In one of the related [articles][1], two requirements are mentioned (emphasis added):

&gt; Before I begin, there are a few things to note about the &quot;Debug Managed Memory&quot; feature discussed in this post:

&gt; 1. The option will only be available from the dump summary page in the **Ultimate version of Visual Studio 2013**.  If you are using Premium or Professional you will not see the option.  
2. **The process the dump file was collected against must have been running on .NET 4.5 or higher.**  If the dump was collected on 3.5 or previous the option will not appear, if it was collected on 4.0 it will fail to launch with an error message.



  [1]: http://blogs.msdn.com/b/visualstudioalm/archive/2013/06/20/using-visual-studio-2013-to-diagnose-net-memory-issues-in-production.aspx

In my PHP script I need to create an array of &gt;600k integers. Unfortunately my webservers `memory_limit` is set to 32M so when initializing the array the script aborts with message 

&gt; **Fatal error:** Allowed memory size of 33554432 bytes exhausted (tried to allocate 71 bytes) in **/home/www/myaccount/html/mem_test.php** on line **8**

I am aware of the fact, that PHP does not store the array values as plain integers, but rather as zvalues which are much bigger than the plain integer value (8 bytes on my 64-bit system). I wrote a small script to estimate how much memory each array entry uses and it turns out, that it&#39;s pretty exactly 128 bytes. 128!!! I&#39;d need &gt;73M just to store the array. Unfortunately the webserver is not under my control so I cannot increase the `memory_limit`.

My question is, is there any possibility in PHP to create an array-like structure that uses less memory. I don&#39;t need this structure to be associative (plain index-access is sufficient). It also does not need to have dynamic resizing - I know exactly how big the array will be. Also, all elements would be of the same type. Just like a good old C-array.

----------------
**Edit:**
So [deceze][1]&#39;s solution works out-of-the-box with 32-bit integers. But even if you&#39;re on a 64-bit system, [pack()][2] does not seem to support 64-bit integers. In order to use 64-bit integers in my array I applied some bit-manipulation. Perhaps the below snippets will be of help for someone:

    function push_back(&amp;$storage, $value)
    {
    	// split the 64-bit value into two 32-bit chunks, then pass these to pack().
    	$storage .= pack(&#39;ll&#39;, ($value&gt;&gt;32), $value);
    }
    
    function get(&amp;$storage, $idx)
    {
    	// read two 32-bit chunks from $storage and glue them back together.
    	return (current(unpack(&#39;l&#39;, substr($storage, $idx * 8, 4)))&lt;&lt;32 |
    			current(unpack(&#39;l&#39;, substr($storage, $idx * 8+4, 4))));
    }

  [1]: https://stackoverflow.com/users/476/deceze &quot;deceze&quot;
  [2]: http://php.net/pack &quot;PHP: pack - Manual&quot;

Need an array-like structure in PHP with minimal memory usage

I am working on something which fetches data from database and constructs protobuff message. Given the possibility that null values can be fetched from the database for certain fields , I will get Null-pointer exception while trying to construct the protobuff message. Getting to know that null is not supported in protobuffs from the thread http://code.google.com/p/protobuf/issues/detail?id=57, I am wondering whether the only other way to handle NPE getting thrown is to insert manual checks into the java file corresponding to the proto like below!

    message ProtoPerson{
        optional string firstName = 1;
        optional string lastName = 2;
        optional string address1 = 3;
    }

    ProtoPerson.Builder builder = ProtoPerson.Builder.newBuilder();
    if (p.getFirstName() != null) builder.setFirstName(p.getFirstName());
    if (p.getLastName() != null) builder.setLastName(p.getLastName());
    if (p.getAddress1() != null) builder.setAddress1(p.getAddress1());
    ...

So can someone please clarify whether there is any other possible efficient way to handle the null values during protobuff construction??

Handling null values in protobuffers

Why I can not find &quot;Debug Managed Memory&quot; on Action menu as described at this MSDN article: [Analyze .NET Framework memory issues](http://msdn.microsoft.com/en-us/library/dn342825.aspx)?

My Visual Studio:
![enter image description here][1]

How it is supposed to look:
![enter image description here][2]


  [1]: http://i.stack.imgur.com/SZQv7.png
  [2]: http://i.stack.imgur.com/m5roI.png

Why I can not find &quot;Debug Managed Memory&quot; on Actions menu?

