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Questions tagged [asynchronous-programming]

The tag has no usage guidance.

1
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1answer
85 views

Refactor asynchronous code in C#

I got the following code snippet: public Task DistributeAsync(BankAccount account, decimal amount) { lock (account) { return repository.AddLoanAsync(account, amount).ContinueWith(task ...
0
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1answer
62 views

Binding to Task<T> property and seting IsAsync to true

I'm trying to figure out a good way to bind the view to viewmodel properties that needs to be populated using an async method. The latest I got is using IsAsync like so. ViewModel.cs public class ...
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0answers
52 views

Request for a service that takes a long time to execute

I'd like to train neural networks by making HTTP requests, which in turn train the model. Now, this might take a while with fetching data, processing, training and evaluating the network. I was ...
1
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2answers
68 views

Is it okay for async function to update a common object

I have a couple of functions, each function verifies a set of rules and updates a common object. The common object is just a container that holds a list of rules that passed or failed. I would like to ...
1
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2answers
280 views

Who did async/await first?

Python added the async/await constructs in 3.5 in 2015. The Javascript community made steps towards it for a bazzillion years and finally added a very similar implementation to the draft in ES8 ...
3
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1answer
89 views

Future/Promise objects in Controllers - Best practice - MVC

I was going through some articles related to Futures and Callables today and was thinking about the best practices when working in an MVC based environment. I was wondering, should one be creating ...
3
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3answers
95 views

How are new bounded contexts deployed, and bugs fixed, in message-driven “autonomous” microservice architectures?

I'm coming from the monolith background, using a single large relational database. From my research, many proponents of the microservice architecture favor the event-driven rather than REST driven ...
1
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1answer
90 views

sequential command processing with an async io cloud upsert

We are new to c# and still trying to grok the async idioms. We have a windows service that requires us to iterate a list of results queried from a PC database to feed the parse cloud server (which ...
2
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2answers
150 views

When consuming an api, what is a good way to deal with their request limits?

My app is consuming a third party api. One of the requirements of this api is that my app cannot send more than 20 requests per second. Because of the nature of this app, and because my user base is ...
3
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1answer
312 views

Is it generally bad to await async operations in background processing (not needing the result)

So I've been working with background processing and event-driven systems, namely Azure WebJobs and ServiceBus. And while there is extensive use of async/await programming, I'm always wondering if it ...
-1
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1answer
477 views

How to avoid synchronous communication between microservices

Let's say we're talking about a webshop. Microservice 1: Manages products and their prices Microservice 2: Responsible for payment and checkout. If a user wants to pay for a product, the payment ...
0
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0answers
87 views

How do I not lose the “reactive” nature of my services, simply because one of the services isn't reactive?

I've lately been very interested in reactive microservice design with streaming and event-driven architectures. When one writes (i.e., manages) services, this paradigm works extremely well by simply ...
3
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2answers
328 views

CQRS async query from command handler

In a CQRS/async microservices context, I have a command handler e.g. SendOrderConfirmationEmailCommandHandler implemented in a communications service. This depends on information from the orders ...
0
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2answers
161 views

When to check if the user is logged in?

I have an app with an optional login where some functionality requires the user to login. When checking if the user is logged in I use a framework that runs an async function that requests an access ...
3
votes
1answer
152 views

Design for avoiding concurrent calls to an interface implementation

The application I'm developing requires that some data is obtained through different channels. As this is a network process, I have decided to use async programming. I have designed the following ...
1
vote
1answer
43 views

How do I approach polyglot plugins for asynchrous python applications?

I've been looking at ways to let my app's users write plugins for it. However, to give them more options, I decided to implement a polyglot plugin system. From the engineering perspective there are ...
0
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0answers
41 views

Patterns for pre-emptive background work scheduling

Here is problem I hope the community can help me analyze: I want to execute a set of jobs with one background worker (or several). Whenever a job is done, a message is fired, and a listener on the ...
1
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1answer
120 views

How do I set up short-lived queues?

This scenario seems pretty ordinary, and yet, strangely, messaging systems (like Google Cloud PubSub and Task Queues and ActiveMQ) do not seem to support it -- they assume that topics/queues are long-...
0
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1answer
679 views

An elegant way to detect the end of an asynchronous recursive file search?

Given a recursive subroutine in single threaded environment which starts numerous asynchronous I/O operations and registers callback functions for each of them. This callbacks will be called on the ...
-1
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2answers
435 views

Straight line coding - How multithreading simplify asynchronous workflow?

Java author mentions: Threads can simplify the development of complex systems by turning complicated asynchronous code into simpler straight-line code. Again the book says: Threads make it easier to ...
3
votes
1answer
203 views

Composable asynchronous programming in Java without too much GC

Assume I'm writing a library in Java for performing network calls. I want it to be efficient for cases like highly loaded reverse proxies etc (10s to 100s Krps coming in and out; client requests ...
0
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1answer
607 views

Best practice to callbacks in OOP (JavaScript)?

For anyone who uses callbacks, how do I approach it when the method is an asynchronous setter? Here's an example class API { constructor() { this.token = null; } refreshToken(callback) ...
3
votes
1answer
15k views

Correct usage of async/await and Task.Run()

I am developing an application that will read excel files from disk and then process tests based on the data in the files. In order to keep the user interface from locking up when loading files and ...
5
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4answers
2k views

How do I know if my async function is truly asynchronous?

I'm writing a function in the node.js-style asynchronous way, but how do I know if these functions are truly asynchronous, i.e., that they run in parallel and not sequentially? Here is my code (...
4
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3answers
320 views

Is there a pattern for a chain of asynchronous calls, followed by a cleanup?

