It is preallocated by the runtime. If you explore the heap of any managed process you&#39;ll find an instance of that exception.

Here are the preallocated exceptions of a Hello World app:

    0:003&gt; !dumpheap -stat -type Exception
    Statistics:
          MT    Count    TotalSize Class Name
    735f2920        1           84 System.ExecutionEngineException
    735f28dc        1           84 System.StackOverflowException
    735f2898        1           84 System.OutOfMemoryException
    735f2744        1           84 System.Exception
    735f2964        2          168 System.Threading.ThreadAbortException


When an out-of-memory condition is encountered inside the runtime, it calls [ThrowOutOfMemory](https://github.com/dotnet/coreclr/blob/master/src/utilcode/ex.cpp#L1688). This calls [Exception::GetOOMException](https://github.com/dotnet/coreclr/blob/master/src/utilcode/ex.cpp#L41), which constructs the object on the stack and then copies it to a statically-allocated global instance, which is then thrown.

This is not the managed Exception, though, it a C++ exception declared in [ex.h](https://github.com/dotnet/coreclr/blob/master/src/inc/ex.h). C++ Exceptions are converted to managed Exceptions in [clrex.cpp](https://github.com/dotnet/coreclr/blob/master/src/vm/clrex.cpp), which contains code to specifically throw the preallocated _managed_ OutOfMemoryException, which was originally allocated and constructed in [appdomain.cpp](https://github.com/dotnet/coreclr/blob/master/src/vm/appdomain.cpp).

Note: Some of these source files are large and may hang your browser for several seconds while it loads the syntax highlighting.

The call sites that Tim Schmelter linked in a comment on the other answer aren&#39;t related to the runtime running out of memory and being unable to construct an object.

After upgrading to Laravel 5.2, none of my `.env` file values are being read. I followed the [upgrade instructions][1]; none of my config files were changed except auth.php. They were all working fine in previous version, 5.1.19

`.env` contains values such as

    DB_DATABASE=mydb
    DB_USERNAME=myuser

`config/database.php` contains

    &#39;mysql&#39; =&gt; [
        &#39;database&#39; =&gt; env(&#39;DB_DATABASE&#39;, &#39;forge&#39;),
        &#39;username&#39; =&gt; env(&#39;DB_USERNAME&#39;, &#39;forge&#39;),
    ]

I get this error:

    PDOException: SQLSTATE[HY000] [1045] Access denied for user &#39;forge&#39;@&#39;localhost&#39; (using password: NO)

Clearly not pulling in my env config. This is affecting every single one of my config files, including third party such as bugsnag.

I also tried

    php artisan config:clear
    php artisan cache:clear

**Update**

Trying `php artisan tinker`

    &gt;&gt;&gt; env(&#39;DB_DATABASE&#39;)
    =&gt; null
    &gt;&gt;&gt; getenv(&#39;DB_DATABASE&#39;)
    =&gt; false
    &gt;&gt;&gt; config(&#39;database.connections.mysql.database&#39;)
    =&gt; &quot;forge&quot;
    &gt;&gt;&gt; dd($_ENV)
    []

I have tried installing a fresh copy of Laravel 5.2. I basically only copied in my `app` folder; no additional composer packages are included. Still having the same issue. I have other Laravel 5.2 projects on the same server that are working fine.

  [1]: http://laravel.com/docs/master/upgrade

Laravel 5.2 not reading env file

Trying to fix errors and debug problems with my application that is split over several containers, I frequently edit files in containers:

- either I am totally lazy and install nano and edit directly in container or

- I docker cp the file out of the container, edit it, copy it back and restart the container

Those are intermediate steps before coming to new content for container build, which takes a lot longer than doing the above (which of course is only intermediate/fiddling around).

Now I frequently break the starting program of the container, which in the breaking cases is either a node script or a python webserver script, both typically fail from syntax errors.

Is there any way to save those containers? Since they do not start, I cannot docker exec into them, and thus they are lost to me. I then go the rm/rmi/build/run route after fixing the offending file in the build input.

