當我通過ctypes調用的c函數實例化python對象時,嵌入式Python 3.3程序出現segfaults。在通過ctypes調用的c函數中實例化python對象
設置解釋器後,我可以成功地從C主要實例化一個蟒INT(以及自定義的C擴展型):
#import <Python/Python.h>
#define LOGPY(x) \
{ fprintf(stderr, "%s: ", #x); PyObject_Print((PyObject*)(x), stderr, 0); fputc('\n', stderr); }
// c function to be called from python script via ctypes.
void instantiate() {
PyObject* instance = PyObject_CallObject((PyObject*)&PyLong_Type, NULL);
LOGPY(instance);
}
int main(int argc, char* argv[]) {
Py_Initialize();
instantiate(); // works fine
// run a script that calls instantiate() via ctypes.
FILE* scriptFile = fopen("emb.py", "r");
if (!scriptFile) {
fprintf(stderr, "ERROR: cannot open script file\n");
return 1;
}
PyRun_SimpleFileEx(scriptFile, scriptPath, 1); // close on completion
return 0;
}
我然後使用PyRun_SimpleFileEx運行Python腳本。它似乎運行得很好,但是當它調用通過ctypes的,裏面PyObject_CallObject程序段錯誤實例化():
import ctypes as ct
dy = ct.CDLL('./emb')
dy.instantiate() # segfaults
LLDB輸出:
instance: 0
Process 52068 stopped
* thread #1: tid = 0x1c03, 0x000000010000d3f5 Python`PyObject_Call + 69, stop reason = EXC_BAD_ACCESS (code=1, address=0x18)
frame #0: 0x000000010000d3f5 Python`PyObject_Call + 69
Python`PyObject_Call + 69:
-> 0x10000d3f5: movl 24(%rax), %edx
0x10000d3f8: incl %edx
0x10000d3fa: movl %edx, 24(%rax)
0x10000d3fd: leaq 2069148(%rip), %rax ; _Py_CheckRecursionLimit
(lldb) bt
* thread #1: tid = 0x1c03, 0x000000010000d3f5 Python`PyObject_Call + 69, stop reason = EXC_BAD_ACCESS (code=1, address=0x18)
frame #0: 0x000000010000d3f5 Python`PyObject_Call + 69
frame #1: 0x00000001000d5197 Python`PyEval_CallObjectWithKeywords + 87
frame #2: 0x0000000201100d8e emb`instantiate + 30 at emb.c:9
爲什麼調用實例()從失敗只有ctypes?這個函數在調用python庫的時候只會崩潰,所以或許某些解釋器狀態正在被ctypes FFI調用消滅?
dy_test()如何獲得實例化?你的日誌消息,如果它通過實例化,表明PyObject_CallObject已完成。否則,你不會看到LOGPY輸出。你可以在Python中嘗試PyLongObject或其他標準的可調用嗎?這會告訴你,如果這是你的類型設置的問題。 –
對不起,我把dy_test改名爲清晰的問題;固定。傳遞&PyLong_Type以同樣的方式失敗;我會相應地減少repro。 – gwk
如果用'PyDLL'替換'CDLL',它會更好嗎? –