The solution for me was to make sure that my Profile scheme was using  the &quot;debug&quot; and not &quot;release&quot; build configuration. 

In Xcode 4 select Product/Edit Scheme from the top menu
then click on the &quot;profile&quot; button on the left. 
On the &quot;info&quot; pane you will see a setting for Build Configuration- set that to &quot;debug&quot;

This error is also thrown if you are trying to test your app on a device with a distribution profile selected. Make sure you have the correct code-sign settings for development.

You CAN profile the release build on the device.  What you have to do is build the release build with a developer certificate.  See [here](https://stackoverflow.com/questions/5442324/why-wont-instruments-execute-my-monotouch-application).

Instruments basically does its work by becoming the debugger for the app. If you can&#39;t run Xcode&#39;s debugger against it, then you can&#39;t run Instruments against it.

Mostly, entitlements need to be set to allow debugging.  

Sometimes after using XCode to debug apps, I find I can&#39;t use Instruments until I reboot the device.

Unlike XCode, Instruments can be confused between two apps with the same name, but different bundle IDs. (Or perhaps same name and similar bundle IDs.) When I have multiple versions of an app on a device, I often have to delete the extra to get Instruments to connect to the correct app. If you have one debug build and one release build, this could be the problem.

So, delete any duplicates of your app and restart the device.  (You could change the display name for release and debug build configurations.)

I&#39;ve got a couple small (500 or 600 lines of template code) Django sites, and I&#39;d like to migrate them to using Jinja2… But I&#39;d like to get some idea of how much work it will be. So, in general, about how much work is it to migrate a small Django site to Jinja2? And is it “worth it”?

Django: Switching to Jinja2?

What&#39;s the easiest way to do a JSON call from the command-line? I have a website that does a JSON call to retrieve additional data.

The **Request Payload** as shown in Google Chrome looks like this:

    {&quot;version&quot;: &quot;1.1&quot;, &quot;method&quot;:&quot;progr&quot;,&quot;id&quot;:2,&quot;params&quot;:{&quot;call&quot;:...} }

It&#39;s about doing the call from (preferably) linux command line and retrieving the JSON content, not about parsing the incoming JSON data.



How to do HTTP-request/call with JSON payload from command-line?

I&#39;m starting to use Instruments-Leaks with an iPhone 3G. When I try to run the app with Instruments on the iPhone I obtain

    Target failed to run: Remote exception encountered: &#39;Failed to get task for pid 280&#39;

Ideas?

The only time I succeed in running the app with instruments it run very slow, I couldn&#39;t test it. 
What are the steps to run the app on the device searching for leaks?


use instruments - leaks with a device

I'm starting to use Instruments-Leaks with an iPhone 3G. When I try to run the app with Instruments on the iPhone I obtain
<pre><code class="hljs language-vbnet">Target failed to run: Remote exception encountered: 'Failed to get task for pid 280'
</code></pre>
Ideas?
The only time I succeed in running the app with instruments it run very slow, I couldn't test it.
What are the steps to run the app on the device searching for leaks?

I have an `NSManagedObject` that has been deleted, and the context containing that managed object has been saved. I understand that `isDeleted` returns `YES` if Core Data will ask the persistent store to delete the object during the next save operation. However, since the save has already happened, `isDeleted` returns `NO`.

What is a good way to tell whether an `NSManagedObject` has been deleted *after* its containing context has been saved?

(In case you&#39;re wondering why the object referring to the deleted managed object isn&#39;t already aware of the deletion, it&#39;s because the deletion and context save was initiated by a background thread which performed the deletion and save using `performSelectorOnMainThread:withObject:waitUntilDone:`.)

How can I tell whether an `NSManagedObject` has been deleted?

I have a button of size width 200 and height 270. I want to have text and image on the same button. Not as a background image on that text. Instead of this, I want to display the text with height 120 and image of height 150 on the same button. How to do it?


UIButton with both image and text possible?

This is a follow-up to [How to get notified when a tableViewController finishes animating the push onto a nav stack.][1]

In a `tableView` I want to deselect a row with animation, but only after the tableView has *finished* animating the scroll to the selected row.  How can I be notified when that happens, or what method gets called the moment that finishes.

