public ARP()
{
DebugPrint("Initializing ARP module\n");
arpTable = new ArpTable(this);
pendingRequests = new Queue();
pendingRequestsFreelist = new Queue();
//start the array list with 256 elements to
for (int i = 0; i < DefaultMaxPendingArpRequests; i++)
{
PendingArpRequest pendingArpRequest =
new PendingArpRequest();
pendingRequestsFreelist.Enqueue(pendingArpRequest);
}
arpHandle = new AutoResetEvent(false);
Thread arpThread = new Thread(this);
DebugStub.Assert(arpThread != null);
arpThread.Start();
}
private AutoResetEvent AddPendingRequest(IPv4 address,
TimeSpan timeout,
EthernetAddress localMac,
Bytes header,
Bytes buffer,
IAdapter adapter
)
{
PendingArpRequest pendingRequest = (PendingArpRequest)pendingRequestsFreelist.Dequeue();
VTable.Assert(pendingRequest != null);
pendingRequest.address = address;
pendingRequest.active = true;
pendingRequest.localMac = localMac;
pendingRequest.adapter = adapter;
VectorQueueByte txBuffer = pendingRequest.txContainer.Acquire();
txBuffer.AddTail(header);
txBuffer.AddTail(buffer);
pendingRequest.txContainer.Release(txBuffer);
using (pendingRequestsLock.Lock()) {
pendingRequests.Enqueue(pendingRequest);
}
SchedulerTime expiration = SchedulerTime.Now;
expiration = expiration.Add(timeout);
pendingRequest.requestExpiration = expiration;
//poke the wait thread
if (pendingRequests.Count == 1)
{
arpHandle.Set();
}
return(pendingRequest.requestEvent);
}
private void ARPManageThread()
{
DebugPrint("ARP managment thread spinning up\n");
//the pending requests list is ordered by deadline...
//finding a requests when we rceive a reply is in the worst case O(n)...
//Hopefully we won't have many oustanding requests, and the first request out
//will often return first...
//track two different timeouts here...ARP requests and ARP table aging.
SchedulerTime ageTableTimeout;
SchedulerTime now;
SchedulerTime nextTimer;
ageTableTimeout = SchedulerTime.Now;
ageTableTimeout = ageTableTimeout.AddMinutes(5);
while (true)
{
now = SchedulerTime.Now;
if (now > ageTableTimeout)
{
arpTable.AgeTable();
ageTableTimeout = SchedulerTime.Now;
ageTableTimeout = ageTableTimeout.AddMinutes(5);
}
using (pendingRequestsLock.Lock()) {
nextTimer = SchedulerTime.MaxValue;
bool done = false;
while (!done)
{
if (pendingRequests.Count == 0)
{
done = true;
continue;
}
PendingArpRequest pendingArpRequest = (PendingArpRequest)pendingRequests.Peek();
if (pendingArpRequest == null)
{
done = true;
continue;
}
if (pendingArpRequest.requestExpiration > now)
{
nextTimer = pendingArpRequest.requestExpiration;
done = true;
continue;
}
else
{
pendingArpRequest = (PendingArpRequest)pendingRequests.Dequeue();
if (pendingArpRequest.active == true)
{
//We need error propagation here...
pendingArpRequest.active = false;
DebugStub.Assert(false);
}
pendingRequestsFreelist.Enqueue(pendingArpRequest);
}
}
}
if (ageTableTimeout < nextTimer)
{
DebugPrint("setting nextTimer ageTableTimeout\n");
nextTimer = ageTableTimeout;
}
bool rc;
rc = arpHandle.WaitOne(nextTimer);
}
}
