openpilot is an open source driver assistance system. openpilot performs the functions of Automated Lane Centering and Adaptive Cruise Control for over 200 supported car makes and models.
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// Copyright (C) 2004, 2011 International Business Machines and others.
// All Rights Reserved.
// This code is published under the Eclipse Public License.
//
// $Id: IpSmartPtr.hpp 2182 2013-03-30 20:02:18Z stefan $
//
// Authors: Carl Laird, Andreas Waechter IBM 2004-08-13
#ifndef __IPSMARTPTR_HPP__
#define __IPSMARTPTR_HPP__
#include "IpReferenced.hpp"
#include "IpDebug.hpp"
#if COIN_IPOPT_CHECKLEVEL > 2
# define IP_DEBUG_SMARTPTR
#endif
#ifndef IPOPT_UNUSED
# if defined(__GNUC__)
# define IPOPT_UNUSED __attribute__((unused))
# else
# define IPOPT_UNUSED
# endif
#endif
namespace Ipopt
{
/** 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 "IpReferenced.hpp"
* namespace Ipopt {
*
* class MyClass : public ReferencedObject // must derive from ReferencedObject
* {
* ...
* }
* } // namespace Ipopt
*
*
* In my_usage.cpp...
*
* #include "IpSmartPtr.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 Referencer
{
public:
#define ipopt_dbg_smartptr_verbosity 0
/**@name Constructors/Destructors */
//@{
/** Default constructor, initialized to NULL */
SmartPtr();
/** Copy constructor, initialized from copy of type T */
SmartPtr(const SmartPtr<T>& copy);
/** Copy constructor, initialized from copy of type U */
template <class U>
SmartPtr(const SmartPtr<U>& copy);
/** Constructor, initialized from T* ptr */
SmartPtr(T* ptr);
/** Destructor, automatically decrements the
* reference count, deletes the object if
* necessary.*/
~SmartPtr();
//@}
/**@name Overloaded operators. */
//@{
/** Overloaded arrow operator, allows the user to call
* methods using the contained pointer. */
T* operator->() const;
/** Overloaded dereference operator, allows the user
* to dereference the contained pointer. */
T& operator*() const;
/** Overloaded equals operator, allows the user to
* set the value of the SmartPtr from a raw pointer */
SmartPtr<T>& operator=(T* rhs);
/** Overloaded equals operator, allows the user to
* set the value of the SmartPtr from another
* SmartPtr */
SmartPtr<T>& operator=(const SmartPtr<T>& rhs);
/** Overloaded equals operator, allows the user to
* set the value of the SmartPtr from another
* SmartPtr of a different type */
template <class U>
SmartPtr<T>& operator=(const SmartPtr<U>& 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);
/** Overloaded less-than comparison operator, allows the
* user to compare the value of two SmartPtrs */
template <class U>
friend
bool operator<(const SmartPtr<U>& lhs, const SmartPtr<U>& rhs);
//@}
/**@name friend method declarations. */
//@{
/** 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.
*/
template <class U>
friend
U* GetRawPtr(const SmartPtr<U>& smart_ptr);
/** Returns a const pointer */
template <class U>
friend
SmartPtr<const U> ConstPtr(const SmartPtr<U>& smart_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)
*/
template <class U>
friend
bool IsValid(const SmartPtr<U>& smart_ptr);
/** Returns true if the SmartPtr is NULL.
* Use this to check if the SmartPtr IsNull.
* This is preferred to if(GetRawPtr(sp) == NULL)
*/
template <class U>
friend
bool IsNull(const SmartPtr<U>& smart_ptr);
//@}
private:
/**@name Private Data/Methods */
//@{
/** Actual raw pointer to the object. */
T* ptr_;
/** Set the value of the internal raw pointer
* from another raw pointer, releasing the
* previously referenced object if necessary. */
SmartPtr<T>& SetFromRawPtr_(T* rhs);
/** Set the value of the internal raw pointer
* from a SmartPtr, releasing the previously referenced
* object if necessary. */
SmartPtr<T>& SetFromSmartPtr_(const SmartPtr<T>& rhs);
/** Release the currently referenced object. */
void ReleasePointer_();
//@}
};
/**@name SmartPtr friend function declarations.*/
//@{
template <class U>
U* GetRawPtr(const SmartPtr<U>& smart_ptr);
template <class U>
SmartPtr<const U> ConstPtr(const SmartPtr<U>& smart_ptr);
template <class U>
bool IsNull(const SmartPtr<U>& smart_ptr);
