go调用so库

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go调用so库

生成so库

load_so.h

#ifndef _LOAD_SO_H
#define _LOAD_SO_H

int do_test_so_func(int a,int b);

#endif  
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load_so.c

#include "load_so.h"

int do_test_so_func(int a,int b)
{
    return a + b;
}
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生成so文件

gcc -fPIC -shared -o libload_so.so load_so.c
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调用so库

创建go项目hello

mkdir cgoTest
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创建main.go

touch main.go
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内容如下

package main

/*
#cgo CFLAGS: -I ./include    
#cgo LDFLAGS: -L /home/dengzr/cgoTest/lib -lload_so
#include "include/load_so.h"
*/
import "C"
import (
	"fmt"
)

func main() {
	val := C.do_test_so_func(1,1)
	fmt.Printf("num1: %v\n", val)
}
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将so库及头文件导入cgoTest目录结构如下

├── include
│   ├── load_so.c
│   └── load_so.h
├── lib
│   └── libload_so.so
└── main.go
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初始化go项目环境

[root@zs3-2 cgoTest]# go mod init cgoTest
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编译go程序

[root@zs3-2 cgoTest]# go build cgoTest
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导入so库环境变量

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/dengzr/cgoTest/lib/
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运行测试用例

[root@zs3-2 cgoTest]# ./cgoTest
num1: 2
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回调函数如何处理

.h

#ifndef _LOAD_SO_H
#define _LOAD_SO_H

typedef void (*Callback)(int);

void callCFunction(Callback fun);

int do_test_so_func(int a,int b);

#endif  
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.c

#include "load_so.h"
int do_test_so_func(int a,int b)
{
    return a + b;
}

void callCFunction(Callback fun)
{
    fun(10);
}
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.go

package main

/*
#cgo CFLAGS: -I ./include    
#cgo LDFLAGS: -L /home/dengzr/fmp4/cgoTest/lib -lload_so -lbsr-fmp4-mux
#include "include/load_so.h"
#include "include/fmp4MuxAPI.h"


// 导出Go函数为C函数
extern void goCallback(int);
*/
import "C"
import (
	"fmt"
	"os"
	"io"
	"bytes"
	"encoding/binary"
)
// Go回调函数
//export goCallback
func goCallback(value C.int) {
    fmt.Println("Go callback called with value:", int(value))
}
func main() {
	val := C.do_test_so_func(1,1)
	fmt.Printf("num1: %v\n", val)

	// 在Go代码中调用C回调函数
	fun := (C.Callback)(C.goCallback)
	C.callCFunction(fun)
}
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注意，go回调函数前必须导入 export goCallback，否则报错

/home/dengzr/go/go/pkg/tool/linux_amd64/link: running gcc failed: exit status 1
/tmp/go-link-267202374/go.o:(.data+0x8): undefined reference to `goCallback'
collect2: error: ld returned 1 exit status
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必须声明extern void goCallback(int);否则未定义C.goCallback