Place your cursor on the `{` and then type :

&lt;kbd&gt;Ctrl&lt;/kbd&gt;+&lt;kbd&gt;B&lt;/kbd&gt;

[Notepad shortcuts][1]


  [1]: http://www.shortcutworld.com/en/win/Notepad-plus-plus_5.9.html

I see that I&#39;m not the first one to ask the question but there was no clear answer to this:  
  
How to use pdb with docker-composer in Python development?  
  
When you ask uncle Google about `django docker` you get awesome docker-composer examples and tutorials and I have an environment working - I can run `docker-compose up` and I have a neat developer environment **but the PDB is not working** (which is very sad).  

I can settle with running `docker-compose run my-awesome-app python app.py 0.0.0.0:8000` but then I can access my application over http://127.0.0.1:8000 from the host (I can with `docker-compose up`) and it seems that each time I use `run` new containers are made like: `dir_app_13` and `dir_db_4` which I don&#39;t desire at all.  

People of good will please aid me.

PS  
I&#39;m using pdb++ for that example and a basic docker-compose.yml from [this django example](https://docs.docker.com/compose/django/). Also I experimented but nothing seems to help me. And I&#39;m using docker-composer [1.3.0rc3](https://github.com/docker/compose/tree/1.3.0rc3) as it has Dockerfile pointing support.

Docker-compose and pdb

I&#39;m running into a deadlock situation when calling [StackExchange.Redis][4].

I don&#39;t know exactly what is going on, which is very frustrating, and I would appreciate any input that could help resolve or workaround this problem.

-----
&gt;**In case you have this problem too and don&#39;t want to read all this;**
&gt;I suggest that you&#39;ll try setting `PreserveAsyncOrder` to `false`.
&gt;
&gt;     ConnectionMultiplexer connection = ...;
&gt;     connection.PreserveAsyncOrder = false;
&gt;
&gt;Doing so will probably resolve the kind of deadlock that this Q&amp;A is about and could also improve performance.

-----


### Our setup ###

* The code is run as either a Console application or as an Azure Worker Role. 
* It exposes a REST api using [HttpMessageHandler][1] so the entry point is async.
* Some parts of the code have thread affinity (is owned by, and must be run by, a single thread).
* Some parts of the code is async-only.
* We are doing the [*sync-over-async*][2] and [*async-over-sync*][3] anti-patterns. (mixing `await` and `Wait()`/`Result`).
* We&#39;re only using async methods when accessing Redis.
* We&#39;re using StackExchange.Redis 1.0.450 for .NET 4.5.

### Deadlock ###

When the application/service is started it runs normally for a while then all of a sudden (almost) all incoming requests stop functioning, they never produce a response. All those requests are deadlocked waiting for a call to Redis to complete.

Interestingly, once the deadlock occur, any call to Redis will hang but only if those calls are made from an incoming API request, which are run on the thread pool.

We are also making calls to Redis from low priority background threads, and these calls continue to function even after the deadlock occurred.

&lt;strike&gt;*It seems as if a deadlock will only occur when calling into Redis on a thread pool thread.*&lt;/strike&gt; I no longer think this is due to the fact that those calls are made on a thread pool thread. Rather, it seems like any async Redis call **without continuation, or with a *sync safe* continuation,** will continue to work even after the deadlock situation has occurred. (See *What I think happens* below)

### Related ###

* https://stackoverflow.com/questions/27235124/stackexchange-redis-deadlocking

  Deadlock caused by mixing `await` and `Task.Result` (sync-over-async, like we do). But our code is run without synchronization context so that doesn&#39;t apply here, right?

* https://stackoverflow.com/questions/24296325/how-to-safely-mix-sync-and-async-code

  Yes, we shouldn&#39;t be doing that. But we do, and we&#39;ll have to continue doing so for a while. Lots of code that needs to be migrated into the async world.

  Again, we don&#39;t have a synchronization context, so this should not be causing deadlocks, right?

  Setting `ConfigureAwait(false)` before any `await` has no effect on this.

* https://stackoverflow.com/questions/25567566/timeout-exception-after-async-commands-and-task-whenany-awaits-in-stackexchange

  This is the thread hijacking problem. What&#39;s the current situation on this? Could this be the problem here?

* https://stackoverflow.com/questions/27258984/stackexchange-redis-async-call-hangs/

  From Marc&#39;s answer:

  &gt; ...mixing Wait and await is not a good idea. In addition to deadlocks, this is &quot;sync over async&quot; - an anti-pattern.

  But he also says:

  &gt; SE.Redis bypasses sync-context internally (normal for library code), so it shouldn&#39;t have the deadlock

  So, from my understanding StackExchange.Redis should be agnostic to whether we&#39;re using the *sync-over-async* anti-pattern. It&#39;s just not recommended as it could be the cause of deadlocks in **other** code.

