diff --git a/src/lib/several-builder.hpp b/src/lib/several-builder.hpp index 30e962de9..5c0f6cbd6 100644 --- a/src/lib/several-builder.hpp +++ b/src/lib/several-builder.hpp @@ -277,7 +277,7 @@ namespace lib { ,class POL =HeapOwn ///< Allocator policy > class SeveralBuilder - : Several + : private Several , util::MoveOnly , POL { @@ -390,15 +390,17 @@ namespace lib { // ensure sufficient element capacity or the ability to adapt element spread if (Coll::spread() < reqSiz() and not (Coll::empty() or canWildMove())) throw err::Invalid{_Fmt{"Unable to place element of type %s (size=%d)" - "into container for element size %d."} + "into Several-container for element size %d."} % util::typeStr() % reqSiz() % Coll::spread()}; // ensure sufficient storage or verify the ability to re-allocate if (not (Coll::empty() or Coll::hasReserve(reqSiz()) or POL::canExpand(reqSiz()) or canDynGrow())) - throw err::Invalid{_Fmt{"Unable to accommodate further element of type %s "} - % util::typeStr()}; + throw err::Invalid{_Fmt{"Several-container is unable to accommodate further element of type %s; " + "storage reserve (%s bytes) exhausted and unable to move elements " + "of mixed unknown detail type, which are not trivially movable." } + % util::typeStr() % Coll::storageBuffSiz()}; size_t elmSiz = reqSiz(); size_t newPos = Coll::size(); @@ -410,11 +412,13 @@ namespace lib { Coll::data_->cnt = newPos+1; } + /** ensure clean-up can be handled properly. + * @throw err::Invalid when \a TY requires a different style + * of deleter than was established for this instance */ template void ensureDeleter() { - // ensure clean-up can be handled properly Deleter deleterFunctor = selectDestructor(); if (Coll::data_->deleter) return; Coll::data_->deleter = deleterFunctor; @@ -424,7 +428,7 @@ namespace lib { adjustStorage (size_t cnt, size_t spread) { size_t demand{cnt*spread}; - size_t buffSiz{Coll::data_? Coll::data_->buffSiz : 0}; + size_t buffSiz{Coll::storageBuffSiz()}; if (demand == buffSiz) return; if (demand > buffSiz) @@ -462,7 +466,7 @@ namespace lib { adjustSpread (size_t newSpread) { REQUIRE (Coll::data_); - REQUIRE (newSpread * Coll::size() <= Coll::data_->buffSiz); + REQUIRE (newSpread * Coll::size() <= Coll::storageBuffSiz()); size_t oldSpread = Coll::spread(); if (newSpread > oldSpread) // need to spread out diff --git a/src/lib/several.hpp b/src/lib/several.hpp index 4446d6cca..b770b5642 100644 --- a/src/lib/several.hpp +++ b/src/lib/several.hpp @@ -210,6 +210,12 @@ namespace lib { return data_? data_->spread : sizeof(I); } + size_t + storageBuffSiz() const + { + return data_? data_->buffSiz : 0; + } + bool hasReserve (size_t extraSize) const { diff --git a/tests/library/several-builder-test.cpp b/tests/library/several-builder-test.cpp index 3ce7d42f5..51db58478 100644 --- a/tests/library/several-builder-test.cpp +++ b/tests/library/several-builder-test.cpp @@ -111,6 +111,18 @@ namespace test{ } }; + + /** + * A non-copyable struct with 16bit alignment + * - not trivially default constructible + * - but trivially destructible + */ + struct ShortBlocker + : util::NonCopyable + { + int16_t val{short(1 + (rand() % 1'000))}; + }; + } // (END) test types @@ -164,7 +176,7 @@ namespace test{ * *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 + * @todo WIP 6/24 ✔ define ⟶ ✔ implement */ void check_Builder() @@ -228,7 +240,17 @@ namespace test{ /** @test TODO proper handling of exceptions during population - * @todo WIP 6/24 🔁 define ⟶ implement + * - 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. + * @todo WIP 6/24 🔁 define ⟶ ✔ implement */ void check_ErrorHandling() @@ -266,7 +288,7 @@ namespace test{ // 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 ("Unable to accommodate further element of type Dummy" + VERIFY_FAIL ("Several-container is unable to accommodate further element of type Dummy" , builder.fillElm (20) ); CHECK (10 == builder.size()); } @@ -274,27 +296,45 @@ namespace test{ { // Scenario-2 : Baseclass and elements of a single fixed subclass SeveralBuilder> builder; - Dummy dum; -SHOW_EXPR(dum.getVal()) - Dummy nem{move(dum)}; -SHOW_EXPR(dum.getVal()) -SHOW_EXPR(nem.getVal()) - Num<5> no5; -SHOW_EXPR(no5.getVal()) - Num<5> ne5{move(no5)}; -SHOW_EXPR(no5.getVal()) -SHOW_EXPR(ne5.getVal()) - 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); - builder.emplace(); + // 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()); - builder.emplace>(); ///////////////////////////////////OOO this should trigger an exception -> need to code an explicit check right at the start of emplaceNewElm() + 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()); + + // 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)); } } @@ -302,7 +342,7 @@ SHOW_EXPR(ne5.getVal()) /** @test TODO verify correct placement of instances within storage * @todo WIP 6/24 🔁 define ⟶ implement */ - void + void check_ElementStorage() { } @@ -311,7 +351,7 @@ SHOW_EXPR(ne5.getVal()) /** @test TODO demonstrate integration with a custom allocator * @todo WIP 6/24 🔁 define ⟶ implement */ - void + void check_CustomAllocator() { } diff --git a/wiki/thinkPad.ichthyo.mm b/wiki/thinkPad.ichthyo.mm index 3337fbb83..ecf404960 100644 --- a/wiki/thinkPad.ichthyo.mm +++ b/wiki/thinkPad.ichthyo.mm @@ -82728,9 +82728,9 @@ Date:   Thu Apr 20 18:53:17 2023 +0200
- + - + @@ -82741,9 +82741,9 @@ Date:   Thu Apr 20 18:53:17 2023 +0200
 - + - + @@ -82757,10 +82757,10 @@ Date:   Thu Apr 20 18:53:17 2023 +0200
 - + - + @@ -82770,8 +82770,8 @@ Date:   Thu Apr 20 18:53:17 2023 +0200
 - - + + @@ -82790,8 +82790,7 @@ Date:   Thu Apr 20 18:53:17 2023 +0200
Soweit die Theorie... in der Praxis aber scheitert das, weil der Compiler versucht, den realloc-Code zu instantiieren und dafür keinen Copy/Move-Konstruktor findet

