编译 *.so 的动态链接 · PHP/Python/前端/Linux 等等学习笔记

[TOC] ## 概述 c-shared模式的golang模块支持c,python,java,nodejs、lua、ruby、Julia等语言的调用 ## 示例 ### 生成 `awesome.so` <details> <summary>awesome.go</summary> ``` package main import "C" import ( "fmt" "math" "sort" "sync" ) var count int var mtx sync.Mutex //export Add func Add(a, b int) int { return a + b } //export Cosine func Cosine(x float64) float64 { return math.Cos(x) } //export Sort func Sort(vals []int) { sort.Ints(vals) } //export Log func Log(msg string) int { mtx.Lock() defer mtx.Unlock() fmt.Println(msg) count++ return count } // 必须声明 func main() { } ``` </details> 生成 `awesome.so` 文件 ``` go build -o awesome.so -buildmode=c-shared awesome.go ``` 编译后生成如下两个文件：`awesome.h`,`awesome.h` ### c语言动态链接调用 <details> <summary>client1.c </summary> ``` #include <stdio.h> #include "awesome.h" int main() { //Call Add() - passing integer params, interger result GoInt a = 12; GoInt b = 99; printf("awesome.Add(12,99) = %d\n", Add(a, b)); //Call Cosine() - passing float param, float returned printf("awesome.Cosine(1) = %f\n", (float)(Cosine(1.0))); //Call Sort() - passing an array pointer GoInt data[6] = {77, 12, 5, 99, 28, 23}; GoSlice nums = {data, 6, 6}; Sort(nums); printf("awesome.Sort(77,12,5,99,28,23): "); for (int i = 0; i < 6; i++){ printf("%d,", ((GoInt *)nums.data)[i]); } printf("\n"); //Call Log() - passing string value GoString msg = {"Hello from C!", 13}; Log(msg); } ``` </details> 执行 ``` $> gcc -o client client1.c ./awesome.so $> ./client awesome.Add(12,99) = 111 awesome.Cosine(1) = 0.540302 awesome.Sort(77,12,5,99,28,23): 5,12,23,28,77,99, Hello from C! ``` ### c语言动态加载 <details> <summary>client2.c </summary> ``` #include <stdlib.h> #include <stdio.h> #include <dlfcn.h> // define types needed typedef long long go_int; typedef double go_float64; typedef struct{void *arr; go_int len; go_int cap;} go_slice; typedef struct{const char *p; go_int len;} go_str; int main(int argc, char **argv) { void *handle; char *error; // use dlopen to load shared object handle = dlopen ("./awesome.so", RTLD_LAZY); if (!handle) { fputs (dlerror(), stderr); exit(1); } // resolve Add symbol and assign to fn ptr go_int (*add)(go_int, go_int) = dlsym(handle, "Add"); if ((error = dlerror()) != NULL) { fputs(error, stderr); exit(1); } // call Add() go_int sum = (*add)(12, 99); printf("awesome.Add(12, 99) = %d\n", sum); // resolve Cosine symbol go_float64 (*cosine)(go_float64) = dlsym(handle, "Cosine"); if ((error = dlerror()) != NULL) { fputs(error, stderr); exit(1); } // Call Cosine go_float64 cos = (*cosine)(1.0); printf("awesome.Cosine(1) = %f\n", cos); // resolve Sort symbol void (*sort)(go_slice) = dlsym(handle, "Sort"); if ((error = dlerror()) != NULL) { fputs(error, stderr); exit(1); } // call Sort go_int data[5] = {44,23,7,66,2}; go_slice nums = {data, 5, 5}; sort(nums); printf("awesome.Sort(44,23,7,66,2): "); for (int i = 0; i < 5; i++){ printf("%d,", ((go_int *)data)[i]); } printf("\n"); // resolve Log symbol go_int (*log)(go_str) = dlsym(handle, "Log"); if ((error = dlerror()) != NULL) { fputs(error, stderr); exit(1); } // call Log go_str msg = {"Hello from C!", 13}; log(msg); // close file handle when done dlclose(handle); } ``` </details> 执行 ``` $> gcc -o client client2.c -ldl $> ./client awesome.Add(12, 99) = 111 awesome.Cosine(1) = 