object,null,garbage-collection,c++-cx,pin-ptr , How can I save a object, so that it won't get collected by the GC in C++/CX


How can I save a object, so that it won't get collected by the GC in C++/CX

Question:

Tag: object,null,garbage-collection,c++-cx,pin-ptr

This is the code that I have for the constructor:

LmiVideoCapturer* LmiVideoCapturerConstruct_(LmiVideoCapturer* x, const void* implementation)
{
std::vector<LmiVideoCapturerInfo> &deviceList = LmiVideoCapturerDeviceList::Instance();
LmiVideoCapturerInfo &capturerInfo = LmiVideoCapturerInfo();
for (std::vector<LmiVideoCapturerInfo>::iterator it = deviceList.begin(); it != deviceList.end(); it++){
    if (LmiStringCompare(&it->uniqueId, &x->uniqueId) == 0){
        capturerInfo = *it;
        break;
    }
}

if (capturerInfo.uniqueId.size > 0){
    x->isBuiltin = LMI_TRUE;

    // set basic device info 
    LmiStringAssign(&x->name, &capturerInfo.name);
    LmiStringAssign(&x->model, &capturerInfo.model);
    LmiStringAssign(&x->manufacturer, &capturerInfo.manufacturer);
    x->position = capturerInfo.position;

    // set video capabilities
    LmiAllocator *a = LmiMallocAllocatorGetDefault();
    Platform::String ^deviceId = LmiStringWinRTString(&capturerInfo.uniqueId, a);
    XTRACE(L"=========================Will call from LMIVideoCapturerConstruct\n");
    LmiVideoCapturerWinRTImplementation ^impl = ref new LmiVideoCapturerWinRTImplementation(deviceId);
    if (impl->Initialize()){
        //TODO will need to save impl inside a pin_ptr (pinned pointer) so it will not be deconstructed by the GC
        x->implementation = reinterpret_cast<void*>(impl);
        LmiVideoCapturerCapability capability;
        LmiVideoCapturerCapabilityConstructDefault(&capability, a);
        capability.height = impl->encodingProfile->Video->Height;
        capability.width = impl->encodingProfile->Video->Width;
        LmiMediaFormat format; 
        LmiMediaFormatConstructFromNative(&format, impl->encodingProfile->Video->ProfileId);
        LmiVectorPushBack(LmiMediaFormat)(&capability.formats, &format);
        double usecs = ((double)impl->encodingProfile->Video->FrameRate->Denominator / impl->encodingProfile->Video->FrameRate->Numerator) * LMI_USECS_PER_SEC;
        LmiTimeRange range;
        LmiTimeRangeConstruct(&range, LmiTimeUsecs(usecs), LmiTimeUsecs(usecs));
        LmiVectorPushBack(LmiTimeRange)(&capability.ranges, &range);
        LmiVectorPushBack(LmiVideoCapturerCapability)(&x->capabilities, &capability);

        return x;
    }

}

return nullptr;

}

Now I want to save "impl" somewhere, thats why I saved it in X that I will return at the end of the function. BUT as soon as this function is ended, a GC calls the deconstructor for this object. How can I set this object to be avoided by the GC, when it is called?

EDIT: After hours of searching on the internet I noticed that c++ has something called pinned pointers (pin_ptr) but all the examples I found on it, shows saving arrays of int inside. Is it possible to save a object inside a pinned pointer?


Answer:

There is no garbage collection in C++/CX.

The LmiVideoCapturerWinRTImplementation^ impl variable you defined is a smart pointer type that will automatically manage the lifetime of the object for you. More information on C++/CX types can be found here: http://blogs.msdn.com/b/vcblog/archive/2012/09/17/cxxcxpart02typesthatwearhats.aspx


Related:


Object property is undefined


javascript,object,gulp
I don't know if I'm missing something here, but for some reason a configuration object I create is always undefined upon using: gulpfile.config.js var config = { src_path: "Client/" }; gulpfile.js var config = require("./gulpfile.config.js"); gulp.task("test", function() { util.log(config.src_path); // results in 'undefined' }); Do objects have to be initialized...

