Tutorial by Examples: d

A shared_lock can be used in conjunction with a unique lock to allow multiple readers and exclusive writers. #include <unordered_map> #include <mutex> #include <shared_mutex> #include <thread> #include <string> #include <iostream> class PhoneBook { ...

std::call_once ensures execution of a function exactly once by competing threads. It throws std::system_error in case it cannot complete its task. Used in conjunction with std::once_flag. #include <mutex> #include <iostream> std::once_flag flag; void do_something(){ std::ca...

Kernel manages operating system resources. User program can only access to those resources by making system calls to the kernel. System call is similar to an API of kernel, which in term, runs kernel tasks your program needs. str = "something" // run on user space x = x + 1 // run on use...

Use top command to exam CPU time allocation between user space and kernel space. Explanation: 24.8 us (user space): 24.8% of CPU time is spent on user process. 0.5 sy (system): 0.5% of CPU time is spent on kernel space. ni (niceness): the ratio of CPU time spent on low priority processes. i...

using UnityEngine; using UnityEngine.Advertisements; public class Example : MonoBehaviour { #if !UNITY_ADS // If the Ads service is not enabled public string gameId; // Set this value from the inspector public bool enableTestMode = true; // Enable this during development #en...

Steps to copy heroku database to local database: 1. Run copy process in terminal: heroku pg:pull DATABASE_URL change_to_your_data_base_name --app change_to_your_app_name 2. Change db owner using this query: GRANT ALL PRIVILEGES ON DATABASE change_to_your_data_base_name to change_to_your_user; A...

Disabling calculation of the worksheet can decrease running time of the macro significantly. Moreover, disabling events, screen updating and page breaks would be beneficial. Following Sub can be used in any macro for this purpose. Sub OptimizeVBA(isOn As Boolean) Application.Calculation = IIf(...

$service = new NetSuiteService(); $search = new TransactionSearchAdvanced(); $internalId = '123';//transaction internalId $search->criteria->basic->internalIdNumber->searchValue = $internalId; $search->criteria->basic->internalIdNumber->operator = "equalTo"; ...

Dim duplicateFruits = New List(Of String) From {"Grape", "Apple", "Grape", "Apple", "Grape"} 'At this point, duplicateFruits.Length = 5 Dim uniqueFruits = duplicateFruits.Distinct(); 'Now, uniqueFruits.Count() = 2 'If iterated over at this poin...

You can define the signing configuration to sign the apk in the build.gradle file. You can define: storeFile : the keystore file storePassword: the keystore password keyAlias: a key alias name keyPassword: A key alias password You have to define the signingConfigs block to create a signin...

platform.ready().then(() => { // Okay, so the platform is ready and our plugins are available. // Here you can do any higher level native things you might need. var url= "https://blog.knoldus.com/"; var browserRef = window.cordova.InAppBrowser.open(url, &qu...

Instead of this (unfortunately too often seen in the real code) "masterpiece": function isEven(n) { return n % 2 == 0; } function isOdd(n) { if (isEven(n)) { return false; } else { return true; } } You can do the parity check much more effecti...

var a = 11, b = 22; a = a ^ b; b = a ^ b; a = a ^ b; console.log("a = " + a + "; b = " + b);// a is now 22 and b is now 11

We can create dynamic component and get the instances of component into an array and finally rendered it on template. For example, we can can consider two widget component, ChartWidget and PatientWidget which extended the class WidgetComponent that I wanted to add in the container. ChartWidget.ts ...

The Roslyn Quoter A tool for converting an sample C# program to syntax tree API calls. The tool itself can be found here. Enhanced source viewer An easy way to view the Roslyn source code can be found here.

Here we are having a list of todo items that is passed to the props of our component. Each todo item has a text and id property. Imagine that the id property comes from a backend datastore and is a unique numeric value: todos = [ { id: 1, text: 'value 1' }, { id: 2, te...

If you don't have unique database ids at hand, you could also use the numeric index of your array like this: render() { const { todos } = this.props; return ( <ul> { todos.map((todo, index) => <li key={ `todo-${index}` }> { todo.text } &...

app = QApplication( sys.argv ) box = QMessageBox() # Window Title box.setWindowTitle( "Hello World." ) # Icon: Information, Warning, Question, Critical box.setIcon( QMessageBox.Information ) # Short version of the information box.setText( "Hello World!" ) # Inform...

Add the hyperloop gem to your rails (4.0 - 5.1) Gemfile bundle install Add the hyperloop manifest to the application.js file: // app/assets/javascripts/application.js ... //= hyperloop-loader Create your react components, and place them in the hyperloop/components directory # app/hyperl...

class Hello < Hyperloop::Component # params (= react props) are declared using the param macro param :guest render do "Hello there #{params.guest}" end end # to "mount" Hello with guest = "Matz" say Hello(guest: 'Matz') # params can be giv...