I have two asynchronous tasks that need to get completed - say they're "make a pie" (make) and "bake a pie" (bake). I also need to cleanup after everything's done - "clean the kitchen" (cleanup). bake ...
4
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3answers
713 views

Providing a non-blocking IO API in a C library

I am working on a C library (SlipRock) for interprocess communication. The library currently exposes a simple, blocking API. This is easy to use, makes misuse (relatively) difficult (this is C after ...
6
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3answers
790 views

Why do many languages semantically distinguish “async” functions from “non-async” ones?

I've seen this in C#, Hack, and now Kotlin: await or an equivalent operation can only be performed in special "async" contexts. Return values from these are, to borrow Hack's terminology, "awaitable" ...
4
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2answers
217 views

Design of asynchronous component

I'm trying to design an asynchronous component. Requirements on this component are : Component might receive events at any point in time Component might start a long-running operation and wait for ...
1
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0answers
71 views

Capturing keyboard events for a limited time

I'm trying to code a kind of simple video game where there are two kind of players: Human Players: They enter an keyboard input CPU Players: A random input is calculated For Human Players there is a ...
4
votes
1answer
103 views

Building objects from multiple async server queries

I'm building a system that uses objects that are built using multiple Async queries to a remote server (Firebase) and queries to a local DB. How should I design a module to generate these objects? ...
3
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1answer
106 views

How to document logical proofs against race conditions?

Specific Background I'm writing a library to extend the async backbone of a language with cooperative multitasking. (The language is Hack, but C# also implements async-await with Task, if the concept ...
3
votes
1answer
667 views

Task Parallel Library Console Application Design - How do I lock a thread to a specific context?

I'm currently developing an application which relies on multiple sockets listening for chat messages. When the messages come in, they're passed off to a bot that's associated with their channels. ...
2
votes
1answer
64 views

Asyncronous processes competing for the output area

You enter the URL in the address string of your browser. It takes long time to appear in the client area. You are bored and type another address instead and click enter. Which page will be rendered in ...
14
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3answers
19k views

Calling multiple async services in parallel

I have few async REST services which are not dependent on each other. That is while "awaiting" a response from Service1, I can call Service2, Service3 and so on. For example, refer below code: var ...
2
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1answer
631 views

Animations and React — is it bad practice to mix them?

I have been in arguments with programmers that mixing elements with animations and react is very bad practice, and that all animations should be in a style sheet because that is something ...
2
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3answers
105 views

Synchronising results from asynchronous tasks

In Android, I rather frequently need to get results from more than one service that utilizes an asynchronous callback pattern and I want to know if there's a better way to handle this pattern than ...
7
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1answer
420 views

API design: stream objects vs. functions vs. messages

I'm designing API for a python library that accepts asynchronous input and produces the asynchronous output: various signals come in, and various signals are generated in response (there's no one-to-...
3
votes
2answers
238 views

What to call a method that calls itself asynchronously?

In UI-related code, I often end up writing a construct like this: function doItOnceAndRepeat() { if (!stillNeededToDoIt()) { return; } doIt(); runLater(doItOnceAndRepeat, 1000)...
1
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1answer
2k views

Does omitting await keyword once in the call stack break the asynchronous behavior of the whole stack?

Call stack may contain several methods returning Task. If all of them are decorated with async, the flow of execution is quite simple. However, what if one of them is not awaited - are other method ...
1
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2answers
477 views

Why are Promises not “awaited” by default?

In the latest version of languages like TypeScript or ECMAScript you can use async/await constructs to write code that combines the clean structure of synchronous programming with the performance ...
1
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0answers
46 views

How to display a very delayed success message after async method call in WinForms after Form is closed

The users are on a Windows Form where they fill out a fax cover sheet and hit Send. The remote fax service takes anywhere from two seconds to two minutes to return a result (long timeout). By that ...
0
votes
1answer
531 views

Android Activitiy and Service Sync

I've looked for the solution of my problem but I've failed in finding a suitable answer. I've been trying to develop an Android application with heavy asyncronous networking capabilities. The problem ...
3
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1answer
289 views

What is the functional programming method for combining two “streams” of data?

I'm trying to figure out what the appropriate way to deal with this problem is in a functional way. I'm assuming there's a functional data structure or technique that will make this easy to handle. ...
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2answers
133 views

Designing an application with safe paralleled tasking

The title may have been a little vague... I am working on a piece of software that is designed to perform one task. I would like this task to work in parallel, allowing for multiple asynchronous ...
0
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0answers
49 views

How should I implement a real-time endpoint server to handle new posts and events for a forum?

I am writing a forum component for a site and decided on using either nio or twisted for a real-time endpoint to accept users posts and notify other users who are in the same forum or page of new ...
1
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1answer
369 views

Multi threaded and event driven [closed]

I got this problem in an interview and want to confirm multi threading adds no value here. Case: You are writing an agent to buy stocks. The agent is initialized with a set of stocks to buy when ...
1
vote
1answer
289 views

Need Async/Await equivalent for BackgroundWorker

Given the following code in the DoWork() event of a BackgroundWorker object, how can the concept be converted to the Async/Await model? I wish to execute multiple downloads simultaneously in order to ...
0
votes
1answer
92 views

What is the difference between running two blocks of code on the same thread and running them on two synchronous threads?

Suppose I have two blocks of code, A and B. A is to be executed before B. As I understand, I can do one of two things: 1) Put B in a separate thread that is to be executed after A's thread, or 2) Put ...
57
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8answers
9k views

Are events only used for GUI programming?

Are events only used for GUI programming? How do you handle in normal backend programming when something happens to this other thing?
2
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2answers
1k views

Using asynchronous calls for heavy IO operation: How to prevent crushing the CPU?

I have an application that reads a large binary file (1GB on average) and compresses into a bzip2 archive. I started out at first compressing these files synchronously, as I didn't want to impede ...