  In this case, however, as far as I can tell, the deadlock is really inside StackExchange.Redis. Please correct me if I&#39;m wrong.

### Debug findings ###

I&#39;ve found that the deadlock seems to have its source in `ProcessAsyncCompletionQueue` on [line 124 of `CompletionManager.cs`][5].

Snippet of that code:

	while (Interlocked.CompareExchange(ref activeAsyncWorkerThread, currentThread, 0) != 0)
	{
		// if we don&#39;t win the lock, check whether there is still work; if there is we
		// need to retry to prevent a nasty race condition
		lock(asyncCompletionQueue)
		{
			if (asyncCompletionQueue.Count == 0) return; // another thread drained it; can exit
		}
		Thread.Sleep(1);
	}

I&#39;ve found that during the deadlock; `activeAsyncWorkerThread` is one of our threads that is waiting for a Redis call to complete. (*our thread* = a thread pool thread running *our code*). So the loop above is deemed to continue forever.

Without knowing the details, this sure feels wrong; StackExchange.Redis is waiting for a thread that it thinks is the *active async worker thread* while it is in fact a thread that is quite the opposite of that.

I wonder if this is due to the *thread hijacking problem* (which I don&#39;t fully understand)?

### What to do? ###

The main two question I&#39;m trying to figure out:

 1. Could mixing `await` and `Wait()`/`Result` be the cause of deadlocks even when running without synchronization context?

 2. Are we running into a bug/limitation in StackExchange.Redis?

### A possible fix? ###

From my debug findings it seems as the problem is that:

    next.TryComplete(true);

...on [line 162 in `CompletionManager.cs`][6] could under some circumstances let the current thread (which is the *active async worker thread*) wander off and start processing other code, possibly causing a deadlock.

Without knowing the details and just thinking about this &quot;fact&quot;, then it would seem logical to temporarily release the *active async worker thread* during the `TryComplete` invocation.

I guess that something like this could work:

    // release the &quot;active thread lock&quot; while invoking the completion action
    Interlocked.CompareExchange(ref activeAsyncWorkerThread, 0, currentThread);

    try
    {
        next.TryComplete(true);
        Interlocked.Increment(ref completedAsync);
    }
    finally
    {
        // try to re-take the &quot;active thread lock&quot; again
        if (Interlocked.CompareExchange(ref activeAsyncWorkerThread, currentThread, 0) != 0)
        {
            break; // someone else took over
        }
    }

I guess my best hope is that [Marc Gravell][7] would read this and provide some feedback :-)

### No synchronization context = The default synchronization context

I&#39;ve written above that our code does not use a [synchronization context][9]. This is only partially true: The code is run as either a Console application or as an Azure Worker Role. In these environments [`SynchronizationContext.Current`][11] is `null`, which is why I wrote that we&#39;re running *without* synchronization context.

However, after reading [*It&#39;s All About the SynchronizationContext*][10] I&#39;ve learned that this is not really the case:

&gt; By convention, if a thread’s current SynchronizationContext is null, then it implicitly has a default SynchronizationContext.

The default synchronization context should not be the cause of deadlocks though, as UI-based (WinForms, WPF) synchronization context could - because it does not imply thread affinity.

### What I think happens ###

When a message is completed its completion source is checked for whether it is considered *sync safe*. If it is, the completion action is executed inline and everything is fine.

If it is not, the idea is to execute the completion action on a newly allocated thread pool thread. This too works just fine when `ConnectionMultiplexer.PreserveAsyncOrder` is `false`.

However, when `ConnectionMultiplexer.PreserveAsyncOrder` is `true` (the default value), then those thread pool threads will serialize their work using a *completion queue* and by ensuring that at most one of them is the *active async worker thread* at any time.

When a thread becomes the *active async worker thread* it will continue to be that until it have drained the *completion queue*.

The problem is that the completion action is *not sync safe* (from above), still it is executed on a thread that **must not be blocked** as that will prevent other *non sync safe* messages from being completed.

Notice that other messages that are being completed with a completion action that *is sync safe* will continue to work just fine, even though the *active async worker thread* is blocked.

My suggested &quot;fix&quot; (above) would not cause a deadlock in this way, it would however mess with the notion of *preserving async completion order*.

So maybe the conclusion to make here is that **it is not safe to mix `await` with `Result`/`Wait()` when `PreserveAsyncOrder` is `true`**, no matter whether we are running without synchronization context?

