Python Ctypes傳入指針並獲得結構

Question

這是我在解決實際有用問題之前嘗試工作的一個簡單示例。 C代碼：

typedef struct {
  uint32_t seconds;
  uint32_t nanoseconds;
} geoTime;

int myTest(geoTime *myTime){
  printf("Time: %d %d\n", myTime->seconds, myTime->nanoseconds);
  myTime->seconds = myTime->nanoseconds;
  geoTime T = {314, 159};
  printf("MyTime: %d %d      retValue: %d %d\n", myTime->seconds, myTime->nanoseconds, T.seconds, T.nanoseconds);
  return 314;
}

Python代碼：

import ctypes
import time
import math

lib_astro = ctypes.CDLL("libastroC.so")

class geoTime(ctypes.Structure):
    _fields_ = [("seconds", ctypes.c_uint),
                ("nanoseconds", ctypes.c_uint)]  

now = time.time()
print "Python Now: ", now

now_geoTime = geoTime()
now_geoTime.seconds = ctypes.c_uint(int((math.floor(now))))
now_geoTime.nanoseconds = ctypes.c_uint(int(math.floor(math.modf(now)[0] * 1000000000)))
print "Python geoTime now:", now_geoTime.seconds, now_geoTime.nanoseconds

lib_astro.myTest.argtypes = [ctypes.POINTER(geoTime)]
lib_astro.myTest.restype = geoTime
print "************* ENTERING C ********************"
test = lib_astro.myTest(ctypes.byref(now_geoTime))
print "************* EXITING C **********************"
print "Modified now_geoTime: ",now_geoTime.seconds, now_geoTime.nanoseconds
print "test: ",test

輸出：

Python Now:  1336401085.43
Python geoTime now: 1336401085 432585000
************* ENTERING C ********************
Time: 1336401085 432585000
MyTime: 432585000 432585000      retValue: 314 159
************* EXITING C **********************
Modified now_geoTime:  432585000 432585000
test:  314

上面的代碼完全按照我的預期工作，我的指針進入並被修改，我得到了我的整數。 當我嘗試在C中創建一個geoTime結構並將其返回給Python時，就會出現問題。

在C中添加/修改代碼：

geoTime patTest(geoTime *myTime){
    printf("Time: %d %d\n", myTime->seconds, myTime->nanoseconds);
    myTime->seconds = myTime->nanoseconds;
    geoTime T = {314, 159};
    printf("MyTime: %d %d      retValue: %d %d\n", myTime->seconds, myTime->nanoseconds, T.seconds, T.nanoseconds);
    return T;

}

修改后的Python代碼：

lib_astro.patTest.argtypes = [ctypes.POINTER(geoTime)]
lib_astro.patTest.restype = geoTime
print "************* ENTERING C ********************"
test = lib_astro.patTest(ctypes.byref(now_geoTime))
print "************* EXITING C **********************"
print "Modified now_geoTime: ",now_geoTime.seconds, now_geoTime.nanoseconds
print "Type of test: ",test
print "Information in test: ", test.seconds, test.nanoseconds

一旦我改變我的代碼，C代碼就會變成myTime而不是來自Python的信息，並且返回值被放入now_geoTime而不是test。 關於可能出錯的任何想法？ 看起來python代碼沒有像我期望的那樣做，因為C代碼似乎與傳入的值一起正常工作。

上一個例子的輸出：

Python Now:  1336404920.77
Python geoTime now: 1336404920 773674011
************* ENTERING C ********************
Time: 90500 -17037640
MyTime: -17037640 -17037640      retValue: 314 159
************* EXITING C **********************
Modified now_geoTime:  314 159
Type of test:  <__main__.geoTime object at 0x82bedf4>
Information in test:  137096800 134497384

任何想法都會非常感激，我一直試圖讓它工作一段時間。 提前致謝！

Answer 1

我切換到64位python / 64位dll，問題就消失了。 當我感覺有點靈感時，我可能會嘗試將它分離到編譯器，os或python但是現在我將用它來運行。