**How can I either edit files in a stopped container, or cp them in or start a shell in a stopped container - anything that allows me to fix this container?**

(It seems a bit like working on a remote computer and breaking the networking configuration - connection is lost &quot;forever&quot; this way and one has to use a fallback, if that exists.)

https://stackoverflow.com/questions/24553790/how-to-edit-docker-container-files-from-the-host looks relevant but is outdated.

How to edit files in stopped/not starting docker container

In C++ it&#39;s actually possible to throw an exception by value without allocating memory on a heap, so this situation makes sense. But in .NET framework `OutOfMemoryException` is a reference type, therefore it is allocated on a heap. 
How does .NET framework allocates memory for `OutOfMemoryException` when there is not enough memory to create a new object?

How does .NET framework allocate memory for OutOfMemoryException?

<p>In C++ it's actually possible to throw an exception by value without allocating memory on a heap, so this situation makes sense. But in .NET framework <code>OutOfMemoryException</code> is a reference type, therefore it is allocated on a heap.
How does .NET framework allocates memory for <code>OutOfMemoryException</code> when there is not enough memory to create a new object?</p>


I tried to use the conditional operator inside an interpolated string, but because it has a colon in it, the compiler thinks that after the colon comes a format string.

    $&quot;test {foo ? &quot;foo is true&quot; : &quot;foo is false&quot;}&quot;;

How can I use this type of statement?
The only thing that comes to my mind is something like this:

    var fooString = foo ? &quot;foo is true&quot; : &quot;foo is false&quot;;
    $&quot;test {fooString}&quot;;

C# interpolated string with conditional-operator

I am trying to use the EF7 InMemory provider for unit tests, but the persistent nature of the InMemory database between tests is causing me problems.

The following code demonstrates my issue. One test will work and the other test will always fail. Even though I set the `_context` to `null` between tests, the second test run will always have 4 records in it.

    [TestClass]
    public class UnitTest1
    {
        private SchoolContext _context;

        [TestInitialize]
        public void Setup()
        {
            Random rng = new Random();
            
            var optionsBuilder = new DbContextOptionsBuilder&lt;SchoolContext&gt;();
            optionsBuilder.UseInMemoryDatabase();

            _context = new SchoolContext(optionsBuilder.Options);
            _context.Students.AddRange(
                new Student { Id = rng.Next(1,10000), Name = &quot;Able&quot; },
                new Student { Id = rng.Next(1,10000), Name = &quot;Bob&quot; }
            );
            _context.SaveChanges();
        }

        [TestCleanup]
        public void Cleanup()
        {
            _context = null;
        }

        [TestMethod]
        public void TestMethod1()
        {
            Assert.AreEqual(2, _context.Students.ToList().Count());
        }

        [TestMethod]
        public void TestMethod2()
        {
            Assert.AreEqual(2, _context.Students.ToList().Count());
        }
    }

    public class Student
    {
        public int Id { get; set; }
        public string Name { get; set; }
    }

    public class SchoolContext : DbContext
    {
        public SchoolContext(DbContextOptions options) : base(options) { }

        public DbSet&lt;Student&gt; Students { get; set; }
    }

How can I reset an EF7 InMemory provider between unit tests?

I have added a new property to my existing model. It&#39;s a bool property with a default value of true. There are existing data in this table and I would like to set one specific row&#39;s new property to false right after creating the new field, in the Up method. 

    public override void Up()
    {
        AddColumn(&quot;dbo.RequestValidationErrors&quot;, &quot;IsBreaking&quot;,
             c =&gt; c.Boolean(nullable: false));
        using (Context ctx = new Context())
        {
            var validation = 
                ctx.RequestValidationErrorSet
                .FirstOrDefault
                    (x =&gt; x.WordCode == &quot;RequestValidationError.MoreThanOneItemFound&quot;);
                if (validation != null)
                {
                    validation.IsBreaking = false;
                    ctx.SaveChanges();
                }
            }
        }
    }
This way EF throws an error during saying 

&gt; System.InvalidOperationException: The model backing the
&gt; &#39;DbContext&#39; context has changed since the database was created.
&gt; Consider using Code First Migrations to update the database

Is it possible to change the database here or should I do it elsewhere?


