search
HomeBackend DevelopmentGolangWhat is the correct way to convert Go func to uintptr?

将 Go func 转换为 uintptr 的正确方法是什么?

In the Go language, converting a `func` type to a `uintptr` type is a common operation, but the correct method is not to convert directly, because this may leading to some potential problems. The correct method is to use the `Pointer` function in the `unsafe` package to convert the `func` type value to the `unsafe.Pointer` type first, and then convert it to the `uintptr` type. This ensures the safety of type conversion and avoids unpredictable errors. Although this method requires the use of the `unsafe` package, under the right circumstances, it can effectively solve the problem of converting `Go func` to `uintptr`.

Question content

I need to pass and receive go functions in go code.

Due to the way system calls work in the go language, the type used for "passage" is uintptr.

I have no choice but uintptr since syscall.syscalln accepts and returns this type.

What is the correct way to convert go func to uintptr?

I tried using it in the sandbox but I can't simply convert it.

package main

import (
    "fmt"
    "unsafe"
)

func main() {
    var f MyFunc = SumInt
    fmt.Println(f(1, 2))
    test(uintptr(f))                 // Cannot convert an expression of the type 'MyFunc' to the type 'uintptr'
    test(uintptr(unsafe.Pointer(f))) // Cannot convert an expression of the type 'MyFunc' to the type 'unsafe.Pointer'
}

type MyFunc func(a int, b int) (sum int)

func SumInt(a, b int) int {
    return a + b
}

func test(x uintptr) {
    var xf MyFunc
    xf = MyFunc(x)                 // Cannot convert an expression of the type 'uintptr' to the type 'MyFunc'
    xf = MyFunc(unsafe.Pointer(x)) // Cannot convert an expression of the type 'unsafe.Pointer' to the type 'MyFunc'
    fmt.Println(xf(1, 2))
}

I searched on the internet but this information cannot be seen directly in google.

Thanks.

Solution

I found a solution! I need to pass a function pointer.

package main

import (
    "fmt"
    "unsafe"
)

func main() {
    var f myfunc = sumint
    fmt.println(f(1, 2))
    test(uintptr(unsafe.pointer(&f)))
}

type myfunc func(a int, b int) (sum int)

func sumint(a, b int) int {
    return a + b
}

func test(x uintptr) {
    var xfp *myfunc
    xfp = (*myfunc)(unsafe.pointer(x))

    var xf myfunc
    xf = *xfp
    fmt.println(xf(1, 2))
}
3
3

Process finished with the exit code 0

The above is the detailed content of What is the correct way to convert Go func to uintptr?. For more information, please follow other related articles on the PHP Chinese website!

Statement
This article is reproduced at:stackoverflow. If there is any infringement, please contact admin@php.cn delete
go语言有没有缩进go语言有没有缩进Dec 01, 2022 pm 06:54 PM

go语言有缩进。在go语言中,缩进直接使用gofmt工具格式化即可(gofmt使用tab进行缩进);gofmt工具会以标准样式的缩进和垂直对齐方式对源代码进行格式化,甚至必要情况下注释也会重新格式化。

go语言为什么叫gogo语言为什么叫goNov 28, 2022 pm 06:19 PM

go语言叫go的原因:想表达这门语言的运行速度、开发速度、学习速度(develop)都像gopher一样快。gopher是一种生活在加拿大的小动物,go的吉祥物就是这个小动物,它的中文名叫做囊地鼠,它们最大的特点就是挖洞速度特别快,当然可能不止是挖洞啦。

一文详解Go中的并发【20 张动图演示】一文详解Go中的并发【20 张动图演示】Sep 08, 2022 am 10:48 AM

Go语言中各种并发模式看起来是怎样的?下面本篇文章就通过20 张动图为你演示 Go 并发,希望对大家有所帮助!

【整理分享】一些GO面试题(附答案解析)【整理分享】一些GO面试题(附答案解析)Oct 25, 2022 am 10:45 AM

本篇文章给大家整理分享一些GO面试题集锦快答,希望对大家有所帮助!

tidb是go语言么tidb是go语言么Dec 02, 2022 pm 06:24 PM

是,TiDB采用go语言编写。TiDB是一个分布式NewSQL数据库;它支持水平弹性扩展、ACID事务、标准SQL、MySQL语法和MySQL协议,具有数据强一致的高可用特性。TiDB架构中的PD储存了集群的元信息,如key在哪个TiKV节点;PD还负责集群的负载均衡以及数据分片等。PD通过内嵌etcd来支持数据分布和容错;PD采用go语言编写。

go语言是否需要编译go语言是否需要编译Dec 01, 2022 pm 07:06 PM

go语言需要编译。Go语言是编译型的静态语言,是一门需要编译才能运行的编程语言,也就说Go语言程序在运行之前需要通过编译器生成二进制机器码(二进制的可执行文件),随后二进制文件才能在目标机器上运行。

go语言能不能编译go语言能不能编译Dec 09, 2022 pm 06:20 PM

go语言能编译。Go语言是编译型的静态语言,是一门需要编译才能运行的编程语言。对Go语言程序进行编译的命令有两种:1、“go build”命令,可以将Go语言程序代码编译成二进制的可执行文件,但该二进制文件需要手动运行;2、“go run”命令,会在编译后直接运行Go语言程序,编译过程中会产生一个临时文件,但不会生成可执行文件。

golang map怎么删除元素golang map怎么删除元素Dec 08, 2022 pm 06:26 PM

删除map元素的两种方法:1、使用delete()函数从map中删除指定键值对,语法“delete(map, 键名)”;2、重新创建一个新的map对象,可以清空map中的所有元素,语法“var mapname map[keytype]valuetype”。

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks agoBy尊渡假赌尊渡假赌尊渡假赌
R.E.P.O. Best Graphic Settings
2 weeks agoBy尊渡假赌尊渡假赌尊渡假赌
R.E.P.O. How to Fix Audio if You Can't Hear Anyone
2 weeks agoBy尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Safe Exam Browser

Safe Exam Browser

Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Atom editor mac version download

Atom editor mac version download

The most popular open source editor

PhpStorm Mac version

PhpStorm Mac version

The latest (2018.2.1) professional PHP integrated development tool

VSCode Windows 64-bit Download

VSCode Windows 64-bit Download

A free and powerful IDE editor launched by Microsoft