This is the order of things:

 1. Push view controller
 2. In `viewWillAppear` I select a certain row.
 3. In `viewDidAppear` I `scrollToRowAtIndexPath` (to the selected row).
 4. Then when that finishes scrolling I want to `deselectRowAtIndexPath: animated:YES`

This way, the user will know why they were scrolled there, but then I can fade away the selection.  
Step 4 is the part I haven&#39;t figured out yet. If I call it in `viewDidAppear` then by the time the tableView scrolls there, the row has been deselected already which is no good.

  [1]: https://stackoverflow.com/questions/4354678/how-to-get-notified-when-a-tableviewcontroller-finishes-animating-the-push-onto-a

How to get notified when scrollToRowAtIndexPath finishes animating

I&#39;m writing a web app to be used offline on iOS.  I&#39;ve created a manifest, am serving it up as `text/cache-manifest`, and it usually works fine, when running inside Safari.

If I add it as an app to my home screen, then turn on Airplane mode, it can&#39;t open the app at all -- I get an error and it offers to close the app.  (I thought this was the entire purpose of an offline app!)

 * When I load the app a first time when online, I can see in my logs that it&#39;s requesting every page listed in the manifest.

 * If I turn off Airplane mode, and load the app, I can see the first file it&#39;s requesting is my main.html file (which is both listed in the manifest, and has the `manifest=...` attribute).  It then requests the manifest, and all my other files, getting 200&#39;s for all (and 304&#39;s for anything requested a second time during this load).

 * When I load the page in Chrome, and click around, the logs show the only thing it&#39;s trying to reach on the server is &quot;/favicon.ico&quot; (which is a 404, and which I don&#39;t think iOS Safari tries to load, anyway).  All of the files listed in the manifest are valid and served without error.

 * The Chrome inspector lists, under &quot;APPLICATION CACHE&quot;, all the cached files I&#39;ve listed which I expect.  The entire set of files is about 50 KB, way under any limit on offline resources that I&#39;ve found.

Is this supposed to work, i.e., am I supposed to be able to create an offline iOS app using only HTML/CSS/JS?  And where do I go about figuring out why it&#39;s failing to work offline?


(Related but doesn&#39;t sound quite the same to me, since it&#39;s about Safari and not a standalone app: &quot;[Can&#39;t get a web app to work offline on iPod][1]&quot;)


  [1]: https://stackoverflow.com/questions/4230748/cant-get-a-web-app-to-work-offline-on-ipod

Offline iOS web app: loads my manifest, but doesn&#39;t work offline

Using the **CoreGraphics** framework is tedious work, in my honest opinion, when it comes to programmatically drawing a PDF file.

I would like to programmatically create a **PDF**, using various objects from views throughout my app.

I am interested to know if there are any good PDF tutorials around for the iOS SDK, maybe a drop in library.

I&#39;ve seen this tutorial, [PDF Creation Tutorial][1], but it was mostly written in C. Looking for more Objective-C style. This also seems like a ridiculous way to write to a PDF file, having to calculate where lines and other objects will be placed.


    void CreatePDFFile (CGRect pageRect, const char *filename) 
    {	
        // This code block sets up our PDF Context so that we can draw to it
        CGContextRef pdfContext;
        CFStringRef path;
        CFURLRef url;
        CFMutableDictionaryRef myDictionary = NULL;

        // Create a CFString from the filename we provide to this method when we call it
        path = CFStringCreateWithCString (NULL, filename,
                                          kCFStringEncodingUTF8);

        // Create a CFURL using the CFString we just defined
        url = CFURLCreateWithFileSystemPath (NULL, path,
                                             kCFURLPOSIXPathStyle, 0);
        CFRelease (path);
        // This dictionary contains extra options mostly for &#39;signing&#39; the PDF
        myDictionary = CFDictionaryCreateMutable(NULL, 0,
                                                 &amp;kCFTypeDictionaryKeyCallBacks,
                                                 &amp;kCFTypeDictionaryValueCallBacks);

        CFDictionarySetValue(myDictionary, kCGPDFContextTitle, CFSTR(&quot;My PDF File&quot;));
        CFDictionarySetValue(myDictionary, kCGPDFContextCreator, CFSTR(&quot;My Name&quot;));
        // Create our PDF Context with the CFURL, the CGRect we provide, and the above defined dictionary
        pdfContext = CGPDFContextCreateWithURL (url, &amp;pageRect, myDictionary);
        // Cleanup our mess
        CFRelease(myDictionary);
        CFRelease(url);
        // Done creating our PDF Context, now it&#39;s time to draw to it
        
