private async Task <RpcCallResult <T> > CallCore <T>(
Func <TrackedConnection, BondCallTracker, Task <T> > callAsync,
CancellationToken cancellationToken,
string functionName,
BondCallTracker callTracker,
bool allowInactive = false,
Func <T, bool> shouldRetry = null,
uint maxTryCount = 0)
{
Contract.Requires(functionName != null);
callTracker = callTracker ?? CreateLoggingCallTracker(functionName);
TimeSpan waitForConnectionDuration = default(TimeSpan);
Failure lastFailure = null;
m_outstandingCalls.AddOrUpdate(functionName, 1, (k, i) => i + 1);
// For heartbeat only try once
if (maxTryCount == 0)
{
maxTryCount = DefaultMaxRetryCount;
}
for (uint retryCount = 0; retryCount < maxTryCount; retryCount++)
{
callTracker.TryCount = retryCount;
if (retryCount != 0)
{
// For retries, log a call start with the call tracker's updated retry count
callTracker.OnStateChanged(BondCallState.Started);
// Yield after first iteration to ensure
// we don't overflow the stack with async continuations
await Task.Yield();
}
TrackedConnection connection = null;
try
{
var startWaitForConnection = m_stopwatch.Elapsed;
callTracker.OnStateChanged(BondCallState.WaitingForConnection);
// Wait for a connection to become active via the a successful heartbeat
using (var connectionScope = await WaitForConnectionAsync(callTracker, allowInactive, cancellationToken))
{
// Log wait for connection success
var iterationWaitForConnectionDuration = GetElapsed(startWaitForConnection);
waitForConnectionDuration += iterationWaitForConnectionDuration;
callTracker.OnStateChanged(BondCallState.CompletedWaitForConnection);
// connection is not returned in the case that the proxy is shutting down or timed out
// other case is that this is a failed heartbeat call. In which case, just continue.
if (connectionScope.Connection == null)
{
if (m_isShuttingDown || m_exceededInactivityTimeout)
{
// Log the failure
lastFailure = new RecoverableExceptionFailure(new BuildXLException(m_isShuttingDown ?
"Bond RPC Call failure: Proxy is shutting down" :
"Bond RPC Call failure: Proxy timed out"));
callTracker.LogMessage("Could not retrieve connection. Failure={0}", lastFailure.DescribeIncludingInnerFailures());
callTracker.OnStateChanged(BondCallState.Failed);
return(new RpcCallResult <T>(RpcCallResultState.Failed, retryCount + 1, callTracker.TotalDuration, waitForConnectionDuration, lastFailure));
}
continue;
}
connection = connectionScope.Connection;
// Make the actual call
var result = await callAsync(connection, callTracker);
// Check if call should be retried
if (shouldRetry != null && shouldRetry(result))
{
continue;
}
// Log the call completion
callTracker.OnStateChanged(BondCallState.Succeeded);
m_proxyLogger.LogSuccessfulCall(m_loggingContext, functionName, retryCount);
connectionScope.MarkSucceeded();
m_services.Counters.AddToCounter(DistributionCounter.SendPipBuildRequestCallDurationMs, (long)callTracker.TotalDuration.TotalMilliseconds);
return(new RpcCallResult <T>(result, retryCount + 1, callTracker.TotalDuration, waitForConnectionDuration));
}
}
catch (OperationCanceledException)
{
callTracker.OnStateChanged(BondCallState.Canceled);
return(new RpcCallResult <T>(RpcCallResultState.Cancelled, retryCount + 1, callTracker.TotalDuration, waitForConnectionDuration));
}
catch (Exception ex)
{
// If shutting down just return the failed result
if (ex is ObjectDisposedException && m_isShuttingDown)
{
lastFailure = new RecoverableExceptionFailure(new BuildXLException("Bond RPC Call failure: Proxy is shutting down", ex));
callTracker.LogMessage("{0}", lastFailure.DescribeIncludingInnerFailures());
callTracker.OnStateChanged(BondCallState.Failed);
return(new RpcCallResult <T>(RpcCallResultState.Failed, retryCount + 1, callTracker.TotalDuration, waitForConnectionDuration));
}
if (DistributionServices.IsBuildIdMismatchException(ex))
{
m_proxyLogger.LogCallException(m_loggingContext, functionName, retryCount, ex);
// If a message with different build is received, it means that the sender has participated in a different distributed build.
// Then, we need to lose the connection with the sender.
