--- /dev/null
+/*
+Minetest
+Copyright (C) 2018 numzero, Lobachevskiy Vitaliy <numzer0@yandex.ru>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+#include <type_traits>
+#include "irrlichttypes.h"
+#include "IReferenceCounted.h"
+
+/** Shared pointer for IrrLicht objects.
+ *
+ * It should only be used for user-managed objects, i.e. those created with
+ * the @c new operator or @c create* functions, like:
+ * `irr_ptr<scene::IMeshBuffer> buf{new scene::SMeshBuffer()};`
+ *
+ * It should *never* be used for engine-managed objects, including
+ * those created with @c addTexture and similar methods.
+ */
+template <class ReferenceCounted,
+ class = typename std::enable_if<std::is_base_of<IReferenceCounted,
+ ReferenceCounted>::value>::type>
+class irr_ptr
+{
+ ReferenceCounted *value = nullptr;
+
+ /** Drops stored pointer replacing it with the given one.
+ * @note Copy semantics: reference counter *is* increased.
+ */
+ void grab(ReferenceCounted *object)
+ {
+ if (object)
+ object->grab();
+ reset(object);
+ }
+
+public:
+ irr_ptr() {}
+
+ irr_ptr(std::nullptr_t) noexcept {}
+
+ irr_ptr(const irr_ptr &b) noexcept { grab(b.get()); }
+
+ irr_ptr(irr_ptr &&b) noexcept { reset(b.release()); }
+
+ template <typename B, class = typename std::enable_if<std::is_convertible<B *,
+ ReferenceCounted *>::value>::type>
+ irr_ptr(const irr_ptr<B> &b) noexcept
+ {
+ grab(b.get());
+ }
+
+ template <typename B, class = typename std::enable_if<std::is_convertible<B *,
+ ReferenceCounted *>::value>::type>
+ irr_ptr(irr_ptr<B> &&b) noexcept
+ {
+ reset(b.release());
+ }
+
+ /** Constructs a shared pointer out of a plain one
+ * @note Move semantics: reference counter is *not* increased.
+ */
+ explicit irr_ptr(ReferenceCounted *object) noexcept { reset(object); }
+
+ ~irr_ptr() { reset(); }
+
+ irr_ptr &operator=(const irr_ptr &b) noexcept
+ {
+ grab(b.get());
+ return *this;
+ }
+
+ irr_ptr &operator=(irr_ptr &&b) noexcept
+ {
+ reset(b.release());
+ return *this;
+ }
+
+ template <typename B, class = typename std::enable_if<std::is_convertible<B *,
+ ReferenceCounted *>::value>::type>
+ irr_ptr &operator=(const irr_ptr<B> &b) noexcept
+ {
+ grab(b.get());
+ return *this;
+ }
+
+ template <typename B, class = typename std::enable_if<std::is_convertible<B *,
+ ReferenceCounted *>::value>::type>
+ irr_ptr &operator=(irr_ptr<B> &&b) noexcept
+ {
+ reset(b.release());
+ return *this;
+ }
+
+ ReferenceCounted &operator*() const noexcept { return *value; }
+ ReferenceCounted *operator->() const noexcept { return value; }
+ explicit operator ReferenceCounted *() const noexcept { return value; }
+ explicit operator bool() const noexcept { return !!value; }
+
+ /** Returns the stored pointer.
+ */
+ ReferenceCounted *get() const noexcept { return value; }
+
+ /** Returns the stored pointer, erasing it from this class.
+ * @note Move semantics: reference counter is not changed.
+ */
+ ReferenceCounted *release() noexcept
+ {
+ ReferenceCounted *object = value;
+ value = nullptr;
+ return object;
+ }
+
+ /** Drops stored pointer replacing it with the given one.
+ * @note Move semantics: reference counter is *not* increased.
