internal void Execute(HostNode host, UseSocket use)
{
MSocket sock = null;
try
{
//Acquire a socket
sock = host.Acquire();
//Use the socket as a parameter to the delegate and return its result.
if (sock != null)
{
use(sock);
}
}
catch (Exception e)
{
logger.Error("Error in Execute: " + host.Host, e);
//Socket is probably broken
if (sock != null)
{
sock.Close();
}
}
finally
{
if (sock != null)
{
sock.ReturnPool();
}
}
}
/// <summary>
/// Gets a socket from the pool.
/// If there are no free sockets, a new one will be created. If something goes
/// wrong while creating the new socket, this pool's endpoint will be marked as dead
/// and all subsequent calls to this method will return null until the retry interval
/// has passed.
/// 这个方法扩展（备份链接池）
/// </summary>
internal MSocket Acquire()
{
//检测当前是否挂科，如果是(15分钟内)，由备份服务器提供服务
if (socketDeadTime.AddMinutes(15) >= DateTime.Now && HostNodeBak != null)
{
return(HostNodeBak.Acquire());
}
//Do we have free sockets in the pool?
//if so - return the first working one.
//if not - create a new one.
Interlocked.Increment(ref Acquired);
lock (socketQueue)
{
while (socketQueue.Count > 0)
{
MSocket socket = socketQueue.Dequeue();
if (socket != null && socket.IsAlive)
{
Interlocked.Increment(ref ReusedSockets);
return(socket);
}
Interlocked.Increment(ref DeadSocketsInPool);
}
}
//If we know the endpoint is dead, check if it is time for a retry, otherwise return null.
if (IsEndPointDead)
{
if (DateTime.Now > DeadEndPointRetryTime)
{
//Retry
IsEndPointDead = false;
}
else
{
//Still dead
return(null);
}
}
//Try to create a new socket. On failure, mark endpoint as dead and return null.
try
{
MSocket socket = new MSocket(this, Host);
Interlocked.Increment(ref NewSockets);
//Reset retry timer on success.
//不抛异常，则正常链接。
if (OnAfterSocketCreateEvent != null)
{
OnAfterSocketCreateEvent(socket);
}
deadEndPointSecondsUntilRetry = 1;
return(socket);
}
catch (Exception e)
{
Interlocked.Increment(ref FailedNewSockets);
logger.Error("Error connecting to: " + Host, e);
//Mark endpoint as dead
IsEndPointDead = true;
//Retry in 2 minutes
DeadEndPointRetryTime = DateTime.Now.AddSeconds(deadEndPointSecondsUntilRetry);
if (deadEndPointSecondsUntilRetry < maxDeadEndPointSecondsUntilRetry)
{
deadEndPointSecondsUntilRetry = deadEndPointSecondsUntilRetry * 2; //Double retry interval until next time
}
socketDeadTime = DateTime.Now;
//返回备份的池
if (HostNodeBak != null)
{
return(HostNodeBak.Acquire());
}
return(null);
}
}
