Most recent Microsoft&#39;s stuff in IPC is [Windows Communication Foundation][1]. Actually there is nothing new in the lower level (tcp, upd, named pipes etc) But WCF simplifies IPC development greatly.

Useful resource:

  - [Interprocess Communication with WCF][2] on Dr. Dobb&#39;s portal
  - [WCF Communication Options in the .NET Framework 3.5][3]

and of course [MSDN on WCF][4]


  [1]: http://en.wikipedia.org/wiki/Windows_Communication_Foundation
  [2]: http://www.ddj.com/windows/196802111
  [3]: http://www.infoq.com/news/2008/01/wcf-comm-options
  [4]: http://msdn.microsoft.com/en-us/netframework/aa663324.aspx

Apart from the obvious (WCF), there is a ZeroMQ binding for C#/CLR which is pretty good:

http://www.zeromq.org/bindings:clr

Does message-oriented IPC, pub/sub and various other strategies with much less code and config than WCF.

It&#39;s also at least an order of magnitude faster than anything else and has less latency if you require low latency comms.

With respects to semaphores, locks, mutexes etc.  If you share by communicating rather than communicate by sharing, you&#39;ll have a whole load less hassle than the traditional paradigm.

I tend to use named pipes or Unix sockets (depending on whether I&#39;m targetting MS.NET or Mono -- I have a class that abstracts it away) since it&#39;s easy to use, portable, and allows me to easily interoperate with unmanaged code.  That said, if you&#39;re only dealing with managed code, go with WCF or remoting -- the latter if you need Mono support, since their WCF support simply isn&#39;t there yet.

I would recommend using Memory Mapped Files if you need to use on the machine domain not communication through network. See the following link.

[http://techmikael.blogspot.com/2010/02/blazing-fast-ipc-in-net-4-wcf-vs.html][1]


  [1]: http://techmikael.blogspot.com/2010/02/blazing-fast-ipc-in-net-4-wcf-vs.html

There is also .NET Remoting, which I found quite cool, but I guess they are obsoleting it now that they have WCF.

It sounds as though you&#39;re interested in synchronization techniques rather than communication. If so, you might like to start [here][1], or perhaps this more [concise overview][2].

  [1]: http://msdn.microsoft.com/en-us/library/ms228964.aspx
  [2]: http://marekblog.wordpress.com/2007/02/05/net-framework-synchronization-primitives/

What would be the best way to calculate someone&#39;s age in years, months, and days in T-SQL (SQL Server 2000)?

The `datediff` function doesn&#39;t handle year boundaries well, plus getting the months and days separate will be a bear.  I know I can do it on the client side relatively easily, but I&#39;d like to have it done in my [stored procedure][1].

  [1]: http://en.wikipedia.org/wiki/Stored_procedure


How to calculate age in T-SQL with years, months, and days

I would like to know how can i escape a # in velocity. Backslash seems to escape it but it prints itself as well



This:    

    \#\#

prints:   

    \#\#

I would like:   

    ## 

How to escape a # in velocity

I have used IPC in Win32 code a while ago - critical sections, events, and semaphores.

How is the scene in the .NET environment?
Are there any tutorial explaining all available options and when to use and why?

IPC Mechanisms in C# - Usage and Best Practices

<p>I have used IPC in Win32 code a while ago - critical sections, events, and semaphores.</p>
<p>How is the scene in the .NET environment?
Are there any tutorial explaining all available options and when to use and why?</p>


In C# are the nullable primitive types (i.e. `bool?`) just aliases for their corresponding `Nullable&lt;T&gt;` type or is there a difference between the two?

Is there any difference between type? and Nullable&lt;type&gt;?

How do you perform a CROSS JOIN with LINQ to SQL?

I am building on C++ dll, by writing code in C#.

I get an error, saying 

&gt; LoaderLock was detected Message:
&gt; Attempting managed execution inside OS
&gt; Loader lock. Do not attempt to run
&gt; managed code inside a DllMain or image
&gt; initialization function since doing so
&gt; can cause the application to hang.

I tried seraching what this error exactly means, but I am drawing pointless articles, mostly saying that it&#39;s just a warning, and I should switch that off in Visual Studio.
The other solutions seem to be due to ITunes, or this problem occurring when programming with DirectX. My problem is connected to neither.

