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author | Kjell Ahlstedt <kjell.ahlstedt@bredband.net> | 2011-07-19 11:34:05 +0200 |
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committer | Murray Cumming <murrayc@murrayc.com> | 2011-07-19 11:34:05 +0200 |
commit | 2f6fdd52f88ad97e7a260fca08d31c815e426dad (patch) | |
tree | 7001bda37a736a7080ef0055514d50b757f5e988 | |
parent | ad1bce5b0ad1caeee5c499b3a80d3455e326b63c (diff) | |
download | sigc++-2f6fdd52f88ad97e7a260fca08d31c815e426dad.tar.gz |
Add a test case for the previous commit.
* tests/Makefile.am:
* tests/test_bind_refptr.cc: A version of this test is also in glibmm.
Note that this includes a copy/paste of RefPtr.
See Bug #564005#14
-rw-r--r-- | tests/test_bind_refptr.cc | 470 |
1 files changed, 470 insertions, 0 deletions
diff --git a/tests/test_bind_refptr.cc b/tests/test_bind_refptr.cc new file mode 100644 index 0000000..577b285 --- /dev/null +++ b/tests/test_bind_refptr.cc @@ -0,0 +1,470 @@ +// Bug 564005 - Valgrind errors and crash on exit with Gtk::UIManager +// Bug 154498 - Unnecessary warning on console: signalproxy_connectionnode.cc + +// libsigc++-only test case. (Or almost so. RefPtr is stolen from glibmm.) + +// -*- c++ -*- +#ifndef _GLIBMM_REFPTR_H +#define _GLIBMM_REFPTR_H + +/* Copyright 2002 The gtkmm Development Team + * + * This library 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 library 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 library; if not, write to the Free + * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +//#include <glibmmconfig.h> + +namespace Glib +{ + +/** RefPtr<> is a reference-counting shared smartpointer. + * + * Some objects in gtkmm are obtained from a shared + * store. Consequently you cannot instantiate them yourself. Instead they + * return a RefPtr which behaves much like an ordinary pointer in that members + * can be reached with the usual <code>object_ptr->member</code> notation. + * Unlike most other smart pointers, RefPtr doesn't support dereferencing + * through <code>*object_ptr</code>. + * + * Reference counting means that a shared reference count is incremented each + * time a RefPtr is copied, and decremented each time a RefPtr is destroyed, + * for instance when it leaves its scope. When the reference count reaches + * zero, the contained object is deleted, meaning you don't need to remember + * to delete the object. + * + * RefPtr<> can store any class that has reference() and unreference() methods. + * In gtkmm, that is anything derived from Glib::ObjectBase, such as + * Gdk::Pixmap. + * + * See the "Memory Management" section in the "Programming with gtkmm" + * book for further information. + */ +template <class T_CppObject> +class RefPtr +{ +public: + /** Default constructor + * + * Afterwards it will be null and use of -> will cause a segmentation fault. + */ + inline RefPtr(); + + /// Destructor - decrements reference count. + inline ~RefPtr(); + + /// For use only by the ::create() methods. + explicit inline RefPtr(T_CppObject* pCppObject); + + /** Copy constructor + * + * This increments the shared reference count. + */ + inline RefPtr(const RefPtr<T_CppObject>& src); + + /** Copy constructor (from different, but castable type). + * + * Increments the reference count. + */ + template <class T_CastFrom> + inline RefPtr(const RefPtr<T_CastFrom>& src); + + /** Swap the contents of two RefPtr<>. + * This method swaps the internal pointers to T_CppObject. This can be + * done