Why I can not find "Debug Managed Memory" on Action menu as described at this MSDN article: <a href="http://msdn.microsoft.com/en-us/library/dn342825.aspx" target="_blank" rel="noopener noreferrer">Analyze .NET Framework memory issues</a>?
My Visual Studio:
<img src="http://i.stack.imgur.com/SZQv7.png" alt="enter image description here">
How it is supposed to look:
<img src="http://i.stack.imgur.com/m5roI.png" alt="enter image description here">

I&#39;ve got an interface which declares

    Task DoSomethingAsync();
I&#39;m using MoqFramework for my tests:

    [TestMethod()]
    public async Task MyAsyncTest()
    {
       Mock&lt;ISomeInterface&gt; mock = new Mock&lt;ISomeInterface&gt;();
       mock.Setup(arg =&gt; arg.DoSomethingAsync()).Callback(() =&gt; { &lt;my code here&gt; });
       ...
    }

Then in my test I execute the code which invokes `await DoSomethingAsync()`. And the test just fails on that line. What am I doing wrong?

How can I tell Moq to return a Task?

I&#39;m trying to deserialize an object from JSON data to a C# class (I&#39;m using Newtonsoft Json.NET). The data contains dates as string values like `09/12/2013` where the format is `dd/MM/yyyy`.

If I call `JsonConvert.DeserializeObject&lt;MyObject&gt;(data)`,
dates are loaded to the `DateTime` property of the C# class with the `MM/dd/yyyy` format, this causes the date value to be `12 September 2013` (instead of `9 December 2013`).

Is it possible to configure `JsonConvert` to get the date in the correct format?

Deserializing dates with dd/MM/yyyy format using Json.Net

I assume this code has concurrency issues:


    const string CacheKey = &quot;CacheKey&quot;;
    static string GetCachedData()
    {
        string expensiveString =null;
        if (MemoryCache.Default.Contains(CacheKey))
        {
            expensiveString = MemoryCache.Default[CacheKey] as string;
        }
        else
        {
            CacheItemPolicy cip = new CacheItemPolicy()
            {
                AbsoluteExpiration = new DateTimeOffset(DateTime.Now.AddMinutes(20))
            };
            expensiveString = SomeHeavyAndExpensiveCalculation();
            MemoryCache.Default.Set(CacheKey, expensiveString, cip);
        }
        return expensiveString;
    }

The reason for the concurrency issue is that multiple threads can get a null key and then attempt to  insert data into cache.

What would be the shortest and cleanest way to make this code concurrency proof? I like to follow a good pattern across my cache related code. A link to an online article would be a great help.


UPDATE:

I came up with this code based on @Scott Chamberlain&#39;s answer. Can anyone find any performance or concurrency issue with this?
If this works, it would save many line of code and errors. 

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using System.Runtime.Caching;

    namespace CachePoc
    {
        class Program
        {
            static object everoneUseThisLockObject4CacheXYZ = new object();
            const string CacheXYZ = &quot;CacheXYZ&quot;;
            static object everoneUseThisLockObject4CacheABC = new object();
            const string CacheABC = &quot;CacheABC&quot;;

            static void Main(string[] args)
            {
                string xyzData = MemoryCacheHelper.GetCachedData&lt;string&gt;(CacheXYZ, everoneUseThisLockObject4CacheXYZ, 20, SomeHeavyAndExpensiveXYZCalculation);
                string abcData = MemoryCacheHelper.GetCachedData&lt;string&gt;(CacheABC, everoneUseThisLockObject4CacheXYZ, 20, SomeHeavyAndExpensiveXYZCalculation);
            }

            private static string SomeHeavyAndExpensiveXYZCalculation() {return &quot;Expensive&quot;;}
            private static string SomeHeavyAndExpensiveABCCalculation() {return &quot;Expensive&quot;;}

            public static class MemoryCacheHelper
            {
                public static T GetCachedData&lt;T&gt;(string cacheKey, object cacheLock, int cacheTimePolicyMinutes, Func&lt;T&gt; GetData)
                    where T : class
                {
                    //Returns null if the string does not exist, prevents a race condition where the cache invalidates between the contains check and the retreival.
                    T cachedData = MemoryCache.Default.Get(cacheKey, null) as T;

                    if (cachedData != null)
                    {
                        return cachedData;
                    }

                    lock (cacheLock)
                    {
                        //Check to see if anyone wrote to the cache while we where waiting our turn to write the new value.
                        cachedData = MemoryCache.Default.Get(cacheKey, null) as T;

                        if (cachedData != null)
                        {
                            return cachedData;
                        }

                        //The value still did not exist so we now write it in to the cache.
                        CacheItemPolicy cip = new CacheItemPolicy()
                        {
                            AbsoluteExpiration = new DateTimeOffset(DateTime.Now.AddMinutes(cacheTimePolicyMinutes))
                        };
                        cachedData = GetData();
                        MemoryCache.Default.Set(cacheKey, cachedData, cip);
                        return cachedData;
                    }
                }
            }
        }
    }



Locking pattern for proper use of .NET MemoryCache

Consider this code:

    int age = 25;
    short newAge = 25;
    Console.WriteLine(age == newAge);&#160;&#160;//true
    Console.WriteLine(newAge.Equals(age));&#160;//false
    Console.ReadLine();

Both `int` and `short` are primitive types, but a comparison with `==` returns true and a comparison with `Equals` returns false.

