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    Python提示[Errno 32]Broken pipe导致线程crash错误解决方法

    作者:admin 时间:2021-07-17 18:41

    本文实例讲述了Python提示[Errno 32]Broken pipe导致线程crash错误解决方法。分享给大家供大家参考。具体方法如下:

    1. 错误现象
    ThreadingHTTPServer 实现的 http 服务,如果客户端在服务器返回前,主动断开连接,则服务器端会报 [Errno 32] Broken pipe 错,并导致处理线程 crash.
    下面先看个例子,python 版本: 2.7
    示例代码

    复制代码 代码如下:
    #!/usr/bin/env python
    #!coding=utf-8
     
    import os
    import time
    import socket
    import threading
    from BaseHTTPServer import HTTPServer ,BaseHTTPRequestHandler
    from SocketServer import ThreadingMixIn
     
    class RequestHandler(BaseHTTPRequestHandler):
        def do_GET(self):
            """
            处理get请求
            """      
            query=self.path
            print "query: %s thread=%s" % (query, str(threading.current_thread()))
            
            #ret_str="<html>" + self.path + "<br>" + str(self.server) + "<br>" + str(self.responses) +  "</html>"
            ret_str="<html>" + self.path + "<br>" + str(self.server) +  "</html>"
            
            time.sleep(5)
            
            try:
                self.send_response(200)
                self.send_header('Content-type','text/html')
                self.end_headers()
                self.wfile.write(ret_str)
            except socket.error, e:
                print "socket.error : Connection broke. Aborting" + str(e)
                self.wfile._sock.close()  # close socket
                self.wfile._sock=None
                return False
           
            print "success prod query :%s" % (query)
            return True
     
    #多线程处理
    class ThreadingHTTPServer(ThreadingMixIn,HTTPServer):
        pass
        
    if __name__ == '__main__':
        serveraddr = ('',9001)
     
        ser = ThreadingHTTPServer(serveraddr,RequestHandler)
        ser.serve_forever()
        sys.exit(0)

    运行服务
    ./thread_http_server_error.py
    第1次 curl ,等待返回
    复制代码 代码如下:
    [~]$curl -s 'http://10.232.41.142:9001/hello1′
    <html>/hello1<br><__main__.ThreadingHTTPServer instance at 0x37483b0></html>[~]$
    此时服务器端输出日志如下:
    $./thread_http_server_error.py
    query: /hello1 thread=
    search041142.sqa.cm4.tbsite.net – - [15/May/2014 15:02:27] “GET /hello1 HTTP/1.1″ 200 -
    success prod query :/hello1

     第2次 curl ,不等待返回,ctrl +C 来模拟客户端断开
    复制代码 代码如下:
    [~]$curl -s 'http://10.232.41.142:9001/hello2′
    [~]$ ctrl+C

    此时服务器端输出日志如下:
    复制代码 代码如下:
    query: /hello2 thread=
    search041142.sqa.cm4.tbsite.net – - [15/May/2014 15:33:10] “GET /hello2 HTTP/1.1″ 200 -
    socket.error : Connection broke. Aborting[Errno 32] Broken pipe
    —————————————-
    Exception happened during processing of request from ('10.232.41.142′, 48769)
    Traceback (most recent call last):
    File “/home/wuzhu/tools/python_2_7_1/lib/python2.7/SocketServer.py”, line 582, in process_request_thread
    self.finish_request(request, client_address)
    File “/home/wuzhu/tools/python_2_7_1/lib/python2.7/SocketServer.py”, line 323, in finish_request
    self.RequestHandlerClass(request, client_address, self)
    File “/home/wuzhu/tools/python_2_7_1/lib/python2.7/SocketServer.py”, line 639, in __init__
    self.handle()
    File “/home/wuzhu/tools/python_2_7_1/lib/python2.7/BaseHTTPServer.py”, line 337, in handle
    self.handle_one_request()
    File “/home/wuzhu/tools/python_2_7_1/lib/python2.7/BaseHTTPServer.py”, line 326, in handle_one_request
     self.wfile.flush() #actually send the response if not already done.
    File “/home/wuzhu/tools/python_2_7_1/lib/python2.7/socket.py”, line 303, in flush
    self._sock.sendall(view[write_offset:write_offset+buffer_size])
    AttributeError: 'NoneType' object has no attribute 'sendall'

    2. 原因分析

    “[Errno 32] Broken pipe “ 产生的原因还是比较明确的,由于 client 在服务器返回前主动断开连接,所以服务器在返回时写 socket 收到SIGPIPE报错。虽然在我们的程序中也对异常进行了处理,将handler 的 wfile._sock 对象close 掉 ,但python 的库里BaseHTTPServer.py中BaseHTTPRequestHandler 类的成员函数handle_one_request还是会直接调用 wfile.flush ,而没有判断 wfile 是否已经 close。

    复制代码 代码如下:
    def handle_one_request(self):
        """Handle a single HTTP request.
     