+ */
+ void reset(ReferenceCounted *object = nullptr) noexcept
+ {
+ if (value)
+ value->drop();
+ value = object;
+ }
+};
--- /dev/null
+/*
+Minetest
+Copyright (C) 2018 numzero, Lobachevskiy Vitaliy <numzer0@yandex.ru>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "test.h"
+
+#include "exceptions.h"
+#include "irr_ptr.h"
+
+class TestIrrPtr : public TestBase
+{
+public:
+ TestIrrPtr() { TestManager::registerTestModule(this); }
+ const char *getName() { return "TestIrrPtr"; }
+
+ void runTests(IGameDef *gamedef);
+
+ void testRefCounting();
+ void testSelfAssignment();
+ void testNullHandling();
+};
+
+static TestIrrPtr g_test_instance;
+
+void TestIrrPtr::runTests(IGameDef *gamedef)
+{
+ TEST(testRefCounting);
+ TEST(testSelfAssignment);
+ TEST(testNullHandling);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+#define UASSERT_REFERENCE_COUNT(object, value, info) \
+ UTEST((object)->getReferenceCount() == value, \
+ info "Reference count is %d instead of " #value, \
+ (object)->getReferenceCount())
+
+void TestIrrPtr::testRefCounting()
+{
+ IReferenceCounted *obj = new IReferenceCounted(); // RC=1
+ obj->grab();
+ UASSERT_REFERENCE_COUNT(obj, 2, "Pre-condition failed: ");
+ {
+ irr_ptr<IReferenceCounted> p1{obj}; // move semantics
+ UASSERT(p1.get() == obj);
+ UASSERT_REFERENCE_COUNT(obj, 2, );
+
+ irr_ptr<IReferenceCounted> p2{p1}; // copy ctor
+ UASSERT(p1.get() == obj);
+ UASSERT(p2.get() == obj);
+ UASSERT_REFERENCE_COUNT(obj, 3, );
+
+ irr_ptr<IReferenceCounted> p3{std::move(p1)}; // move ctor
+ UASSERT(p1.get() == nullptr);
+ UASSERT(p3.get() == obj);
+ UASSERT_REFERENCE_COUNT(obj, 3, );
+
+ p1 = std::move(p2); // move assignment
+ UASSERT(p1.get() == obj);
+ UASSERT(p2.get() == nullptr);
+ UASSERT_REFERENCE_COUNT(obj, 3, );
+
+ p2 = p3; // copy assignment
+ UASSERT(p2.get() == obj);
+ UASSERT(p3.get() == obj);
+ UASSERT_REFERENCE_COUNT(obj, 4, );
+
+ p1.release();
+ UASSERT(p1.get() == nullptr);
+ UASSERT_REFERENCE_COUNT(obj, 4, );
+ }
+ UASSERT_REFERENCE_COUNT(obj, 2, );
+ obj->drop();
+ UTEST(obj->drop(), "Dropping failed: reference count is %d",
+ obj->getReferenceCount());
+}
+
+void TestIrrPtr::testSelfAssignment()
+{
+ irr_ptr<IReferenceCounted> p1{new IReferenceCounted()};
+ UASSERT(p1);
+ UASSERT_REFERENCE_COUNT(p1, 1, );
+ p1 = p1;
+ UASSERT(p1);
+ UASSERT_REFERENCE_COUNT(p1, 1, );
+ p1 = std::move(p1);
+ UASSERT(p1);
+ UASSERT_REFERENCE_COUNT(p1, 1, );
+}
+
+void TestIrrPtr::testNullHandling()
+{
+ // In the case of an error, it will probably crash with SEGV.
+ // Nevertheless, UASSERTs are used to catch possible corner cases.
+ irr_ptr<IReferenceCounted> p1{new IReferenceCounted()};
+ UASSERT(p1);
+ irr_ptr<IReferenceCounted> p2;
+ UASSERT(!p2);
+ irr_ptr<IReferenceCounted> p3{p2};
+ UASSERT(!p2);
+ UASSERT(!p3);
+ irr_ptr<IReferenceCounted> p4{std::move(p2)};
+ UASSERT(!p2);
+ UASSERT(!p4);
+ p2 = p2;
+ UASSERT(!p2);
+ p2 = std::move(p2);
+ UASSERT(!p2);
+ p3 = p2;
+ UASSERT(!p2);
+ UASSERT(!p3);
+ p3 = std::move(p2);
+ UASSERT(!p2);
+ UASSERT(!p3);
+}
projects / oweals / minetest.git / commitdiff