"System.Threading.LockRecursionException" error in NT8

[ttodua]

I try to fire two consecutive (at the same time) MessageBox.Show().
in NT, the script stops execution and I get the following message:

"Failed to call 'Add' method: System.Threading.LockRecursionException: Write lock may not be acquired with read lock held. This pattern is prone to deadlocks. Please ensure that read locks are released before taking a write lock. If an upgrade is necessary, use an upgrade lock in place of the read lock. at System.Threading.ReaderWriterLockSlim.TryEnterWrit eLockCore(TimeoutTracker timeout) at System.Threading.ReaderWriterLockSlim.TryEnterWrit eLock(TimeoutTracker timeout) "


what are remedies? should i fire MessageBox.Show() in "invoke", to avoid Thread locking?

[NinjaTrader_Jim]

Hello TazoTodua,

Thanks for your post.

Calling MessageBox.Show() will lock the current thread. Depending on how this is called, it would be possible to encounter such an error.

You could use a Dispatcher to avoid the error, but you would not be locking that thread and likely not achieve your intended result. This can be tested with the code below to observe what the result will be:

this.Dispatcher.InvokeAsync(new Action(() => {
// Your code here
}));

From a NinjaTrader perspective, I would like to point out the built in Alert methods we offer which would be recommended for firing alert message box windows.

I've included publicly available reference for using Alerts and for Multi Threading Considerations.

Alert() - https://ninjatrader.com/support/help...n-us/alert.htm

MultiThreading Considerations - https://ninjatrader.com/support/help...-threading.htm

Please let us know if we can be of further assistance.

[ttodua]

Jim, thanks! ! !

one question - the Alert() functionality is not as we imagine.
in other Trading platforms, the Alert() fires a visual message/popup box,
but in NT, it's only logged into the backend AlertLog window, with sound.
but i wanted to have a Popup-box like message.

it was good, that likely to other platforms, NT has also it's method to fire the popup/messageboxes, with alert.

can you submit that to developers, to create a simple message/popupbox, and could be called with Alert() function (you might need to create another overload for alert(), accepting the true/false as the argument to show/dont-show that messagebox).

btw, at this moment, i am using custom simple c# `Form` instead of `MessageBox.Show()`

[NinjaTrader_Jim]

Hello TazoTodua,

I had mistaken Chart Alert functionality with the NinjaScript method. My apologies for any confusion. I've submitted your request and the ticket ID is SFT-3478.

Also to point out, you can create your own windows through NinjaScript. I'll provide a link to a related thread and reference for creating windows in NinjaTrader.

Opening a window from a strategy - https://ninjatrader.com/support/foru...ad.php?t=78876

AddOn Development Overview - https://ninjatrader.com/support/help...t_overview.htm

Please let us know if we can be of further assistance.