(*At least until we can use .NET 4.6 and the new [`TaskCreationOptions.RunContinuationsAsynchronously`][8], I suppose*)

[1]: https://msdn.microsoft.com/en-us/library/system.net.http.httpmessagehandler(v=vs.118).aspx

[2]: http://blogs.msdn.com/b/pfxteam/archive/2012/04/13/10293638.aspx

[3]: http://blogs.msdn.com/b/pfxteam/archive/2012/03/24/10287244.aspx

[4]: https://github.com/StackExchange/StackExchange.Redis

[5]: https://github.com/StackExchange/StackExchange.Redis/blob/master/StackExchange.Redis/StackExchange/Redis/CompletionManager.cs#L124

[6]: https://github.com/StackExchange/StackExchange.Redis/blob/master/StackExchange.Redis/StackExchange/Redis/CompletionManager.cs#L162

[7]: https://stackoverflow.com/users/23354/marc-gravell

[8]: https://msdn.microsoft.com/en-us/library/system.threading.tasks.taskcreationoptions(v=vs.110).aspx

[9]: https://msdn.microsoft.com/en-us/library/system.threading.synchronizationcontext(v=vs.110).aspx

[10]: https://msdn.microsoft.com/magazine/gg598924.aspx

[11]: https://msdn.microsoft.com/en-us/library/system.threading.synchronizationcontext.current(v=vs.110).aspx

Deadlock when accessing StackExchange.Redis

I am using the `JSONViewer` plugin in Notepad++ and viewing many large and nested json elements in a file. What keyboard shortcuts can I use to jump to a `}` or `]`? This would be similar to Visual Studio&#39;s &lt;kbd&gt;CTRL&lt;/kbd&gt;+&lt;kbd&gt;]&lt;/kbd&gt;.

Keyboard shortcut to jump to closing curly brace or square bracket in json view in Notepad++?

<p>I am using the <code>JSONViewer</code> plugin in Notepad++ and viewing many large and nested json elements in a file. What keyboard shortcuts can I use to jump to a <code>}</code> or <code>]</code>? This would be similar to Visual Studio's <kbd>CTRL</kbd>+<kbd>]</kbd>.</p>


I accidentally opened a very, very large file (well not accidentally, but I didn&#39;t think it would crash Notepad++). Now whenever I try to open Notepad++, the program crashes, so I can&#39;t just turn off the setting. I also don&#39;t have admin privileges.

How do I clear the previously opened files list in Notepad++?

I have a file with text and numbers with a length of 5 (i.e. `12000`, `11153`, etc.). I want to append all of these numbers with a `0`. So `11153` becomes `111530`. Is this possible in Notepad++?

I know I can find all numbers with the following regex: `[0-9]{5}`, but how can I replace these with the same number, plus an appending `0`?

In the replacement box I tried the following things:

* `[0-9]{5}0` - Which it took literally, so `11153` was replaced with `[0-9]{5}0`
* `\10`  - I read somewhere that `\1` would take the match, but it doesn&#39;t seem to work. This will replace `11153` with `0`
* EDIT: `\00` - Based on this [SO answer](https://stackoverflow.com/a/19575551/1682559) I see I need to use `\0` instead of `\1`. It still doesn&#39;t work though. This will replace `11153` with  ` `

So, I&#39;ve got the feeling I&#39;m close with the `\1` or `\0`, but not close enough.

Notepad++ Replace regex match for same text plus appending character

I am trying to install a Notepad++ plugin from `Plugins -&gt; Plugin Manager`, but my office firewall is restricting its download.
Is there any alternate way to download plugin offline?

How to install a Notepad++ plugin offline?

I am using notepad++ , after end of line when i press enter CR LF is printed . I tried a lot but not able to remove it . Please help me to change the setting so that I can restore it back and there wont be CR LF anyomre.

[![enter image description here][1]][1]


  [1]: https://i.stack.imgur.com/Nvpjd.png

CR LF notepad++ removal

I downloaded Notepad++ from [https://notepad-plus-plus.org/repository/7.x/7.5.1/npp.7.5.1.Installer.x64.exe][1].

And I installed the same. Now I need to install few plugins, but in the menu option *Plugins* there are only *Converter* and *MIME tools* listed, but not Plugin Manager.

[![enter image description here][2]][2]

Edit: They have removed Plugin Manager with the version 7.5. Still it can be added by following @johnny &#39;s instruction in the best solution.
P.S: The plugin manager is only supporting the 32-bit version.


  [1]: https://notepad-plus-plus.org/repository/7.x/7.5.1/npp.7.5.1.Installer.x64.exe
  [2]: https://i.stack.imgur.com/Mh3AC.png

Content Type	Original Author	Original Content on Stackoverflow
Question	Tony_Henrich	View Question on Stackoverflow
Solution 1 - Notepad++	hdoghmen	View Answer on Stackoverflow

Keyboard shortcut to jump to closing curly brace or square bracket in json view in Notepad++?

Notepad++ Problem Overview

Notepad++ Solutions

Solution 1 - Notepad++

Deadlock when accessing StackExchange.Redis

Docker-compose and pdb

Attributions