// must be called under tsocket.Gate
public void UpdateEPollControl(TSocket tsocket, EPollEvents flags, bool registered)
{
flags &= EPollEvents.Readable | EPollEvents.Writable | EPollEvents.Error;
EPollInterop.EPollControl(_epollFd,
registered ? EPollOperation.Modify : EPollOperation.Add,
tsocket.Fd,
flags | EPollEvents.OneShot,
EPollData(tsocket.Fd));
}
public unsafe void Run()
{
try
{
Start();
CompleteStateChange(TransportThreadState.Started);
}
catch (Exception e)
{
CompleteStateChange(TransportThreadState.Stopped, e);
return;
}
try
{
int notPacked = !EPoll.PackedEvents ? 1 : 0;
var buffer = stackalloc int[EventBufferLength * (3 + notPacked)];
int statReadEvents = 0;
int statWriteEvents = 0;
int statAcceptEvents = 0;
int statAccepts = 0;
int statZeroCopySuccess = 0;
int statZeroCopyCopied = 0;
var acceptableSockets = new List <TSocket>(1);
var readableSockets = new List <TSocket>(EventBufferLength);
var writableSockets = new List <TSocket>(EventBufferLength);
var reregisterEventSockets = new List <TSocket>(EventBufferLength);
var zeroCopyCompletions = new List <TSocket>(EventBufferLength);
bool pipeReadable = false;
bool running = true;
do
{
int numEvents = EPollInterop.EPollWait(_epollFd, buffer, EventBufferLength, timeout: EPoll.TimeoutInfinite).Value;
// actions can be scheduled without unblocking epoll
SetEpollNotBlocked();
// check events
// we don't handle them immediately:
// - this ensures we don't mismatch a closed socket with a new socket that have the same fd
// ~ To have the same fd, the previous fd must be closed, which means it is removed from the epoll
// ~ and won't show up in our next call to epoll.Wait.
// ~ The old fd may be present in the buffer still, but lookup won't give a match, since it is removed
// ~ from the dictionary before it is closed. If we were accepting already, a new socket could match.
// - this also improves cache/cpu locality of the lookup
int *ptr = buffer;
lock (_sockets)
{
for (int i = 0; i < numEvents; i++)
{
// Packed Non-Packed
// ------ ------
// 0:Events == Events
// 1:Int1 = Key [Padding]
// 2:Int2 = Key == Int1 = Key
// 3:~~~~~~~~~~ Int2 = Key
// ~~~~~~~~~~
EPollEvents events = (EPollEvents)ptr[0];
int key = ptr[2];
ptr += 3 + notPacked;
TSocket tsocket;
if (_sockets.TryGetValue(key, out tsocket))
{
var type = tsocket.Type;
if (type == SocketFlags.TypeClient)
{
lock (tsocket.Gate)
{
var pendingEventState = tsocket.PendingEventState;
// zero copy
if ((pendingEventState & EPollEvents.Error & events) != EPollEvents.None)
{
var copyResult = SocketInterop.CompleteZeroCopy(tsocket.Fd);
if (copyResult != PosixResult.EAGAIN)
{
events &= ~EPollEvents.Error;
pendingEventState &= ~EPollEvents.Error;
zeroCopyCompletions.Add(tsocket);
if (copyResult == SocketInterop.ZeroCopyCopied)
{
tsocket.ZeroCopyThreshold = LinuxTransportOptions.NoZeroCopy;
statZeroCopyCopied++;
}
else if (copyResult == SocketInterop.ZeroCopySuccess)
{
statZeroCopySuccess++;
}
else
{
Environment.FailFast($"Error occurred while trying to complete zero copy: {copyResult}");
}
}
}
// treat Error as Readable, Writable
if ((events & EPollEvents.Error) != EPollEvents.None)
{
events |= EPollEvents.Readable | EPollEvents.Writable;
}
events &= pendingEventState & (EPollEvents.Readable | EPollEvents.Writable);
// readable
if ((events & EPollEvents.Readable) != EPollEvents.None)
{
readableSockets.Add(tsocket);
