Questions tagged [async]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
-3
votes
1answer
103 views

Why isn't JavaScript always async? [duplicate]

In JS, code runs single-threaded, that's why asynchronicity is necessary. I cannot use code like result = someRequest(), instead I need to give it a callback someRequest(resultCallback) or write a ...
2
votes
2answers
128 views

Should I create two synchronous or a single asynchronous rest APIs?

Here is the situation. System A sends the notification as it completes the work items to System B. System A does not know how many items the project consists of. It's just a pass-through system. ...
-2
votes
2answers
232 views

Measuring async/await overhead

A while ago I read an article stating that overhead of an async/await call was around 50ms. More recently I read an article that it was around 5ms. I was having a discussion about whether we should ...
1
vote
3answers
317 views

Is it bad practice to do additional work in IAsyncEnumerable generator method?

Imagine you have to process each row in a large table. For every single row you have to download some data from a web service and store it in a different database. Loading all rows at once into the ...
-3
votes
1answer
57 views

How does a site API determine the difference between a user and program request in a browser?

So this is in regards to scraping yes; no language in particular. Some sites allow you to see a JSON modal if you pull it directly from a web browser. But, at any notion a program is used, immediately ...
0
votes
2answers
141 views

Why/When do we need to call an async method from a sync method?

It is my first question here so I hope I'm not doing a mistake. I see a plethora of questions in SO that people ask "how can I call an async method from a sync method?". Given my little ...
1
vote
1answer
117 views

C# design for handling a high rate of async network operations that complete with a callback (hundreds per second)

I am working with a message broker technology, to which events will be published (following an "event carried state transfer" architecture) for consumption by other applications. The vendor ...
1
vote
1answer
159 views

C#: Should I define methods as async?

I have a C# (WPF) application which consumes a particular 3rd party API/tool (let's call this Tool A). My colleagues and I are trying to decouple that from our application, so that it is possible to ...
2
votes
1answer
202 views

What are the different messaging patterns for multiple producers to single consumer through a distributed queue?

We have multiple producers that publish messages to the same SQS queue. We have a single consumer that processes the messages. The producers do not care about the response. It is more like a broadcast ...
-2
votes
1answer
155 views

Designing a sqlite component in C++

I work on a small component in an embedded device (sensor). This component : Every 5 seconds, sends requests to other components using sockets (get health check status, operating status etc) and ...
1
vote
1answer
486 views

Why no async functions for Utf8JsonReader and ReadOnlySequence

I have used Utf8Json a lot (it is very good) but have since adapted some lower level code and started using Utf8JsonReader directly. Looking into the code of the Utf8Json library, I see ...
-2
votes
2answers
159 views

Async Value Object Creation (DDD)

Suppose that I have a Value Object representing an Image URL of a Cake. To check that it really is a cake, I make an asynchronous API call to a server that checks whether the image really represents ...
3
votes
3answers
193 views

Issues with an interface treating a synchronous action as async

Let's say I'm trying to write a library that abstracts certain actions. In this example I want to turn a light on or off. There could be hundreds of different kinds of lights that are controlled in ...
0
votes
1answer
75 views

Organizing Parallel Arrays of Promises / Async tasks

I'm struggling a bit for a preferred way to organize a sequence of asynchronous tasks that can be applied in parallel. Say, you are parsing data from many files. In my case I'm using javascript and ...
4
votes
3answers
393 views

How does an hexagonal architecture help with async/await async-over-sync?

In his book "Concurrency in C# Cookbook", Stephen Cleary writes: If you can, try to organize your code along modern design guidelines, like Ports and Adapters (Hexagonal Architecture), which ...
3
votes
1answer
292 views

Difference Between AsyncResult and Task in c#

So, in C#, I understand the historical difference between the two vaguely; a Task is a newer concept and the highest level concurrency native C# offers. AsyncResult is a bit more ambiguous. For ...
0
votes
2answers
140 views

What is the best practice for incorporating asynchronous code in this case?

Context: I'm building a popup widget. The html and css files are stored in S3. I need to get those files asynchronously and then continue with the rest of the logic. In the code below, I'm getting ...
2
votes
1answer
212 views

Implementing both Sync and Async clients with DRY

I'm developing a client library. I'd like to provide both Sync and Async interfaces to endpoints on a server. They would be rather easy to implement as completely separate entities, but I would like ...
0
votes
1answer
357 views

Unit testing async tcp server

I built an async multi-client TCP server for RPC usage. It's working well but I've found it difficult to unit test certain functionality: Connect 2x clients, is client count 2 Connect 1x ...
3
votes
1answer
1k views

How do JavaScript engines convert async/await to promises under the hood?

I'm curious how the async/await syntax is converted to Promises. Maybe I'm just not thinking about it properly, but I don't know how this code would be converted to a Promise: async function myFunc(...
1
vote
1answer
137 views

How is an async stack implemented?

I am working on creating a simple VM sort of thing in JS: let sp = 0 // stack pointer let m = [] // memory initialize: sp = 0 invoke: m[sp] = m[sp - 1] // position in stack m[sp + 1] = input[m[...
0
votes
0answers
47 views

Streaming Promises in NodeJS

Imagine a typical HTTP service that does async db queries. If HTTP requests are received more quickly than the db can complete queries (such as because the db disk or network is slow), the Promises ...
1
vote
0answers
31 views

Using TPL to manage hundreds of contexts

Overview of application: A chat bot that connects via IRC, using TPL. As messages come from the socket (from .ReadAsync()), they are ultimately parsed and passed to a handler within the bot itself (...
8
votes
3answers
11k views

How to justify using await instead of .Result() or .Wait() in .NET Core?