0.540302 awesome.Sort(44,23,7,66,2): 2,7,23,44,66, Hello from C! ``` ### python ctypes 方式调用 <details> <summary>client.py</summary> ``` from ctypes import * lib = cdll.LoadLibrary("./awesome.so") # describe and invoke Add() lib.Add.argtypes = [c_longlong, c_longlong] lib.Add.restype = c_longlong print "awesome.Add(12,99) = %d" % lib.Add(12,99) # describe and invoke Cosine() lib.Cosine.argtypes = [c_double] lib.Cosine.restype = c_double print "awesome.Cosine(1) = %f" % lib.Cosine(1) # define class GoSlice to map to: # C type struct { void *data; GoInt len; GoInt cap; } class GoSlice(Structure): _fields_ = [("data", POINTER(c_void_p)), ("len", c_longlong), ("cap", c_longlong)] nums = GoSlice((c_void_p * 5)(74, 4, 122, 9, 12), 5, 5) # call Sort lib.Sort.argtypes = [GoSlice] lib.Sort.restype = None lib.Sort(nums) print "awesome.Sort(74,4,122,9,12) = [", for i in range(nums.len): print "%d "% nums.data[i], print "]" # define class GoString to map: # C type struct { const char *p; GoInt n; } class GoString(Structure): _fields_ = [("p", c_char_p), ("n", c_longlong)] # describe and call Log() lib.Log.argtypes = [GoString] lib.Log.restype = c_longlong msg = GoString(b"Hello Python!", 13) print "log id %d"% lib.Log(msg) ``` </details> ### java调用 <details> <summary>Client.java</summary> ``` import com.sun.jna.*; import java.util.*; import java.lang.Long; public class Client { public interface Awesome extends Library { // GoSlice class maps to: // C type struct { void *data; GoInt len; GoInt cap; } public class GoSlice extends Structure { public static class ByValue extends GoSlice implements Structure.ByValue {} public Pointer data; public long len; public long cap; protected List getFieldOrder(){ return Arrays.asList(new String[]{"data","len","cap"}); } } // GoString class maps to: // C type struct { const char *p; GoInt n; } public class GoString extends Structure { public static class ByValue extends GoString implements Structure.ByValue {} public String p; public long n; protected List getFieldOrder(){ return Arrays.asList(new String[]{"p","n"}); } } // Foreign functions public long Add(long a, long b); public double Cosine(double val); public void Sort(GoSlice.ByValue vals); public long Log(GoString.ByValue str); } static public void main(String argv[]) { Awesome awesome = (Awesome) Native.loadLibrary( "./awesome.so", Awesome.class); System.out.printf("awesome.Add(12, 99) = %s\n", awesome.Add(12, 99)); System.out.printf("awesome.Cosine(1.0) = %s\n", awesome.Cosine(1.0)); // Call Sort // First, prepare data array long[] nums = new long[]{53,11,5,2,88}; Memory arr = new Memory(nums.length * Native.getNativeSize(Long.TYPE)); arr.write(0, nums, 0, nums.length); // fill in the GoSlice class for type mapping Awesome.GoSlice.ByValue slice = new Awesome.GoSlice.ByValue(); slice.data = arr; slice.len = nums.length; slice.cap = nums.length; awesome.Sort(slice); System.out.print("awesome.Sort(53,11,5,2,88) = ["); long[] sorted = slice.data.getLongArray(0,nums.length); for(int i = 0; i < sorted.length; i++){ System.out.print(sorted[i] + " "); } System.out.println("]"); // Call Log Awesome.GoString.ByValue str = new Awesome.GoString.ByValue(); str.p = "Hello Java!"; str.n = str.p.length(); System.out.printf("msgid %d\n", awesome.Log(str)); } } ``` </details>