Python:forkingHTTP服务器（ForkingMixIn）与MTCNN一起使用时，在任何请求上都会停止

Question

我正在尝试编写一个简单的web服务器，它将图像的路径作为参数，检测图像上的人脸，并以JSON格式返回检测到的人脸信息

它可以在没有线程或分叉的情况下正常工作，但当我使用ForkingMixIn使服务器能够一次处理多个请求时就不行了

代码如下：

#!/usr/bin/python


from http.server import BaseHTTPRequestHandler, HTTPServer
from socketserver import ThreadingMixIn, ForkingMixIn
import threading

import cv2
import numpy as np
import os
import sys
import getopt
import glob
import time
from PIL import Image
from io import BytesIO

import web
import logging
import urllib.parse as urlparse

import json

from matplotlib import pyplot
from mtcnn.mtcnn import MTCNN


class Handler(BaseHTTPRequestHandler):
    def _set_response(self):
        self.send_response(200)
        self.send_header('Content-type', 'text/html')
        self.end_headers()

    def do_GET(self):
        logging.info("GET request,\nPath: %s\nHeaders:\n%s\n", str(self.path), str(self.headers))
        self._set_response()
        self.wfile.write("GET request for {}".format(self.path).encode('utf-8'))

    def do_POST(self):

        res = {}
        errors = []


        self._set_response()

        orig_image_path = "".encode("utf-8")

        if self.rfile:
             for key,value in dict(urlparse.parse_qs(self.rfile.read(int(self.headers['Content-Length'])))).items():
                if key == "path".encode("utf-8"):
                   orig_image_path = value[0]

        if not orig_image_path:           
           errors.append("image_file_not_defined")

        else:   

           try:
              with open(orig_image_path) as f:
                 n = 1
           except IOError:
              errors.append("image_file_not_found")

        if len(errors) > 0:
           res = {
              "res": "error",
              "errors": errors
           }

           self.wfile.write(json.dumps(res).encode("utf-8"))
           return


        res.update({"res": "ok"})

        if orig_image_path:
           image = cv2.imread(orig_image_path.decode("utf-8"))
           faces = process_faces(image)
           res.update({"faces":  faces})

        #Return result
        self.wfile.write(json.dumps(res).encode("utf-8"))




def process_faces(image):

   faces_list = []

   faces = detector.detect_faces(image)


   for face in faces:

       face_obj = {
        "mtcnn_data": face
       }

       faces_list.append(face_obj)

   return faces_list



class ThreadedHTTPServer(ThreadingMixIn, HTTPServer):
    pass

class ForkingHTTPServer(ForkingMixIn, HTTPServer):
    pass


#This does not work (HTTP request halts)
def run(server_class=ForkingHTTPServer, handler_class=Handler, port=7000):

#This works as expected
#def run(server_class=HTTPServer, handler_class=Handler, port=7000):

    logging.basicConfig(level=logging.INFO)
    server_address = ('127.0.0.1', port)
    httpd = server_class(server_address, handler_class)
    logging.info('\n\nStarting httpd on port %s...\n', port)
    try:
        httpd.serve_forever()
    except KeyboardInterrupt:        
        httpd.server_close()
        logging.info('Stopping httpd...\n')




if __name__ == '__main__':
    from sys import argv


    #---FACE DETECTOR---
    detector = MTCNN()
    #---/FACE DETECTOR---

     #Run server
    run()

你知道怎么处理吗