lib::explore; using util::isSameObject; using util::isLimited; using util::getAddr; using util::isnil; using util::join; namespace lib { namespace test{ namespace { // diagnostic test types /** * Instance tracking sub-dummy * - implements the Dummy interface * - holds additional storage * - specific implementation of the virtual operation * - includes content of the additional storage into the * checksum calculation, allowing to detect memory corruption */ template class Num : public test::Dummy { std::array ext_; public: Num (uint seed=i) : Dummy(seed) { ext_.fill(seed); setVal ((i+1)*seed); } ~Num() { setVal (getVal() - explore(ext_).resultSum()); } long calc (int ii) override { return i+ii + explore(ext_).resultSum(); } /// allow for move construction Num (Num && oNum) noexcept : Num(0) { swap (*this, oNum); } Num& operator= (Num && oNum) { if (&oNum != this) swap (*this, oNum); return *this; } friend void swap (Num& num1, Num& num2) ///< checksum neutral { std::swap (static_cast (num1) ,static_cast (num2)); std::swap (num1.ext_, num2.ext_); } }; /** * A non-copyable struct with 16bit alignment * - not trivially default constructible * - but trivially destructible */ struct ShortBlocker : util::NonCopyable { int16_t val; ShortBlocker (short r = 1 + (rand() % 1'000)) : val(r) { }; }; } // (END) test types /***************************************************************//** * @test use lib::Several to establish small collections of elements, * possibly with sub-classing and controlled allocation. * - the container is populated through a separate builder * - the number of elements is flexible during population * - the actual container allows random-access via base interface * @see several-builder.hpp */ class SeveralBuilder_test : public Test { virtual void run (Arg) { simpleUsage(); check_Builder(); check_ErrorHandling(); check_ElementStorage(); check_CustomAllocator(); } /** @test demonstrate basic behaviour * @todo WIP 6/24 ✔ define ⟶ ✔ implement */ void simpleUsage() { auto elms = makeSeveral({1,1,2,3,5,8,13}).build(); CHECK (elms.size() == 7); CHECK (elms.back() == 13); CHECK (elms[3] == 3); CHECK (join (elms,"-") == "1-1-2-3-5-8-13"_expect); } /** @test various ways to build an populate the container * - with a defined interface type \a I, instances of arbitrary subclasses * can be added, assuming there is sufficient pre-allocated buffer space; * all these subclass instances are accessed through the common interface. * - yet the added elements can also be totally unrelated, in which case an * *unchecked wild cast* will happen on access; while certainly dangerous, * this behaviour allows for special low-level data layout tricks. * - the results from an iterator can be used to populate by copy * @todo WIP 6/24 ✔ define ⟶ ✔ implement */ void check_Builder() { // prepare to verify proper invocation of all constructors / destructors Dummy::checksum() = 0; { // Scenario-1 : Baseclass and arbitrary subclass elements SeveralBuilder builder; CHECK (isnil (builder)); builder.emplace>() .emplace>(1); CHECK (2 == builder.size()); builder.fillElm(2); CHECK (4 == builder.size()); builder.fillElm(3, 5); CHECK (7 == builder.size()); Several elms = builder.build(); CHECK ( isnil(builder)); CHECK (not isnil(elms)); CHECK (7 == elms.size()); CHECK (elms[0].getVal() == (3+1)*3); // indeed a Num<3> with default-seed ≡ 3 CHECK (elms[0].calc(1) == 3 + 1 + (3+3+3)); // indeed called the overridden calc() operation CHECK (elms[1].getVal() == (2+1)*1); // indeed a Num<2> with seed ≡ 1 CHECK (elms[1].calc(1) == 2 + 1 + (1+1)); // indeed the overridden calc() picking from the Array(1,1) CHECK (isLimited (1, elms[2].getVal(), 100'000'000)); // indeed a Dummy with default random seed CHECK (isLimited (1, elms[3].getVal(), 100'000'000)); // and this one too, since we filled in two instances CHECK (elms[4].getVal() == 5); // followed by tree instances Dummy(5) CHECK (elms[5].getVal() == 5); CHECK (elms[6].getVal() == 5); CHECK (elms[6].calc(1) == 5+1); // indeed invoking the base implementation of calc() } { // Scenario-2 : unrelated