public static MemBlock ReadBlock(int addr)
{
MemBlock b = FindBlock(addr);
if (b == null)
{
// Simulate reading from main memory
b = new MemBlock();
AddBlock(addr, b);
}
return(b);
}
public static void WriteBlock(int addr, MemBlock b)
{
MemBlock b2 = FindBlock(addr);
if (b2 == null)
{
AddBlock(addr, b);
}
else
{
b2.someValue = b.someValue;
}
}
static void AddBlock(int addr, MemBlock b)
{
if (GetCount() > MAX_COUNT)
{
KeyValuePair <DateTime, int> kp = lru.First();
lru.Remove(kp.Key);
dict.Remove(kp.Value);
Console.WriteLine("REMOVE: time = {0} addr = {1}", kp.Key.ToString("ffffff"), kp.Value);
}
b.lastUsedTime = DateTime.Now;
dict[addr] = b;
lru.Add(b.lastUsedTime, addr);
Console.WriteLine("ADD: time = {0} addr = {1}", b.lastUsedTime.ToString("ffffff"), addr);
}
static MemBlock FindBlock(int addr)
{
if (dict.ContainsKey(addr))
{
MemBlock b = dict[addr];
lru.Remove(b.lastUsedTime);
b.lastUsedTime = DateTime.Now;
dict[addr] = b; // updated
lru.Add(b.lastUsedTime, addr);
Console.WriteLine("FOUND: {0}", addr);
return(b);
}
Console.WriteLine("NOT FOUND: {0}", addr);
return(null);
}
static void Main(string[] args)
{
Random rn = new Random();
for (int i = 0; i < 25; i++)
{
Thread.Sleep(3); // make time stamps distint
int addr = -1;
if ((rn.Next() % 2) == 0)
{
addr = GetExistingAddressForTest();
}
if (addr == -1)
{
addr = rn.Next(1000, 9999);
}
int op = (rn.Next() % 2); // decide read or write
MemBlock b;
if (op == 0)
{
b = ReadBlock(addr);
}
else
{
b = new MemBlock();
WriteBlock(addr, b);
}
}
// print final status
Console.WriteLine("FINAL CACHE");
foreach (KeyValuePair <DateTime, int> kp in lru)
{
Console.WriteLine("{0}:{1}", kp.Key.ToString("ffffff"), kp.Value);
}
}
