使用pigpio连接树莓派时能否设置连接超时属性？

使用pigpio远程连接树莓派时，发现其没有内置方法设置连接超时——即指定尝试连接多久后中止操作。

现有代码如下：

def _connect_to_linked_pi(self):
    try:
        if self.linked_pi is None:
            pi = pigpio.pi(device_ip, PIGPIO_PORT)
            sock = pi.sl.s
            sock.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)
            sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPIDLE, 1)
            sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPINTVL, 1)
            sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPCNT, 3)
    except Exception as e:
        print(f"Error trying to connect -> {e}")

当前问题：即使无法连接到目标端，仍会创建连接对象，首次连接失败需等待30秒才会输出如下警告，后续尝试也需等待3秒：

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Can't connect to pigpio at 192.168.108.1(8888)

Did you start the pigpio daemon? E.g. sudo pigpiod

Did you specify the correct Pi host/port in the environment
variables PIGPIO_ADDR/PIGPIO_PORT?
E.g. export PIGPIO_ADDR=soft, export PIGPIO_PORT=8888

Did you specify the correct Pi host/port in the
pigpio.pi() function? E.g. pigpio.pi('soft', 8888)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

需求：设置连接超时，避免长时间等待，并能捕获该特定错误。

pigpio本身未提供连接超时的内置参数，但可以通过手动创建并配置socket，再将其绑定到pigpio实例的方式实现超时控制，具体实现如下：

import socket
import pigpio

def _connect_to_linked_pi(self):
    self.linked_pi = None
    try:
        # 创建TCP socket并设置连接超时
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.settimeout(5)  # 自定义超时时间，示例为5秒
        
        # 配置TCP保活参数（与原代码保持一致）
        sock.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)
        sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPIDLE, 1)
        sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPCNT, 3)
        sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPINTVL, 1)
        
        # 主动连接目标树莓派的pigpio端口
        sock.connect((device_ip, PIGPIO_PORT))
        
        # 初始化pigpio实例并绑定已连接的socket
        pi = pigpio.pi()
        pi.set_sock(sock)
        
        # 验证连接状态
        if not pi.connected:
            raise ConnectionError("pigpio connection initialization failed")
        
        self.linked_pi = pi
        
    except socket.timeout:
        print("连接超时：未能在指定时间内连接到目标设备")
    except ConnectionRefusedError:
        print("连接被拒绝：目标设备未启动pigpio守护进程，或IP/端口配置错误")
    except Exception as e:
        print(f"连接出错：{str(e)}")

核心要点： #

1. 手动控制连接超时：通过sock.settimeout()直接设置连接阶段的超时时间，替代pigpio默认的30秒/3秒等待
2. 提前捕获特定异常：在socket连接阶段就能捕获socket.timeout、ConnectionRefusedError等明确错误，无需等待pigpio的警告输出
3. 绑定socket到pigpio：使用pi.set_sock()将已连接的socket交给pigpio实例，后续可正常调用所有pigpio方法
4. 验证连接有效性：通过pi.connected属性确认pigpio是否成功初始化连接，避免后续操作出错

内容的提问来源于stack exchange，提问作者RedRum69