Why is Go So Good at Concurrency?

Concurrency in Go (often referred to as "goroutines and channels") is a core feature of the programming language that allows you to efficiently execute multiple tasks concurrently, making the most of modern multi-core processors. Concurrency is the ability to run multiple independent computations or tasks simultaneously while not necessarily executing them at the exact same time. It enables efficient utilization of system resources and responsiveness in programs.

In Go, concurrency is achieved primarily through two mechanisms: goroutines and channels.

What are Goroutines? 

Goroutines are the bread and butter of Go. Often, they are called implicitly in Go standard libraries, such as the sync and atomic library. That means when you leverage the methods in these libraries, they utilize Goroutines to atomically write concurrent programming for you.

In addition to libraries, you can start a new goroutine using the go keyword followed by a function call.

go function()

A Goroutine is a lightweight, independent concurrent thread in Go. Pretty much every programming language has threads, so what makes a Goroutine so special? Goroutine has far less overhead compared to other threads in programming languages, such as Java or C#. The small stack size is only a few kilobytes—and this makes them very easy to create and destroy. That means a typical backend server could handle millions of requests with ease.

That’s not all; Goroutines abstract out much of the deck plate code required in other programming languages. This makes the code far easier to write and way more readable. These simple abstractions boost developer productivity and cut the time needed for your app to start generating revenue.

Lastly, the very nature of Goroutines facilitates concurrent code. Goroutines have the ability to synchronize via different channels. This provides a safe and efficient method to pass complex data between different threads.

What are Channels?

Channels are a little complex, but think of them as a pipeline in which data flows. Goroutines can read off that pipeline to transact data between different threads. Channels in Go are assigned a specific type, which is an important concept to remember.  

Without going too deep into syntax, the actual way to create a channel is with the make keyword. For example,

ch := make(chan int)

go func() {
    ch <- 42 // Send data into the channel
}()

value := <-ch // Receive data from the channel

Now, let’s touch on the relationship between Goroutines and channels. When a Goroutine transmits data to a channel, it halts execution until another Goroutine is ready to receive that data. This increases coordination between threads and ensures data is sent and received at the appropriate times. It also prevents data integrity issues that can often arise from threaded programming.

Utilizing channels with Goroutines will allow programmers to create highly scalable and concurrent programs, and the risk of race conditions will be highly mitigated. Go has great built-in features, but it also interacts elegantly with the hardware itself. 

Golang Concurrency and Multi-Core Utilization

It is safe to say that Go was designed with the modern computing era in mind. Go can use multi-core processors to increase the throughput of applications.

For instance, Goroutines often must stop and wait for another Goroutine to retrieve the data placed into the channel. However, keep in mind thousands of other processes are occurring simultaneously. Go allows the Go Scheduler to assign idle CPU cores to other threads while waiting for the blocked thread to resolve. This concept is called work stealing. 

Go has successfully replicated the behavior of work stealing with minimal overhead and developer effort despite the long-standing existence of this concept.

Golang Concurrency: Key Terms to Know

Lastly, let's discuss the essential keywords related to Golang concurrency. Unlike most other programming languages, Go provides native types that allow for quick and easy Golang concurrency. The following is a list of three important ones to remember:

What are Mutexes? 

Mutex is short for mutual exclusion. This keyword is used on a variable that ensures no two Goroutines can use the same variable.

What are Wait roups?

Wait groups will assist in ensuring multiple Goroutines are executed synchronously. This keyword will ensure a new operation will occur only after several specified threads have concluded.

What are Atomic Operations? 

Atomic operations allow users to mutate variables that will be manipulated by Goroutines. Atomic operations, such as atomic.AddInt32 and atomic.LoadUint64 ensures that these operations are performed atomically and avoid race conditions.

These examples represent only a small fraction of the numerous keywords that Go offers. It proves that Go was created by and for developers who need scalable architecture.

Final Thoughts

The use of Go for scalability and concurrency in Golang is not coincidental. Go was specifically designed to write software that would receive countless responses at a time, efficiently scale, yet still maintain readability. All of these qualities make it perfect for writing highly efficient cloud applications. 

The Go programming language offers various tools to facilitate scalable software. This article covered Goroutines, Channels, Multi-Core Utilization, and Keywords.

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