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Diffstat (limited to 'newstructure/thirdparty/linux/include/coin/CoinSmartPtr.hpp')
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1 files changed, 528 insertions, 0 deletions
diff --git a/newstructure/thirdparty/linux/include/coin/CoinSmartPtr.hpp b/newstructure/thirdparty/linux/include/coin/CoinSmartPtr.hpp new file mode 100644 index 0000000..93366a2 --- /dev/null +++ b/newstructure/thirdparty/linux/include/coin/CoinSmartPtr.hpp @@ -0,0 +1,528 @@ +// Copyright (C) 2004, 2006 International Business Machines and others. +// All Rights Reserved. +// This code is published under the Eclipse Public License. +// +// $Id: CoinSmartPtr.hpp 1520 2012-01-29 00:43:31Z tkr $ +// +// Authors: Carl Laird, Andreas Waechter IBM 2004-08-13 +// Removed lots of debugging stuff and reformatted: Laszlo Ladanyi, IBM +#ifndef CoinSmartPtr_hpp +#define CoinSmartPtr_hpp + +#include <list> +#include <cassert> +#include <cstddef> +#include <cstring> + +namespace Coin { + + //######################################################################### + + /** ReferencedObject class. + * This is part of the implementation of an intrusive smart pointer + * design. This class stores the reference count of all the smart + * pointers that currently reference it. See the documentation for + * the SmartPtr class for more details. + * + * A SmartPtr behaves much like a raw pointer, but manages the lifetime + * of an object, deleting the object automatically. This class implements + * a reference-counting, intrusive smart pointer design, where all + * objects pointed to must inherit off of ReferencedObject, which + * stores the reference count. Although this is intrusive (native types + * and externally authored classes require wrappers to be referenced + * by smart pointers), it is a safer design. A more detailed discussion of + * these issues follows after the usage information. + * + * Usage Example: + * Note: to use the SmartPtr, all objects to which you point MUST + * inherit off of ReferencedObject. + * + * \verbatim + * + * In MyClass.hpp... + * + * #include "CoinSmartPtr.hpp" + + * + * class MyClass : public Coin::ReferencedObject // must derive from ReferencedObject + * { + * ... + * } + * + * In my_usage.cpp... + * + * #include "CoinSmartPtr.hpp" + * #include "MyClass.hpp" + * + * void func(AnyObject& obj) + * { + * Coin::SmartPtr<MyClass> ptr_to_myclass = new MyClass(...); + * // ptr_to_myclass now points to a new MyClass, + * // and the reference count is 1 + * + * ... + * + * obj.SetMyClass(ptr_to_myclass); + * // Here, let's assume that AnyObject uses a + * // SmartPtr<MyClass> internally here. + * // Now, both ptr_to_myclass and the internal + * // SmartPtr in obj point to the same MyClass object + * // and its reference count is 2. + * + * ... + * + * // No need to delete ptr_to_myclass, this + * // will be done automatically when the + * // reference count drops to zero. + * + * } + * + * \endverbatim + * + * Other Notes: + * The SmartPtr implements both dereference operators -> & *. + * The SmartPtr does NOT implement a conversion operator to + * the raw pointer. Use the GetRawPtr() method when this + * is necessary. Make sure that the raw pointer is NOT + * deleted. + * The SmartPtr implements the comparison operators == & != + * for a variety of types. Use these instead of + * \verbatim + * if (GetRawPtr(smrt_ptr) == ptr) // Don't use this + * \endverbatim + * SmartPtr's, as currently implemented, do NOT handle circular references. + * For example: consider a higher level object using SmartPtrs to point + * to A and B, but A and B also point to each other (i.e. A has a + * SmartPtr to B and B has a SmartPtr to A). In this scenario, when the + * higher level object is finished with A and B, their reference counts + * will never drop to zero (since they reference each other) and they + * will not be deleted. This can be detected by memory leak tools like + * valgrind. If the circular reference is necessary, the problem can be + * overcome by a number of techniques: + * + * 1) A and B can have a method that "releases" each other, that is + * they set their internal SmartPtrs to NULL. + * \verbatim + * void AClass::ReleaseCircularReferences() + * { + * smart_ptr_to_B = NULL; + * } + * \endverbatim + * Then, the higher level class can call these methods before + * it is done using A & B. + * + * 2) Raw pointers can be used in A and B to reference each other. + * Here, an implicit assumption is made that the lifetime is + * controlled by the higher level object and that A and B will + * both exist in a controlled manner. Although this seems + * dangerous, in many situations, this type of referencing + * is very controlled and this is reasonably safe. + * + * 3) This SmartPtr class could be redesigned with the Weak/Strong + * design concept. Here, the SmartPtr is identified as being + * Strong (controls