safely without involving a reference/unreference cycle and is + * therefore highly efficient. + */ + inline void swap(RefPtr<T_CppObject>& other); + + /// Copy from another RefPtr: + inline RefPtr<T_CppObject>& operator=(const RefPtr<T_CppObject>& src); + + /** Copy from different, but castable type). + * + * Increments the reference count. + */ + template <class T_CastFrom> + inline RefPtr<T_CppObject>& operator=(const RefPtr<T_CastFrom>& src); + + /// Tests whether the RefPtr<> point to the same underlying instance. + inline bool operator==(const RefPtr<T_CppObject>& src) const; + + /// See operator==(). + inline bool operator!=(const RefPtr<T_CppObject>& src) const; + + /** Dereferencing. + * + * Use the methods of the underlying instance like so: + * <code>refptr->memberfun()</code>. + */ + inline T_CppObject* operator->() const; + + /** Test whether the RefPtr<> points to any underlying instance. + * + * Mimics usage of ordinary pointers: + * @code + * if (ptr) + * do_something(); + * @endcode + */ + inline operator bool() const; + +#ifndef GLIBMM_DISABLE_DEPRECATED + /// @deprecated Use reset() instead because this leads to confusion with clear() methods on the underlying class. For instance, people use .clear() when they mean ->clear(). + inline void clear(); +#endif //GLIBMM_DISABLE_DEPRECATED + + /** Set underlying instance to 0, decrementing reference count of existing instance appropriately. + * @newin{2,16} + */ + inline void reset(); + + /** Dynamic cast to derived class. + * + * The RefPtr can't be cast with the usual notation so instead you can use + * @code + * ptr_derived = RefPtr<Derived>::cast_dynamic(ptr_base); + * @endcode + */ + template <class T_CastFrom> + static inline RefPtr<T_CppObject> cast_dynamic(const RefPtr<T_CastFrom>& src); + + /** Static cast to derived class. + * + * Like the dynamic cast; the notation is + * @code + * ptr_derived = RefPtr<Derived>::cast_static(ptr_base); + * @endcode + */ + template <class T_CastFrom> + static inline RefPtr<T_CppObject> cast_static(const RefPtr<T_CastFrom>& src); + + /** Cast to non-const. + * + * The RefPtr can't be cast with the usual notation so instead you can use + * @code + * ptr_unconst = RefPtr<UnConstType>::cast_const(ptr_const); + * @endcode + */ + template <class T_CastFrom> + static inline RefPtr<T_CppObject> cast_const(const RefPtr<T_CastFrom>& src); + + //TODO: Maybe remove these if we replace operator bool() with operator const void* after + //an API/ABI break, as suggested by Daniel Elstner? murrayc. + //See bug https://bugzilla.gnome.org/show_bug.cgi?id=626858 + + /** Compare based on the underlying instance address. + * + * This is needed in code that requires an ordering on + * RefPtr<T_CppObject> instances, e.g. std::set<RefPtr<T_CppObject> >. + * + * Without these, comparing two RefPtr<T_CppObject> instances + * is still syntactically possible, but the result is semantically + * wrong, as p1 REL_OP p2 is interpreted as (bool)p1 REL_OP (bool)p2. + */ + inline bool operator<(const RefPtr<T_CppObject>& src) const; + + /// See operator<(). + inline bool operator<=(const RefPtr<T_CppObject>& src) const; + + /// See operator<(). + inline bool operator>(const RefPtr<T_CppObject>& src) const; + + /// See operator<(). + inline bool operator>=(const RefPtr<T_CppObject>& src) const; + +private: + T_CppObject* pCppObject_; +}; + + +#ifndef DOXYGEN_SHOULD_SKIP_THIS + +// RefPtr<>::operator->() comes first here since it's used by other methods. +// If