        You normally don't need to override this method; see the class
        __doc__ string for information on how to handle specific HTTP
        commands such as GET and POST.
     
        """
        try:
            self.raw_requestline = self.rfile.readline(65537)
            if len(self.raw_requestline) > 65536:
                self.requestline = ''
                self.request_version = ''
                self.command = ''
                self.send_error(414)
                return
            if not self.raw_requestline:
                self.close_connection = 1
                return
            if not self.parse_request():
                # An error code has been sent, just exit
                return
            mname = 'do_' + self.command
            if not hasattr(self, mname):
                self.send_error(501, "Unsupported method (%r)" % self.command)
                return
            method = getattr(self, mname)
            method()
            #没有判断 wfile 是否已经 close 就直接调用 flush()
            self.wfile.flush() #actually send the response if not already done.
        except socket.timeout, e:
            #a read or a write timed out.  Discard this connection
            self.log_error("Request timed out: %r", e)
            self.close_connection = 1
            return

    3. 解决办法

    只要在RequestHandler重载其基类BaseHTTPRequestHandler的成员函数handle_one_reques(),在调用 wfile.flush() 前加上 wfile 是否已经 close 即可。

    复制代码 代码如下:
    #!/usr/bin/env python
    #!coding=utf-8

    import os
    import time
    import socket
    import threading
    from BaseHTTPServer import HTTPServer ,BaseHTTPRequestHandler
    from SocketServer import ThreadingMixIn

    class RequestHandler(BaseHTTPRequestHandler):
        
        def handle_one_request(self):
            """Handle a single HTTP request.
     
            You normally don't need to override this method; see the class
            __doc__ string for information on how to handle specific HTTP
            commands such as GET and POST.
     
            """
            try:
                self.raw_requestline = self.rfile.readline(65537)
                if len(self.raw_requestline) > 65536:
                    self.requestline = ''
                    self.request_version = ''
                    self.command = ''
                    self.send_error(414)
                    return
                if not self.raw_requestline:
                    self.close_connection = 1
                    return
                if not self.parse_request():
                    # An error code has been sent, just exit
                    return
                mname = 'do_' + self.command
                if not hasattr(self, mname):
                    self.send_error(501, "Unsupported method (%r)" % self.command)
                    return
                method = getattr(self, mname)
                print "before call do_Get"
                method()
                #增加 debug info 及 wfile 判断是否已经 close
                print "after call do_Get"
                if not self.wfile.closed:
                    self.wfile.flush() #actually send the response if not already done.
                print "after wfile.flush()"
            except socket.timeout, e:
                #a read or a write timed out.  Discard this connection
                self.log_error("Request timed out: %r", e)
                self.close_connection = 1
                return
        
        def do_GET(self):
            """
            处理get请求
            """
            query=self.path
            print "query: %s thread=%s" % (query, str(threading.current_thread()))
     
            ret_str="<html>" + self.path + "<br>" + str(self.server) +  "</html>"
     
            time.sleep(5)
            
            try:
                self.send_response(200)
                self.send_header('Content-type','text/html')
                self.end_headers()         
                self.wfile.write(ret_str)
            except socket.error, e:
                print "socket.error : Connection broke. Aborting" + str(e)
                self.wfile._sock.close()
                self.wfile._sock=None
                return False
           
            print "success prod query :%s" % (query)
            return True
     
    #多线程处理
    class ThreadingHTTPServer(ThreadingMixIn,HTTPServer):
        pass
        
    if __name__ == '__main__':
        serveraddr = ('',9001)
     
        ser = ThreadingHTTPServer(serveraddr,RequestHandler)
        ser.serve_forever()
        sys.exit(0)


    运行服务
    ./thread_http_server.py
    curl ,不等待返回,ctrl +C 来模拟客户端断开
    复制代码 代码如下:
    [~]$curl -s 'http://10.232.41.142:9001/hello2'
    [~]$ ctrl+C

    此时服务器端输出日志如下:
    复制代码 代码如下:
    $./thread_http_server.pybefore call do_Get
    query: /hello2 thread=<Thread(Thread-1, started 1103210816)>
    search041142.sqa.cm4.tbsite.net - - [15/May/2014 15:54:09] "GET /hello2 HTTP/1.1" 200 -
    socket.error : Connection broke. Aborting[Errno 32] Broken pipe
    after call do_Get
    after wfile.flush()

    希望本文所述对大家的Python程序设计有所帮助。

    jsjbwy
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