Why?

What is the difference between == and Equals() for primitives in C#?

See this code:

    object x = &quot;mehdi emrani&quot;;
    string y = &quot;mehdi emrani&quot;;
    Console.WriteLine(y == x);

that returns `true`.

But this code:
   
    object x = &quot;mehdi emrani&quot;;
    string y = &quot;mehdi &quot;;
    y += &quot;emrani&quot;;
    Console.WriteLine(y == x);

returns `false`.

So when I compare String and Object in first code I get `true`.  
But when I compare them in  second code I get `false`.

Both strings are same but why when I append to the string, my result returns `false`?

Compare String and Object in C#

I need to run web.exe file from my developer command prompt in Visual Studio 2013. By default, the command prompt is not installed in Visual Studio 2013.

Previously, I was using Visual Studio 2012. It had developer command prompt installed by default.

Does anyone know why VS2013 doesn&#39;t have developer command prompt by default? How can I setup developer command prompt for VS2013?




Where is Developer Command Prompt for VS2013?

I&#39;ve checked autohide and the bar disappeared but now how can I see it again?

How to show / unhide Web Essential bar from chrome?

I can&#39;t believe I couldn&#39;t find a working solution to this after an hour of searching. I&#39;m following [this article](http://www.dotnetcurry.com/showarticle.aspx?ID=941) on Entity Framework 6.0 which gives a simple walk-through on Code First. I created the project and installed the latest [EF Nuget package](https://www.nuget.org/packages/EntityFramework/6.0.2) for the project to compile. I also verified that I have Microsoft SQL Server 2012 Express LocalDB installed which came with Visual Studio 2013. I don&#39;t have any other instances of SQL installed on my local computer. The program runs and entries are added to the database and outputted in the console. But when the article says &quot;check your localdb&quot; it doesn&#39;t say how! I don&#39;t see any &#39;.mdf&#39; or &#39;.ldf&#39; files created under the project folder. I tried every way to connect Visual Studio&#39;s Server Explorer to LocalDB. The wizard cannot locate `(localdb)` or cannot find any provider in Server Explorer to accept connection string like `(localdb)\v11.0;Integrated Security=true;` I&#39;ve seen this asked several places in StackOverflow but no answer works or marked as answer. Please help, this doesn&#39;t have to be this frustrating!

What are the steps to connect Visual Studio Server Explorer to LocalDB?

How to connect to LocalDB in Visual Studio Server Explorer?

I&#39;m working with an ASP.NET MVC project that seems to be having some issues when attaching to the IIS process (w3wp.exe). I&#39;m running the solution and IIS 8.5 on my own local machine so I wouldn&#39;t think that this has anything to do with our network. What&#39;s strange to me is that I&#39;m able to hit the breakpoints on any other solution I debug locally.

The issue I&#39;m having exactly is that the breakpoints turn to red, hollow circles and never get hit. Usually the fix for this is a Clean/Rebuild of the solution but this hasn&#39;t worked. I&#39;ve confirmed the code is being updated by adding &quot;throw new Exception&quot; to a page and ensuring it shows the exception. Again, this problem is only happening with this one solution. Any other solution I run the debugger with works fine. I&#39;ve also tried restarting the app pool, the website, IIS, and also my computer. 

A few of the articles I read mentioned that anti-virus programs can block a remote debugger from accessing the process. However, the entire setup is contained on my local machine so it doesn&#39;t sound like that would be the issue. It does concern me a bit though because we recently hired a new IT guy that&#39;s been making a lot of changes to everyone&#39;s machine. 

One other point to add that&#39;s unique about this web application is the binding in IIS. The binding is &quot;*&quot; in order to leverage some custom functionality related to subdomains. 

In the meantime, I&#39;ll continue to look for a solution but if anybody has any ideas what may be causing this one solution to not debug properly I&#39;d really appreciate it. 

EDIT: Found a solution that suggested deleting the ASP.NET temporary files. No luck.

Visual Studio breakpoints not being hit

&lt;pre&gt;
Could not load file or assembly &#39;Microsoft.VisualStudio.Web.PageInspector.Loader, Version=1.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a&#39; or one of its dependencies. The module was expected to contain an assembly manifest.


Assembly manager loaded from:  C:\Windows\Microsoft.NET\Framework\v4.0.30319\clr.dll
Running under executable  C:\Program Files (x86)\Common Files\Microsoft Shared\DevServer\11.0\WebDev.WebServer40.exe
--- A detailed error log follows. 