it would come after them it wouldn't be inlined. + +template <class T_CppObject> inline +T_CppObject* RefPtr<T_CppObject>::operator->() const +{ + return pCppObject_; +} + +template <class T_CppObject> inline +RefPtr<T_CppObject>::RefPtr() +: + pCppObject_ (0) +{} + +template <class T_CppObject> inline +RefPtr<T_CppObject>::~RefPtr() +{ + if(pCppObject_) + pCppObject_->unreference(); // This could cause pCppObject to be deleted. +} + +template <class T_CppObject> inline +RefPtr<T_CppObject>::RefPtr(T_CppObject* pCppObject) +: + pCppObject_ (pCppObject) +{} + +template <class T_CppObject> inline +RefPtr<T_CppObject>::RefPtr(const RefPtr<T_CppObject>& src) +: + pCppObject_ (src.pCppObject_) +{ + if(pCppObject_) + pCppObject_->reference(); +} + +// The templated ctor allows copy construction from any object that's +// castable. Thus, it does downcasts: +// base_ref = derived_ref +template <class T_CppObject> + template <class T_CastFrom> +inline +RefPtr<T_CppObject>::RefPtr(const RefPtr<T_CastFrom>& src) +: + // A different RefPtr<> will not allow us access to pCppObject_. We need + // to add a get_underlying() for this, but that would encourage incorrect + // use, so we use the less well-known operator->() accessor: + pCppObject_ (src.operator->()) +{ + if(pCppObject_) + pCppObject_->reference(); +} + +template <class T_CppObject> inline +void RefPtr<T_CppObject>::swap(RefPtr<T_CppObject>& other) +{ + T_CppObject *const temp = pCppObject_; + pCppObject_ = other.pCppObject_; + other.pCppObject_ = temp; +} + +template <class T_CppObject> inline +RefPtr<T_CppObject>& RefPtr<T_CppObject>::operator=(const RefPtr<T_CppObject>& src) +{ + // In case you haven't seen the swap() technique to implement copy + // assignment before, here's what it does: + // + // 1) Create a temporary RefPtr<> instance via the copy ctor, thereby + // increasing the reference count of the source object. + // + // 2) Swap the internal object pointers of *this and the temporary + // RefPtr<>. After this step, *this already contains the new pointer, + // and the old pointer is now managed by temp. + // + // 3) The destructor of temp is executed, thereby unreferencing the + // old object pointer. + // + // This technique is described in Herb Sutter's "Exceptional C++", and + // has a number of advantages over conventional approaches: + // + // - Code reuse by calling the copy ctor. + // - Strong exception safety for free. + // - Self assignment is handled implicitely. + // - Simplicity. + // - It just works and is hard to get wrong; i.e. you can use it without + // even thinking about it to implement copy assignment whereever the + // object data is managed indirectly via a pointer, which is very common. + + RefPtr<T_CppObject> temp (src); + this->swap(temp); + return *this; +} + +template <class T_CppObject> + template <class T_CastFrom> +inline +RefPtr<T_CppObject>& RefPtr<T_CppObject>::operator=(const RefPtr<T_CastFrom>& src) +{ + RefPtr<T_CppObject> temp (src); + this->swap(temp); + return *this; +} + +template <class T_CppObject> inline +bool RefPtr<T_CppObject>::operator==(const RefPtr<T_CppObject>& src) const +{ + return (pCppObject_ == src.pCppObject_); +} + +template <class T_CppObject> inline +bool RefPtr<T_CppObject>::operator!