protected async Task <bool> RunFunctionIfOpenAsyncT_MT(Func <Task> funcAsync)
{
if (!_isOpen)
{
return(false);
}
try
{
await _isOpenSemaphore.WaitAsync(CancToken); //.ConfigureAwait(false);
if (_isOpen && funcAsync != null)
{
await Task.Run(funcAsync, CancToken).ConfigureAwait(false);
return(true);
}
}
catch (OperationCanceledException) { }
catch (Exception ex)
{
if (SemaphoreSlimSafeRelease.IsAlive(_isOpenSemaphore))
{
await Logger.AddAsync(GetType().Name + ex.ToString(), Logger.ForegroundLogFilename);
}
}
finally
{
SemaphoreSlimSafeRelease.TryRelease(_isOpenSemaphore);
}
return(false);
}
protected void SetPropertyLockingUpdatingDb <T>(ref T fldValue, T newValue, object locker, bool raise = true, bool onlyIfDifferent = true, [CallerMemberName] string propertyName = "")
{
bool isValueChanged = false;
lock (locker)
{
T oldValue = fldValue;
if (!newValue.Equals(oldValue) || !onlyIfDifferent)
{
fldValue = newValue;
isValueChanged = true;
}
}
// separate to avoid deadlocks
if (!isValueChanged)
{
return;
}
if (raise)
{
RaisePropertyChanged_UI(propertyName);
}
Task db = RunFunctionIfOpenAsyncA_MT(async delegate
{
if (UpdateDbMustOverride() == false)
{
// string attributeName = '_' + propertyName[0].ToString().ToLower() + propertyName.Substring(1); // only works if naming conventions are respected
// GetType().GetField(attributeName)?.SetValue(this, oldValue);
// RaisePropertyChanged_UI(propertyName);
await Logger.AddAsync(GetType().ToString() + "." + propertyName + " could not be set", Logger.ForegroundLogFilename).ConfigureAwait(false);
}
});
}
private async Task <bool> SetIsEnabledAsync(bool enable)
{
if (!_isOpen || IsEnabled == enable)
{
return(false);
}
try
{
await _isOpenSemaphore.WaitAsync().ConfigureAwait(false);
if (_isOpen && IsEnabled != enable)
{
IsEnabledAllowed = enable;
return(true);
}
}
catch (Exception ex)
{
if (SemaphoreSlimSafeRelease.IsAlive(_isOpenSemaphore))
{
await Logger.AddAsync(GetType().Name + ex.ToString(), Logger.ForegroundLogFilename);
}
}
finally
{
SemaphoreSlimSafeRelease.TryRelease(_isOpenSemaphore);
}
return(false);
}
private async Task LogMessage(string message, LogBotEntryLevel level)
{
await Task.Factory.StartNew(() =>
{
Logger.AddAsync(
new LogBotEntry(
message,
level)
, _uiDispatcher);
});
}
// LOLLO NOTE important! The Mutex can work across AppDomains (ie across main app and background task) but only if you give it a name!
// Also, if you declare initially owned true, the second thread trying to cross it will stay locked forever. So, declare it false.
// All this is not well documented.
public static async Task LoadAsync()
{
string errorMessage = string.Empty;
try
{
await _suspensionSemaphore.WaitAsync().ConfigureAwait(false);
if (_isLoaded)
{
return;
}
var file = await ApplicationData.Current.LocalCacheFolder.CreateFileAsync(SessionDataFilename, CreationCollisionOption.OpenIfExists).AsTask().ConfigureAwait(false);
//string ssss = null; //this is useful when you debug and want to see the file as a string
//using (IInputStream inStream = await file.OpenSequentialReadAsync())
//{
// using (StreamReader streamReader = new StreamReader(inStream.AsStreamForRead()))
// {
// ssss = streamReader.ReadToEnd();
// }
//}
using (IInputStream inStream = await file.OpenSequentialReadAsync().AsTask().ConfigureAwait(false))
{
using (var iinStream = inStream.AsStreamForRead())
{
DataContractSerializer serializer = new DataContractSerializer(typeof(PersistentData));
iinStream.Position = 0;
PersistentData newPersistentData = (PersistentData)(serializer.ReadObject(iinStream));
await iinStream.FlushAsync().ConfigureAwait(false);
PersistentData.GetInstanceWithProperties(newPersistentData);
}
}
Debug.WriteLine("ended reading settings");
}
catch (System.Xml.XmlException ex)
{
errorMessage = "could not restore the settings";
await Logger.AddAsync(ex.ToString(), Logger.FileErrorLogFilename);
}
catch (Exception ex)
{
errorMessage = "could not restore the settings";
await Logger.AddAsync(ex.ToString(), Logger.FileErrorLogFilename);
}
finally
{
PersistentData.GetInstance().LastMessage = errorMessage;
IsLoaded = true;
SemaphoreSlimSafeRelease.TryRelease(_suspensionSemaphore);
}
}
public async Task <bool> CloseAsync(object args = null)