Filter array of objects with another array of objects


javascript,jquery,arrays,object,filter
This question is similar to this one Jquery filter array of object with loop but this time I need to do the filter with an array of objects. Exemple: I have an array of objects like this: myArray = [ { userid: "100", projectid: "10", rowid: "0" }, { userid:...

Use of self when creating objects in Python


python,object,self
I made several classes which are doing the same thing, but I still don't completely understand the difference, and which is best to use. Also, the 4th object is not working. It says 'NameError: name 'self' is not defined', although I don't understand what is going wrong. This is what...

Is it possible to create a queue of object arrays in C++?


c++,arrays,object,queue
For example: class Hooks { public: std::string text; std::string hookfont; HookFromEncouter() { text = "Would you befriend an elf? "; hookfont = "COPRGTB.ttf"; } HookFromEncouter(string text1, string hookfont1) { text = text; hookfont = hookfont1; } }; I need to store arrays of this object in a queue: How do...

ActionScript: How to call an objects function within an array?


arrays,flash,object,actionscript
In Java it is possible to set the datatype of an array, and by setting the datatype to the object I am using, I can call the methods and variables of that object. For instance: ArrayList<Object> name = new ArrayList<Object>(); name.add(new Object(variables)); name.get(0).method; Is there any way I can do...

Sort when values are None or empty strings python


python,list,sorting,null
I have a list with dictionaries in which I sort them on different values. I'm doing it with these lines of code: def orderBy(self, col, dir, objlist): if dir == 'asc': sorted_objects = sorted(objlist, key=lambda k: k[col]) else: sorted_objects = sorted(objlist, key=lambda k: k[col], reverse=True) return sorted_objects Now the problem...

Empty object in Javascript


javascript,object
I have a weird situation. I take some values from a form and save it in an object. I print out the values and it prints fine to the console log. But when I try to access it or print again in next line. It returns empty. Here is the...

Javascript Sorting Array of Objects [duplicate]


javascript,arrays,sorting,object
This question already has an answer here: Sorting an array of JavaScript objects 14 answers (Please excuse any errors - this is my first post and I am also relatively new to Javascript) I'm trying to sort an array of objects by a specific property value in Javascript. I...

Object.length undefined in javascript [duplicate]


javascript,arrays,object
This question already has an answer here: Length of a JavaScript object (that is, associative array) 21 answers I have an javascript object of arrays like, var coordinates = { "a": [ [1, 2], [8, 9], [3, 5], [6, 1] ], "b": [ [5, 8], [2, 4], [6, 8],...

meaning of the super keyword in the parent class python


python,object,super
I do not understand the meaning of the super keyword when it is not used in a child class. The question comes from this class here that I found on a git hub project where I am working (the link is https://github.com/statsmodels/statsmodels/pull/2374/files) Look for example at the fit method where...

Avoid EF update the null image to database in .Net MVC


asp.net-mvc,entity-framework,null,edit,httppostedfilebase
In my SachController, there is an Edit method like below. In the view, there are several textbox and one file-input for upload image object. Sometime, user doesn't want to change the image and they just don't select a new image. And the image (HttpPostedFileBase) is null. How can I avoid...

Excel vba code using ThisWorkbook.Sheets(1).Range not working, but Sheet1.Range works fine. Why?


excel,vba,excel-vba,object
When I use wb.Sheets(1).Range("A:A").Find(What:=ID, LookIn:=xlValues) I get error 91 - Object Variable or With Block not set. When I use Sheet1.Range("A:A").Find(What:=ID, LookIn:=xlValues) it returns correct value. Why the difference? Is there a flowchart I can reference or any simple information available to understand which sub-commands (I don't know the proper...

Changing the property values of an object in an array using another property value


javascript,arrays,object
I have an array as below. What I'd like to implement is a function that takes the node's ID, x and y as its inputs and make changes accordingly in the array. var nodes = [{ID:"101", x:100, y:200} ,{ID:"102", x:200, y:200} ,{ID:"103", x:300, y:300} ,{ID:"104", x:200, y:300}]; For example, function...

Spawn random objects without overlapping (Java)?


java,object,overlap,spawn
I'm developing a game in Java, and part of it requires that objects spawn at the top of the screen and proceed to fall down. I have three objects that can possibly spawn, and three possible x coordinates for them to spawn at, all stored in an array called xCoordinate[]....

