Perform a `WaitOne` on the event with a timeout value of zero.

It will return true if the event is set, or false if the timeout occurs.
In other words, true -&gt; event is set, false -&gt; event is not set.




Here is working code:

    private ManualResetEvent pause = new ManualResetEvent(false);
    pause.WaitOne(); // caller thread pauses
    pause.Set();    // another thread releases paused thread
    
    // Check pause state
    public bool IsPaused { get { return !pause.WaitOne(0); } }


You can make function calls in the Debugger Watch window.
Add a call to `mreVariable.WaitOne(0)` in the Watch window and see what it evaluates to.
Note: You should not use this for AutoResetEvents since that could change the actual state.

I often use this code pattern:

    while(true) {
    	
    	//do something
    	
    	if(&lt;some condition&gt;) {
    		break;
    	}
    	
    }	

Another programmer told me that this was bad practice and that I should replace it with the more standard:

    while(!&lt;some condition&gt;) {
    	
    	//do something
    	
    }	

His reasoning was that you could &quot;forget the break&quot; too easily and have an endless loop. I told him that in the second example you could just as easily put in a condition which never returned true and so just as easily have an endless loop, so both are equally valid practices.

Further, I often prefer the former as it makes the code easier to read when you have multiple break points, i.e. multiple conditions which get out of the loop.

Can anyone enrichen this argument by adding evidence for one side or the other?


Is while (true) with break bad programming practice?

How can I obtain the .NET Framework directory path inside my C# application?

The folder that I refer is &quot;C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727&quot;

Getting the .NET Framework directory path

I am using an instance of `ManualResetEvent` to control thread access to a resource but I&#39;m running into problems with it.  Does anyone know how I can find out during debugging what the state of the object is?

That is to say I would like to know if the `ManualResetEvent` is currently blocking any threads and maybe even how many and which threads it is blocking.

How to find what state ManualResetEvent is in?

<p>I am using an instance of <code>ManualResetEvent</code> to control thread access to a resource but I'm running into problems with it.  Does anyone know how I can find out during debugging what the state of the object is?</p>
<p>That is to say I would like to know if the <code>ManualResetEvent</code> is currently blocking any threads and maybe even how many and which threads it is blocking.</p>


Is there a good, free telnet library available for C# (not ASP .NET)? I have found a few on google, but they all have one issue or another (don&#39;t support login/password, don&#39;t support a scripted mode).

I am assuming that MS still has not included a telnet library as part of .NET v3.5 as I couldn&#39;t find it if it was. I would loooooove to be wrong though.

C# Telnet Library

How to make `NameValueCollection` accessible to LINQ query operator such as where, join, groupby?

I tried the below:

    private NameValueCollection RequestFields()
    {
        NameValueCollection nvc = new NameValueCollection()
                                      {
                                          {&quot;emailOption: blah Blah&quot;, &quot;true&quot;},
                                          {&quot;emailOption: blah Blah2&quot;, &quot;false&quot;},
                                          {&quot;nothing&quot;, &quot;false&quot;},
                                          {&quot;nothinger&quot;, &quot;true&quot;}
                                      };
        return nvc;
        
    }

    public void GetSelectedEmail()
    {
        NameValueCollection nvc = RequestFields();
        IQueryable queryable = nvc.AsQueryable();
    }


But I got an *ArgumentException* telling me that the **source is not IEnumerable&lt;&gt;**. 

Make NameValueCollection accessible to LINQ Query

I saw this reply from Jon on [Initialize generic object with unknown type][1]:

&gt; If you want a single collection to
&gt; contain multiple unrelated types of
&gt; values, however, you will have to use
&gt; `List&lt;object&gt;`

I&#39;m not comparing `ArrayList` vs `List&lt;&gt;`, but `ArrayList` vs `List&lt;object&gt;`, as both will be exposing elements of type `object`. What would be the benefit of using either one in this case?

EDIT: It&#39;s no concern for type safety here, since both class is exposing `object` as its item. One still needs to cast from `object` to the desired type. I&#39;m more interested in anything other than type safety.

EDIT: Thanks Marc Gravell and Sean for the answer. Sorry, I can only pick 1 as answer, so I&#39;ll up vote both.

  [1]: https://stackoverflow.com/questions/386500/initialize-generic-object-with-unknown-type

ArrayList vs List&lt;object&gt;

Will the following code result in a deadlock using C# on .NET?

     class MyClass
     {
        private object lockObj = new object();
    
        public void Foo()
        {
            lock(lockObj)
            { 
                 Bar();
            }
        }
    
        public void Bar()
        {
            lock(lockObj)
            { 
              // Do something 
            }
        }       
     }

Re-entrant locks in C#

I do not want the user to be able to change the value displayed in the combobox. I have been using `Enabled = false` but it grays out the text, so it is not very readable. I want it to behave like a textbox with `ReadOnly = true`, where the text is displayed normally, but the user can&#39;t edit it.

Is there is a way of accomplishing this?


How to make Combobox in winforms readonly

I have a method which should be delayed running for a specified amount of time.

Should I use

    Thread thread = new Thread(() =&gt; {
        Thread.Sleep(millisecond);
        action();
    });
    thread.IsBackground = true;
    thread.Start();

Or

    Timer timer = new Timer(o =&gt; action(), null, millisecond, -1);

I had read some [articles][1] about using `Thread.Sleep` is bad design. But I don&#39;t really understand why.

But for using Timer, Timer has dispose method. Since the execution is delayed, I don&#39;t know how to dispose Timer. Do you have any suggestions?

Or if you have alternative codes for delayed execution are also appreciate.