Can anybody explain, what this actually means?


Loader lock error

Consider the class below that represents a Broker:

    public class Broker
    {
        public string Name = string.Empty;
        public int Weight = 0;

        public Broker(string n, int w)
        {
            this.Name = n;
            this.Weight = w;
        }
    }


I&#39;d like to randomly select a Broker from an array, taking into account their weights.

What do you think of the code below?

    class Program
        {
            private static Random _rnd = new Random();
    
            public static Broker GetBroker(List&lt;Broker&gt; brokers, int totalWeight)
            {
                // totalWeight is the sum of all brokers&#39; weight
                
                int randomNumber = _rnd.Next(0, totalWeight);
    
                Broker selectedBroker = null;
                foreach (Broker broker in brokers)
                {
                    if (randomNumber &lt;= broker.Weight)
                    {
                        selectedBroker = broker;
                        break;
                    }
    
                    randomNumber = randomNumber - broker.Weight;
                }
    
                return selectedBroker;
            }
    
    
            static void Main(string[] args)
            {
                List&lt;Broker&gt; brokers = new List&lt;Broker&gt;();
                brokers.Add(new Broker(&quot;A&quot;, 10));
                brokers.Add(new Broker(&quot;B&quot;, 20));
                brokers.Add(new Broker(&quot;C&quot;, 20));
                brokers.Add(new Broker(&quot;D&quot;, 10));
    
                // total the weigth
                int totalWeight = 0;
                foreach (Broker broker in brokers)
                {
                    totalWeight += broker.Weight;
                }
    
                while (true)
                {
                    Dictionary&lt;string, int&gt; result = new Dictionary&lt;string, int&gt;();
    
                    Broker selectedBroker = null;
    
                    for (int i = 0; i &lt; 1000; i++)
                    {
                        selectedBroker = GetBroker(brokers, totalWeight);
                        if (selectedBroker != null)
                        {
                            if (result.ContainsKey(selectedBroker.Name))
                            {
                                result[selectedBroker.Name] = result[selectedBroker.Name] + 1;
                            }
                            else
                            {
                                result.Add(selectedBroker.Name, 1);
                            }
                        }
                    }
    
                    
                    Console.WriteLine(&quot;A\t\t&quot; + result[&quot;A&quot;]);
                    Console.WriteLine(&quot;B\t\t&quot; + result[&quot;B&quot;]);
                    Console.WriteLine(&quot;C\t\t&quot; + result[&quot;C&quot;]);
                    Console.WriteLine(&quot;D\t\t&quot; + result[&quot;D&quot;]);
                    
                    result.Clear();
                    Console.WriteLine();
                    Console.ReadLine();
                }
            }
        }

I&#39;m not so confident. When I run this, Broker A always gets more hits than Broker D, and they have the same weight.

Is there a more accurate algorithm?

Thanks!

Random weighted choice

I am calling, through reflection, a method which may cause an exception. How can I pass the exception to my caller without the wrapper reflection puts around it?  
I am rethrowing the InnerException, but this destroys the stack trace.  
Example code:

    public void test1()
    {
        // Throw an exception for testing purposes
        throw new ArgumentException(&quot;test1&quot;);
    }

    void test2()
    {
        try
        {
            MethodInfo mi = typeof(Program).GetMethod(&quot;test1&quot;);
            mi.Invoke(this, null);
        }
        catch (TargetInvocationException tiex)
        {
            // Throw the new exception
            throw tiex.InnerException;
        }
    }

How to rethrow InnerException without losing stack trace in C#?

I have a console app in which I want to give the user *x* seconds to respond to the prompt.  If no input is made after a certain period of time, program logic should continue.  We assume a timeout means empty response.

What is the most straightforward way of approaching this?

How to add a Timeout to Console.ReadLine()?

Now, before you say it: I **did** Google and my `hbm.xml` file **is** an Embedded Resource. 