pendingEventState &= ~EPollEvents.Readable;
}
// writable
if ((events & EPollEvents.Writable) != EPollEvents.None)
{
writableSockets.Add(tsocket);
pendingEventState &= ~EPollEvents.Writable;
}
// reregister
tsocket.PendingEventState = pendingEventState;
if ((pendingEventState & (EPollEvents.Readable | EPollEvents.Writable)) != EPollEvents.None)
{
tsocket.PendingEventState |= TSocket.EventControlPending;
reregisterEventSockets.Add(tsocket);
}
}
}
else
{
statAcceptEvents++;
acceptableSockets.Add(tsocket);
}
}
else if (key == PipeKey)
{
pipeReadable = true;
}
}
}
// zero copy
for (int i = 0; i < zeroCopyCompletions.Count; i++)
{
zeroCopyCompletions[i].OnZeroCopyCompleted();
}
zeroCopyCompletions.Clear();
// handle accepts
statAcceptEvents += acceptableSockets.Count;
for (int i = 0; i < acceptableSockets.Count; i++)
{
statAccepts += HandleAccept(acceptableSockets[i]);
}
acceptableSockets.Clear();
// handle writes
statWriteEvents += writableSockets.Count;
for (int i = 0; i < writableSockets.Count; i++)
{
writableSockets[i].OnWritable(stopped: false);
}
writableSockets.Clear();
// handle reads
statReadEvents += readableSockets.Count;
if (!_transportOptions.AioReceive)
{
Span <MemoryHandle> receiveMemoryHandles = MemoryHandles;
for (int i = 0; i < readableSockets.Count; i++)
{
TSocket socket = readableSockets[i];
var receiveResult = socket.Receive(receiveMemoryHandles);
socket.OnReceiveFromSocket(receiveResult);
}
readableSockets.Clear();
}
else if (readableSockets.Count > 0)
{
AioReceive(readableSockets);
}
// reregister for events
for (int i = 0; i < reregisterEventSockets.Count; i++)
{
var tsocket = reregisterEventSockets[i];
lock (tsocket.Gate)
{
var pendingEventState = tsocket.PendingEventState & ~TSocket.EventControlPending;
tsocket.PendingEventState = pendingEventState;
UpdateEPollControl(tsocket, pendingEventState, registered: true);
}
}
reregisterEventSockets.Clear();
// handle pipe
if (pipeReadable)
{
PosixResult result;
do
{
result = _pipeEnds.ReadEnd.TryReadByte();
if (result.Value == PipeStopSockets)
{
StopSockets();
}
else if (result.Value == PipeStopThread)
{
running = false;
}
else if (result.Value == PipeCloseAccept)
{
CloseAccept();
}
} while (result);
pipeReadable = false;
}
// scheduled work
// note: this may write a byte to the pipe
DoScheduledWork(_transportOptions.AioSend);
} while (running);
_logger.LogDebug($"Stats A/AE:{statAccepts}/{statAcceptEvents} RE:{statReadEvents} WE:{statWriteEvents} ZCS/ZCC:{statZeroCopySuccess}/{statZeroCopyCopied}");
CompleteStateChange(TransportThreadState.Stopped);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
Console.WriteLine(ex.StackTrace);
Environment.FailFast("TransportThread", ex);
}
}
public PosixResult TryControl(EPollOperation operation, SafeHandle fd, EPollEvents events, EPollData data)
{
return(EPollInterop.EPollControl(this, operation, fd, events, data.Long));
}
public void Control(EPollOperation operation, SafeHandle fd, EPollEvents events, EPollData data)
{
TryControl(operation, fd, events, data)
.ThrowOnError();
}
public static PosixResult EPollControl(EPoll epoll, EPollOperation operation, SafeHandle fd, EPollEvents events, long data) => EPollControl(epoll.DangerousGetHandle().ToInt32(), operation, fd.DangerousGetHandle().ToInt32(), events, data);
public static extern PosixResult EPollControl(int epoll, EPollOperation operation, int fd, EPollEvents events, long data);