element types SeveralBuilder builder; auto urgh = array{"Urgh"}; auto phi = (1+sqrtf(5))/2; builder.append (urgh, phi, -1); // can emplace arbitrary data CHECK (3 == builder.size()); Several elms = builder.build(); // WARNING: data accessed by wild cast to interface type CHECK (3 == elms.size()); CHECK (elms[0] == * reinterpret_cast ("Urgh")); CHECK (elms[1] == * reinterpret_cast (&phi)); CHECK (elms[2] == uint32_t(-1)); } { // Scenario-3 : copy values from iterator SeveralBuilder builder; VecI seq = getTestSeq_int (10); builder.appendAll (seq); CHECK (10 == builder.size()); auto elms = builder.build(); CHECK (10 == elms.size()); CHECK (join (elms,"-") == "0-1-2-3-4-5-6-7-8-9"_expect); } CHECK (0 == Dummy::checksum()); } /** @test proper handling of exceptions during population * - when the container is filled with arbitrary subclasses * of a base interface with virtual destructor, the first element is used * to accommodate the storage spread; larger elements or elements of a completely * different type can not be accommodated and the container can not grow beyond * the initially allocated reserve (defined to be 10 elements by default). * - when the container is defined to hold elements of a specific fixed subclass, * it can be filled with default-constructed instances, and the initial allocation * can be expanded by move-relocation. Yet totally unrelated elements can not be * accepted (due to unknown destructor); and when accepting another unspecific * subclass instance, the ability to grow by move-relocation is lost. * - a container defined for trivial data elements (trivially movable and destructible) * can grow dynamically just by moving data around with `memmove`. Only in this case * the _element spread_ can easily be adjusted after the fact, since a trivial element * can be relocated to accommodate an increased spread. It is possible to add various * different data elements into such a container, yet all will be accessed through an * unchecked hard cast to the base element (`uint8_t` in this case). However, once we * add a _non-copyable_ element, this capability for arbitrarily moving elements around * is lost — we can not adapt the spread any more and the container can no longer * grow dynamically. * - all these failure conditions are handled properly, including exceptions emanating * from element constructors; the container remains sane and no memory is leaked. * @todo WIP 6/24 ✔ define ⟶ ✔ implement */ void check_ErrorHandling() { CHECK (0 == Dummy::checksum()); { // Scenario-1 : Baseclass and arbitrary subclass elements SeveralBuilder builder; // The first element will _prime_ the container for a suitable usage pattern builder.emplace>(); CHECK (1 == builder.size()); // Notably the first element established the _spread_ between index positions, // which effectively limits the size of objects to be added. Moreover, since // the element type was detected to be non-trivial, we can not correct this // element spacing by shifting existing allocations (`memmove()` not possible) CHECK (sizeof(Num<1>) < sizeof(Num<5>)); VERIFY_FAIL ("Unable to place element of type Num<5u> (size=" , builder.emplace>() ); CHECK (1 == builder.size()); // Furthermore, the first element was detected to be a subclass, // and the interface type `Dummy` has a virtual destructor; // all added elements must comply to this scheme, once established VERIFY_FAIL ("Unable to handle (trivial-)destructor for element type long, " "since this container has been primed to use virtual-baseclass-destructors." , builder.emplace(55) ); CHECK (1 == builder.size()); // the initial allocation added some reserve buffer space (for 10 elements) // and we can fill that space with arbitrary subclass instances builder.fillElm (5); CHECK (6 == builder.size()); // But the initial allocation can not be increased, since that would require // a re-allocation of a larger buffer, followed by copying the elements; // but since the established scheme allows for _arbitrary_ subclasses, // the builder does not know the exact type for safe element relocation. VERIFY_FAIL ("Several-container is unable to accommodate further element of type Dummy" , builder.fillElm (20) ); CHECK (10 == builder.size()); } // in spite of all the provoked failures, // all element destructors were invoked CHECK (0 == Dummy::checksum()); { // Scenario-2 : Baseclass and elements of a single fixed subclass SeveralBuilder> builder; builder.fillElm(5); CHECK (5 == builder.size()); // trigger re-alloc by moving into larger memory block builder.fillElm(14); CHECK (19 == builder.size()); CHECK (builder.size() > INITIAL_ELM_CNT); // with the elements added thus far, this instance has been primed to // rely on a fixed well known element type for move-growth and to use // the virtual base class destructor for clean-up. It is thus not possible // to add another element that is not related to this baseclass... VERIFY_FAIL ("Unable to handle (trivial-)destructor for element type ShortBlocker, " "since this container has been primed to use virtual-baseclass-destructors." , builder.emplace() ); CHECK (19 == builder.size()); CHECK (sizeof(ShortBlocker) < sizeof(Num<5>)); // it was not rejected due to size... // However, a subclass /different than the defined element type/ is acceptable, // but only to the condition to lock any further container growth by move-reallocation. // The rationale is that we can still destroy through the virtual base destructor, // but we aren't able to move elements safely any more, since we don't capture the type. builder.emplace>(); CHECK (20 == builder.size()); CHECK (20 == builder.capacity()); CHECK ( 0 == builder.capReserve()); // But here comes the catch: since we choose to accept arbitrary sub-types not identified in detail, // the container has lost its ability of move-reallocation; with 20 elements the current reserve // is exhausted and we are now unable to add any further elements beyond that point. VERIFY_FAIL ("unable to move elements of mixed unknown detail type, which are not trivially movable" , builder.fillElm(5); ); // the container is still sound however auto elms = builder.build(); CHECK (20 == elms.size()); // verify that member fields were not corrupted for (uint i=0; i<=18; ++i) CHECK (elms[i].calc(i) == 5 + i + (5+5+5+5+5)); CHECK (elms.back().calc(0) == 1 + 0 + (1)); } CHECK (0 == Dummy::checksum()); { // Scenario-3 : arbitrary elements of trivial type SeveralBuilder builder; builder.reserve(16); CHECK ( 0 == builder.size()); CHECK (16 == builder.capacity()); CHECK (16 == builder.capReserve()); string BFR{"starship is"}; builder.appendAll (BFR); CHECK (11 == builder.size()); CHECK (16 == builder.capacity()); CHECK ( 5 == builder.capReserve()); // append element that is much larger than a char // => since elements are trivial, they can be moved to accommodate builder.append (int64_t(32)); CHECK (12 == builder.size()); CHECK (16 == builder.capacity()); // note: capacity remained nominally the same CHECK ( 4 == builder.capReserve()); // while in fact the spread and thus the buffer were increased // emplace a completely unrelated object type, // which is also trivially destructible, but non-copyable builder.emplace ('c'); // can emplace further trivial objects, since there is still capacity left builder.append (int('o'), long('o')); CHECK (15 == builder.size()); CHECK ( 1 == builder.capReserve()); VERIFY_FAIL ("Unable to place element of type Num<5u>" , builder.append (Num<5>{}) ); CHECK (sizeof(Num<5>) > sizeof(int64_t)); // not surprising: this one was too large, // and due to the non-copyable element we can not adapt anymore class NonTrivial { public: ~NonTrivial() { } }; // adding data of a non-trivial type is rejected, // since the container does not capture individual element types // and thus does not know how to delete it CHECK (sizeof(NonTrivial) <= sizeof(int64_t)); VERIFY_FAIL ("Unsupported kind of destructor for element type SeveralBuilder_test::check_ErrorHandling()::NonTrivial" , builder.append (NonTrivial{}) ); CHECK ( 1 == builder.capReserve()); // space for a single one left... builder.append ('l'); CHECK (16 == builder.size()); CHECK ( 0 == builder.capReserve()); // and now we've run out of space, and due to the non-copyable object, move-relocation is rejected VERIFY_FAIL ("Several-container is unable to accommodate further element of type char; " "storage reserve (128 bytes ≙ 16 elms) exhausted and unable to move " "elements of mixed unknown detail type, which are not trivially movable." , builder.append ('!') ); // yet the container is still fine.... auto elms = builder.build(); CHECK (16 == elms.size()); CHECK (join(elms, "·") == "s·t·a·r·s·h·i·p· ·i·s· ·c·o·o·l"_expect); } CHECK (0 == Dummy::checksum()); { // Scenario-4 : exception from element constructor SeveralBuilder builder; builder.emplace>(42); CHECK (1 == builder.size()); Dummy::activateCtorFailure(true); try { builder.emplace>(23); NOTREACHED ("did not throw"); } catch(...) { // Exception emanated from Dummy(baseclass) ctor; // at that point, the local val was set to the seed (≙23). // When a constructor fails in C++, the destructor is not called, // thus we have to compensate here to balance the checksum Dummy::checksum() -= 23; } CHECK (1 == builder.size()); Dummy::activateCtorFailure(false); builder.emplace>(23); auto elms = builder.build(); CHECK (2 == elms.size()); CHECK (elms.front().calc(1) == 3 + 1 + (42+42+42)); CHECK (elms.back().calc(5) == 3 + 5 + (23+23+23)); } // all other destructors properly invoked... CHECK (0 == Dummy::checksum()); } /** @test verify correct placement of instances within storage * - use a low-level pointer calculation for this test to * draw conclusions regarding the spacing of objects accepted * into the lib::Several-container * - demonstrate the simple data elements are packed efficiently * - verify that special alignment requirements are observed * - emplace several ''non copyable objects'' and then * move-assign the lib::Several container instance; this * demonstrates that the latter is just a access front-end, * while the data elements reside in a fixed storage buffer * @todo WIP 6/24 ✔ define ⟶ ✔ implement */ void check_ElementStorage() { auto loc = [](auto& something){ return size_t(getAddr (something)); }; auto calcSpread = [&](auto& several){ return loc(several[1]) - loc(several[0]); }; { // Scenario-1 : tightly packed values Several elms = makeSeveral({21,34,55}).build(); CHECK (21 == elms[0]); CHECK (34 == elms[1]); CHECK (55 == elms[2]); CHECK (3 == elms.size()); CHECK (sizeof(elms) == sizeof(void*)); CHECK (sizeof(int) == alignof(int)); size_t spread = calcSpread (elms); CHECK (spread == sizeof(int)); CHECK (loc(elms.back()) == loc(elms.front()) + 2*spread); } { // Scenario-2 : alignment struct Ali { alignas(64) char charm = 'u'; }; auto elms = makeSeveral().fillElm(5).build(); CHECK (5 == elms.size()); CHECK (sizeof(elms) == sizeof(void*)); size_t spread = calcSpread (elms); CHECK (spread == alignof(Ali)); CHECK (loc(elms.front()) % alignof(Ali) == 0); CHECK (loc(elms.back()) == loc(elms.front()) + 4*spread); } { // Scenario-3 : noncopyable objects auto elms = makeSeveral().fillElm(5).build(); auto v0 = elms[0].val; auto p0 = loc(elms[0]); auto v1 = elms[1].val; auto p1 = loc(elms[1]); auto v2 = elms[2].val; auto p2 = loc(elms[2]); auto v3 = elms[3].val; auto p3 = loc(elms[3]); auto v4 = elms[4].val; auto p4 = loc(elms[4]); CHECK (5 == elms.size()); auto moved = move(elms); CHECK (5 == moved.size()); CHECK (isnil (elms)); CHECK (loc(moved[0]) == p0); CHECK (loc(moved[1]) == p1); CHECK (loc(moved[2]) == p2); CHECK (loc(moved[3]) == p3); CHECK (loc(moved[4]) == p4); CHECK (moved[0].val == v0); CHECK (moved[1].val == v1); CHECK (moved[2].val == v2); CHECK (moved[3].val == v3); CHECK (moved[4].val == v4); CHECK (calcSpread(moved) == sizeof(ShortBlocker)); } } /** @test TODO demonstrate integration with a custom allocator * @todo WIP 6/24 🔁 define ⟶ 🔁 implement */ void check_CustomAllocator() { { auto builder = makeSeveral() .withAllocator(); SHOW_TYPE(decltype(builder)) SHOW_EXPR(builder.size()) SHOW_EXPR(builder.capacity()) } } }; /** Register this test class... */ LAUNCHER (SeveralBuilder_test, "unit common"); }} // namespace lib::test