lifetime of the object) or Weak (merely + * referencing the object). The Strong SmartPtr increments + * (and decrements) the reference count in ReferencedObject + * but the Weak SmartPtr does not. In the example above, + * the higher level object would have Strong SmartPtrs to + * A and B, but A and B would have Weak SmartPtrs to each + * other. Then, when the higher level object was done with + * A and B, they would be deleted. The Weak SmartPtrs in A + * and B would not decrement the reference count and would, + * of course, not delete the object. This idea is very similar + * to item (2), where it is implied that the sequence of events + * is controlled such that A and B will not call anything using + * their pointers following the higher level delete (i.e. in + * their destructors!). This is somehow safer, however, because + * code can be written (however expensive) to perform run-time + * detection of this situation. For example, the ReferencedObject + * could store pointers to all Weak SmartPtrs that are referencing + * it and, in its destructor, tell these pointers that it is + * dying. They could then set themselves to NULL, or set an + * internal flag to detect usage past this point. + * + * Comments on Non-Intrusive Design: + * In a non-intrusive design, the reference count is stored somewhere other + * than the object being referenced. This means, unless the reference + * counting pointer is the first referencer, it must get a pointer to the + * referenced object from another smart pointer (so it has access to the + * reference count location). In this non-intrusive design, if we are + * pointing to an object with a smart pointer (or a number of smart + * pointers), and we then give another smart pointer the address through + * a RAW pointer, we will have two independent, AND INCORRECT, reference + * counts. To avoid this pitfall, we use an intrusive reference counting + * technique where the reference count is stored in the object being + * referenced. + */ + class ReferencedObject { + public: + ReferencedObject() : reference_count_(0) {} + virtual ~ReferencedObject() { assert(reference_count_ == 0); } + inline int ReferenceCount() const { return reference_count_; } + inline void AddRef() const { ++reference_count_; } + inline void ReleaseRef() const { --reference_count_; } + + private: + mutable int reference_count_; + }; + + //######################################################################### + + +//#define IP_DEBUG_SMARTPTR +#if COIN_IPOPT_CHECKLEVEL > 2 +# define IP_DEBUG_SMARTPTR +#endif +#ifdef IP_DEBUG_SMARTPTR +# include "IpDebug.hpp" +#endif + + /** Template class for Smart Pointers. + * A SmartPtr behaves much like a raw pointer, but manages the lifetime + * of an object, deleting the object automatically. This class implements + * a reference-counting, intrusive smart pointer design, where all + * objects pointed to must inherit off of ReferencedObject, which + * stores the reference count. Although this is intrusive (native types + * and externally authored classes require wrappers to be referenced + * by smart pointers), it is a safer design. A more detailed discussion of + * these issues follows after the usage information. + * + * Usage Example: + * Note: to use the SmartPtr, all objects to which you point MUST + * inherit off of ReferencedObject. + * + * \verbatim + * + * In MyClass.hpp... + * + * #include "CoinSmartPtr.hpp" + * + * class MyClass : public Coin::ReferencedObject // must derive from ReferencedObject + * { + * ... + * } + * + * In my_usage.cpp... + * + * #include "CoinSmartPtr.hpp" + * #include "MyClass.hpp" + * + * void func(AnyObject& obj) + * { + * SmartPtr<MyClass> ptr_to_myclass = new MyClass(...); + * // ptr_to_myclass now points to a new MyClass, + * // and the reference count is 1 + * + * ... + * + * obj.SetMyClass(ptr_to_myclass); + * // Here, let's assume that AnyObject uses a + * // SmartPtr<MyClass> internally here. + * // Now, both ptr_to_myclass and the internal + * // SmartPtr in obj point to the same MyClass object + * // and its reference count is 2. + * + * ... + * + * // No need to delete ptr_to_myclass, this + * // will be done automatically when the + * // reference count drops to zero. + * + * } + * + * \endverbatim + * + * It is not necessary to use SmartPtr's in all cases where an + * object is used that has been allocated "into" a SmartPtr. It is + * possible to just pass objects by reference or regular pointers, + * even if lower down in the stack a SmartPtr is to be held on to. + * Everything should work fine as long as a pointer created by "new" + * is immediately passed into a SmartPtr, and if SmartPtr's are used + * to hold on to objects. + * + * Other Notes: + * The SmartPtr implements both dereference operators -> & *. + * The SmartPtr does NOT implement a conversion operator to + * the raw pointer. Use the GetRawPtr() method when this + * is necessary. Make sure