  [1]: http://msmvps.com/blogs/peterritchie/archive/2007/04/26/thread-sleep-is-a-sign-of-a-poorly-designed-program.aspx

Compare using Thread.Sleep and Timer for delayed execution

I came across [this][1] article discussing why the double-check locking paradigm is broken in Java. Is the paradigm valid for .NET (in particular, C#), if variables are declared `volatile`?


  [1]: http://www.cs.umd.edu/~pugh/java/memoryModel/DoubleCheckedLocking.html

Double-checked locking in .NET

In Java, the idiomatic way to declare critical sections in the code is the following:

    private void doSomething() {
      // thread-safe code
      synchronized(this) {
        // thread-unsafe code
      }
      // thread-safe code
    }

Almost all blocks synchronize on  `this`, but is there a particular reason for this? Are there other possibilities? Are there any best practices on what object to synchronize on? (such as private instances of `Object`?)

In Java critical sections, what should I synchronize on?

Looking for some sample code (C#) for a simple thread pool implementation.

I found one on codeproject, but the codebase was just huge and I don&#39;t need all that functionality.

This is more for educational purposes anyways.



Code for a simple thread pool in C#

This is a detail question for C#.

Suppose I&#39;ve got a class with an object, and that object is protected by a lock:

    Object mLock = new Object();
    MyObject property;
    public MyObject MyProperty {
        get {
             return property;
        }
        set { 
             property = value; 
        }
    }

I want a polling thread to be able to query that property.  I also want the thread to update properties of that object occasionally, and sometimes the user can update that property, and the user wants to be able to see that property.  

Will the following code properly lock the data?

    Object mLock = new Object();
    MyObject property;
    public MyObject MyProperty {
        get {
             lock (mLock){
                 return property;
             }
        }
        set { 
             lock (mLock){
                  property = value; 
             }
        }
    }

By &#39;properly&#39;, what I mean is, if I want to call

    MyProperty.Field1 = 2;

or whatever, will the field be locked while I do the update?  Is the setting that&#39;s done by the equals operator inside the scope of the &#39;get&#39; function, or will the &#39;get&#39; function (and hence the lock) finish first, and then the setting, and then &#39;set&#39; gets called, thus bypassing the lock?

Edit:  Since this apparently won&#39;t do the trick,  what will?  Do I need to do something like:


    Object mLock = new Object();
    MyObject property;
    public MyObject MyProperty {
        get {
             MyObject tmp = null;
             lock (mLock){
                 tmp = property.Clone();
             }
             return tmp;
        }
        set { 
             lock (mLock){
                  property = value; 
             }
        }
    }

which more or less just makes sure that I only have access to a copy, meaning that if I were to have two threads call a &#39;get&#39; at the same time, they would each start with the same value of Field1 (right?).  Is there a way to do read and write locking on a property that makes sense?  Or should I just constrain myself to locking on sections of functions rather than the data itself?

Just so that this example makes sense:  MyObject is a device driver that returns status asynchronously.  I send it commands via a serial port, and then the device responds to those commands in its own sweet time.  Right now, I have a thread that polls it for its status (&quot;Are you still there?  Can you accept commands?&quot;), a thread that waits for responses on the serial port (&quot;Just got status string 2, everything&#39;s all good&quot;), and then the UI thread which takes in other commands (&quot;User wants you to do this thing.&quot;) and posts the responses from the driver (&quot;I&#39;ve just done the thing, now update the UI with that&quot;).  That&#39;s why I want to lock on the object itself, rather than the fields of the object; that would be a huge number of locks, a, and b, not every device of this class has the same behavior, just general behavior, so I&#39;d have to code lots of individual dialogs if I individualized the locks.

C# thread safety with get/set

Can any one tell me the advantage of synchronized method over synchronized block with an example?

Is there an advantage to use a Synchronized Method instead of a Synchronized Block?

I want to known who is locking a file on a network share.

Here is the problem : the network share is on a NAS, so I can&#39;t log on. I need a tool to find out remotely who is locking the file. It is not practical to reboot the NAS every time, because there are several users.

[Handle.exe][1], Process Explorer and [PsFile][2] seems to be limited to files on the local machine, so they don&#39;t work for me.


  [1]: https://stackoverflow.com/questions/241178/command-line-tool-for-finding-out-who-is-locking-a-file
  [2]: https://stackoverflow.com/questions/208283/is-it-possible-to-programatically-find-out-what-process-is-locking-a-file-acros

Find out who is locking a file on a network share

In a c# threading app, if I were to lock an object, let us say a queue, and if an exception occurs, will the object stay locked?  Here is the pseudo-code:

    int ii;
    lock(MyQueue)
    {
       MyClass LclClass = (MyClass)MyQueue.Dequeue();
       try
       {
          ii = int.parse(LclClass.SomeString);
       }
       catch
       {
         MessageBox.Show(&quot;Error parsing string&quot;);
       }
    }

As I understand it, code after the catch doesn&#39;t execute - but I have been wondering if the lock will be freed.    
   

Content Type	Original Author	Original Content on Stackoverflow
Question	George Mauer	View Question on Stackoverflow
Solution 1 - .Net	Andrew Rollings	View Answer on Stackoverflow
Solution 2 - .Net	fab	View Answer on Stackoverflow
Solution 3 - .Net	Robert Biro	View Answer on Stackoverflow

How to find what state ManualResetEvent is in?

.Net Problem Overview

.Net Solutions

Solution 1 - .Net

Solution 2 - .Net

Solution 3 - .Net

Getting the .NET Framework directory path

Is while (true) with break bad programming practice?

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