Here is the code I am calling:

    ISession session = GetCurrentSession();
    var returnObject =  session.Get&lt;T&gt;(Id);

Here is my mapping file for the class:

&lt;!-- language: lang-xml --&gt;

    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot; ?&gt;
    &lt;hibernate-mapping xmlns=&quot;urn:nhibernate-mapping-2.2&quot;&gt;
      &lt;class name=&quot;HQData.Objects.SubCategory, HQData&quot; table=&quot;SubCategory&quot; lazy=&quot;true&quot;&gt;
        &lt;id name=&quot;ID&quot; column=&quot;ID&quot; unsaved-value=&quot;0&quot;&gt;
          &lt;generator class=&quot;identity&quot; /&gt;
        &lt;/id&gt;
    
        &lt;property name=&quot;Name&quot; column=&quot;Name&quot; /&gt;
        &lt;property name=&quot;NumberOfBuckets&quot; column=&quot;NumberOfBuckets&quot;  /&gt;
        &lt;property name=&quot;SearchCriteriaOne&quot; column=&quot;SearchCriteriaOne&quot; /&gt;
        
        &lt;bag name=&quot;_Businesses&quot; cascade=&quot;all&quot;&gt;
          &lt;key column=&quot;SubCategoryId&quot;/&gt;
          &lt;one-to-many 
             class=&quot;HQData.Objects.Business, HQData&quot;/&gt;
        &lt;/bag&gt;
    
        &lt;bag name=&quot;_Buckets&quot; cascade=&quot;all&quot;&gt;
          &lt;key column=&quot;SubCategoryId&quot;/&gt;
          &lt;one-to-many
             class=&quot;HQData.Objects.Bucket, HQData&quot;/&gt;
        &lt;/bag&gt;
    
      &lt;/class&gt;
    &lt;/hibernate-mapping&gt;

Has anyone run to this issue before?

Here is the full error message:

&gt; &lt;pre&gt;MappingException: No persister for:  HQData.Objects.SubCategory]NHibernate.Impl.SessionFactoryImpl.GetEntityPersister(String entityName, Boolean throwIfNotFound)
 in c:\CSharp\NH2.0.0\nhibernate\src\NHibernate\Impl\SessionFactoryImpl.cs:766 NHibernate.Impl.SessionFactoryImpl.GetEntityPersister(String entityName)
 in c:\CSharp\NH2.0.0\nhibernate\src\NHibernate\Impl\SessionFactoryImpl.cs:752 NHibernate.Event.Default.DefaultLoadEventListener.OnLoad(LoadEvent event, LoadType loadType)
 in c:\CSharp\NH2.0.0\nhibernate\src\NHibernate\Event\Default\DefaultLoadEventListener.cs:37 NHibernate.Impl.SessionImpl.FireLoad(LoadEvent event, LoadType loadType)
 in c:\CSharp\NH2.0.0\nhibernate\src\NHibernate\Impl\SessionImpl.cs:2054 NHibernate.Impl.SessionImpl.Get(String entityName, Object id)
 in c:\CSharp\NH2.0.0\nhibernate\src\NHibernate\Impl\SessionImpl.cs:1029 NHibernate.Impl.SessionImpl.Get(Type entityClass, Object id)
 in c:\CSharp\NH2.0.0\nhibernate\src\NHibernate\Impl\SessionImpl.cs:1020 NHibernate.Impl.SessionImpl.Get(Object id)
 in c:\CSharp\NH2.0.0\nhibernate\src\NHibernate\Impl\SessionImpl.cs:985 HQData.DataAccessUtils.NHibernateObjectHelper.LoadDataObject(Int32 Id)
 in C:\Development\HQChannelRepo\HQ Channel Application\HQChannel\HQData\DataAccessUtils\NHibernateObjectHelper.cs:42 HQWebsite.LocalSearch.get_subCategory()
 in C:\Development\HQChannelRepo\HQ Channel Application\HQChannel\HQWebsite\LocalSearch.aspx.cs:17 HQWebsite.LocalSearch.Page_Load(Object sender, EventArgs e)
 in C:\Development\HQChannelRepo\HQ Channel Application\HQChannel\HQWebsite\LocalSearch.aspx.cs:27 System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +15 System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +33 System.Web.UI.Control.OnLoad(EventArgs e) +99 System.Web.UI.Control.LoadRecursive() +47 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1436&lt;/pre&gt;

**Update**, here&#39;s what the solution for *my* scenario was: I had changed some code and I wasn&#39;t adding the Assembly to the config file during runtime. 

NHibernate.MappingException: No persister for: XYZ

I&#39;ve been writing C / C++ code for almost twenty years, and I know Perl, Python, PHP, and some Java as well, and I&#39;m teaching myself JavaScript. But I&#39;ve never done any .NET, VB, or C# stuff. What exactly does **managed** code mean?