=== Pre-bind state information ===
LOG: User = TTLWIN2K\miralp
LOG: DisplayName = Microsoft.VisualStudio.Web.PageInspector.Loader, Version=1.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
 (Fully-specified)
LOG: Appbase = file:///C:/SVN/temp/components/src/MasterpassProxy/src/Webservice/
LOG: Initial PrivatePath = C:\SVN\temp\components\src\MasterpassProxy\src\Webservice\bin
Calling assembly : (Unknown).
===
LOG: This bind starts in default load context.
LOG: Using application configuration file: C:\SVN\temp\components\src\MasterpassProxy\src\Webservice\web.config
LOG: Using host configuration file: 
LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework\v4.0.30319\config\machine.config.
LOG: Post-policy reference: Microsoft.VisualStudio.Web.PageInspector.Loader, Version=1.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
&lt;/pre&gt;

Could not load file or assembly &#39;Microsoft.VisualStudio.Web.PageInspector.Loader

I&#39;m studying computer engineering, and I have some electronics courses. I heard, from two of my professors (of these courses) that it is possible to avoid using the `free()` function (after `malloc()`, `calloc()`, etc.) because the memory spaces allocated likely won&#39;t be used again to allocate other memory. That is, for example, if you allocate 4 bytes and then release them you will have 4 bytes of space that likely won&#39;t be allocated again: you will have a *hole*.

I think that&#39;s crazy: you can&#39;t have a *not-toy-program* where you allocate memory on the heap without releasing it. But I don&#39;t have the knowledge to explain exactly why it&#39;s so important that for each `malloc()` there must be a `free()`.

So: are there ever circumstances in which it might be appropriate to use a `malloc()` without using `free()`? And if not, how can I explain this to my professors?

Is it ever OK to *not* use free() on allocated memory?

My view controller displays a WKWebView. I installed a message handler, a cool Web Kit feature that allows my code to be notified from inside the web page:

    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)
        let url = // ...
        self.wv.loadRequest(NSURLRequest(URL:url))
        self.wv.configuration.userContentController.addScriptMessageHandler(
            self, name: &quot;dummy&quot;)
    }

    func userContentController(userContentController: WKUserContentController,
        didReceiveScriptMessage message: WKScriptMessage) {
            // ...
    }


So far so good, but now I&#39;ve discovered that my view controller is leaking - when it is supposed to be deallocated, it isn&#39;t:

    deinit {
        println(&quot;dealloc&quot;) // never called
    }

It appears that merely installing myself as a message handler causes a retain cycle and hence a leak!

WKWebView causes my view controller to leak

https://docs.angularjs.org/guide/directive

&gt; By listening to this event, you can remove event listeners that might cause memory leaks. Listeners registered to scopes and elements are automatically cleaned up when they are destroyed, but if you registered a listener on a service, or registered a listener on a DOM node that isn&#39;t being deleted, you&#39;ll have to clean it up yourself or you risk introducing a memory leak.
&gt;
&gt; Best Practice: Directives should clean up after themselves. You can use element.on(&#39;$destroy&#39;, ...) or scope.$on(&#39;$destroy&#39;, ...) to run a clean-up function when the directive is removed.

Question:

I have a `element.on &quot;click&quot;, (event) -&gt;` inside my directive:

 1. When the directive is destroyed, are there any memory references to the `element.on` to keep it from being garbage collected?
 2. Angular documentation states that I should use a handler to remove event listeners on the `$destroy` emitted event. I was under the impression that `destroy()` removed event listeners, is this not the case?

AngularJS - Does $destroy remove event listeners?

How do memory leak detectors actually work? What are the underlying concepts in general? Can take C++ as the language to explain this.

Memory Leak Detectors Working Principle

I have an iOS app written in Swift that is leaking memory - in certain situation some objects should be released but they are not. I have learnt about the issue by simply adding `deinit` debug messages like this:

    deinit {
        println(&quot;DEINIT: KeysProvider released&quot;)
    }

So, the deinit message should be present in console after such events that should cause the object to release. However, for some of the objects that should be released, the message is missing. Still, Leaks Developer Tool does not show any leaks. How do I solve such situation?

How to debug memory leaks when Leaks instrument does not show them?

I am trying to log a long array so I can copy it quickly in my terminal. However, if I try and log the array it looks like:

    [&#39;item&#39;,
     &#39;item&#39;,
      &gt;&gt;more items&lt;&lt;&lt;
      ... 399 more items ]

How can I log the entire array so I can copy it really quickly? 

Content Type	Original Author	Original Content on Stackoverflow
Question	Vinicius Rocha	View Question on Stackoverflow
Solution 1 - C#	Mike Zboray	View Answer on Stackoverflow

Why I can not find "Debug Managed Memory" on Actions menu?

C# Problem Overview

C# Solutions

Solution 1 - C#

Handling null values in protobuffers

Need an array-like structure in PHP with minimal memory usage

Attributions