Since the inception of .NET Core, console apps, function apps, ASP.NET etc. are not using synchronization context in async methods (so they're synchronizing straight to Thread Pool). This means that ...
2
votes
1answer
298 views

Isn't asynchronicity an implementation detail?

Consider a simple — and fake — interface: interface ISuperGetter { Super Get(); } An implementation would get some Super from RAM. On would store what it needs on disk. Yet another could fetch the ...
2
votes
2answers
137 views

Name of locking approach

I've seen this approach several times, both in async and multithreaded code. A counter is used to track asynchronous behavior or thread behavior - whenever a new action is started, the counter is ...
3
votes
3answers
2k views

Why is it necessary for every new api to be async?

I'm expressing my frustration here somewhat, but why do many new libraries only have asynchronous APIs? For example I'm creating a small utility to fetch a web page and parse some data from it. ...
5
votes
2answers
366 views

balance between UI responsiveness and avoiding race conditions

To keep scope small I will talk about UI race conditions initiated by the same user in the same app sessions. The question is general and not specific to mobile, web or desktop UI. The issue Modern ...
0
votes
1answer
140 views

I'm writing an application that needs to log error/ exception messages but should still continue execution if it not a fatal error

I'm writing an application that needs to log error/ exception messages but should still continue execution if the error is not a fatal error. I was thinking of making a method that returns a Task but ...
9
votes
1answer
4k views

Is the C# async/Task construct equivalent to Java's Executor/Future?

I'm a long time Java developer, but with so little traffic on SE, I don't limit my viewing to any single tags. I've noticed that C# questions with async/await come up a lot, and as far as I've read it'...
0
votes
1answer
1k views

Async - why have an async for a login?

C# web scaffolding has an async call for every member. Why? For example: Async for a login call makes no sense. User has to wait for validation. What else would the app do until the application ...
2
votes
1answer
198 views

Must we define methods and async when we don't know whether the implementation is synchronous or asynchronous?

I think I know the answer to this, but it's particular enough that I don't want to go telling other people stuff until I'm 100% certain. Suppose I have a class with some dependency: public interface ...
0
votes
0answers
484 views

Using signalR for streaming alongside a microservice architecture

I have a cluster of micro services with an exposed search API serving a client app. I want to "stream" in real time the aggregated results of a complex search. The search will be kicked of by the ...
-1
votes
1answer
134 views

Does avoiding Promises and Async leads to clean code?

While applying for a job interview I found this line in requirements. Experience with clean code writing practices like avoiding callback hell like promises, async Does this line make any sense ? ...
-4
votes
2answers
135 views

Should I use async for networking application/library [closed]

I decided to make an application, networking application, don't know what it has to do yet but mainly it should be a cross-client kind of like framework networking application/library. Since ...
0
votes
3answers
260 views

If callback function, promises and async/await patterns all can be used to achieve asynchronous behaviour then why don't we stick to one?

As far as I have seen then async/await, callbacks and promises are and can only be used to achieve asynchronous programming. Correct? So my questions are: 1) Is it correct that the former three is ...
1
vote
1answer
955 views

Will (await method).ToList() block the thread? [closed]

I'm using a lot of async Task<IEnumerable<T>> methods and I want to stop doing this everytime to get the items as a list: var items = await AsyncMethodThatReturnsEnumerable(); var ...
1
vote
1answer
309 views

What does await do in JavaScript?

Sorry for this naive question. Reading some existing JavaScript I see a function with code like ... async function _load() { await ensureDir(path); return await readFile(filename); } ... why ...
1
vote
1answer
55 views

How to control multiply consoles from Java code?

I have Java application. I try to realize multiplayer chat with TCP protocol, but I have an issue. I cannot output all messages I get on client tier (server tier works perfectly), because I give ...
108
votes
5answers
12k views

Aren't the guidelines of async/await usage in C# contradicting the concepts of good architecture and abstraction layering?

This question concerns the C# language, but I expect it to cover other languages such as Java or TypeScript. Microsoft recommends best practices on using asynchronous calls in .NET. Among these ...
3
votes
2answers
2k 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
vote
0answers
97 views

Wrapper method for ConfigureAwait(false)?

Does it make sense to declare a async method as private and then create a public method to act as a wrapper that calls the private method with ConfigureAwait(false)? The intended purpose is design an ...
2
votes
2answers
1k views

Is it conventional to use both await and .then()?

I've written a bit of code that looks like this: async function fetchData() { const json = await fetch(ENDPOINT + key.key).then(data => data.json()); //Do something with the data } It's ...
30
votes
2answers
7k 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 ...
2
votes
2answers
7k views

Better to block on async with HttpClient than use synchronous API like WebRequest?

I have been a staunch advocate of never blocking on async code. I felt it was always better to use a synchronous API than to run the less efficient state machine generated by the compiler even if ...
0
votes
1answer
315 views

Best approach for web service that calls other web services

The scenario is: client makes request to server A Server A makes potentially multiple requests to server B. Edit to clarify, server A makes the requests concurrently using Futures. Server A blocks ...
1
vote
4answers
1k views

Problem with async/await pattern — in C# and JavaScript — how to return sync value

In old-style await'less NodeJS, when you call a function that had an asynchronous aspect, you'd pass in the well-known callback which gets called when the asynchronous portion is done. This didn't ...
1
vote
1answer
144 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 ...
1
vote
1answer
166 views

Design: HTTP and Websockets working together

I'm at a bit of crossroads here and I wanted to ask the opinion of the community. I am creating a chat application for our company. Now, like every chat application out there, the messages are saved ...
0
votes
1answer
112 views

How to statically check you didn't forget to await for an async function

A common bug in JavaScript is to forget the await keyword when calling an async function. Of course you don't always want to await, sometimes you really want to get a promise. And of course you can't ...