OnConnectionTimeOut?.Invoke(this, EventArgs.Empty);
return(new RpcCallResult <T>(RpcCallResultState.Failed, retryCount + 1, callTracker.TotalDuration, waitForConnectionDuration));
}
// If not a transient exception, log and throw
if (!DistributionHelpers.IsTransientBondException(ex, m_services.Counters) && !m_services.IsChecksumMismatchException(ex))
{
m_proxyLogger.LogCallException(m_loggingContext, functionName, retryCount, ex);
throw;
}
// Otherwise, the exception is transient, so log exception and try again
lastFailure = new RecoverableExceptionFailure(new BuildXLException("Failed Bond RPC call", ex));
callTracker.LogMessage("{0}", lastFailure.DescribeIncludingInnerFailures());
// Deactivate connection so subsequent calls on the proxy will wait for heartbeat before trying to make call.
DeactivateConnection(connection);
m_services.Counters.AddToCounter(DistributionCounter.FailedSendPipBuildRequestCallDurationMs, (long)callTracker.TotalDuration.TotalMilliseconds);
m_services.Counters.IncrementCounter(DistributionCounter.FailedSendPipBuildRequestCount);
m_proxyLogger.LogFailedCall(m_loggingContext, functionName, retryCount, lastFailure);
}
finally
{
m_outstandingCalls.AddOrUpdate(functionName, 0, (k, i) => i - 1);
}
}
// Exceeded retry count.
callTracker.LogMessage("Call failed and exhausted allowed retries. LastFailure={0}", lastFailure?.DescribeIncludingInnerFailures() ?? string.Empty);
callTracker.OnStateChanged(BondCallState.Failed);
return(new RpcCallResult <T>(RpcCallResultState.Failed, DefaultMaxRetryCount, callTracker.TotalDuration, waitForConnectionDuration, lastFailure));
}
/// <summary>
/// Heartbeat timer callback which initiates heartbeat calls to check that bond service is alive.
/// </summary>
private async void HeartbeatTimerCallback(object state)
{
var heartbeatCallTracker = CreateLoggingCallTracker("Heartbeat");
if (m_isShuttingDown)
{
heartbeatCallTracker.OnStateChanged(BondCallState.HeartbeatTimerShutdown);
return;
}
heartbeatCallTracker.OnStateChanged(BondCallState.HeartbeatBeforeCall);
var heartbeatResult = await HeartbeatAsync(heartbeatCallTracker);
heartbeatCallTracker.OnStateChanged(BondCallState.HeartbeatAfterCall);
if (heartbeatResult.State == RpcCallResultState.Succeeded)
{
heartbeatCallTracker.OnStateChanged(BondCallState.HeartbeatSuccess);
// TODO: Should any successful call reactivate the connection?
// Successful heartbeat
// Activate the connection if necessary
m_lastSuccessfulHeartbeat = DateTime.UtcNow;
OnActivateConnection?.Invoke(this, EventArgs.Empty);
lock (m_syncLock)
{
if (!m_isActiveCompletionSource.Task.IsCompleted)
{
m_isActiveCompletionSource.TrySetResult(true);
}
}
heartbeatCallTracker.OnStateChanged(BondCallState.HeartbeatAfterActivateConnection);
}
else
{
TimeSpan timeSinceLastSuccessfulHeartbeat = DateTime.UtcNow - m_lastSuccessfulHeartbeat;
// Check if proxy has timed out
if (timeSinceLastSuccessfulHeartbeat > InactivityTimeout)
{
heartbeatCallTracker.OnStateChanged(BondCallState.HeartbeatTimerInactive);
m_exceededInactivityTimeout = true;
DeactivateConnection(null);
Logger.Log.DistributionDisableServiceProxyInactive(
m_loggingContext,
Server,
Port,
timeSinceLastSuccessfulHeartbeat.ToString());
OnConnectionTimeOut?.Invoke(this, EventArgs.Empty);
// Return without setting new timer due time to stop the timer
// since the proxy has timed out
return;
}
}
lock (m_syncLock)
{
if (!m_isShuttingDown)
{
heartbeatCallTracker.OnStateChanged(BondCallState.HeartbeatQueueTimer);
m_heartbeatTimer.Change(dueTime: m_heartbeatInterval, period: Timeout.InfiniteTimeSpan);
}
else
{
heartbeatCallTracker.OnStateChanged(BondCallState.HeartbeatDeactivateTimer);
}
}
}
