$ go version
go version go1.5beta2 linux/amd64

$ uname -a
Linux vagrant-ubuntu-trusty-64 3.13.0-55-generic #92-Ubuntu SMP Sun Jun 14 18:32:20 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

#include <stdio.h>
#include <dlfcn.h>

int main(int argc, char **argv) {
    printf("runtime_load started\n");
    void *handle = dlopen("libgodll.so", RTLD_LAZY);
    if (!handle) {
        printf("dlopen failed\n");
        return 1;
    }
    printf("after dlopen. handle=%llx\n", (long long unsigned)handle);
    int *i_ptr = dlsym(handle, "i");
    printf("i=%d\n", *i_ptr);
#ifndef NO_DLCLOSE
    printf("calling dlclose\n");
    dlclose(handle);
    printf("after dlclose\n");
#endif
    return 0;
}

package main

// int i;
import "C"

func init() {
    C.i = 1
}

//export libInit
func libInit() {}

func main() {}

test_runtime: runtime_load libgodll.so
    LD_LIBRARY_PATH=. ./runtime_load
    echo status=$$?

test_compiletime: compiletime_load libgodll.so
    LD_LIBRARY_PATH=. ./compiletime_load
    echo status=$$?

runtime_load: runtime_load.c
    $(CC) -o runtime_load runtime_load.c $(CFLAGS) -ldl

compiletime_load: libgodll.so compiletime_load.c
    $(CC) -o compiletime_load compiletime_load.c -L. -lgodll

libgodll.so: libgodll.go
    go build -buildmode=c-shared -o libgodll.so libgodll.go

clean:
    -rm runtime_load compileitme_load core libgodll.h libgodll.so

#include <stdio.h>
#include <dlfcn.h>

int main(int argc, char **argv) {
    printf("runtime_load started\n");
    void *handle = dlopen("libgodll.so", RTLD_LAZY);
    if (!handle) {
        printf("dlopen failed\n");
        return 1;
    }
    printf("after dlopen. handle=%llx\n", (long long unsigned)handle);
    usleep(1000 * 1000);
    int *i_ptr = dlsym(handle, "i");
    printf("i=%d\n", *i_ptr);
#ifndef NO_DLCLOSE
    printf("calling dlclose\n");
    dlclose(handle);
    printf("after dlclose\n");
#endif
    return 0;
}