template <class U>
bool IsValid(const SmartPtr<U>& smart_ptr);
template <class U1, class U2>
bool operator==(const SmartPtr<U1>& lhs, const SmartPtr<U2>& rhs);
template <class U1, class U2>
bool operator==(const SmartPtr<U1>& lhs, U2* raw_rhs);
template <class U1, class U2>
bool operator==(U1* lhs, const SmartPtr<U2>& raw_rhs);
template <class U1, class U2>
bool operator!=(const SmartPtr<U1>& lhs, const SmartPtr<U2>& rhs);
template <class U1, class U2>
bool operator!=(const SmartPtr<U1>& lhs, U2* raw_rhs);
template <class U1, class U2>
bool operator!=(U1* lhs, const SmartPtr<U2>& raw_rhs);
//@}
template <class T>
SmartPtr<T>::SmartPtr()
:
ptr_(0)
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_METH("SmartPtr<T>::SmartPtr()", ipopt_dbg_smartptr_verbosity);
#endif
#ifndef NDEBUG
const ReferencedObject* IPOPT_UNUSED trying_to_use_SmartPtr_with_an_object_that_does_not_inherit_from_ReferencedObject_ = ptr_;
#endif
}
template <class T>
SmartPtr<T>::SmartPtr(const SmartPtr<T>& copy)
:
ptr_(0)
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_METH("SmartPtr<T>::SmartPtr(const SmartPtr<T>& copy)", ipopt_dbg_smartptr_verbosity);
#endif
#ifndef NDEBUG
const ReferencedObject* IPOPT_UNUSED trying_to_use_SmartPtr_with_an_object_that_does_not_inherit_from_ReferencedObject_ = ptr_;
#endif
(void) SetFromSmartPtr_(copy);
}
template <class T>
template <class U>
SmartPtr<T>::SmartPtr(const SmartPtr<U>& copy)
:
ptr_(0)
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_METH("SmartPtr<T>::SmartPtr(const SmartPtr<U>& copy)", ipopt_dbg_smartptr_verbosity);
#endif
#ifndef NDEBUG
const ReferencedObject* IPOPT_UNUSED trying_to_use_SmartPtr_with_an_object_that_does_not_inherit_from_ReferencedObject_ = ptr_;
#endif
(void) SetFromSmartPtr_(GetRawPtr(copy));
}
template <class T>
SmartPtr<T>::SmartPtr(T* ptr)
:
ptr_(0)
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_METH("SmartPtr<T>::SmartPtr(T* ptr)", ipopt_dbg_smartptr_verbosity);
#endif
#ifndef NDEBUG
const ReferencedObject* IPOPT_UNUSED trying_to_use_SmartPtr_with_an_object_that_does_not_inherit_from_ReferencedObject_ = ptr_;
#endif
(void) SetFromRawPtr_(ptr);
}
template <class T>
SmartPtr<T>::~SmartPtr()
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_METH("SmartPtr<T>::~SmartPtr(T* ptr)", ipopt_dbg_smartptr_verbosity);
#endif
ReleasePointer_();
}
template <class T>
T* SmartPtr<T>::operator->() const
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_METH("T* SmartPtr<T>::operator->()", ipopt_dbg_smartptr_verbosity);
#endif
// cannot deref a null pointer
#if COIN_IPOPT_CHECKLEVEL > 0
assert(ptr_);
#endif
return ptr_;
}
template <class T>
T& SmartPtr<T>::operator*() const
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_METH("T& SmartPtr<T>::operator*()", ipopt_dbg_smartptr_verbosity);
#endif
// cannot dereference a null pointer
#if COIN_IPOPT_CHECKLEVEL > 0
assert(ptr_);
#endif
return *ptr_;
}
template <class T>
SmartPtr<T>& SmartPtr<T>::operator=(T* rhs)
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_METH("SmartPtr<T>& SmartPtr<T>::operator=(T* rhs)", ipopt_dbg_smartptr_verbosity);
#endif
return SetFromRawPtr_(rhs);
}
template <class T>
SmartPtr<T>& SmartPtr<T>::operator=(const SmartPtr<T>& rhs)
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_METH(
"SmartPtr<T>& SmartPtr<T>::operator=(const SmartPtr<T>& rhs)",
ipopt_dbg_smartptr_verbosity);
#endif
return SetFromSmartPtr_(rhs);
}
template <class T>
template <class U>
SmartPtr<T>& SmartPtr<T>::operator=(const SmartPtr<U>& rhs)
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_METH(
"SmartPtr<T>& SmartPtr<T>::operator=(const SmartPtr<U>& rhs)",
ipopt_dbg_smartptr_verbosity);
#endif
return SetFromSmartPtr_(GetRawPtr(rhs));
}
template <class T>
SmartPtr<T>& SmartPtr<T>::SetFromRawPtr_(T* rhs)
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_METH(
"SmartPtr<T>& SmartPtr<T>::SetFromRawPtr_(T* rhs)", ipopt_dbg_smartptr_verbosity);
#endif
if (rhs != 0)
rhs->AddRef(this);
// Release any old pointer
ReleasePointer_();
ptr_ = rhs;
return *this;
}
template <class T>
SmartPtr<T>& SmartPtr<T>::SetFromSmartPtr_(const SmartPtr<T>& rhs)
