Python調(diào)用C的SDK出現(xiàn)返回值不符合預(yù)期以及Segmentationfault的解決方法

>>> strchr = libc.strchr
>>> strchr("abcdef", ord("d")) 
8059983
>>> strchr.restype = c_char_p # c_char_p is a pointer to a string
>>> strchr("abcdef", ord("d"))
'def'
>>> print strchr("abcdef", ord("x"))
None
>>>

index = userdata # c_uint(userdata).value
_buf_cond.acquire()
# time.sleep(0.2)

# 復(fù)制圖片到內(nèi)存
# _pic_buf.buf = pBuf c_char 和 c_byte轉(zhuǎn)換
try:
 temp = [pBuf[i] for i in xrange(0, RevLen)]
 _buf_list[index].buf = struct.pack('%db' % RevLen, *temp)
 # 序列號(hào)
 _buf_list[index].sn = c_ulong(CmdSerial).value
 _buf_list[index].id = index
 _buf_list[index].size = c_uint(RevLen).value
 _buf_list[index].ext = 'jpeg' # encode_dict.get(EncodeType, 'jpeg')
except Exception, e:
 logger.error('截圖緩存發(fā)生異常:%s' % str(e))
finally:
 _buf_cond.notify()
 _buf_cond.release()

讀

_buf_cond.acquire()

_buf_cond.wait(timeout=15.0)
# 等待200ms再訪(fǎng)問(wèn)數(shù)據(jù)
# time.sleep(0.2)
if _buf_list[self.index].sn == snap.CmdSerial and _buf_list[self.index].id == self.index:
 self.save_picture(_buf_list[self.index].buf, _buf_list[self.index].ext)
 self.info('針對(duì)通道%d截圖成功，IP：%s，Port：%s' % (channel, self.ip, self.port))
 pass
_buf_cond.release()

self.callback = CFUNCTYPE(c_void_p, c_longlong, POINTER(c_byte), c_uint, c_uint, c_ulong, c_ulonglong)

def set_callback(self, save_after_recv_pic, index):
 self.dll.CLIENT_SetSnapRevCallBack(self._callback(save_after_recv_pic), index)

子類(lèi)中定義，_save_after_recv_pic也在子類(lèi)中定義為staticmethod

def _set_callback(self):
 try:
 if 0 <= self.index < _buf_size:

 self.set_callback(self._save_after_recv_pic, self.index) # 函數(shù)調(diào)用層次太深，經(jīng)常報(bào)segmentation fault
 return True
 else:
 self.error('設(shè)置截圖保存回調(diào)函數(shù)的userdata參數(shù)錯(cuò)誤:%d' % self.index)
 return False
 except Exception, e:
 self.error('設(shè)置截圖保存回調(diào)函數(shù)失敗,%s' % str(e))
 return False

self.capture_callback = self.callback(self._save_after_recv_pic)

子類(lèi)中直接注冊(cè)回調(diào)函數(shù)

def _set_callback(self):
 try:
 if 0 <= self.index < _buf_size:
 self.dll.CLIENT_SetSnapRevCallBack(self.capture_callback, self.index)
 # self.set_callback(self._save_after_recv_pic, self.index) # 函數(shù)調(diào)用層次太深，經(jīng)常報(bào)segmentation fault
 return True
 else:
 self.error('設(shè)置截圖保存回調(diào)函數(shù)的userdata參數(shù)錯(cuò)誤:%d' % self.index)
 return False
 except Exception, e:
 self.error('設(shè)置截圖保存回調(diào)函數(shù)失敗,%s' % str(e))
 return False