        // Starts our first page
        CGContextBeginPage (pdfContext, &amp;pageRect);
        
        // Draws a black rectangle around the page inset by 50 on all sides
        CGContextStrokeRect(pdfContext, CGRectMake(50, 50, pageRect.size.width - 100, pageRect.size.height - 100));
        
        // This code block will create an image that we then draw to the page
        const char *picture = &quot;Picture&quot;;
        CGImageRef image;
        CGDataProviderRef provider;
        CFStringRef picturePath;
        CFURLRef pictureURL;
        
        picturePath = CFStringCreateWithCString (NULL, picture,
                                                 kCFStringEncodingUTF8);
        pictureURL = CFBundleCopyResourceURL(CFBundleGetMainBundle(), picturePath, CFSTR(&quot;png&quot;), NULL);
        CFRelease(picturePath);
        provider = CGDataProviderCreateWithURL (pictureURL);
        CFRelease (pictureURL);
        image = CGImageCreateWithPNGDataProvider (provider, NULL, true, kCGRenderingIntentDefault);
        CGDataProviderRelease (provider);
        CGContextDrawImage (pdfContext, CGRectMake(200, 200, 207, 385),image);
        CGImageRelease (image);
        // End image code
        
        // Adding some text on top of the image we just added
        CGContextSelectFont (pdfContext, &quot;Helvetica&quot;, 16, kCGEncodingMacRoman);
        CGContextSetTextDrawingMode (pdfContext, kCGTextFill);
        CGContextSetRGBFillColor (pdfContext, 0, 0, 0, 1);
        const char *text = &quot;Hello World!&quot;;
        CGContextShowTextAtPoint (pdfContext, 260, 390, text, strlen(text));
        // End text
        
        // We are done drawing to this page, let&#39;s end it
        // We could add as many pages as we wanted using CGContextBeginPage/CGContextEndPage
        CGContextEndPage (pdfContext);
        
        // We are done with our context now, so we release it
        CGContextRelease (pdfContext);
    }

**EDIT:** Here&#39;s an example on [**GitHub using libHaru**][2] in an iPhone project. 


  [1]: http://www.iphonedevsdk.com/forum/iphone-sdk-tutorials/10989-pdf-creation-tutorial.html
  [2]: https://github.com/akisute/iPhonePDF

iOS SDK - Programmatically generate a PDF file

Here are the facts:

- the language Go has a garbage collector. 

- Java has a garbage collection

- a lot of Java programs have (subtle or not) memory leaks

As an example of a Java program that has memory leaks (not for the faint of heart, the question may shake your beliefs), see here about a little Java program called Tomcat that even has a &quot;find leaks&quot; button: https://stackoverflow.com/questions/4565105

So I am wondering: will programs written in Go exhibit the same kind of (subtle or not) memory leaks that some programs written in Java exhibit?

Is Go subject to the same subtle memory-leaks that Java is?

I just came to realize, by reading some questions and answers on StackOverflow, that adding event handlers using `+=` in C# (or i guess, other .net languages) can cause common memory leaks...

I have used event handlers like this in the past many times, and never realized that they can cause, or have caused, memory leaks in my applications.

How does this work (meaning, why does this actually cause a memory leak) ?&lt;br/&gt;
How can I fix this problem ? Is using `-=` to the same event handler enough ?&lt;br/&gt;
Are there common design patterns or best practices for handling situations like this ?&lt;br/&gt;
Example : How am I supposed to handle an application that has many different threads, using many different event handlers to raise several events on the UI ?

Are there any good and simple ways to monitor this efficiently in an already built big application?


Why and How to avoid Event Handler memory leaks?

This question is for anyone who&#39;s ever tested the &quot;Find leaks&quot; button in the Tomcat manager and got some results like this:

&gt; The following web applications were stopped (reloaded, undeployed), but their classes from previous runs are still loaded in memory, thus causing a memory leak (use a profiler to confirm): &lt;br&gt;
&gt; /leaky-app-name

I&#39;m assuming this has something to do with that &quot;Perm Gen space&quot; error you often get with frequent redeployments.

So what I&#39;m seeing in jconsole when I deploy is that my loaded classes goes from about 2k to 5k. Then you would think an undeployment should drop them back down to 2k but they remain at 5k.

