pbprasad99 / cache-simulator Goto Github PK

I got a segmentation fault when I ran your code with the mcf.trace file. I found the error in the LRUblock function in Set.cpp. You never initialized the variable 'unsigned int z' which means that if 'z' is not assigned a value in the for loop, it is assigned a random value which is used as an index in your writeBlock function.

In order to get the code to work when I changed edited the code in LRUBlock from this:

unsigned int Set::LRUblock(void)
{
unsigned int z;
int x = Blocks[0].timestamp;

	for (int i=0; i <= (blkcount-1); i++)
	{			
		if (Blocks[i].timestamp > x)
		{
			x = Blocks[i].timestamp;
			z = i;
		}
	}
	return z;

}

to this

unsigned int Set::LRUblock(void)
{
unsigned int z = 0; // initialized 'z'
int x = Blocks[0].timestamp;

	for (int i=0; i <= (blkcount-1); i++)
	{			
		if (Blocks[i].timestamp >= x) // Changed '>' to '>='
		{
			x = Blocks[i].timestamp;
			z = i;
		}
	}
	return z;

}

The change I made insured that 'z' was assigned a value no matter what.