ProtectedObject.hpp

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#ifndef ProtectedObject_Included
#define ProtectedObject_Included
 
#include "RexxActivity.hpp"
#include "ActivityManager.hpp"
 
class RexxInstruction;
 
class ProtectedObject
{
friend class RexxActivity;
public:
    inline ProtectedObject() : protectedObject(OREF_NULL)
    {
        // save the activity
        activity = ActivityManager::currentActivity;
 
        // it would be better to have the activity class do this, but because
        // we're doing this with inline methods, we run into a bit of a
        // circular reference problem
        next = activity->protectedObjects;
        activity->protectedObjects = this;
    }
 
    inline ProtectedObject(RexxActivity *a) : protectedObject(OREF_NULL), activity(a)
    {
        // it would be better to have the activity class do this, but because
        // we're doing this with inline methods, we run into a bit of a
        // circular reference problem
        next = activity->protectedObjects;
        activity->protectedObjects = this;
    }
 
    inline ProtectedObject(RexxObject *o) : protectedObject(o), next(NULL)
    {
        // save the activity
        activity = ActivityManager::currentActivity;
        next = activity->protectedObjects;
        activity->protectedObjects = this;
    }
 
    inline ProtectedObject(RexxObject *o, RexxActivity *a) : protectedObject(o), next(NULL), activity(a)
    {
        next = activity->protectedObjects;
        activity->protectedObjects = this;
    }
 
    inline ProtectedObject(RexxInternalObject *o) : protectedObject((RexxObject *)o), next(NULL)
    {
        // save the activity
        activity = ActivityManager::currentActivity;
        next = activity->protectedObjects;
        activity->protectedObjects = this;
    }
 
    inline ProtectedObject(RexxInternalObject *o, RexxActivity *a) : protectedObject((RexxObject *)o), next(NULL), activity(a)
    {
        next = activity->protectedObjects;
        activity->protectedObjects = this;
    }
 
    inline ~ProtectedObject()
    {
        // remove ourselves from the list and give this object a
        // little hold protection.
        activity->protectedObjects = next;
        if (protectedObject != OREF_NULL)
        {
            holdObject(protectedObject);
        }
    }
 
    inline ProtectedObject & operator=(RexxObject *o)
    {
        protectedObject = o;
        return *this;
    }
 
    inline bool operator == (RexxObject *o)
    {
        return protectedObject == o;
    }
 
    inline bool operator != (RexxObject *o)
    {
        return protectedObject != o;
    }
 
    // cast conversion operators for some very common uses of protected object.
    inline operator RexxObject *()
    {
        return protectedObject;
    }
 
    inline operator RexxObjectPtr ()
    {
        return (RexxObjectPtr)protectedObject;
    }
 
    inline operator RexxString *()
    {
        return (RexxString *)protectedObject;
    }
 
    inline operator RexxMethod *()
    {
        return (RexxMethod *)protectedObject;
    }
 
    inline operator RexxArray *()
    {
        return (RexxArray *)protectedObject;
    }
 
    // this conversion helps the parsing process protect objects
    inline operator RexxInstruction *()
    {
        return (RexxInstruction *)protectedObject;
    }
 
    inline operator void *()
    {
        return (void *)protectedObject;
    }
 
// To let the compiler tell you it's forbidden !
// You want to assign a rexx object, not an other protected object.
// The list of protected objects is broken if such an assignement is done
// because the attribute next is overwritten.
private:
    ProtectedObject(const ProtectedObject&);
    ProtectedObject &operator=(const ProtectedObject&);
 
 
protected:
    RexxObject *protectedObject;       // next in the chain of protected object
    ProtectedObject *next;             // the pointer protected by the object
    RexxActivity *activity;            // the activity we're running on
};
 
 
class ProtectedSet : public ProtectedObject
{
public:
    inline ProtectedSet() : ProtectedObject() { }
    inline ProtectedSet(RexxActivity *a) : ProtectedObject(a) { }
    inline ~ProtectedSet() { }
 
    void add(RexxObject *);
};
 
 
#endif