=(const RefPtr<T_CppObject>& src) const +{ + return (pCppObject_ != src.pCppObject_); +} + +template <class T_CppObject> inline +RefPtr<T_CppObject>::operator bool() const +{ + return (pCppObject_ != 0); +} + +#ifndef GLIBMM_DISABLE_DEPRECATED +template <class T_CppObject> inline +void RefPtr<T_CppObject>::clear() +{ + reset(); +} +#endif //GLIBMM_DISABLE_DEPRECATED + +template <class T_CppObject> inline +void RefPtr<T_CppObject>::reset() +{ + RefPtr<T_CppObject> temp; // swap with an empty RefPtr<> to clear *this + this->swap(temp); +} + +template <class T_CppObject> + template <class T_CastFrom> +inline +RefPtr<T_CppObject> RefPtr<T_CppObject>::cast_dynamic(const RefPtr<T_CastFrom>& src) +{ + T_CppObject *const pCppObject = dynamic_cast<T_CppObject*>(src.operator->()); + + if(pCppObject) + pCppObject->reference(); + + return RefPtr<T_CppObject>(pCppObject); +} + +template <class T_CppObject> + template <class T_CastFrom> +inline +RefPtr<T_CppObject> RefPtr<T_CppObject>::cast_static(const RefPtr<T_CastFrom>& src) +{ + T_CppObject *const pCppObject = static_cast<T_CppObject*>(src.operator->()); + + if(pCppObject) + pCppObject->reference(); + + return RefPtr<T_CppObject>(pCppObject); +} + +template <class T_CppObject> + template <class T_CastFrom> +inline +RefPtr<T_CppObject> RefPtr<T_CppObject>::cast_const(const RefPtr<T_CastFrom>& src) +{ + T_CppObject *const pCppObject = const_cast<T_CppObject*>(src.operator->()); + + if(pCppObject) + pCppObject->reference(); + + return RefPtr<T_CppObject>(pCppObject); +} + +template <class T_CppObject> inline +bool RefPtr<T_CppObject>::operator<(const RefPtr<T_CppObject>& src) const +{ + return (pCppObject_ < src.pCppObject_); +} + +template <class T_CppObject> inline +bool RefPtr<T_CppObject>::operator<=(const RefPtr<T_CppObject>& src) const +{ + return (pCppObject_ <= src.pCppObject_); +} + +template <class T_CppObject> inline +bool RefPtr<T_CppObject>::operator>(const RefPtr<T_CppObject>& src) const +{ + return (pCppObject_ > src.pCppObject_); +} + +template <class T_CppObject> inline +bool RefPtr<T_CppObject>::operator>=(const RefPtr<T_CppObject>& src) const +{ + return (pCppObject_ >= src.pCppObject_); +} + +#endif /* DOXYGEN_SHOULD_SKIP_THIS */ + +/** @relates Glib::RefPtr */ +template <class T_CppObject> inline +void swap(RefPtr<T_CppObject>& lhs, RefPtr<T_CppObject>& rhs) +{ + lhs.swap(rhs); +} + +} // namespace Glib + + +#endif /* _GLIBMM_REFPTR_H */ + + +#include <sigc++/sigc++.h> +#include <iostream> +#include <stdlib.h> + +#define ACTIVATE_BUG 1 + +class Action : public sigc::trackable +{ +public: + Action() : ref_count(1) { } + + void reference() { ++ref_count; } + void unreference() { if (--ref_count <= 0) delete this; } + + void emit_sig1(int n) { sig1.emit(n); } + + sigc::signal<void, int>& signal_sig1() { return sig1; } + +private: + sigc::signal<void, int> sig1; + int ref_count; + +}; + +class Test : public sigc::trackable +{ +public: + Test() + : action(new Action) + { + //std::cout << "new Test" << std::endl; +#ifdef ACTIVATE_BUG //See https://bugzilla.gnome.org/show_bug.cgi?id=564005#c15s + action->signal_sig1().connect(sigc::bind(sigc::mem_fun(this, &Test::on_sig1), action)); +#else + Glib::RefPtr<Action> action2(new Action); + action->signal_sig1().connect(sigc::bind(sigc::mem_fun(this, &Test::on_sig1), action2)); +#endif + } + + ~Test() + { + //std::cout << "delete Test" << std::endl; + } + + void on_sig1(int /* n */, Glib::RefPtr<Action> /* action */) + { + //std::cout << "Test::on_sig1, n=" << n << std::endl; + } + + Glib::RefPtr<Action> action; + +}; // end Test + +int main(int, char**) +{ + Test* test = new Test; + + test->action->emit_sig1(23); + delete test; + + return EXIT_SUCCESS; +} |