{
if (!_isOpen)
{
return(await RunFunctionIfOpenAsyncA(delegate { IsEnabledAllowed = false; }).ConfigureAwait(false));
}
lock (_ctsLocker)
{
_cts?.CancelSafe(true);
}
try
{
await _isOpenSemaphore.WaitAsync().ConfigureAwait(false);
if (_isOpen)
{
lock (_ctsLocker)
{
_cts?.Dispose();
_cts = null;
_cancToken = new CancellationToken(true); // CancellationToken is not nullable and not disposable
}
await UnregisterBackEventHandlersAsync();
IsEnabledAllowed = false;
IsOpen = false;
await CloseMayOverrideAsync(args).ConfigureAwait(false);
return(true);
}
}
catch (Exception ex)
{
if (SemaphoreSlimSafeRelease.IsAlive(_isOpenSemaphore))
{
await Logger.AddAsync(GetType().Name + ex.ToString(), Logger.ForegroundLogFilename);
}
}
finally
{
lock (_isOpenSemaphoreLocker)
{
SemaphoreSlimSafeRelease.TryDispose(_isOpenSemaphore);
_isOpenSemaphore = null;
}
}
return(false);
}
public async Task <bool> OpenAsync(object args = null)
{
if (_isOpen)
{
return(await RunFunctionIfOpenAsyncA(delegate { IsEnabledAllowed = true; }).ConfigureAwait(false));
}
lock (_isOpenSemaphoreLocker)
{
if (!SemaphoreSlimSafeRelease.IsAlive(_isOpenSemaphore))
{
_isOpenSemaphore = new SemaphoreSlimSafeRelease(1, 1);
}
}
try
{
await _isOpenSemaphore.WaitAsync().ConfigureAwait(false);
if (!_isOpen)
{
lock (_ctsLocker)
{
_cts?.Dispose();
_cts = new SafeCancellationTokenSource();
_cancToken = _cts.Token;
}
await OpenMayOverrideAsync(args).ConfigureAwait(false);
IsOpen = true;
IsEnabledAllowed = true;
await RegisterBackEventHandlersAsync().ConfigureAwait(false);
//Logger.Add_TPL($"OpenableObservablePage.OpenAsync: {GetType().Name} is now open", Logger.AppEventsLogFilename, Logger.Severity.Info, false);
return(true);
}
}
catch (Exception ex)
{
if (SemaphoreSlimSafeRelease.IsAlive(_isOpenSemaphore))
{
await Logger.AddAsync(GetType().Name + ex.ToString(), Logger.ForegroundLogFilename);
}
}
finally
{
SemaphoreSlimSafeRelease.TryRelease(_isOpenSemaphore);
}
return(false);
}
public async Task <bool> OpenAsync(object args = null)
{
if (!_isOpen)
{
lock (_isOpenSemaphoreLocker)
{
if (!SemaphoreSlimSafeRelease.IsAlive(_isOpenSemaphore))
{
_isOpenSemaphore = new SemaphoreSlimSafeRelease(1, 1);
}
}
try
{
await _isOpenSemaphore.WaitAsync().ConfigureAwait(false);
if (!_isOpen)
{
lock (_ctsLocker)
{
_cts?.Dispose();
_cts = new SafeCancellationTokenSource();
_cancToken = _cts.Token;
}
await OpenMayOverrideAsync(args).ConfigureAwait(false);
IsOpen = true;
IsEnabledAllowed = true;
return(true);
}
}
catch (Exception ex)
{
if (SemaphoreSlimSafeRelease.IsAlive(_isOpenSemaphore))
{
await Logger.AddAsync(GetType().Name + ex.ToString(), Logger.ForegroundLogFilename);
}
}
finally
{
SemaphoreSlimSafeRelease.TryRelease(_isOpenSemaphore);
}
}
if (_isOpen)
{
await SetIsEnabledAsync(true).ConfigureAwait(false);
}
return(false);
}
protected async Task <BoolWhenOpen> RunFunctionIfOpenThreeStateAsyncT(Func <Task> funcAsync)
{
if (!_isOpen)
{
return(BoolWhenOpen.ObjectClosed);
}
try
{
await _isOpenSemaphore.WaitAsync(CancToken); //.ConfigureAwait(false);
if (_isOpen)
{
await funcAsync().ConfigureAwait(false);
return(BoolWhenOpen.Yes);
}
}
catch (OperationCanceledException)
{
return(BoolWhenOpen.ObjectClosed);
}
catch (Exception ex)
{
if (SemaphoreSlimSafeRelease.IsAlive(_isOpenSemaphore))
{
await Logger.AddAsync(GetType().Name + ex.ToString(), Logger.ForegroundLogFilename);
return(BoolWhenOpen.Error);
}
}
finally
{
SemaphoreSlimSafeRelease.TryRelease(_isOpenSemaphore);
}
return(BoolWhenOpen.ObjectClosed);
}
private async void OnUnhandledException(object sender, UnhandledExceptionEventArgs e)
{
// this does not always work when the device force-shuts the app
await Logger.AddAsync("UnhandledException: " + e.Exception.ToString(), Logger.AppExceptionLogFilename);
}
/// <summary>
/// Invoked when Navigation to a certain page fails
/// </summary>
/// <param name="sender">The Frame which failed navigation</param>
/// <param name="e">Details about the navigation failure</param>
private async void OnNavigationFailed(object sender, NavigationFailedEventArgs e)
{
await Logger.AddAsync(e.Exception.ToString(), Logger.AppEventsLogFilename);
throw new Exception("Failed to load Page " + e.SourcePageType.FullName);
}