Change data in migration Up method - Entity Framework

I have a console application that manages images. Now i need something like a preview of the Images within the console application. Is there a way to display them in the console?



Here is a comparison of the current character based answers:

Input:

[![enter image description here][1]][1]

Output:

[![enter image description here][2]][2]

[![enter image description here][3]][3]

[![enter image description here][4]][4]

[![enter image description here][5]][5]


  [1]: http://i.stack.imgur.com/teq9P.jpg
  [2]: http://i.stack.imgur.com/hLdnj.png
  [3]: http://i.stack.imgur.com/JmIGw.png
  [4]: http://i.stack.imgur.com/YrbAn.png
  [5]: http://i.stack.imgur.com/Z4DWa.png

Display a Image in a console application

I&#39;m working with C# and .NET Framework 4.5.1 retrieving data from a SQL Server database with Entity Framework 6.1.3.

I have this:

    codes = codesRepo.SearchFor(predicate)
          .Select(c =&gt; new Tuple&lt;string, byte&gt;(c.Id, c.Flag))
          .ToList();

And when I run it, I get this message:

&gt; Only parameterless constructors and initializers are supported in LINQ
&gt; to Entities.

I don&#39;t know how I have to create the Tuple because all the examples that I have found are mostly like this one.

I have tried this:

    codes = codesRepo.SearchFor(predicate)
          .Select(c =&gt; Tuple.Create(c.Id, c.Flag))
          .ToList();

And get this error:

&gt; LINQ to Entities does not recognize the method
&gt; &#39;System.Tuple`2[System.String,System.Byte]
&gt; Create[String,Byte](System.String, Byte)&#39; method, and this method
&gt; cannot be translated into a store expression.

Where is the problem?

Create a Tuple in a Linq Select

I am publishing my ASP.NET 5 MVC6 project from Visual Studio 2015. I have imported publish profile from my server. Connection validates successfully, however when I publish my project I have the following error:

ERROR_CERTIFICATE_VALIDATION_FAILED

&gt; Connected to the remote computer (&quot;XXXXXXXXX&quot;) using the specified
&gt; process (&quot;Web Management Service&quot;), but could not verify the server&#39;s
&gt; certificate. If you trust the server, connect again and allow
&gt; untrusted certificates.

There is no option to allow untrusted certificates in publishing settings. 

Publishing from Visual Studio 2015 - allow untrusted certificates

Maybe I have a miss understanding of what &quot;.NET Core Library&quot; means, but when I try to add a .NET Core Library in a .NET 4.6 Assembly using Visual Studio 2015, I get the error:
&gt; A reference to &#39;...&#39; could not be added. 

Did I understand something wrong?

This is what I configured in project.json of the .NET Core assembly

    &quot;frameworks&quot;: {
       &quot;net451&quot;: { },
       &quot;dotnet5.4&quot;: {
         &quot;dependencies&quot;: {
         &quot;Microsoft.CSharp&quot;: &quot;4.0.1-beta-23516&quot;,
         &quot;System.Collections&quot;: &quot;4.0.11-beta-23516&quot;,
         &quot;System.Linq&quot;: &quot;4.0.1-beta-23516&quot;,
         &quot;System.Runtime&quot;: &quot;4.0.21-beta-23516&quot;,
         &quot;System.Threading&quot;: &quot;4.0.11-beta-23516&quot;
      }
    }

Reference a .NET Core Library in a .NET 4.6 project

Let’s consider this very simple async method:
	
	static async Task myMethodAsync() 
	{
		await Task.Delay(500);
	}

When I compile this with VS2013 (pre Roslyn compiler) the generated state-machine is a struct. 

	private struct &lt;myMethodAsync&gt;d__0 : IAsyncStateMachine
	{  
		...
	    void IAsyncStateMachine.MoveNext()
	    {
			...
	    }
	}

When I compile it with VS2015  (Roslyn) the generated code is this:

	private sealed class &lt;myMethodAsync&gt;d__1 : IAsyncStateMachine
	{
		...
		void IAsyncStateMachine.MoveNext()
		{
			...
		}
	}

