private async Task <MyCatSession> CreateSessionAsync(IOBehavior ioBehavior, CancellationToken cancellationToken)
{
var connectTimeout = m_connectionSettings.ConnectionTimeout == 0 ? Timeout.InfiniteTimeSpan : TimeSpan.FromSeconds(checked ((int)m_connectionSettings.ConnectionTimeout));
using (var timeoutSource = new CancellationTokenSource(connectTimeout))
using (var linkedSource = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken, timeoutSource.Token))
{
try
{
// get existing session from the pool if possible
if (m_connectionSettings.Pooling)
{
var pool = ConnectionPool.GetPool(m_connectionSettings);
// this returns an open session
return(await pool.GetSessionAsync(ioBehavior, linkedSource.Token).ConfigureAwait(false));
}
else
{
var session = new MyCatSession();
await session.ConnectAsync(m_connectionSettings, ioBehavior, linkedSource.Token).ConfigureAwait(false);
return(session);
}
}
catch (OperationCanceledException ex) when(timeoutSource.IsCancellationRequested)
{
throw new MyCatException("Connect Timeout expired.", ex);
}
}
}
public async Task <MyCatSession> GetSessionAsync(IOBehavior ioBehavior, CancellationToken cancellationToken)
{
cancellationToken.ThrowIfCancellationRequested();
// wait for an open slot
if (ioBehavior == IOBehavior.Asynchronous)
{
await m_sessionSemaphore.WaitAsync(cancellationToken).ConfigureAwait(false);
}
else
{
m_sessionSemaphore.Wait(cancellationToken);
}
try
{
MyCatSession session;
// check for a pooled session
if (m_sessions.TryDequeue(out session))
{
if (session.PoolGeneration != m_generation || !await session.TryPingAsync(ioBehavior, cancellationToken).ConfigureAwait(false))
{
// session is either old or cannot communicate with the server
await session.DisposeAsync(ioBehavior, cancellationToken).ConfigureAwait(false);
}
else
{
// session is valid, reset if supported
if (m_connectionSettings.ConnectionReset)
{
await session.ResetConnectionAsync(m_connectionSettings, ioBehavior, cancellationToken).ConfigureAwait(false);
}
// pooled session is ready to be used; return it
return(session);
}
}
session = new MyCatSession(this, m_generation);
await session.ConnectAsync(m_connectionSettings, ioBehavior, cancellationToken).ConfigureAwait(false);
return(session);
}
catch
{
m_sessionSemaphore.Release();
throw;
}
}
public void Return(MyCatSession session)
{
try
{
if (session.PoolGeneration == m_generation)
{
m_sessions.Enqueue(session);
}
else
{
session.DisposeAsync(IOBehavior.Synchronous, CancellationToken.None).ConfigureAwait(false);
}
}
finally
{
m_sessionSemaphore.Release();
}
}
