Python:[Errno 32] Broken pipe 导致线程crash解决方法

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

#!/usr/bin/env python#!coding=utf-8import osimport timeimport socketimport threadingfrom BaseHTTPServer import HTTPServer ,BaseHTTPRequestHandlerfrom SocketServer import ThreadingMixInclass 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):    passif __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

[~]$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[~]$curl -s ‘http://10.232.41.142:9001/hello2′

[~]$ ctrl+C

此时服务器端输出日志如下:

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。

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。

#!/usr/bin/env python#!coding=utf-8import osimport timeimport socketimport threadingfrom BaseHTTPServer import HTTPServer ,BaseHTTPRequestHandlerfrom SocketServer import ThreadingMixInclass 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):    passif __name__ == '__main__':    serveraddr = ('',9001)    ser = ThreadingHTTPServer(serveraddr,RequestHandler)    ser.serve_forever()    sys.exit(0)

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

[~]$ ctrl+C

此时服务器端输出日志如下:

$./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()

Python:[Errno 32] Broken pipe 导致线程crash解决方法

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