that the raw pointer is NOT + * deleted. + * The SmartPtr implements the comparison operators == & != + * for a variety of types. Use these instead of + * \verbatim + * if (GetRawPtr(smrt_ptr) == ptr) // Don't use this + * \endverbatim + * SmartPtr's, as currently implemented, do NOT handle circular references. + * For example: consider a higher level object using SmartPtrs to point to + * A and B, but A and B also point to each other (i.e. A has a SmartPtr + * to B and B has a SmartPtr to A). In this scenario, when the higher + * level object is finished with A and B, their reference counts will + * never drop to zero (since they reference each other) and they + * will not be deleted. This can be detected by memory leak tools like + * valgrind. If the circular reference is necessary, the problem can be + * overcome by a number of techniques: + * + * 1) A and B can have a method that "releases" each other, that is + * they set their internal SmartPtrs to NULL. + * \verbatim + * void AClass::ReleaseCircularReferences() + * { + * smart_ptr_to_B = NULL; + * } + * \endverbatim + * Then, the higher level class can call these methods before + * it is done using A & B. + * + * 2) Raw pointers can be used in A and B to reference each other. + * Here, an implicit assumption is made that the lifetime is + * controlled by the higher level object and that A and B will + * both exist in a controlled manner. Although this seems + * dangerous, in many situations, this type of referencing + * is very controlled and this is reasonably safe. + * + * 3) This SmartPtr class could be redesigned with the Weak/Strong + * design concept. Here, the SmartPtr is identified as being + * Strong (controls lifetime of the object) or Weak (merely + * referencing the object). The Strong SmartPtr increments + * (and decrements) the reference count in ReferencedObject + * but the Weak SmartPtr does not. In the example above, + * the higher level object would have Strong SmartPtrs to + * A and B, but A and B would have Weak SmartPtrs to each + * other. Then, when the higher level object was done with + * A and B, they would be deleted. The Weak SmartPtrs in A + * and B would not decrement the reference count and would, + * of course, not delete the object. This idea is very similar + * to item (2), where it is implied that the sequence of events + * is controlled such that A and B will not call anything using + * their pointers following the higher level delete (i.e. in + * their destructors!). This is somehow safer, however, because + * code can be written (however expensive) to perform run-time + * detection of this situation. For example, the ReferencedObject + * could store pointers to all Weak SmartPtrs that are referencing + * it and, in its destructor, tell these pointers that it is + * dying. They could then set themselves to NULL, or set an + * internal flag to detect usage past this point. + * + * Comments on Non-Intrusive Design: + * In a non-intrusive design, the reference count is stored somewhere other + * than the object being referenced. This means, unless the reference + * counting pointer is the first referencer, it must get a pointer to the + * referenced object from another smart pointer (so it has access to the + * reference count location). In this non-intrusive design, if we are + * pointing to an object with a smart pointer (or a number of smart + * pointers), and we then give another smart pointer the address through + * a RAW pointer, we will have two independent, AND INCORRECT, reference + * counts. To avoid this pitfall, we use an intrusive reference counting + * technique where the reference count is stored in the object being + * referenced. + */ + template <class T> + class SmartPtr { + public: + /** Returns the raw pointer contained. Use to get the value of the + * raw ptr (i.e. to pass to other methods/functions, etc.) Note: This + * method does NOT copy, therefore, modifications using this value + * modify the underlying object contained by the SmartPtr, NEVER + * delete this returned value. + */ + T* GetRawPtr() const { return ptr_; } + + /** Returns true if the SmartPtr is NOT NULL. + * Use this to check if the SmartPtr is not null + * This is preferred to if(GetRawPtr(sp) != NULL) + */ + bool IsValid() const { return ptr_ != NULL; } + + /** Returns true if the SmartPtr is NULL. + * Use this to check if the SmartPtr IsNull. + * This is preferred to if(GetRawPtr(sp) == NULL) + */ + bool IsNull() const { return ptr_ == NULL; } + + private: + /**@name Private Data/Methods */ + //@{ + /** Actual raw pointer to the object. */ + T* ptr_; + + /** Release the currently referenced object. */ + void ReleasePointer_() { + if (ptr_) { + ptr_->ReleaseRef(); + if (ptr_->ReferenceCount() == 0) { + delete ptr_; + } + ptr_ = NULL; + } + } + + /** Set the value of the internal raw pointer from another raw + * pointer, releasing the previously referenced object