Creation of object using abstraction fails, likely a simple fix I cannot see


java,object,constructor,abstraction
A novice question about abstraction and constructors. I feel like I'm missing something obvious. I have an abstract class Piece, this is the constructor: public abstract class Piece { private int[] location = new int[2]; private final char color; public Piece(char color, int[] location) { this.location = location; this.color =...

Parsing JSON object within a JSON response [duplicate]


javascript,json,object
This question already has an answer here: Access / process (nested) objects, arrays or JSON 6 answers I'm trying to get a bit of javascript working to pull back a currency conversion. Using the API from fixer.io, I'm requesting http://api.fixer.io/latest?symbols=USD&base=GBP I get an object back, but I don't know...

How to get the public objects


php,object,guzzle,rackspace-cloud,rackspace
I'm working on PHP with Rackspace API, this is what I have used here: $file->setContent(fopen('sites/default/files/rackspace/' . $end_element, 'r+')); $cdnUrl = $file->getPublicUrl(); print_r($cdnUrl); And its returning me the below mentioned structure. Guzzle\Http\Url Object ( [scheme:protected] => http [host:protected] => something.r2.cf3.rackcdn.com [port:protected] => [username:protected] => [password:protected] => [path:protected] => /something-abc.jpg [fragment:protected] =>...

Object returns null


java,object,null
Summary: New to Java, tried looking through other posts but didn't find an answer. I'm learning inheritance and have an AddressBook class extended by a Runner class. When I write a program to test the inheritance I create a Runner object. If I get the first String parameter it returns...

Access object variables dynamically in php


php,object
There are multiple response type from my service provider and that is why i created a config array like below. $configArray = array( 'type_1' => array( 'name' => array('parent', 'user', 'profile', 'name', 'fullName') ), 'type_2' => array( 'name' => array('parent', 'person', 'info', 'basic', 'name') ) ); So if the return...

c++: Passing objects to functions


c++,templates,object
I was going through a code where I encountered some problem and was able to crack this piece of code: #include <iostream> #include <stdint.h> #include <unistd.h> #include <errno.h> #include <vector> #include <sys/types.h> using namespace std; class abc { public: abc(int x,int y) { cout << "x:" << x << endl;...

How to iterate an object and build a new one


javascript,object,nested
I am using JavaScript to iterate customers in an object which is constructed as follows: [ { "customer": "Customer 1", "project": "1" }, { "customer": "Customer 2", "project": "2" }, { "customer": "Customer 2", "project": "3" } ] I wish to build a new object in iteration which would be...

Don't run Object animator [closed]


java,android,object,objectanimator,animator
Why this code don't run? When run the app, i faced with stopped app error message.. ImageButton img=(ImageButton)findViewById(R.id.img0); ObjectAnimator[] imganim = new ObjectAnimator[10]; imganim[0].setTarget(img); ...

Object Read-Only Properties


javascript,object
I was reading this question about read-only properties, and I came upon this snippet: var myObject = { get readOnlyProperty() { return 42; } }; alert(myObject.readOnlyProperty); // 42 myObject.readOnlyProperty = 5; // Assignment is allowed, but doesn't do anything alert(myObject.readOnlyProperty); // 42 Now, I know to hide the scope, you...

Dynamic creation of objects vs storing them as fields


java,performance,object
I have this loop which runs about 1,000,000 times. while ((line = br.readLine()) != null) { if(!(line.isEmpty())){ data = new JSONObject(line); name = (String)data.get("name"); surname = (String)data.get("surname"); ar.put(name, surname); //an array } } What are the advantages (if any) in terms of efficiency of having it like that were data,name...

Search inside objects javascript


javascript,object,firebase
I'm experimenting on login with firebase. I can make an account, and it'll store additional information too. The problem is retrieving this information. I can get it using: usersRef.on("value", function(snapshot) { console.log(snapshot.val()) }, function (errorObject) {...}); When I do this I get two things (because I have two accounts): -JrrzEOqZQU0HVeYVXCm:...

