CrystalSpace

Public API Reference

csutil/ref.h

Go to the documentation of this file.
00001 /*
00002   Crystal Space Smart Pointers
00003   Copyright (C) 2002 by Jorrit Tyberghein and Matthias Braun
00004 
00005   This library is free software; you can redistribute it and/or
00006   modify it under the terms of the GNU Library General Public
00007   License as published by the Free Software Foundation; either
00008   version 2 of the License, or (at your option) any later version.
00009 
00010   This library is distributed in the hope that it will be useful,
00011   but WITHOUT ANY WARRANTY; without even the implied warranty of
00012   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013   Library General Public License for more details.
00014 
00015   You should have received a copy of the GNU Library General Public
00016   License along with this library; if not, write to the Free
00017   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
00018 */
00019 
00020 #ifndef __CS_REF_H__
00021 #define __CS_REF_H__
00022 
00027 #include "csextern.h"
00028 
00029 #define CS_VOIDED_PTR ((intptr_t)-1)
00030 
00031 template <class T> class csRef;
00032 
00033 #if defined(CS_DEBUG)
00034 #  define CS_TEST_VOIDPTRUSAGE
00035 #else
00036 #  undef CS_TEST_VOIDPTRUSAGE
00037 #endif
00038 
00039 #ifdef CS_REF_TRACKER
00040  #include <typeinfo>
00041  #include "csutil/reftrackeraccess.h"
00042 
00043  #define CSREF_TRACK(x, cmd, refCount, obj, tag)    \
00044   {                                                 \
00045     const int rc = obj ? refCount : -1;             \
00046     if (obj)                                        \
00047     {                                               \
00048       cmd;                                          \
00049       csRefTrackerAccess::SetDescription (obj,      \
00050         typeid(T).name());                          \
00051       csRefTrackerAccess::Match ## x (obj, rc, tag);\
00052     }                                               \
00053   }
00054  #define CSREF_TRACK_INCREF(obj,tag)    \
00055   CSREF_TRACK(IncRef, obj->IncRef(), obj->GetRefCount(), obj, tag);
00056  #define CSREF_TRACK_DECREF(obj,tag)    \
00057   CSREF_TRACK(DecRef, obj->DecRef(), obj->GetRefCount(), obj, tag);
00058  #define CSREF_TRACK_ASSIGN(obj,tag)    \
00059   CSREF_TRACK(IncRef, void(0), obj->GetRefCount() - 1, obj, tag);
00060 #else
00061  #define CSREF_TRACK_INCREF(obj,tag) \
00062   if (obj) obj->IncRef();
00063  #define CSREF_TRACK_DECREF(obj,tag) \
00064   if (obj) obj->DecRef();
00065  #define CSREF_TRACK_ASSIGN(obj,tag)
00066 #endif
00067 
00078 template <class T>
00079 class  csPtr
00080 {
00081 private:
00082   friend class csRef<T>;
00083   T* obj;
00084 
00085 public:
00086   csPtr (T* p) : obj (p) { CSREF_TRACK_ASSIGN(obj, this); }
00087 
00088   template <class T2>
00089   explicit csPtr (csRef<T2> const& r) : obj((T2*)r) 
00090   { 
00091     CSREF_TRACK_INCREF (obj, this);
00092   }
00093 
00094 #ifdef CS_TEST_VOIDPTRUSAGE
00095   ~csPtr ()
00096   {
00097     // If not assigned to a csRef we have a problem (leak).
00098     // So if this assert fires for you, then you are calling
00099     // a function that returns a csPtr and not using the result
00100     // (or at least not assigning it to a csRef). This is a memory
00101     // leak and you should fix that.
00102     CS_ASSERT_MSG ("csPtr<> was not assigned to a csRef<> prior destruction", 
00103       obj == (T*)CS_VOIDED_PTR);
00104   }
00105 #endif
00106 
00107   csPtr (const csPtr<T>& copy)
00108   {
00109     obj = copy.obj;
00110 #ifdef CS_TEST_VOIDPTRUSAGE
00111     ((csPtr<T>&)copy).obj = (T*)CS_VOIDED_PTR;
00112 #endif
00113   }
00114 };
00115 
00122 template <class T>
00123 class  csRef
00124 {
00125 private:
00126   T* obj;
00127 
00128 public:
00134   csRef () : obj (0) {}
00135 
00141   csRef (const csPtr<T>& newobj)
00142   {
00143     obj = newobj.obj;
00144 #   ifdef CS_TEST_VOIDPTRUSAGE
00145     CS_ASSERT_MSG ("csPtr<> was already assigned to a csRef<>",