I&#39;ve also tried using the following JVM options: 

`-XX:+CMSClassUnloadingEnabled -XX:+UseConcMarkSweepGC -XX:+CMSPermGenSweepingEnabled`

I did see VERY minor dips in the amount of Perm Gen space used but not what I expected and the loaded class counts did not drop.

So is there a way to configure Tomcat or design your app to unload better on an undeployment? Or are we stuck with restarting the server after some major debugging sessions?

Tomcat version output:

&gt; Server version: Apache Tomcat/6.0.29 &lt;br&gt;
&gt; Server built:   July 19 2010 1458 &lt;br&gt;
&gt; Server number:  6.0.0.29 &lt;br&gt;
&gt; OS Name:        Windows 7 &lt;br&gt;
&gt; OS Version:     6.1 &lt;br&gt;
&gt; Architecture:   x86 &lt;br&gt;
&gt; JVM Version:    1.6.0_18-b07 &lt;br&gt;
&gt; JVM Vendor:     Sun Microsystems Inc. &lt;br&gt;

**Update:**

Thanks to celias&#39; answer I decided to do a little more digging and I think I determined the culprit to be in my application thanks to CXF, Spring and JAXB.

After I learned how to profile a Java application, I pointed the profiler at Tomcat and took some heap dumps and snapshots to see what the objects and classes looked like in memory. I discovered that some of the enumerations from my XML schema used in my CXF/JAXB (wsdl2java) generated classes were lingering after an undeployment. According to my heap dump it looks like the objects were tied to a Map. Disclaimer: I admit I&#39;m still a little green with profiling and tracing an object&#39;s call tree can be challenging in Java.

Also I should mention that I didn&#39;t even invoke the service, just deployed then undeployed it. The objects themselves appeared to be loaded via reflection initiated from Spring on deployment. I believe I followed the convention for setting up a CXF service in Spring. So I&#39;m not 100% sure if this is Spring/CXF, JAXB, or reflection&#39;s fault.

As a side note: the application in question is a web service using Spring/CXF and the XML happens to be a rather complex schema (an extension of [NIEM][1]).


  [1]: http://www.niem.gov/implementationguide.php

Is there a way to avoid undeployment memory leaks in Tomcat?

In Linux, I have been using valgrind for checking if there are memory leaks in an application. What is the equivalent in Windows? Can this be done with Visual Studio 2010?


Finding memory leaks in a C++ application with Visual Studio

I am using Red Gates ANTS memory profiler to debug a memory leak. It keeps warning me that:

&gt; Memory Fragmentation may be causing
&gt; .NET to reserver too much free memory.

or

&gt; Memory Fragmentation is affecting the size of the largest object that can be allocated

Because I have OCD, this problem must be resolved. 

What are some standard coding practices that help avoid memory fragmentation.
Can you defragment it through some .NET methods? Would it even help?

What causes memory fragmentation in .NET

so--i switched on &quot;color misaligned images&quot; to improve drawing performance in our app. The documentation states: 

&gt; Puts a magenta overlay over images
&gt; whose source pixels aren&#39;t aligned to
&gt; destination pixels

I don&#39;t know what the yellow means however. (There is a &quot;Color Offscreen-Rendered&quot; option that uses yellow... does &quot;Color Misaligned Images&quot; also turn on this option?)

Anybody know?

TIA

What does yellow tinting represent when using &quot;color misaligned images&quot; on iPhone/iOS

Of all the Instruments Trace Templates, I love using:

* Zombies to detect where an object is getting over-released, great for debugging `EXEC_BAD_ACCESS` errors.
* Leaks to detect memory leaks.
* Core Animation w Color Blended Layers to detect frame rate &amp; translucent subviews, great for smoothing up `UITableView` scrolling.

I always hear people saying to profile my app&#39;s memory usage &amp; performance.

1. Why should I profile memory usage &amp; performance? My app runs fine.
2. How do I do it?

I&#39;ve used Allocations and see that my iPhone app starts at 1 MB total allocated memory and grows to 5 MB after normal usage. What is too high amount of memory usage on the iPhone? iPad? Mac?

How to profile memory usage &amp; performance with Instruments?

