Usefull tiny snippet

Anthony · Post by **Anthony** » Sat Feb 05, 2011 1:18 pm

The snippet

#define safeDrop( obj ) if( obj ) if( obj->drop() ) obj = 0

to use this:

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CRefCountedClass* rcc = new CRefCountedClass();

rcc->grab(); // ref count = 2
rcc->grab();
safeDrop( rcc ); // drops it
rcc->grab(); // ref count = 2
rcc->grab(); // ref count = 3
rcc->grab(); // ref count = 4

while( rcc ) safeDrop( rcc ); // drop until deleted, if deleted rcc is set to NULL

if( rcc ) // check if rcc is a valid pointer to prefend access violation
{
  // will not be executed
};

EDIT: Bugfix that Seven pointed out to me

Seven · Post by **Seven** » Sat Feb 05, 2011 1:40 pm

very useful.

you missed a 'rcc' when typing though....

while( rcc ) safeDrop(rcc); // drop until deleted, if deleted rcc is set to

I use these also...

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#define CS_INIT(x)		x=0;
#define CS_SAFE_DELETE(x)	if(x) { delete(x);	x=0; }
#define CS_SAFE_DROP(x)		if(x) x->drop();	x=0;
#define CS_SAFE_RELEASE(x)	if(x) x->release(); x=0;
#define CS_SAFE_REMOVE(x)	if(x) x->remove();	x=0;

Anthony · Post by **Anthony** » Sat Feb 05, 2011 1:49 pm

ever thought rcc was already delete

, thanks

also thanks for the nice add-ons

however your safe drop isn't quite safe as it will nil it even when the ref counter isn't 0, or isn't this for the irrlicht IReferenceCounter?
#define CS_SAFE_DROP(x) if(x) x->drop(); x=0;

Seven · Post by **Seven** » Sat Feb 05, 2011 2:03 pm

took me a minute to see what you were asking. yes, you are right about it. not sure why it never showed up in my code though. thanks for showing, i will investigate to see if i have some dangling objects around.

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#define CS_INIT(x)      x=0; 
#define CS_SAFE_DELETE(x)   if(x) { delete(x);   x=0; } 
#define CS_SAFE_DROP(x)      if(x) (while(!x->drop()) {}   x=0; 
#define CS_SAFE_RELEASE(x)   if(x) (while(!x->release()) {} x=0; 
#define CS_SAFE_REMOVE(x)   if(x) while(!x->remove()) {}   x=0;

or similar. I will investigate. Thanks for the post which pushed me

Anthony · Post by **Anthony** » Sun Feb 06, 2011 12:58 pm

Memory leaks are tedious creepy crawlers.

Sometimes I see (around the net) people writing they never have to check for it as memory leaks won't happen to them.

Can never believe this as even the most clean coder can forget just one bit - times infinity - and there you have it. And that would clearify the amount of tedious applications on the internet.

Starterz · Post by **Starterz** » Tue Mar 22, 2011 2:33 pm

We can use this:

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#define SAFE_DELETE(x)         {if(x) delete(x),x=NULL;}
#define IRR_SAFE_REMOVE(x)     {if(x) while(!x->remove());x=NULL;}
#define IRR_SAFE_DROP(x)       {if(x->drop()) x=NULL;}

/// Special drops:
/// As we can see drop() method just delete an object when ref. counter is 0.
/// But this method DO NOT remove an object from SceneGraph so this structure have grows and memory leak..
/// Other hand remove() method do the same WITH erasing an object from Children AND (*object)->Parent = 0;
#define IRR_SAFE_NODE_DROP(x)  {if(x->getReferenceCount()>1) x->drop(); else IRR_SAFE_REMOVE(x);}
#define IRR_SAFE_GUIE_DROP(x)  IRR_SAFE_NODE_DROP(x)

See also http://irrlicht.sourceforge.net/phpBB2/ ... ht=#237978