我一直在通過ctypes將一些C++類擴展爲python。 我首先嚐試通過GDB和代碼驗證地址不等於NULL。它確實不等於NULL。我嘗試通過printf打印指針,並將地址輸出,但涉及指針的下一行代碼會引發分段錯誤。奇怪的是,如果沒有這個printf語句,printf語句後面的下一行代碼將會工作。然而,涉及指針的下一個函數會像printf一樣引發一個分段錯誤。ctypes不允許多次提取指針
這裏是我的參考代碼:
C++ - 「çctypes的包裝器
#include <jetfuelmedia.h>
#define MAX_FILE_NAME_SIZE 1024
extern "C"{
jetfuel::media::Music *Music_new(){
return new jetfuel::media::Music();
}
void Music_delete(jetfuel::media::Music *music){
puts("Destroyed Music object");
delete music;
}
bool Music_is_music_playing(){
return Mix_PlayingMusic();
}
bool Music_is_music_paused(){
return Mix_PausedMusic();
}
bool Music_load_music_file(jetfuel::media::Music *music,
const wchar_t *musicfilepath){
char musicfilepathchar[MAX_FILE_NAME_SIZE];
wcstombs(musicfilepathchar,musicfilepath,
MAX_FILE_NAME_SIZE);
puts("Music file is:");
puts(musicfilepathchar);
puts("Music ref is:");
printf("%p",music);
if(!music->Load_music_file(musicfilepathchar)){
puts(musicfilepathchar);
puts(Mix_GetError());
return false;
}
puts("C/C++ code ran");
return true;
}
bool Music_play(jetfuel::media::Music *music){
puts("C/C++ Play code ran");
return music->Play();
}
void Music_pause(jetfuel::media::Music *music){
music->Pause();
}
void Music_resume(jetfuel::media::Music *music){
music->Resume();
}
const char *Get_music_error(){
const char *sdlerror = Mix_GetError();
if(sdlerror == NULL){
return "Music object was equal to NULL";
}
return Mix_GetError();
}
}
Python類包裝:
from ctypes import cdll
from ctypes import c_wchar_p
from ctypes import c_void_p
from ctypes import c_bool
class music():
_jetfuel = None;
_musicref = None;
def __init__(self,jetfuelsofilepath):
self._jetfuel = cdll.LoadLibrary(jetfuelsofilepath);
self._musicref = self._jetfuel.Music_new();
def __enter__(self):
return self;
def __exit__(self, exc_type, exc_value, traceback):
if(self._musicref != None):
self._jetfuel.Music_delete(c_void_p(self._musicref));
def is_music_playing(self):
return self._jetfuel.Music_is_music_playing();
def is_music_paused(self):
return self._jetfuel.Music_is_music_paused();
def load_music_file(self, musicfilepath):
loadmusicfile = self._jetfuel.Music_load_music_file;
loadmusicfile.argtypes = [c_void_p, c_wchar_p];
loadmusicfile.restype = c_bool;
return loadmusicfile(c_void_p(self._musicref),
c_wchar_p(musicfilepath));
def play(self):
return self._jetfuel.Music_play(c_void_p(self._musicref));
def pause(self):
self._jetfuel.Music_pause(c_void_p(self._musicref));
def resume(self):
self._jetfuel.Music_resume(c_void_p(self._musicref));
def print_debug(self):
print("Music ref is ="+str(c_void_p(self._musicref)));
def get_music_error(self):
return self._jetfuel.Get_music_error();
我怎樣才能使此代碼工作的指針,可以多次解除引用?
如果這涉及到什麼,我的系統的信息是:
- 的Ubuntu 17.04 64位
- GCC(G ++)5.4.1
- GDB 50年12月7日
- 的Python 3.6
- SDL 2.0.3
說真的,只要用'cffi',你的生活就會變得更加健康。 – o11c
你只是加載'jetfuelsofilepath'一次嗎?如果是這樣,這種設計很奇怪。移動加載庫並將函數原型定義到類或模塊範圍。不要爲每個實例或每次調用某個方法時執行此操作。另外,如果原型設置正確,則不必浪費時間並將代碼手動包裝爲'c_void_p'和'c_wchar_p'實例。 – eryksun