Wikipedia [describes it][1] simply as
&gt;Code that executes under the management of a virtual machine

and it specifically says that Java is (usually) managed code, so

- **why does the term only seem to apply to C# / .NET?**
- **Can you compile C# into a .exe that contains the VM as well, or do you have to package it up and give it to another .exe (a la java)?**

In a similar vein,

- **is .NET a *language* or a *framework*, and what exactly does &quot;framework&quot; mean here?**

OK, so that&#39;s more than one question, but for someone who&#39;s been in the industry as long as I have, I&#39;m feeling rather N00B-ish right now...

  [1]: http://en.wikipedia.org/wiki/Managed_code

What exactly is &quot;managed&quot; code?

I&#39;m looking for suggestions on possible IPC mechanisms that are:

 - **Cross platform** (Win32 and Linux at least)
 - Simple to implement in **C++** as well as the **most common scripting languages** (perl, ruby, python, etc).
 - Finally, **simple to use** from a programming point of view!

What my options are? I&#39;m programming under Linux, but I&#39;d like what I write to be portable to other OSes in the future. I&#39;ve thought about using sockets, named pipes, or something like DBus.


Cross platform IPC

Should I use Named Pipes, or .NET Remoting to communicate with a running process on my machine?


 

What is the best choice for .NET inter-process communication?

Lots of IPCs are offered by Unix/Linux: pipes, sockets, shared memory, dbus, message-queues...

What are the most suitable applications for each, and how do they perform?

Comparing Unix/Linux IPC

I want to create a communication between a parent and a child process, both written in C#.

It should be asynchronous, event-driven.

I don&#39;t want to run a thread in every process to handle the very rare communication.

What is the best solution for it?


What is the simplest method of inter-process communication between 2 C# processes?

I&#39;ve been playing with message queues (System V, but POSIX should be ok too) in Linux recently and they seem perfect for my application, but after reading The Art of Unix Programming I&#39;m not sure if they are really a good choice.

[http://www.faqs.org/docs/artu/ch07s02.html#id2922148][1]
&gt; The upper, message-passing layer of System V IPC has largely fallen out of use. The lower layer, which consists of shared memory and semaphores, still has significant applications under circumstances in which one needs to do mutual-exclusion locking and some global data sharing among processes running on the same machine. These System V shared memory facilities evolved into the POSIX shared-memory API, supported under Linux, the BSDs, MacOS X and Windows, but not classic MacOS.

[http://www.faqs.org/docs/artu/ch07s03.html#id2923376][2]
&gt;The System V IPC facilities are present in Linux and other modern Unixes. However, as they are a legacy feature, they are not exercised very often. The Linux version is still known to have bugs as of mid-2003. Nobody seems to care enough to fix them.

Are the System V message queues still buggy in more recent Linux versions? I&#39;m not sure if the author means that POSIX message queues should be ok?

It seems that sockets are the preferred IPC for almost anything(?), but I cannot see how it would be very simple to implement message queues with sockets or something else. Or am I thinking too complexly?

I don&#39;t know if it&#39;s relevant that I&#39;m working with embedded Linux?

  [1]: http://www.faqs.org/docs/artu/ch07s02.html#id2922148
  [2]: http://www.faqs.org/docs/artu/ch07s03.html#id2923376

Content Type	Original Author	Original Content on Stackoverflow
Question	prakash	View Question on Stackoverflow
Solution 1 - C#	aku	View Answer on Stackoverflow
Solution 2 - C#	Deleted	View Answer on Stackoverflow
Solution 3 - C#	Serafina Brocious	View Answer on Stackoverflow
Solution 4 - C#	Demir	View Answer on Stackoverflow
Solution 5 - C#	ibz	View Answer on Stackoverflow
Solution 6 - C#	Kent Boogaart	View Answer on Stackoverflow

IPC Mechanisms in C# - Usage and Best Practices

C# Problem Overview

C# Solutions

Solution 1 - C#

Solution 2 - C#

Solution 3 - C#

Solution 4 - C#

Solution 5 - C#

Solution 6 - C#

How to escape a # in velocity

How to calculate age in T-SQL with years, months, and days

Attributions