CrystalSpace

Public API Reference

Main Page | Modules | Namespace List | Class Hierarchy | Alphabetical List | Class List | Directories | File List | Namespace Members | Class Members | File Members | Related Pages

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 0xffffffff
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) cmd;                                   \
00047     if (obj)                                        \
00048     {                                               \
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, (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   
00165   template <class T2>
00166   csRef (csRef<T2> const& other) : obj ((T2*)other)
00167   {
00168     CSREF_TRACK_INCREF (obj, this);
00169   }
00170 
00174   csRef (csRef const& other) : obj (other.obj)
00175   {
00176     CSREF_TRACK_INCREF (obj, this);
00177   }
00178 
00182   ~csRef ()
00183   {
00184     CSREF_TRACK_DECREF (obj, this);
00185   }
00186 
00196   csRef& operator = (const csPtr<T>& newobj)
00197   {
00198     T* oldobj = obj;
00199     // First assign and then DecRef() of old object!
00200     obj = newobj.obj;
00201 #   ifdef CS_TEST_VOIDPTRUSAGE
00202     CS_ASSERT_MSG ("csPtr<> was already assigned to a csRef<>",
00203       newobj.obj != (T*)CS_VOIDED_PTR);
00204 #   endif
00205     // The following line is outside the ifdef to make sure
00206     // we have binary compatibility.
00207     ((csPtr<T>&)newobj).obj = (T*)CS_VOIDED_PTR;
00208     CSREF_TRACK_DECREF (oldobj, this);
00209     return *this;
00210   }
00211 
00224   csRef& operator = (T* newobj)
00225   {
00226     if (obj != newobj)
00227     {
00228       T* oldobj = obj;
00229       // It is very important to first assign the new value to
00230       // 'obj' BEFORE calling DecRef() on the old object. Otherwise
00231       // it is easy to get in infinite loops with objects being
00232       // destructed forever (when ref=0 is used for example).
00233       obj = newobj;
00234       CSREF_TRACK_INCREF (newobj, this);
00235       CSREF_TRACK_DECREF (oldobj, this);
00236     }
00237     return *this;
00238   }
00239 
00262   void AttachNew (csPtr<T> newObj)
00263   {
00264     // Note: The parameter usage of csPtr<T> instead of csPtr<T>& is
00265     // deliberate and not to be considered a bug.
00266 
00267     // Just Re-use csPtr assignment logic
00268     *this = newObj;
00269   }
00270 
00272   template <class T2>
00273   csRef& operator = (csRef<T2> const& other)
00274   {
00275     T* p = (T2*)other;
00276     this->operator=(p);
00277     return *this;
00278   }
00279 
00281   csRef& operator = (csRef const& other)
00282   {
00283     this->operator=(other.obj);
00284     return *this;
00285   }
00286 
00288   inline friend bool operator == (const csRef& r1, const csRef& r2)
00289   {
00290     return r1.obj == r2.obj;
00291   }
00293   inline friend bool operator != (const csRef& r1, const csRef& r2)
00294   {
00295     return r1.obj != r2.obj;
00296   }
00298   inline friend bool operator == (const csRef& r1, T* obj)
00299   {
00300     return r1.obj == obj;
00301   }
00303   inline friend bool operator != (const csRef& r1, T* obj)
00304   {
00305     return r1.obj != obj;
00306   }
00308   inline friend bool operator == (T* obj, const csRef& r1)
00309   {
00310     return r1.obj == obj;
00311   }
00313   inline friend bool operator != (T* obj, const csRef& r1)
00314   {
00315     return r1.obj != obj;
00316   }
00322   inline friend bool operator < (const csRef& r1, const csRef& r2)
00323   {
00324     return r1.obj < r2.obj;
00325   }
00326 
00327 
00329   T* operator -> () const
00330   { return obj; }
00331   
00333   operator T* () const
00334   { return obj; }
00335   
00337   T& operator* () const
00338   { return *obj; }
00339 
00344   bool IsValid () const
00345   { return (obj != 0); }
00346 
00348   void Invalidate()
00349   { *this = (T*)0; }
00350 
00352   uint GetHash() const
00353   { return (uintptr_t)obj;  }
00354 };
00355 
00356 #undef CSREF_TRACK_INCREF
00357 #undef CSREF_TRACK_DECREF
00358 #undef CSREF_TRACK_ASSIGN
00359 
00360 #endif // __CS_REF_H__

Generated for Crystal Space by doxygen 1.4.4