00146       newobj.obj != (T*)CS_VOIDED_PTR);
00147 #   endif
00148     // The following line is outside the ifdef to make sure
00149     // we have binary compatibility.
00150     ((csPtr<T>&)newobj).obj = (T*)CS_VOIDED_PTR;
00151   }
00152 
00157   csRef (T* newobj) : obj (newobj)
00158   {
00159     CSREF_TRACK_INCREF (obj, this);
00160   }
00161 
00166   template <class T2>
00167   csRef (T2* newobj) : obj ((T2*)newobj)
00168   {
00169     CSREF_TRACK_INCREF (obj, this);
00170   }
00171   
00175   template <class T2>
00176   csRef (csRef<T2> const& other) : obj ((T2*)other)
00177   {
00178     CSREF_TRACK_INCREF (obj, this);
00179   }
00180 
00184   csRef (csRef const& other) : obj (other.obj)
00185   {
00186     CSREF_TRACK_INCREF (obj, this);
00187   }
00188 
00192   ~csRef ()
00193   {
00194     CSREF_TRACK_DECREF (obj, this);
00195   }
00196 
00206   csRef& operator = (const csPtr<T>& newobj)
00207   {
00208     T* oldobj = obj;
00209     // First assign and then DecRef() of old object!
00210     obj = newobj.obj;
00211 #   ifdef CS_TEST_VOIDPTRUSAGE
00212     CS_ASSERT_MSG ("csPtr<> was already assigned to a csRef<>",
00213       newobj.obj != (T*)CS_VOIDED_PTR);
00214 #   endif
00215     // The following line is outside the ifdef to make sure
00216     // we have binary compatibility.
00217     ((csPtr<T>&)newobj).obj = (T*)CS_VOIDED_PTR;
00218     CSREF_TRACK_DECREF (oldobj, this);
00219     return *this;
00220   }
00221 
00234   csRef& operator = (T* newobj)
00235   {
00236     if (obj != newobj)
00237     {
00238       T* oldobj = obj;
00239       // It is very important to first assign the new value to
00240       // 'obj' BEFORE calling DecRef() on the old object. Otherwise
00241       // it is easy to get in infinite loops with objects being
00242       // destructed forever (when ref=0 is used for example).
00243       obj = newobj;
00244       CSREF_TRACK_INCREF (newobj, this);
00245       CSREF_TRACK_DECREF (oldobj, this);
00246     }
00247     return *this;
00248   }
00249 
00272   void AttachNew (csPtr<T> newObj)
00273   {
00274     // Note: The parameter usage of csPtr<T> instead of csPtr<T>& is
00275     // deliberate and not to be considered a bug.
00276 
00277     // Just Re-use csPtr assignment logic
00278     *this = newObj;
00279   }
00280 
00282   template <class T2>
00283   csRef& operator = (csRef<T2> const& other)
00284   {
00285     T* p = (T2*)other;
00286     this->operator=(p);
00287     return *this;
00288   }
00289 
00291   csRef& operator = (csRef const& other)
00292   {
00293     this->operator=(other.obj);
00294     return *this;
00295   }
00296 
00298   inline friend bool operator == (const csRef& r1, const csRef& r2)
00299   {
00300     return r1.obj == r2.obj;
00301   }
00303   inline friend bool operator != (const csRef& r1, const csRef& r2)
00304   {
00305     return r1.obj != r2.obj;
00306   }
00308   inline friend bool operator == (const csRef& r1, T* obj)
00309   {
00310     return r1.obj == obj;
00311   }
00313   inline friend bool operator != (const csRef& r1, T* obj)
00314   {
00315     return r1.obj != obj;
00316   }
00318   inline friend bool operator == (T* obj, const csRef& r1)
00319   {
00320     return r1.obj == obj;
00321   }
00323   inline friend bool operator != (T* obj, const csRef& r1)
00324   {
00325     return r1.obj != obj;
00326   }
00332   inline friend bool operator < (const csRef& r1, const csRef& r2)
00333   {
00334     return r1.obj < r2.obj;
00335   }
00336 
00337 
00339   T* operator -> () const
00340   { return obj; }
00341   
00343   operator T* () const
00344   { return obj; }
00345   
00347   T& operator* () const
00348   { return *obj; }
00349 
00354   bool IsValid () const
00355   { return (obj != 0); }
00356 
00358   void Invalidate()
00359   { *this = (T*)0; }
00360 
00362   uint GetHash() const
00363   { return (uintptr_t)obj;  }
00364 };
00365 
00366 #undef CSREF_TRACK_INCREF
00367 #undef CSREF_TRACK_DECREF
00368 #undef CSREF_TRACK_ASSIGN
00369 
00370 #endif // __CS_REF_H__

Generated for Crystal Space by doxygen 1.4.7