As you can see Roslyn generates a class (and not a struct). If I remember correctly the first implementations of the async/await support in the old compiler (CTP2012 i guess) also generated classes and then it was changed to struct from performance reasons. (in some cases you can completely avoid boxing and heap allocation…) (See [this][1])

Does anyone know why this was changed again in Roslyn? (I don’t have any problem regarding this, I know that this change is transparent and does not change the behavior of any code, I’m just curious) 


  [1]: https://stackoverflow.com/questions/23609110/why-are-awaiters-async-await-structs-and-not-classes-can-classes-be-used

**Edit:**

The answer from @Damien_The_Unbeliever (and the source code :) ) imho explains everything. The described behaviour of Roslyn only applies for debug build (and that&#39;s needed because of the CLR limitation mentioned in the comment). In Release it also generates a struct (with all the benefits of that..). So this seems to be a very clever solution to support both Edit and Continue and better performance in production. Interesting stuff, thanks for everyone who participated! 

Why are async state machines classes (and not structs) in Roslyn?

Would this be classified as an O(1) algorithm for &quot;Hello, World!&quot; ??

    public class Hello1
    {
       public static void Main()
       {
          DateTime TwentyYearsLater = new DateTime(2035,01,01);
          while ( DateTime.Now &lt; TwentyYearsLater )
          { 
              System.Console.WriteLine(&quot;It&#39;s still not time to print the hello ...&quot;);
          }
          System.Console.WriteLine(&quot;Hello, World!&quot;);
       }
    }

I&#39;m thinking of using the 

    DateTime TwentyYearsLater = new DateTime(2035,01,01);
    while ( DateTime.Now &lt; TwentyYearsLater )
    { 
       // ... 
    }

snippet of code as a busy loop to put in as a joke whenever someone asks for an algorithm of a certain complexity. Would this be correct?

Is this technically an O(1) algorithm for &quot;Hello World&quot;?

In C# I can convert doubles to floats by a cast `(float)` or by `Convert.ToSingle()`.

	double x = 3.141592653589793238463;
	float a = (float)x;
	float b = Convert.ToSingle(x);

`a` and `b` become equal.

Are there any differences between both techniques? Which one should I prefer and why?

Convert double to float by cast or Convert.ToSingle()?

I just had a rather unpleasant experience in our production environment, causing `OutOfMemoryErrors: heapspace..`

I traced the issue to my use of `ArrayList::new` in a function.

To verify that this is actually performing worse than normal creation via a declared constructor (`t -&gt; new ArrayList&lt;&gt;()`), I wrote the following small method:

    public class TestMain {
      public static void main(String[] args) {
        boolean newMethod = false;
        Map&lt;Integer,List&lt;Integer&gt;&gt; map = new HashMap&lt;&gt;();
        int index = 0;

        while(true){
          if (newMethod) {
            map.computeIfAbsent(index, ArrayList::new).add(index);
         } else {
            map.computeIfAbsent(index, i-&gt;new ArrayList&lt;&gt;()).add(index);
          }
          if (index++ % 100 == 0) {
            System.out.println(&quot;Reached index &quot;+index);
          }
        }
      }
    }

Running the method with `newMethod=true;` will cause the method to fail with `OutOfMemoryError` just after index hits 30k. With `newMethod=false;` the program does not fail, but keeps pounding away until killed (index easily reaches 1.5 milion).

Why does `ArrayList::new` create so many `Object[]` elements on the heap that it causes `OutOfMemoryError` so fast?

(By the way - it also happens when the collection type is `HashSet`.)


Horrendous performance &amp; large heap footprint of Java 8 constructor reference?

Today I ran my script for filesystem indexing to refresh RAID files index and after 4h it crashed with following error:

    [md5:]  241613/241627 97.5%  
    [md5:]  241614/241627 97.5%  
    [md5:]  241625/241627 98.1%
    Creating missing list... (79570 files missing)
    Creating new files list... (241627 new files)

    &lt;--- Last few GCs ---&gt;

    11629672 ms: Mark-sweep 1174.6 (1426.5) -&gt; 1172.4 (1418.3) MB, 659.9 / 0 ms [allocation failure] [GC in old space requested].
    11630371 ms: Mark-sweep 1172.4 (1418.3) -&gt; 1172.4 (1411.3) MB, 698.9 / 0 ms [allocation failure] [GC in old space requested].
    11631105 ms: Mark-sweep 1172.4 (1411.3) -&gt; 1172.4 (1389.3) MB, 733.5 / 0 ms [last resort gc].
    11631778 ms: Mark-sweep 1172.4 (1389.3) -&gt; 1172.4 (1368.3) MB, 673.6 / 0 ms [last resort gc].


