Programming Forums > Application Development > C++

Soulstorm · May 26th, 2006, 4:32 PM

Quote:

I'd also use C++ strings, but I don't know if you are prohibited to do that or anything. C++ strings have their own memory management, which is ideal.

I am not prohibited to anything, this thing is for my satisfaction only. I like C++ strings, I use them extensively, but I wanted to create a class that 'simulates' a string, just for the sake of it.

As for the header files, I have already made all these things, and had created separate files, but until my problem was fixed, I thought it would be good to put all those things into one file, for the users in here to read it all-in-one. Thanks for the advice anyway.

DaWei · May 26th, 2006, 4:42 PM

Quote:

So then the following would function correctly:

Nopey.

Soulstorm · May 26th, 2006, 4:46 PM

Quote:

Originally Posted by nnxion

A side question: I see Soulstorm doing:

(Toggle Plain Text)

void stash::clearStash(){
	currentSize = 0;
	currentStorage = 0;
	ch = new char [0];
	next = currentStorage - currentSize;
}

So he doesn't delete [] anything, will new do a resize next time it's called (like realloc)?

That is exactly what I have noticed right now... you beat me to it. The problem is, that when I try to do this:

(Toggle Plain Text)

//--reset the stash
void stash::clearStash(){
	delete [] ch;
	ch = new char [gIncrement];
	currentSize = 0;
	currentStorage = gIncrement;
	next =  gIncrement - currentSize;
}

and this main:

(Toggle Plain Text)

int main(){
	stash o("hello world");
	
	
	stash b;
	b = o;
	
	o.show();
	b.show();
	return 0;
}

I get this error:

Quote:

C++ tool 3(1885) malloc: *** Deallocation of a pointer not malloced: 0x8fe067a8; This could be a double free(), or free() called with the middle of an allocated block; Try setting environment variable MallocHelp to see tools to help debug
currentStorage: 12
current size: 11
Next: 1
hello world
currentStorage: 12
current size: 11
Next: 1
hello world

I thought this method (deleting and reallocatind 'ch') worked out quite well in inflate()...

What went wrong?

Soulstorm · May 26th, 2006, 6:07 PM

edit: I found it. It was stupid. I think I will turn off the computer now...

DaWei · May 26th, 2006, 6:15 PM

Ouzo time, eh?

Soulstorm · May 26th, 2006, 6:24 PM

Quote:

Ouzo time, eh?

seems you know a bit about greek customs...

DaWei · May 26th, 2006, 6:43 PM

Beats the hell out of Miller!

The Dark · May 26th, 2006, 6:51 PM

Quote:

Originally Posted by Soulstorm

edit: I found it. It was stupid. I think I will turn off the computer now...

Can you post what it was so that other people searching the forum can see the answer?

Soulstorm · May 27th, 2006, 2:09 AM

Of course. I don't have the code in front of me, but i remember that the problem resided in the clearstash() function. When I was deleting the 'ch' pointer, I didn't make sure wether that pointer was allocated or not. The result was in some occasions the compiler to give me warnings and errors (when the 'clearstash()' function was called before a string allocation was made).

The solution was to pass the 'ch' pointer a zero value at the beginning (in my constructors), then with an 'if' statement, make sure every time I call 'clearstash()' the 'ch' pointer is allocated before deallocation. That could be done like this, if I remember correctly:

(Toggle Plain Text)

void stash::clearStash(){
	if(ch)
		delete [] ch;
	ch = new char [gIncrement];
	currentSize = 0;
	currentStorage = gIncrement;
	next =  gIncrement - currentSize;
}

...supposing we have set the 'ch' as 0 at the constructors.

May 26th, 2006, 6:07 PM	#14
Soulstorm Hobbyist Programmer Join Date: Jan 2006 Location: Menidi, Athens, Greece Posts: 239 Rep Power: 3	edit: I found it. It was stupid. I think I will turn off the computer now... __________________ Project::Soulstorm (personal homepage)

May 26th, 2006, 6:15 PM	#15
DaWei Resident Grouch Join Date: Jun 2005 Posts: 6,453 Rep Power: 10	Ouzo time, eh? __________________ Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code. Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

May 26th, 2006, 6:43 PM	#17
DaWei Resident Grouch Join Date: Jun 2005 Posts: 6,453 Rep Power: 10	Beats the hell out of Miller! __________________ Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code. Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

May 27th, 2006, 2:09 AM	#19
Soulstorm Hobbyist Programmer Join Date: Jan 2006 Location: Menidi, Athens, Greece Posts: 239 Rep Power: 3	Of course. I don't have the code in front of me, but i remember that the problem resided in the clearstash() function. When I was deleting the 'ch' pointer, I didn't make sure wether that pointer was allocated or not. The result was in some occasions the compiler to give me warnings and errors (when the 'clearstash()' function was called before a string allocation was made). The solution was to pass the 'ch' pointer a zero value at the beginning (in my constructors), then with an 'if' statement, make sure every time I call 'clearstash()' the 'ch' pointer is allocated before deallocation. That could be done like this, if I remember correctly: (Toggle Plain Text) void stash::clearStash(){ if(ch) delete [] ch; ch = new char [gIncrement]; currentSize = 0; currentStorage = gIncrement; next = gIncrement - currentSize; } void stash::clearStash(){ if(ch) delete [] ch; ch = new char [gIncrement]; currentSize = 0; currentStorage = gIncrement; next = gIncrement - currentSize; } ...supposing we have set the 'ch' as 0 at the constructors. __________________ Project::Soulstorm (personal homepage) Last edited by Soulstorm; May 27th, 2006 at 2:23 AM.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Programming Forums > Application Development > C++

Stash returns... Malloc problem?