If I open Instruments and select a standard application (e.g. Mail or MS Word) it has no issue. 
If I am in Xcode and I go to **Product &gt; Profile** (or press &lt;kbd&gt;Cmd&lt;/kbd&gt; + &lt;kbd&gt;I&lt;/kbd&gt;), it launches Instruments, allows me to select a template, and loads the standard screen. Then the downward arrow starts tracing to the right as it should, and the iOS simulator launches the program. However, nothing is plotted in Instruments. It shows no changes to anything no matter what the app is doing. I can&#39;t click anything in Instruments: no menu&#39;s, can&#39;t stop recording, can&#39;t open tabs, etc. 

I randomly discovered that if I hit &lt;kbd&gt;Cmd&lt;/kbd&gt; + &lt;kbd&gt;Tab&lt;/kbd&gt;, Instruments will start behaving normally. This seems really strange to me. Either it&#39;s a bug or it&#39;s a hole in my knowledge about how to operate Instruments. 


Instruments 4.1 unresponsive to projects launched from Xcode 4.1 until pressing Cmd-Tab

I&#39;ve created a simple javascript for my `iOS` app that I&#39;d like to run simultaneously on multiple `iOSDevices` connected via USB to one host Mac machine. Launching instruments connected to an `iPhone` from the command line works fine but if I attempt to launch a second instruments connected to an `iPad`, the first instruments session hangs.  


----------


Upon terminating the first instruments session, I get one of more of the following lines printed:

&gt; Stopped: Script stopped due to device being disconnected

After extensive research on the subject, with no results on the phrase, I&#39;ve been trying to read into what is meant by Apple&#39;s Instruments Guide:

&gt; When you choose All Processes, Attach to Process, or Choose Target from the Target menu, Instruments sets the default target for all instruments to the program you choose. There are occasions, however, when you might want to set a different target for each instrument. You might want to sample two different programs at the same time, for example, using the Sampler instrument. If you have some instruments that are capable of tracing all processes, you might want them to do just that while single-process instruments sample just one process.

I&#39;m wondering if the `Automation.tracetemplate` is a single-process only instrument and that if another process is started with the same Automation trace then the first is usurped.

Any advice would be grateful as this is a major block for running our time intensive automation tests over multiple `iOSDevices`.


----------


**Update 27 Mar 2012**

The following is from an email received after submitting a bug to Apple on the matter (developer.apple.com/bugreporter):

&gt;I heard back from a UI Automation engineer. UI Automation is a single process Instrument. As such, you cannot use it simultaneously on multiple devices.


Instruments automation trace only allows one target connection?

Is it possible to track the allocation and deallocation of my Objective-C objects? For instance if I have a class Book, I want to track all the allocations and deallocations of the objects of Book type. I can track all the default SKD classes, such as UIViewController, UIWindow, UIView, NSDictionary and all that, but I want to track also the objects that are created from my defined classes.

Instruments Allocations track alloc and dealloc of objects of user defined classes

I tried to install Valgrind with `brew install Valgrind` and got  :

    valgrind: This formula either does not compile or function as expected
    on macOS versions newer than Sierra due to an upstream
    incompatibility. 
    Error: An unsatisfied requirement failed this build.

I tried  `brew install --HEAD Valgrind`. 

Instead, after successfully installing the dependencies `autoconf`, `automake` and `libtool`, when it tries to install valgrind, I get a configure error:

    Valgrind works on Darwin 10.x, 11.x, 12.x, 13.x, 14.x, 15.x, 16.x and
    17.x (Mac OS X 10.6/7/8/9/10/11 and macOS 10.12/13)

My OS is macOS Mojave(10.14), so does it mean that I can&#39;t install a functioning Valgrind with Homebrew presently?

Content Type	Original Author	Original Content on Stackoverflow
Question	Sefran2	View Question on Stackoverflow
Solution 1 - Ios	Peter Johnson	View Answer on Stackoverflow
Solution 2 - Ios	rectWare	View Answer on Stackoverflow
Solution 3 - Ios	William Jockusch	View Answer on Stackoverflow
Solution 4 - Ios	Walt Sellers	View Answer on Stackoverflow

use instruments - leaks with a device

Ios Problem Overview

Ios Solutions

Solution 1 - Ios

Solution 2 - Ios

Solution 3 - Ios

Solution 4 - Ios

How to do HTTP-request/call with JSON payload from command-line?

Django: Switching to Jinja2?

Attributions