new failure golang processing

Preface

When using golang for development, have you ever encountered new failure? When this happens, how should you deal with it?

This article will give you an in-depth understanding of the reasons why new fails in golang, and provide some processing methods to help you solve this problem.

1. What is new?

new is a built-in function used to allocate memory. Its function is equivalent to malloc in C language, new operator in Java, etc.

The function prototype is as follows:

func new(Type) *Type

Let’s take a look at an example:

package main

import "fmt"

func main() {

var ptr *int
ptr = new(int)
fmt.Println("ptr 值为：", ptr)
fmt.Println("*ptr 值为：", *ptr)

}

The above code defines a pointer ptr pointing to int type, and uses new(int) to allocate ptr memory. Next, print out the pointer. The console output is as follows:

ptr value is: 0xc0000140a0
*ptr value is: 0

As you can see, ptr points to an address. And the value of *ptr is 0, which is the default value of int type variable.

2. Reasons for the failure of new

In golang, if the new function fails to allocate memory, a nil value will be returned.

So, why does new fail to allocate? The possible reasons are analyzed below.

1. Insufficient heap memory

The new function allocates memory from the heap. If the heap memory is insufficient, new allocation may fail.

2. Insufficient operating system resources

When a large amount of memory needs to be allocated, the resources of the operating system will gradually be exhausted. Insufficient operating system resources may also cause new allocation to fail.

3. There is a memory leak in the code

If there is a memory leak in the code, it will cause a large number of memory blocks that cannot be released in the system, eventually causing new allocation to fail.

3. How to handle new failure?

What should be done when new fails to allocate memory? Here are several solutions for you.

1. Change the program structure

If the newly allocated memory is used to store a large amount of data, it can be split into multiple small blocks for dynamic allocation. This can not only solve the problem of new allocation failure, but also improve the efficiency of the program.

2. Increase system resources

Once system resources are insufficient, new allocation will fail. At this time, the problem can be solved by increasing system resources. For example, increase memory, expand disk space, etc.

3. Check for memory leaks in the code

Memory leaks are one of the important causes of insufficient system memory. If there is a memory leak, it should be fixed in time to avoid new allocation failure.

4. Use the make function

If allocating memory using the new function fails, you can use the make function to allocate it. Unlike the new function, the make function can only be used to allocate memory of slice, map and channel types. Its function prototype is as follows:

func make(Type, size IntegerType) Type

make function can initialize the allocated memory before allocating the memory, so when dealing with some data types that need to be initialized, use The make function is more convenient than using the new function.

The following is an example of using the make function to allocate slice memory:

package main

import "fmt"

func main() {

var s []int
s = make([]int, 10)
fmt.Println("s 容量为：", cap(s))

}

In the above code, we allocate 10 memory blocks of type int for the s slice through the make function. The output result is as follows:

s capacity is: 10

Summary

This article explains the reasons for the failure of new in golang and how to deal with it. When the new function fails to allocate memory, you can solve the problem by changing the program structure, increasing system resources, repairing memory leaks, and using the make function.

In daily work, we need to always pay attention to memory usage to avoid excessive use of memory and cause new to allocate memory failure. Only through efficient use of memory can the performance and efficiency of the program be improved.

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