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_METH(
"SmartPtr<T>& SmartPtr<T>::SetFromSmartPtr_(const SmartPtr<T>& rhs)",
ipopt_dbg_smartptr_verbosity);
#endif
SetFromRawPtr_(GetRawPtr(rhs));
return (*this);
}
template <class T>
void SmartPtr<T>::ReleasePointer_()
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_METH(
"void SmartPtr<T>::ReleasePointer()",
ipopt_dbg_smartptr_verbosity);
#endif
if (ptr_) {
ptr_->ReleaseRef(this);
if (ptr_->ReferenceCount() == 0)
delete ptr_;
}
}
template <class U>
U* GetRawPtr(const SmartPtr<U>& smart_ptr)
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_FUN(
"T* GetRawPtr(const SmartPtr<T>& smart_ptr)",
0);
#endif
return smart_ptr.ptr_;
}
template <class U>
SmartPtr<const U> ConstPtr(const SmartPtr<U>& smart_ptr)
{
// compiler should implicitly cast
return GetRawPtr(smart_ptr);
}
template <class U>
bool IsValid(const SmartPtr<U>& smart_ptr)
{
return !IsNull(smart_ptr);
}
template <class U>
bool IsNull(const SmartPtr<U>& smart_ptr)
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_FUN(
"bool IsNull(const SmartPtr<T>& smart_ptr)",
0);
#endif
return (smart_ptr.ptr_ == 0);
}
template <class U1, class U2>
bool ComparePointers(const U1* lhs, const U2* rhs)
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_FUN(
"bool ComparePtrs(const U1* lhs, const U2* rhs)",
ipopt_dbg_smartptr_verbosity);
#endif
// Even 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 ReferencedObject* (see also #162)
const ReferencedObject* v_lhs = lhs;
const ReferencedObject* v_rhs = rhs;
return v_lhs == v_rhs;
}
template <class U1, class U2>
bool operator==(const SmartPtr<U1>& lhs, const SmartPtr<U2>& rhs)
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_FUN(
"bool operator==(const SmartPtr<U1>& lhs, const SmartPtr<U2>& rhs)",
ipopt_dbg_smartptr_verbosity);
#endif
U1* raw_lhs = GetRawPtr(lhs);
U2* raw_rhs = GetRawPtr(rhs);
return ComparePointers(raw_lhs, raw_rhs);
}
template <class U1, class U2>
bool operator==(const SmartPtr<U1>& lhs, U2* raw_rhs)
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_FUN(
"bool operator==(SmartPtr<U1>& lhs, U2* rhs)",
ipopt_dbg_smartptr_verbosity);
#endif
U1* raw_lhs = GetRawPtr(lhs);
return ComparePointers(raw_lhs, raw_rhs);
}
template <class U1, class U2>
bool operator==(U1* raw_lhs, const SmartPtr<U2>& rhs)
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_FUN(
"bool operator==(U1* raw_lhs, SmartPtr<U2>& rhs)",
ipopt_dbg_smartptr_verbosity);
#endif
const U2* raw_rhs = GetRawPtr(rhs);
return ComparePointers(raw_lhs, raw_rhs);
}
template <class U1, class U2>
bool operator!=(const SmartPtr<U1>& lhs, const SmartPtr<U2>& rhs)
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_FUN(
"bool operator!=(const SmartPtr<U1>& lhs, const SmartPtr<U2>& rhs)",
ipopt_dbg_smartptr_verbosity);
#endif
bool retValue = operator==(lhs, rhs);
return !retValue;
}
template <class U1, class U2>
bool operator!=(const SmartPtr<U1>& lhs, U2* raw_rhs)
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_FUN(
"bool operator!=(SmartPtr<U1>& lhs, U2* rhs)",
ipopt_dbg_smartptr_verbosity);
#endif
bool retValue = operator==(lhs, raw_rhs);
return !retValue;
}
template <class U1, class U2>
bool operator!=(U1* raw_lhs, const SmartPtr<U2>& rhs)
{
#ifdef IP_DEBUG_SMARTPTR
DBG_START_FUN(
"bool operator!=(U1* raw_lhs, SmartPtr<U2>& rhs)",
ipopt_dbg_smartptr_verbosity);
#endif
bool retValue = operator==(raw_lhs, rhs);
return !retValue;
}
template <class T>
void swap(SmartPtr<T>& a, SmartPtr<T>& b)
{
#ifdef IP_DEBUG_REFERENCED
SmartPtr<T> tmp(a);
a = b;
b = tmp;
#else
std::swap(a.prt_, b.ptr_);
#endif
}
template <class T>
bool operator<(const SmartPtr<T>& lhs, const SmartPtr<T>& rhs)
{
return lhs.ptr_ < rhs.ptr_;
}
template <class T>
bool operator> (const SmartPtr<T>& lhs, const SmartPtr<T>& rhs)
{
return rhs < lhs;
}
template <class T> bool
operator<=(const SmartPtr<T>& lhs, const SmartPtr<T>& rhs)
{
return !( rhs < lhs );
}
template <class T> bool
operator>=(const SmartPtr<T>& lhs, const SmartPtr<T>& rhs)
{
return !( lhs < rhs );
}
} // namespace Ipopt
#undef ipopt_dbg_smartptr_verbosity
#endif