Go: Asynchronous Preemption

ℹ️ This article is based on Go 1.14.

The preemption is an important part of the scheduler that lets it distribute the running time among the goroutines. Indeed, without preemption, a long-running goroutine that hogs the CPU would block the other goroutines from being scheduled. The version 1.14 introduces a new technique of asynchronous preemption, giving more power and control to the scheduler.

For more details about the previous behavior and its drawback, I suggest you read my article “Go: Goroutine and Preemption.”

Workflow

Let’s start with an example where preemption is needed. Here is a code where many goroutines loop for a while without any function call, meaning no opportunity for the scheduler to preempt them:

However, when visualizing the traces from this program, we clearly see the goroutines are preempted and switch among them:

We can also see that all the blocks representing the goroutines have the same length. The goroutines get almost the same running time (around 10/20ms):

The asynchronous preemption is triggered based on a time condition. When a goroutine is running for more than 10ms, Go will try to preempt it.

#internal #go #golang

What is GEEK

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What's new in the go 1.15

Go announced Go 1.15 version on 11 Aug 2020. Highlighted updates and features include Substantial improvements to the Go linker, Improved allocation for small objects at high core counts, X.509 CommonName deprecation, GOPROXY supports skipping proxies that return errors, New embedded tzdata package, Several Core Library improvements and more.

As Go promise for maintaining backward compatibility. After upgrading to the latest Go 1.15 version, almost all existing Golang applications or programs continue to compile and run as older Golang version.

#go #golang #go 1.15 #go features #go improvement #go package #go new features

Secure HTTPS servers in Go

In this article, we are going to look at some of the basic APIs of the http package to create and initialize HTTPS servers in Go.

(source: unsplash.com)

In the “Simple Hello World Server” lesson, we learned about net/http package, how to create routes and how [ServeMux](https://golang.org/pkg/net/http/#ServeMux) works. In the “Running multiple HTTP servers” lesson, we learned about [Server](https://golang.org/pkg/net/http/#Server) structure and how to run multiple HTTP servers concurrently.

In this lesson, we are going to create an HTTPS server using both Go’s standard server configuration and custom configuration (using [_Server_](https://golang.org/pkg/net/http/#Server) structure). But before this, we need to know what HTTPS really is?

HTTPS is a big topic of discussion in itself. Hence while writing this lesson, I published an article just on “How HTTPS works?”. I advise you to read this lesson first before continuing this article. In this article, I’ve also described the encryption paradigm and SSL certificates generation process.

---

If we recall the simplest HTTP server example from previous lessons, we only need http.``[ListenAndServe](https://golang.org/pkg/net/http/#ListenAndServe) function to start an HTTP server and http.``[HandleFunc](https://golang.org/pkg/net/http/#HandleFunc) to register a response handler for a particular endpoint.

(https://play.golang.org/p/t3sOenOYAzS)

In the example above, when we run the command go run server.go , it will start an HTTP server on port 9000. By visiting http://localhost:9000 URL in a browser, you will be able to see a Hello World! message on the screen.

(http://localhost:9000)

As we know, the nil argument to ListenAndServe() call invokes Go to use the [DefaultServeMux](https://golang.org/pkg/net/http/#DefaultServeMux) response multiplexer, which is the default instance of ServeMux structure provided globally by the Go. The HandleFunc() call adds a response handler for a specific route on the multiplexer instance.

The http.ListenAndServe() call uses the Go’s standard HTTP server configuration, however, in the previous lesson, how we can customize a server using [Server](https://golang.org/pkg/net/http/#Server) structure type.

To start an HTTPS server, all we need do is to call ServerAndListenTLS method with some configuration. Just like ServeAndListen method, this method is available on both the http package and the Server structure.

The http.``[ServeAndListenTLS](https://golang.org/pkg/net/http/#ListenAndServeTLS) method uses the Go’s standard server implementation, however, both [Server](https://golang.org/pkg/net/http/#Server) instance and Server.``[ServeAndListenTLS](https://golang.org/pkg/net/http/#Server.ListenAndServeTLS) method can be configured for our needs.

#go-programming-language #go #golang-tutorial #go-programming #golang

Go: Asynchronous Preemption

ℹ️ This article is based on Go 1.14.

The preemption is an important part of the scheduler that lets it distribute the running time among the goroutines. Indeed, without preemption, a long-running goroutine that hogs the CPU would block the other goroutines from being scheduled. The version 1.14 introduces a new technique of asynchronous preemption, giving more power and control to the scheduler.

For more details about the previous behavior and its drawback, I suggest you read my article “Go: Goroutine and Preemption.”

Workflow

Let’s start with an example where preemption is needed. Here is a code where many goroutines loop for a while without any function call, meaning no opportunity for the scheduler to preempt them:

However, when visualizing the traces from this program, we clearly see the goroutines are preempted and switch among them:

We can also see that all the blocks representing the goroutines have the same length. The goroutines get almost the same running time (around 10/20ms):

The asynchronous preemption is triggered based on a time condition. When a goroutine is running for more than 10ms, Go will try to preempt it.