- - + @@ -82809,11 +82808,10 @@ Date:   Thu Apr 20 18:53:17 2023 +0200
- - + - - + + @@ -82942,18 +82940,18 @@ Date:   Thu Apr 20 18:53:17 2023 +0200
- + - + + +

denn der Allocation-Cluster weiß selber die Zahl seiner belegten Roh-Blöcke; zur de-Allokation muß ansonsten gar nichts gemacht werden

- - - - + + @@ -83176,8 +83174,7 @@ Date:   Thu Apr 20 18:53:17 2023 +0200
...also ist das keine gute Idee, da verwirrend

- - + @@ -83416,8 +83413,7 @@ Date:   Thu Apr 20 18:53:17 2023 +0200
...✔ OK — selber schuld

- - + @@ -83432,9 +83428,9 @@ Date:   Thu Apr 20 18:53:17 2023 +0200
- - - + + + @@ -83446,8 +83442,7 @@ Date:   Thu Apr 20 18:53:17 2023 +0200
und der von Dummy muß noexcept sein

- - + @@ -83513,8 +83508,7 @@ Date:   Thu Apr 20 18:53:17 2023 +0200
...es spricht tatsächlich nichts dagegen, diesen Fall auch nachträglich noch zuzulassen — man gibt dann eben die Möglichkeit für re-Allocations auf (und wenn das ein Problem darstellt, macht sich das zu gegebener Zeit eindeutig bemerkbar)

- - + @@ -83538,14 +83532,14 @@ Date:   Thu Apr 20 18:53:17 2023 +0200
 - + - + @@ -83557,13 +83551,16 @@ Date:   Thu Apr 20 18:53:17 2023 +0200
 - + + + +