private void ExitWorkBlocker(WorkBlocker workBlocker)
{
// ReSharper disable once ConditionIsAlwaysTrueOrFalse
Debug.Assert(workBlocker != null, "workBlocker != null");
lock (_workBlockersSyncRoot)
{
// !!! Everything has changed, after we have captured the lock. !!!
////
bool removed = workBlocker.WorkItem.Blockers.Remove(workBlocker);
if (!removed)
{
throw new InvalidOperationException(
$"Error exiting work blocker section. Work blocker already released. {CallerInfoToString(workBlocker.DebugInfo, workBlocker.CallerInfo)}");
}
removed = _workBlockers.Remove(workBlocker);
Debug.Assert(removed, "Double remove error.");
// Scheduling next work item after some grace period.
if (!_workBlockers.Any() && !IsShutdownStarted)
{
// Raising event for starting new work item.
_noMoreBlockersEvent.Set();
}
}
}
private WorkBlocker EnterWorkBlocker(ActiveWorkItem workItem, string debugInfo, CallerInfo callerInfo)
{
// ReSharper disable once ConditionIsAlwaysTrueOrFalse
Debug.Assert(workItem != null, "workItem != null");
// ReSharper disable once ConditionIsAlwaysTrueOrFalse
Debug.Assert(debugInfo != null, "debugInfo != null");
lock (_workBlockersSyncRoot)
{
// Validating work item is active.
if (!_activeWorkItems.Contains(workItem))
{
throw new InvalidOperationException(
$"Error entering work blocker section. Work item already completed. {CallerInfoToString(debugInfo, callerInfo)}");
}
// !!! Everything has changed, after we have captured the lock. !!!
////
// Canceling currently is being created work item.
_workItemValidationId++;
var workBlocker = new WorkBlocker(false, workItem, debugInfo, callerInfo);
// Registering blocker.
_workBlockers.Add(workBlocker);
workBlocker.WorkItem.Blockers.Add(workBlocker);
return(workBlocker);
}
}
private async Task ExecuteNewWorkItem(long workItemValidationId)
{
ActiveWorkItem workItem;
WorkBlocker workBlocker;
lock (_workBlockersSyncRoot)
{
// !!! Everything has changed in the world, after we are captured the lock. !!!
////
_shutdownCancellationToken.ThrowIfCancellationRequested();
// Do nothing, if work item creation has been canceled.
if (workItemValidationId != _workItemValidationId)
{
return;
}
// Creating and registering a new work item.
workItem = new ActiveWorkItem(this);
// Creating initial work blocker for the new work item.
workBlocker = new WorkBlocker(
true,
workItem,
string.Empty,
new CallerInfo("new work item", "initial_blocker", 0));
// Registering blocker.
_workBlockers.Add(workBlocker);
workItem.Blockers.Add(workBlocker);
_activeWorkItems.Add(workItem);
}
try
{
// Running new work item.
await _workItemAction(workItem, new ActiveWorkerBlockerToken(workBlocker));
}
finally
{
lock (_workBlockersSyncRoot)
{
bool removed = _activeWorkItems.Remove(workItem);
Debug.Assert(removed, "Double remove is wrong");
// When no more work items left and termination requested - setting termination finish cts event.
if (IsShutdownStarted && !_activeWorkItems.Any())
{
_shutdownCompletedCts.Cancel();
}
// It's allowed to not dispose initial blocker.
if ((workItem.Blockers.Count == 1) && workItem.Blockers.First().IsInitialBlocker)
{
var blocker = workItem.Blockers.First();
// Disposing last initial blocker.
workItem.Blockers.Remove(blocker);
_workBlockers.Remove(blocker);
// Scheduling next work item after some grace period.
if (!_workBlockers.Any() && !IsShutdownStarted)
{
// Raising event for starting new work item.
_noMoreBlockersEvent.Set();
}
}
else
{
// Raising critical errors if some locks was not released when task exited.
foreach (WorkBlocker unreleasedBlockers in workItem.Blockers)
{
Critical.Assert(
false,
$"Unreleased work blocker section at {CallerInfoToString(unreleasedBlockers.DebugInfo, unreleasedBlockers.CallerInfo)}");
}
}
}
}
}
