避免C编写的Python库的垃圾收集
我正在努力使用我的C语言编写的Python库。该代码用于在cp210x中写入寄存器,以控制中继卡。代码可以工作,但是Python以某种方式清除了对象 换句话说,C变量ttyPort在函数结束后被清除 以下是C代码:避免C编写的Python库的垃圾收集,python,c,python-c-api,Python,C,Python C Api,我正在努力使用我的C语言编写的Python库。该代码用于在cp210x中写入寄存器,以控制中继卡。代码可以工作,但是Python以某种方式清除了对象 换句话说,C变量ttyPort在函数结束后被清除 以下是C代码: #include <Python.h> #include <fcntl.h> #include <stropts.h> // C variable that holds the tty address (e.g. /dev/ttyUSB0) co
#include <Python.h>
#include <fcntl.h>
#include <stropts.h>
// C variable that holds the tty address (e.g. /dev/ttyUSB0)
const char* ttyPort;
int setRelay(int action, int relayNumber)
{
/* more magic over here */
printf("Port :: %s\n", ttyPort);
}
// All python wrappers below
static PyObject*setPort(PyObject* self, PyObject* args)
{
Py_INCREF(self)
// Copy python argument to ttyPort
if (!PyArg_ParseTuple(args, "s", &ttyPort))
return NULL;
printf("RelayModule :: Port set (%s)\n", ttyPort);
Py_RETURN_NONE;
}
static PyObject*fanOff(PyObject* self, PyObject* args)
{
//fanMode = 0;
printf("RelayModule :: Fan off %s\n",ttyPort);
if (setRelay(RELAY_OFF, 0) == 1){
// more magic
}
Py_RETURN_NONE;
}
/* more functions over here */
static PyMethodDef RelayMethods[] =
{
{"setPort", setPort, METH_VARARGS, "Set tty port."},
{"fanOff", fanOff, METH_NOARGS, "Fan off."},
{"fanHalf", fanHalf, METH_NOARGS, "Fan half speed."},
{"fanFull", fanFull, METH_NOARGS, "Fan full on."},
{"pumpOn", pumpOn, METH_NOARGS, "Pump on."},
{"pumpOff", pumpOff, METH_NOARGS, "Pump off."},
{"isPumpOn", isPumpOn, METH_NOARGS, "Check if pump is on."},
{"getFanMode", getFanMode, METH_NOARGS, "Get fan mode."},
{NULL, NULL, 0, NULL}
};
static struct PyModuleDef RelayDefs = {
PyModuleDef_HEAD_INIT,"RelayModule","A Python module that controls the Conrad 4ch relay card.", -1, RelayMethods
};
PyMODINIT_FUNC PyInit_Relay(void)
{
Py_Initialize();
return PyModule_Create(&RelayDefs);
}
我怎样才能声明一个对象?在其他语言中,我会:
RelayObj=新继电器()
或者如何正确存储变量?一个可能的解决方案是在
PyArg\u语法元组(args,“s”和&ttyPort)
中使用“es”格式说明符,而不是“s”。从文件:
通常,当格式设置指向缓冲区的指针时,缓冲区由相应的Python对象管理,缓冲区共享该对象的生存期
除非你用“es”。但是,您必须手动释放内存。将其嵌入到对象中,并使函数成为成员函数。我认为主要问题之一是,我将如何使用您当前的实现来做到这一点,尝试将
PyModule\u Create
的返回值存储在static var中。我怀疑立即返回它可能会导致优化器立即删除它(或者禁用编译器优化以查看它是否确实干扰)。例如:类myrelay(Relay):。。。def uuu init uuu(self,name):…
(加上其他函数)。然后您可以使用thisrelay=myrelay('/dev/ttyS0')
类myrelay(Relay):def\uu init\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu,但是,我还需要像这样添加编码:if(!PyArg_ParseTuple(args,“es”,“utf-8”和&ttyPort))
import Relay
def settty():
Relay.setPort("/dev/ttyUSB0")
def gettty():
Relay.fanOff()
def doAll():
Relay.setPort("/dev/ttyUSB0")
Relay.fanOff()
settty()
gettty() #Error, prints 'Port :: [garbage]'
doAll() #works!