Trying to get property of non-object (valid json) [duplicate]


php,json,object
This question already has an answer here: How can I access an array/object? 3 answers Just a real quick question please, I have this string that came from my query I am able to display the string using xx = dd($sumx) which gave me the string below: string(124) "[{"total":-4107717.58,"alerx":4,"currentYear":-4107717.58,"lastYear":0,"date":2015,"value":{"debit":0,"credit":4107717.58}}]"...

How do I remove duplicate objects in an array by field in Javascript?


javascript,arrays,sorting,object
I have an array of objects: [{ id: 1, name: 'kitten' }, { id: 2, name: 'kitten' },{ id: 3, name: 'cat }] How do I remove the second kitten? Sorting into an array of names doesn't work, because I can't know if I am deleting id 1 or or...

Extending JFrame - how does “super” keyword work?


java,object,jframe,super
I've made a class that extends JFrame, and in my classes constructor, to set the title I can either use: super("title"); setTitle("title"); or just create a JFrame object i.e: JFrame f = new JFrame("title); How does the compiler differentiate from all of these to conclude the same thing? I know...

Swift won't allow me to use `!=`


ios,swift,if-statement,null
Currently trying to check if three values, that I just converted from Strings to doubles, are nil from the UITextFields aValue, bValue, and cValue. I don't get a compile error from these variables until the if statement at the bottom of the code block (shown below) where it causes a...

Object Variable or With Block Variable Not set in loop using find function


vba,excel-vba,loops,object,find
Sub Main() Dim FName As Variant, R As Long, DirLoc As String, i As Integer R = 1 i = 1 DirLoc = ThisWorkbook.Path & "\" 'location of files FName = Dir(DirLoc & "*.csv") Do While FName <> "" ImportCsvFile DirLoc & FName, ActiveSheet.Cells(R, 1) R = ActiveSheet.UsedRange.Rows.Count + 1...

Object declaration in C++


c++,object,constructor
I have two questions about the following code in c++. What does the line A obj() in main() mean? Its not giving any error. And why does the next line obj.fun(); give the following error? request for member 'fun' in 'obj', which is of non-class type 'A()' The code is:...

In Java, How do I cast a Realm Object into the class I wish to write to the Database?


android,class,object,casting,realm
I am currently working on a project where my Database has a very large number of tables (Approx 60 total). I am working to create the Database Helper class that will function as the writer/ reader to/ from the database. And example of my write method would be this: public...

Dynamically create all objects contained in file


java,object,dynamically-generated
I am developing a program to mark algorithms submitted by a group of students; each student will submit their own .java files. I would like to place these .java files into a folder and run my program. My program would then instantiate each class in the folder and add it...

Multiple NULL addition into a List in Java


java,list,concurrency,null,add
I have 2 lists and want to copy some element from one to another, i.e. there are old and new employees list I need to union 2 lists and delete the elements that include to the old list but not include in the new one. I could solve the part...

Creating javascript dates object


javascript,date,object
I am trying to create an object with all the dates from "today" until 60 days from now. My code: var dates = []; getDateRange(); function getDateRange() { var today = new Date(); var date = new Date(); for (var i = 0; i <= 59; i++) { date.setDate(today.getDate()+i); console.log(date);...

Need help converting JSON to C# Objects


c#,asp.net,json,object,serialization
I'm currently trying to convert a JSON string into C# objects and currently am experiencing trouble during my debugging. Below is a sample of the JSON along with my classes. Classes public class Timeline_RootObject { public List<Timeline_Frame> frames { get; set; } public int frameInterval { get; set; } }...

Return two separate arrays from an object in JavaSript


javascript,arrays,object
I need to complete the keysAndValues function so that it takes an object and returns the keys and values as separate arrays. For example: keysAndValues({k: 11, l: 12, m: 13}) // should return [['k', 'l', 'm'], [11, 12, 13]] I have already tried: http://jsfiddle.net/marcusdei/ppfh5fpa/4/...

getting access to javascript object property beginning with number


javascript,object
I am calling an api which returns an object var rain = data[i].rain; $.get( "http://api.openweathermap.org/data/2.5/forecast?q=London,uk&mode=json&units=metric", function( data ) { var data = data.list; for(var i = 0; i < 12; i++){ var rain = data[i].rain; console.log(rain) } }); rain returns the following when I inspect the console: Object {3h: 0.005}...

