How to turn off Golang’s GC

Golang is a statically compiled programming language that was originally developed by Google and officially released in 2012. Golang has a garbage collection mechanism (GC) that can help developers manage memory, but in some application scenarios, developers may need to turn off GC to improve program performance. This article will introduce how to turn off Golang's GC.

What is garbage collection (GC)?

Garbage collection (GC) is an automatic memory management mechanism that automatically handles memory release while the program is running. Golang's GC mechanism is based on mark-sweep and tracking garbage collection, which can automatically handle memory management without requiring developers to manually release memory, which helps improve development efficiency.

GC consists of the following three main parts:

• Marking: GC will traverse all objects in the program and mark all objects that are still in use;
• Sweeping: GC will recycle all unmarked objects and release the memory space back to the operating system;
• Memory Recycler (Memory Allocator): GC uses a memory recycler to reallocate the obtained object and use.

GC also has the following advantages:

• Avoid memory leaks
• Avoid memory errors during debugging
• Automatically manage memory allocation

Why turn off GC?

Although GC can help us automatically manage memory, in some application scenarios, developers need to manually control memory. Common situations include:

• Scientific computing
• Large-scale concurrent programming
• Embedded device development
• Real-time system

In these scenarios, turning off GC can improve program performance, reduce memory usage, and improve stability. This article will introduce how to turn off Golang's GC.

How to turn off GC?

In Golang, we can use the runtime.GOMAXPROCS() function to turn off GC.

The default value of GOMAXPROCS is the currently available number of CPUs. We can turn off GC by setting GOMAXPROCS to 1. This means that the program will not have too many concurrent goroutines, thus reducing memory pressure and garbage collection burden. Here is a simple example program:

package main

import (
    "fmt"
    "runtime"
)

func main() {
    fmt.Println("Default GOMAXPROCS:", runtime.GOMAXPROCS(0))
    runtime.GOMAXPROCS(1) // 禁用go并发
    fmt.Println("New GOMAXPROCS:", runtime.GOMAXPROCS(0))
}

In the above program, we first printed the default GOMAXPROCS value and then set it to 1. Finally, we print the value of GOMAXPROCS again to confirm that we have successfully disabled goroutine concurrency.

In some cases, if we need to restore GC, this can be achieved by setting GOMAXPROCS to the default value. For example, in some large calculations or systems with gc disabled, developers can automatically or manually set it back to the default value when the operation is completed.

Summary

In this article, we introduced Golang’s GC mechanism and how to turn off GC to improve program performance. Although turning off GC may add some extra work, it can improve program performance and stability in certain application scenarios. Final advice: Don't turn off the GC unless you know exactly what you are doing. This will make coding and debugging more difficult.

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