public async Task ExecuteTasksAsync(object sender, EventArgs e, CancellationToken cancellationToken, AspNetSynchronizationContextBase syncContext, IRequestCompletedNotifier requestCompletedNotifier) {
try {
while (_registeredTasks.Count > 0) {
// if canceled, propagate exception to caller and stop executing tasks
cancellationToken.ThrowIfCancellationRequested();
// if request finished, stop executing tasks
if (requestCompletedNotifier.IsRequestCompleted) {
return;
}
// execute this task
IPageAsyncTask task = _registeredTasks.Dequeue();
using (syncContext.AllowVoidAsyncOperationsBlock()) {
await task.ExecuteAsync(sender, e, cancellationToken);
}
}
}
finally {
_executeTasksAsyncHasCompleted = true;
}
}
// References should be nulled a.s.a.p. to reduce working set
internal void ClearReferences() {
_appInstance = null;
_handler = null;
_handlerStack = null;
_currentHandler = null;
_remapHandler = null;
if (_isIntegratedPipeline) {
if (!HasWebSocketRequestTransitionStarted) {
// Items is also used by AspNetWebSocketContext and should only be cleared if we're not transitioning to WebSockets
_items = null;
}
_syncContext = null;
}
}
internal void RestoreSavedAspNetSynchronizationContext(AspNetSynchronizationContextBase syncContext) {
AsyncOperationManager.SynchronizationContext = syncContext;
_syncContext = syncContext;
}
internal AspNetSynchronizationContextBase InstallNewAspNetSynchronizationContext() {
AspNetSynchronizationContextBase syncContext = _syncContext;
if (syncContext != null && syncContext == AsyncOperationManager.SynchronizationContext) {
// using current ASP.NET synchronization context - switch it
_syncContext = CreateNewAspNetSynchronizationContext();
AsyncOperationManager.SynchronizationContext = _syncContext;
return syncContext;
}
return null;
}
// Associates this ThreadContext with the current thread. This restores certain
// ambient values associated with the current HttpContext, such as the current
// user and cultures. It also sets HttpContext.Current.
internal void AssociateWithCurrentThread(bool setImpersonationContext)
{
Debug.Assert(HttpContext != null); // only to be used when context is available
Debug.Assert(Current != this, "This ThreadContext is already associated with this thread.");
Debug.Assert(!HasBeenDisassociatedFromThread, "This ThreadContext has already been disassociated from a thread.");
Debug.Trace("OnThread", GetTraceMessage("Enter1"));
/*
* !! IMPORTANT !!
* Keep this logic in [....] with DisassociateFromCurrentThread and EnterExecutionContext.
*/
// attach http context to the call context
_originalHttpContext = DisposableHttpContextWrapper.SwitchContext(HttpContext);
// set impersonation on the current thread
if (setImpersonationContext)
{
SetImpersonationContext();
}
// set synchronization context for the current thread to support the async pattern
_originalSynchronizationContext = AsyncOperationManager.SynchronizationContext;
AspNetSynchronizationContextBase aspNetSynchronizationContext = HttpContext.SyncContext;
AsyncOperationManager.SynchronizationContext = aspNetSynchronizationContext;
// set ETW trace ID
Guid g = HttpContext.WorkerRequest.RequestTraceIdentifier;
if (g != Guid.Empty)
{
CallContext.LogicalSetData("E2ETrace.ActivityID", g);
}
// set SqlDependecyCookie
HttpContext.ResetSqlDependencyCookie();
// set principal on the current thread
_originalThreadPrincipal = Thread.CurrentPrincipal;
HttpApplication.SetCurrentPrincipalWithAssert(HttpContext.User);
// only set culture on the current thread if it is not initialized
SetRequestLevelCulture();
// DevDivBugs 75042
// set current thread in context if there is not there
// the timeout manager uses this to abort the correct thread
if (HttpContext.CurrentThread == null)
{
_setCurrentThreadOnHttpContext = true;
HttpContext.CurrentThread = Thread.CurrentThread;
}
// Store a reference to the original ThreadContext.Current. It is possible that a parent
// ThreadContext might already be associated with the current thread, e.g. if the current
// stack contains a call to MgdIndicateCompletion (via
// PipelineRuntime.ProcessRequestNotificationHelper). If this is the case, the child
// ThreadContext will temporarily take over.
_originalThreadContextCurrent = Current;
Current = this;
Debug.Trace("OnThread", GetTraceMessage("Enter2"));
}
public AllowAsyncOperationsBlockDisposable(AspNetSynchronizationContextBase syncContext) {
_syncContext = syncContext;
}
