private async Task <T> UpdateAsync(bool force)
{
PollStatus = "UpdateAsync";
if (!force && !IsStale)
{
return(Data);
}
Interlocked.Increment(ref PollingEngine._activePolls);
PollStatus = "Awaiting Semaphore";
await _pollSemaphoreSlim.WaitAsync();
bool errored = false;
try
{
if (!force && !IsStale)
{
return(Data);
}
if (_isPolling)
{
return(Data);
}
CurrentPollDuration = Stopwatch.StartNew();
_isPolling = true;
PollStatus = "UpdateCache";
await _updateFunc();
PollStatus = "UpdateCache Complete";
Interlocked.Increment(ref _pollsTotal);
if (DataTask != null)
{
Interlocked.Increment(ref _pollsSuccessful);
}
}
catch (Exception e)
{
var errorMessage = e.Message;
if (e.InnerException != null)
{
errorMessage += "\n" + e.InnerException.Message;
}
SetFail(e, errorMessage);
errored = true;
}
finally
{
if (CurrentPollDuration != null)
{
CurrentPollDuration.Stop();
LastPollDuration = CurrentPollDuration.Elapsed;
}
CurrentPollDuration = null;
_isPolling = false;
PollStatus = errored ? "Failed" : "Completed";
_pollSemaphoreSlim.Release();
Interlocked.Decrement(ref PollingEngine._activePolls);
}
return(Data);
}
/// <summary>
/// Called on a background thread for when this node is ACTUALLY polling
/// This is not called if we're not due for a poll when the pass runs
/// </summary>
private void InnerPollImpl(bool force = false, bool sync = false)
{
CurrentPollDuration = Stopwatch.StartNew();
try
{
PollStatus = "InnerPoll Started";
if (Polling != null)
{
var ps = new PollStartArgs();
Polling(this, ps);
if (ps.AbortPoll)
{
return;
}
}
int toPoll = 0;
if (sync || FirstPollRun != null)
{
PollStatus = "DataPollers Queueing (Sync)";
var tasks = DataPollers
.Where(p => force || p.ShouldPoll)
.Select(p => p.PollAsync(force))
.ToArray <Task>();
Task.WaitAll(tasks);
PollStatus = "DataPollers Complete (Sync)";
}
else
{
PollStatus = "DataPollers Queueing";
foreach (var p in DataPollers)
{
// Cheap checks to eliminate many uncessary task creations
if (!force && !p.ShouldPoll)
{
continue;
}
// Kick off the poll and don't wait for it to continue;
#pragma warning disable 4014
p.PollStatus = "Kicked off by Node";
Interlocked.Add(ref _totalCacheQueues, 1);
p.PollAsync(force).ContinueWith(t =>
{
if (t.IsFaulted)
{
Current.LogException(t.Exception);
PollStatus = "Faulted";
}
else
{
PollStatus = "Completed";
}
Interlocked.Add(ref _totalCachePolls, t.Result);
}, TaskContinuationOptions.ExecuteSynchronously).ConfigureAwait(false);
toPoll++;
#pragma warning restore 4014
}
PollStatus = toPoll.ToComma() + " DataPollers Started";
}
LastPoll = DateTime.UtcNow;
Polled?.Invoke(this, new PollResultArgs {
Queued = toPoll
});
if (FirstPollRun != null)
{
FirstPollRun.Set();
FirstPollRun = null;
}
Interlocked.Increment(ref _totalPolls);
}
finally
{
CurrentPollDuration.Stop();
LastPollDuration = CurrentPollDuration.Elapsed;
_isPolling = false;
CurrentPollDuration = null;
PollStatus = "InnerPoll Complete";
}
}
public virtual async Task PollAsync(bool force = false)
{
using (MiniProfiler.Current.Step("Poll - " + UniqueKey))
{
// If not forced, perform our "should-run" checks
if (!force && !NeedsPoll)
{
return;
}
// Prevent multiple poll threads for this node from running at once
if (Interlocked.CompareExchange(ref _isPolling, 1, 0) != 0)
{
// We're already running, abort!'
// TODO: Date check for sanity and restart?
return;
}
PollStatus = "Poll Started";
CurrentPollDuration = Stopwatch.StartNew();
try
{
PollStatus = "InnerPoll Started";
if (Polling != null)
{
var ps = new PollStartArgs();
Polling(this, ps);
if (ps.AbortPoll)
{
return;
}
}
PollStatus = "DataPollers Queueing";
var tasks = new List <Task>();
foreach (var p in DataPollers)
{
if (force || p.ShouldPoll)
{
tasks.Add(p.PollGenericAsync(force));
}
}
// Hop out early, run nothing else
if (tasks.Count == 0)
{
PollStatus = "DataPollers Complete (None to run)";
return;
}
PollStatus = "DataPollers Queued (Now awaiting)";
// Await all children (this itself will be a background fire and forget if desired
await Task.WhenAll(tasks).ConfigureAwait(false);
PollStatus = "DataPollers Complete (Awaited)";
LastPoll = DateTime.UtcNow;
Polled?.Invoke(this, new PollResultArgs());
Interlocked.Increment(ref _totalPolls);
}
finally
{
Interlocked.Exchange(ref _isPolling, 0);
if (CurrentPollDuration != null)
{
CurrentPollDuration.Stop();
LastPollDuration = CurrentPollDuration.Elapsed;
}
CurrentPollDuration = null;
}
PollStatus = "Poll Complete";
}
}
private async Task <int> UpdateAsync()
{
PollStatus = "UpdateAsync";
if (!_needsPoll && !IsStale)
{
return(0);
}
PollStatus = "Awaiting Semaphore";
await _pollSemaphoreSlim.WaitAsync().ConfigureAwait(false);
bool errored = false;
try
{
if (!_needsPoll && !IsStale)
{
return(0);
}
if (_isPolling)
{
return(0);
}
CurrentPollDuration = Stopwatch.StartNew();
_isPolling = true;
Interlocked.Increment(ref _pollsTotal);
PollStatus = "UpdateCache";
await UpdateCache(this).ConfigureAwait(false);
PollStatus = "UpdateCache Complete";
_needsPoll = false;
if (DataBacker != null)
{
Interlocked.Increment(ref _pollsSuccessful);
}
return(DataBacker != null ? 1 : 0);
}
catch (Exception e)
{
var errorMessage = e.Message;
if (e.InnerException != null)
{
errorMessage += "\n" + e.InnerException.Message;
}
SetFail(errorMessage);
errored = true;
return(0);
}
finally
{
if (CurrentPollDuration != null)
{
CurrentPollDuration.Stop();
LastPollDuration = CurrentPollDuration.Elapsed;
}
CurrentPollDuration = null;
_isPolling = false;
PollStatus = errored ? "Failed" : "Completed";
_pollSemaphoreSlim.Release();
}
}