    &lt;--- JS stacktrace ---&gt;

    ==== JS stack trace =========================================

    Security context: 0x3d1d329c9e59 &lt;JS Object&gt;
    1: SparseJoinWithSeparatorJS(aka SparseJoinWithSeparatorJS) [native array.js:~84] [pc=0x3629ef689ad0] (this=0x3d1d32904189 &lt;undefined&gt;,w=0x2b690ce91071 &lt;JS Array[241627]&gt;,L=241627,M=0x3d1d329b4a11 &lt;JS Function ConvertToString (SharedFunctionInfo 0x3d1d3294ef79)&gt;,N=0x7c953bf4d49 &lt;String[4]\: ,\n  &gt;)
    2: Join(aka Join) [native array.js:143] [pc=0x3629ef616696] (this=0x3d1d32904189 &lt;undefin...

    FATAL ERROR: CALL_AND_RETRY_LAST Allocation failed - JavaScript heap out of memory
     1: node::Abort() [/usr/bin/node]
     2: 0xe2c5fc [/usr/bin/node]
     3: v8::Utils::ReportApiFailure(char const*, char const*) [/usr/bin/node]
     4: v8::internal::V8::FatalProcessOutOfMemory(char const*, bool) [/usr/bin/node]
     5: v8::internal::Factory::NewRawTwoByteString(int, v8::internal::PretenureFlag) [/usr/bin/node]
     6: v8::internal::Runtime_SparseJoinWithSeparator(int, v8::internal::Object**, v8::internal::Isolate*) [/usr/bin/node]
     7: 0x3629ef50961b

Server is equipped with 16gb RAM and 24gb SSD swap. I highly doubt my script exceeded 36gb of memory. At least it shouldn&#39;t

Script creates index of files stored as Array of Objects with files metadata (modification dates, permissions, etc, no big data)

Here&#39;s full script code:
http://pastebin.com/mjaD76c3

I&#39;ve already experiend weird node issues in the past with this script what forced me eg. split index into multiple files as node was glitching when working on such big files as String. Is there any way to improve nodejs memory management with huge datasets?

Node.js heap out of memory

I am getting this error while making a release build for my react native project:   

    Expiring Daemon because JVM heap space is exhausted
        
    &gt; Task :app:transformDexArchiveWithDexMergerForRelease FAILED
    
    FAILURE: Build failed with an exception.
    
    * What went wrong:
    Execution failed for task &#39;:app:transformDexArchiveWithDexMergerForRelease&#39;.
    &gt; java.lang.OutOfMemoryError (no error message)


Done some research and made some changes, which are below:

 1. Added  `android:largeHeap=&quot;true&quot;` to the application tag in the AndroidManifest.xml
 2. Added 


        dexOptions {
            javaMaxHeapSize &quot;4g&quot; 
        }


    in the android/app/build.gradle file.

 3. Added the below code to gradle.properties

        org.gradle.jvmargs=-Xmx4096m -XX:MaxPermSize=4096m -XX:+HeapDumpOnOutOfMemoryError
        org.gradle.daemon=true
        org.gradle.parallel=true
        org.gradle.configureondemand=true

Still I am not able to get rid of this error. Any permanent way to get rid of this error and how is it caused??


Content Type	Original Author	Original Content on Stackoverflow
Question	RX_DID_RX	View Question on Stackoverflow
Solution 1 - C#	Brian Rasmussen	View Answer on Stackoverflow
Solution 2 - C#	Random832	View Answer on Stackoverflow

How does .NET framework allocate memory for OutOfMemoryException?

C# Problem Overview

C# Solutions

Solution 1 - C#

Solution 2 - C#

How to edit files in stopped/not starting docker container

Laravel 5.2 not reading env file

Attributions