#internal #go #golang

Why Use the Go Language for Your Project?

Golang is a language for open-source programming. It’s typed automatically and generates binaries of compiled computer language. Developers claim that when it comes to syntax, the Go language of Google is the C for the twenty-first era. At present, Go Lang Training in Chennai is very useful to operate in coding language. This new programming language, however, includes tools that enable you to be using memory securely, handle objects, pick up garbage, as well as provide strict typing along with competition.
Advantages of using Go for your project:
Go provides a whole range of benefits. The language started to evolve nearly as soon as it was published back in 2009. It rapidly began to drift from the language of #65 to the important jobs around the globe. Company Insider then named Go the 2016 hottest programming language. Maybe you want to know why Go is on the rise. The explanation is that Go has the same efficiency as C and is much easier to manage than Java, so we don’t need a virtual machine, no warm-up time, no JAR hell, etc. Let’s take a look at the other benefits provided by Golang.
Spend less time and money to create an application
If you’re using Go for your project, you don’t need a big teak stack. In reality, applications generated in Go compile to native machine code and do not require an interpreter or virtual machine. This also implies that Go apps are going to work faster and will not need the warm-up we just described.
Use Go for a range of applications
Go is a very versatile language, capable of solving many problems. It can be used for coding of devices and services, big data, machine learning, sound / visual editing.
Get more production for your application and a broader audience
Go is a compiled language similar to C or C++ and doesn’t need any interpretation. Correspondingly, the absence of an interpreter frees up that power and provides more output to a Go-built app, which users would certainly enjoy. Besides, Go knows how to control the allocated memory correctly.
Another great news is that in terms of device specifications, a Go-based application is less challenging. For users of older computers, this is good as they will still get to enjoy your application. And with more users that use the device, you’re going to get more cash.
Worry less about the app crashing
To use the maximum potential of different processes, Go was developed. In addition, the language can use all the processor resources correctly, so it is great as a single method for operating an app in the background. Thanks to goroutines, that are used instead of loops and need far less RAM because of their non-system loop existence, this is possible. This is why the risk of crashing a Go app is lower due to lack of storage.
Easily find Go developers for your project
It’s blowing up Go. If you look at Stack Overflow’s developer survey, you can see that Go has been one of the top five most loved and most needed languages. So Go Lang Course in Chennai is very useful to develop your career in the IT industry. Evermore experts are plunging into the world of Go. In the coming years, you’ll expect to find even more specialists to create and manage your Go-based application.

#go lang course in chennai #go lang training in chennai #go #lang #golang #training

Tiny Go: Small Is Going Big

Summary

Ron Evans talks about TinyGo - a compiler for Go, written in Go itself, that uses LLVM to achieve very small, fast, and concurrent binaries that can also target devices where Go could never go before. The talk includes live coding of devices, RISC-V, WebAssembly, and a drone, to show some of what can be done today using TinyGo.

Bio

Ron Evans is an open source software developer, businessperson, author, and speaker.

About the conference

Software is changing the world. QCon empowers software development by facilitating the spread of knowledge and innovation in the developer community. A practitioner-driven conference, QCon is designed for technical team leads, architects, engineering directors, and project managers who influence innovation in their teams.

TinyGo

We’re here to talk about TinyGo, which is now officially sponsored by Google. Go is really big in the cloud by which we mean Go is big. Go executable programs are very large in Hello World in Go 1.13, which is the release right before the most recent release. Go programs are very large. That’s not a problem because clouds are infinitely scalable. What about the small places? What about the little places by which we mean microcontrollers, which are the small chips that actually run all the things in the world you care about, like the dialysis machine, or the brake systems, or other types of mission-critical, the refrigerator, and WebAssembly. What we’re talking about is true Edge computing, not this so-called Edge computing. Edge computing is not the data center nearest you. I’m sorry. I must respectfully disagree. The real Edge computing is in what we call the last centimeter. That’s what TinyGo is here for.

How TinyGo works is it’s a trinity between Go, TinyGo, and LLVM. The Go compiler itself is written in Go. All cool languages eventually reach a point where they can be compiled in themselves. It’s very self-referential, but it also proves that it works. The Go compiler tool chain is written in Go and a lot of the things that it uses are actually built into Go standard library. Then you’ve got LLVM. It’s a framework for building compilers. It’s being used by a couple of languages, one of them is a very cool language called Rust. We really admire the Rust community. Also, Swift, another very cool language. Some other cool languages recently Zig, written in LLVM language. The way that TinyGo works is we take the source code of Go and we parse it through the Go standard libraries to create the Go single static assignment form, which is taking the Go code and reducing it down to this very reduced type of syntax. Then we take that and TinyGo translates that into LLVM intermediate representation, which is what LLVM’s tool chain takes. Then using tools like Clang or LLD, which are the built-in tool chain that LLVM itself provides, we can then compile targets in LVM for very small places.

#go language #compilers #qcon london 2020 #demo #go