Broken pipe."解决

一、现象描述

在利用librdkafka同kafka broker通信过程中，当kafka broker意外退出时（如kill -9），librdkafka接口的sendmsg接口报出了“Program received signal SIGPIPE, Broken pipe.” 这个错误具有典型性，根据网络搜索的结果，这个一般是由于向一个被破坏的socket连接或者pipe读写数据造成的，向有经验的同事请教，他们说这种场景不会出现SIGPIPE信号，而是直接send，
write， sendmsg等返回-1，同时errno会被设置成EPIPE。

实践是检验真理的唯一标准，找个例子一试便知。

二、例子程序

为了快速检验，从网上上借了一个简单的客户端、服务器程序，http://hi.baidu.com/dlpucat/item/97ab75c5243b8761f6c95d75，多谢原作者。

服务器端程序 server.c

点击(此处)折叠或打开

#include <netinet/in.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#define HELLO_WORLD_SERVER_PORT 6666

#define LENGTH_OF_LISTEN_QUEUE 20

#define BUFFER_SIZE 1024

int main(int argc, char **argv)

{

struct sockaddr_in server_addr;

bzero(&server_addr,sizeof(server_addr));

server_addr.sin_family = AF_INET;

server_addr.sin_addr.s_addr = htons(INADDR_ANY);

server_addr.sin_port = htons(HELLO_WORLD_SERVER_PORT);

int server_socket = socket(AF_INET,SOCK_STREAM,0);

if( server_socket < 0)

{

printf("Create Socket Failed!");

exit(1);

}

if( bind(server_socket,(struct
sockaddr*)&server_addr,sizeof(server_addr)))

{

printf("Server Bind Port : %d Failed!", HELLO_WORLD_SERVER_PORT);

exit(1);

}

if ( listen(server_socket, LENGTH_OF_LISTEN_QUEUE) )

{

printf("Server Listen Failed!");

exit(1);

}

while (1)

{

struct sockaddr_in client_addr;

socklen_t length = sizeof(client_addr);

int new_server_socket = accept(server_socket,(struct
sockaddr*)&client_addr,&length);

if ( new_server_socket < 0)

{

printf("Server Accept Failed!\n");

break;

}

char buffer[BUFFER_SIZE];

bzero(buffer, BUFFER_SIZE);

strcpy(buffer,"Hello,World from server!");

strcat(buffer,"\n");

send(new_server_socket,buffer,BUFFER_SIZE,0);

bzero(buffer,BUFFER_SIZE);

while(1){

length = recv(new_server_socket,buffer,BUFFER_SIZE,0);

if (length < 0)

{

printf("Server Recieve Data Failed!\n");

exit(1);

}

printf("\n%s",buffer);

}

close(new_server_socket);

}

close(server_socket);

return 0;

}

客户端程序

点击(此处)折叠或打开

#include <netinet/in.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <signal.h>

#include <errno.h>

#define HELLO_WORLD_SERVER_PORT 6666

#define BUFFER_SIZE 1024

int main(int argc, char **argv)

{

if (argc != 2)

{

printf("Usage: ./%s ServerIPAddress\n",argv[0]);

exit(1);

}

struct sockaddr_in client_addr;

bzero(&client_addr,sizeof(client_addr));

client_addr.sin_family = AF_INET;

client_addr.sin_addr.s_addr = htons(INADDR_ANY);

client_addr.sin_port = htons(0);

int client_socket = socket(AF_INET,SOCK_STREAM,0);

if( client_socket < 0)

{

printf("Create Socket Failed!\n");

exit(1);

}

if( bind(client_socket,(struct
sockaddr*)&client_addr,sizeof(client_addr)))

{

printf("Client Bind Port Failed!\n");

exit(1);

}

struct sockaddr_in server_addr;

bzero(&server_addr,sizeof(server_addr));

server_addr.sin_family = AF_INET;

if(inet_aton(argv[1],&server_addr.sin_addr) == 0)

{

printf("Server IP Address Error!\n");

exit(1);

}

server_addr.sin_port = htons(HELLO_WORLD_SERVER_PORT);

socklen_t server_addr_length = sizeof(server_addr);

if(connect(client_socket,(struct
sockaddr*)&server_addr, server_addr_length) < 0)

{

printf("Can Not Connect To %s!\n",argv[1]);

exit(1);

}

char buffer[BUFFER_SIZE];

bzero(buffer,BUFFER_SIZE);

int length = recv(client_socket,buffer,BUFFER_SIZE,0);

if(length < 0)

{

printf("Recieve Data From Server %s Failed!\n", argv[1]);

exit(1);

}

printf("From Server %s :\t%s",argv[1],buffer);

bzero(buffer,BUFFER_SIZE);

strcpy(buffer,"Hello, World! From Client\n");

while(1){

sleep(1);

int ret = send(client_socket,buffer,BUFFER_SIZE,0);

if (ret == -1 && errno == EPIPE){

printf("receive sigpipe\n");

}

}

close(client_socket);

return 0;

}

三、重现方法

step 1）编译： gcc -o server server.c

gcc -o -g client client.c （通过gdb直接看到异常退出）

step 2）启动服务器端：./server

step 3) 启动客户端：（这里假设客户端和服务器部署在同一台服务器） gdb ./client

(gdb) r 127.0.0.1

step 4) 观察正常运行结果：首先是客户端收到服务器端的消息：From Server 127.0.0.1 : Hello,World from server!

然后是服务器端每隔1s收到客户端的消息： Hello, World! From Client

step 5）通过ctrl+c关闭服务器端

step 6）观察客户端结果

Program received signal SIGPIPE, Broken pipe.

0x0000003a7fcd55f5 in send () from /lib64/libc.so.6

重现了！！

四、解决办法

解决办法很多，也很简单。

4.1 client中忽略SIGPIPE信号

点击(此处)折叠或打开

signal(SIGPIPE, SIG_IGN);

4.2 阻止SIGPIPE信号（后来追查，原来同事的程序框架中已经有了这种机制，所以没有经历过程序退出的问题）

点击(此处)折叠或打开

sigset_t set;

sigemptyset(&set);

sigaddset(&set, SIGPIPE);

sigprocmask(SIG_BLOCK, &set, NULL);

4.3 为SIGPIPE添加信号处理函数，处理完程序继续执行

点击(此处)折叠或打开

signal(SIGPIPE, pipesig_handler);

多种选择，总有一款适合您。