Differences between null and StringUtils.isBlank()


java,null
I want to check if a String is empty or not and I would like to know the differences between the following and which one is better and on which occasions. Specially because I'm getting this error if I use "isNotBlank": "cannot be cast to java.lang.String". this.text.getData() != null <---...

Jackson - Extract Data without Brackets, Commas, and =?


java,json,object,jackson,jackson-modules
I don't know a ton about Jackson, I'm just using it because I needed to share data from Python to Java. Anyway my code is pretty simple ObjectMapper mapper = new ObjectMapper(); Map<String,Object> data = mapper.readValue(new File(FileName), Map.class); System.out.println(data.get("SomeInput")); This is what I'm getting: {Y=0.830168776371308, Z=0.16877637130801687, X=0.0010548523206751054} I really just...

Run class methods in different threads


java,multithreading,object,methods
Let's suppose I have this class: public class Myclass { method1(); method2(); method3(); } I want to know if there's a way to run all 3 methods in different threads simultaneously. Is there a way to create a class MyThread : public class MyThread{ //implementation } in way that it...

Java- HashMap.get returns null when it shouldn't


java,android,null,hashmap
I am using a HashMap to link some strings to integers, which are then used to index a list. The strings I am using in .get() are passed to a method, from an android spinner, and are definitely correct as I outputted them to the log, and they match those...

Persist Object's value after copying in Java


java,object
My sample code - private final DataObj dataObj = getDataObjs(); private final DataObj dataObj1 = new DataObjImpl(); dataObj1 = dataObj; //I need the value of dataObj1 to be the same even if the value of dataObj is modified anywhere further down in a class. My problem is that if the...

Javascript - accessing an object with duplicate names


javascript,arrays,xml,object
I have an XML file that I read in to a Javascript object. This is called jsonXML. I can see the object in its entirety in the console when I log it. It is a pretty complex object with a lot of layers and duplication. I need to access some...

Socket.io error in sending arrays


javascript,arrays,object,socket.io
I have 3 variables to send to the client using socket.io, namely, mapRes & location. server.js var mapRes = {width : 720, height: 1040}; var location = [{x:100,y:100,z:100},{x:200,y:200,z:200}]; var obj = {'1':{x:100,y:200}}, '2':{x:200,y:100}}; io.on("connection", function(socket){ socket.emit("mapRes",mapRes); socket.emit("location",location); socket.emit("object",obj); } client.html socket.on('mapRes',function(message){ var mapRes = message; console.log(mapRes); }); socket.on('location',function(message){ var location...

Get and add all properties of type Mname from a list of objects and add them dynamically too a drop down


c#,linq,list,object,properties
Ok so I have an object type called monsters and a list of all monsters I need to get all the strings from the property called MName and add each one to a Drop down text box. here is the class so far.(sorry Im really new to coding.) using System;...

Is a Java class variable a reference to a class object?


java,class,object,reference
I know such question has been asked before but I couldn't find a satisfactory answer. Assume a java class : class Foo{ public int k; Foo(int a){ k=a; } } class My{ public static void main(String args[]){ Foo obj = new Foo(5);//1 obj=new Foo(8); //2 } } I want to...

I'm using AngularFire, How can I retrieve this “email”, “uid” data?


angularjs,object,firebase,angularfire
JS CODE var myFirebaseRef = new Firebase('https://blinding-inferno-7068.firebaseio.com/'); var createdUserRef = myFirebaseRef.child('users').child('createdUser'); $scope.users = $firebaseArray(createdUserRef); HTML CODE <ul ng-repeat="user in users"> <li>{{user.uid}}</li> <li>{{user.email}}</li> <li>{{user}}</li> </ul> What I wanted was user.uid and user.email, but those thing didn't come out. So I checked the user object, and these things came out....

Matlab - object orientated with abstract Interface - How creating object?


matlab,object
Hello lovely community, i am quite new here, but still hope someone can help me out. I just worked a bit with Matlab in the past and want to do a new project. Earlier I just stored all in one Matlab file and didn't had the need to use classes....