if necessary. */ + SmartPtr<T>& SetFromRawPtr_(T* rhs){ + ReleasePointer_(); // Release any old pointer + if (rhs != NULL) { + rhs->AddRef(); + ptr_ = rhs; + } + return *this; + } + + /** Set the value of the internal raw pointer from a SmartPtr, + * releasing the previously referenced object if necessary. */ + inline SmartPtr<T>& SetFromSmartPtr_(const SmartPtr<T>& rhs) { + SetFromRawPtr_(rhs.GetRawPtr()); + return (*this); + } + + //@} + + public: +#define dbg_smartptr_verbosity 0 + + /**@name Constructors/Destructors */ + //@{ + /** Default constructor, initialized to NULL */ + SmartPtr() : ptr_(NULL) {} + + /** Copy constructor, initialized from copy */ + SmartPtr(const SmartPtr<T>& copy) : ptr_(NULL) { + (void) SetFromSmartPtr_(copy); + } + + /** Constructor, initialized from T* ptr */ + SmartPtr(T* ptr) : ptr_(NULL) { + (void) SetFromRawPtr_(ptr); + } + + /** Destructor, automatically decrements the reference count, deletes + * the object if necessary.*/ + ~SmartPtr() { + ReleasePointer_(); + } + //@} + + /**@name Overloaded operators. */ + //@{ + /** Overloaded arrow operator, allows the user to call + * methods using the contained pointer. */ + T* operator->() const { +#if COIN_COINUTILS_CHECKLEVEL > 0 + assert(ptr_); +#endif + return ptr_; + } + + /** Overloaded dereference operator, allows the user + * to dereference the contained pointer. */ + T& operator*() const { +#if COIN_IPOPT_CHECKLEVEL > 0 + assert(ptr_); +#endif + return *ptr_; + } + + /** Overloaded equals operator, allows the user to + * set the value of the SmartPtr from a raw pointer */ + SmartPtr<T>& operator=(T* rhs) { + return SetFromRawPtr_(rhs); + } + + /** Overloaded equals operator, allows the user to + * set the value of the SmartPtr from another + * SmartPtr */ + SmartPtr<T>& operator=(const SmartPtr<T>& rhs) { + return SetFromSmartPtr_(rhs); + } + + /** Overloaded equality comparison operator, allows the + * user to compare the value of two SmartPtrs */ + template <class U1, class U2> + friend + bool operator==(const SmartPtr<U1>& lhs, const SmartPtr<U2>& rhs); + + /** Overloaded equality comparison operator, allows the + * user to compare the value of a SmartPtr with a raw pointer. */ + template <class U1, class U2> + friend + bool operator==(const SmartPtr<U1>& lhs, U2* raw_rhs); + + /** Overloaded equality comparison operator, allows the + * user to compare the value of a raw pointer with a SmartPtr. */ + template <class U1, class U2> + friend + bool operator==(U1* lhs, const SmartPtr<U2>& raw_rhs); + + /** Overloaded in-equality comparison operator, allows the + * user to compare the value of two SmartPtrs */ + template <class U1, class U2> + friend + bool operator!=(const SmartPtr<U1>& lhs, const SmartPtr<U2>& rhs); + + /** Overloaded in-equality comparison operator, allows the + * user to compare the value of a SmartPtr with a raw pointer. */ + template <class U1, class U2> + friend + bool operator!=(const SmartPtr<U1>& lhs, U2* raw_rhs); + + /** Overloaded in-equality comparison operator, allows the + * user to compare the value of a SmartPtr with a raw pointer. */ + template <class U1, class U2> + friend + bool operator!=(U1* lhs, const SmartPtr<U2>& raw_rhs); + //@} + + }; + + template <class U1, class U2> + bool ComparePointers(const U1* lhs, const U2* rhs) { + if (lhs == rhs) { + return true; + } + // If lhs and rhs point to the same object with different interfaces + // U1 and U2, we cannot guarantee that the value of the pointers will + // be equivalent. We can guarantee this if we convert to void*. + return static_cast<const void*>(lhs) == static_cast<const void*>(rhs); + } + +} // namespace Coin + +//############################################################################# + +/**@name SmartPtr friends that are overloaded operators, so they are not in + the Coin namespace. */ +//@{ +template <class U1, class U2> +bool operator==(const Coin::SmartPtr<U1>& lhs, const Coin::SmartPtr<U2>& rhs) { + return Coin::ComparePointers(lhs.GetRawPtr(), rhs.GetRawPtr()); +} + +template <class U1, class U2> +bool operator==(const Coin::SmartPtr<U1>& lhs, U2* raw_rhs) { + return Coin::ComparePointers(lhs.GetRawPtr(), raw_rhs); +} + +template <class U1, class U2> +bool operator==(U1* raw_lhs, const Coin::SmartPtr<U2>& rhs) { + return Coin::ComparePointers(raw_lhs, rhs.GetRawPtr()); +} + +template <class U1, class U2> +bool operator!=(const Coin::SmartPtr<U1>& lhs, const Coin::SmartPtr<U2>& rhs) { + return ! operator==(lhs, rhs); +} + +template <class U1, class U2> +bool operator!=(const Coin::SmartPtr<U1>& lhs, U2* raw_rhs) { + return ! operator==(lhs, raw_rhs); +} + +template <class U1, class U2> +bool operator!=(U1* raw_lhs, const Coin::SmartPtr<U2>& rhs) { + return ! operator==(raw_lhs, rhs); +} +//@} + +#define CoinReferencedObject Coin::ReferencedObject +#define CoinSmartPtr Coin::SmartPtr +#define CoinComparePointers Coin::ComparePointers + +#endif |