我有两个守护进程,A 正在与 B 通话。B 正在监听一个端口,A 打开到该端口的 tcp 连接。 A 能够打开一个到 B 的套接字,但是当它尝试实际写入所说的套接字时,我得到了一个 SIGPIPE,所以我试图找出 B 可以在哪里关闭打开的套接字。
但是,如果我附加到 gdb 中的两个守护程序,则 SIGPIPE 会在调用任何处理数据的代码之前发生。这种是有道理的,因为初始写入永远不会成功,并且监听器是从接收数据中触发的。我的问题是 - 什么可能导致守护进程 B 在发送任何数据之前关闭套接字?套接字在打开后不到一微秒就关闭了,所以我认为它不可能是超时或任何类似的事情。我很想列出一份可能的 list ,因为我已经研究了几天,而且我几乎没有想法。
根据要求,这里是接受和处理通信的代码:
{
extern char *PAddrToString(pbs_net_t *);
int i;
int n;
time_t now;
fd_set *SelectSet = NULL;
int SelectSetSize = 0;
int MaxNumDescriptors = 0;
char id[] = "wait_request";
char tmpLine[1024];
struct timeval timeout;
long OrigState = 0;
if (SState != NULL)
OrigState = *SState;
timeout.tv_usec = 0;
timeout.tv_sec = waittime;
SelectSetSize = sizeof(char) * get_fdset_size();
SelectSet = (fd_set *)calloc(1,SelectSetSize);
pthread_mutex_lock(global_sock_read_mutex);
memcpy(SelectSet,GlobalSocketReadSet,SelectSetSize);
/* selset = readset;*/ /* readset is global */
MaxNumDescriptors = get_max_num_descriptors();
pthread_mutex_unlock(global_sock_read_mutex);
n = select(MaxNumDescriptors, SelectSet, (fd_set *)0, (fd_set *)0, &timeout);
if (n == -1)
{
if (errno == EINTR)
{
n = 0; /* interrupted, cycle around */
}
else
{
int i;
struct stat fbuf;
/* check all file descriptors to verify they are valid */
/* NOTE: selset may be modified by failed select() */
for (i = 0; i < MaxNumDescriptors; i++)
{
if (FD_ISSET(i, GlobalSocketReadSet) == 0)
continue;
if (fstat(i, &fbuf) == 0)
continue;
/* clean up SdList and bad sd... */
pthread_mutex_lock(global_sock_read_mutex);
FD_CLR(i, GlobalSocketReadSet);
pthread_mutex_unlock(global_sock_read_mutex);
} /* END for each socket in global read set */
free(SelectSet);
log_err(errno, id, "Unable to select sockets to read requests");
return(-1);
} /* END else (errno == EINTR) */
} /* END if (n == -1) */
for (i = 0; (i < max_connection) && (n != 0); i++)
{
pthread_mutex_lock(svr_conn[i].cn_mutex);
if (FD_ISSET(i, SelectSet))
{
/* this socket has data */
n--;
svr_conn[i].cn_lasttime = time(NULL);
if (svr_conn[i].cn_active != Idle)
{
void *(*func)(void *) = svr_conn[i].cn_func;
netcounter_incr();
pthread_mutex_unlock(svr_conn[i].cn_mutex);
func((void *)&i);
/* NOTE: breakout if state changed (probably received shutdown request) */
if ((SState != NULL) &&
(OrigState != *SState))
break;
}
else
{
pthread_mutex_lock(global_sock_read_mutex);
FD_CLR(i, GlobalSocketReadSet);
pthread_mutex_unlock(global_sock_read_mutex);
close_conn(i, TRUE);
pthread_mutex_unlock(svr_conn[i].cn_mutex);
pthread_mutex_lock(num_connections_mutex);
sprintf(tmpLine, "closed connections to fd %d - num_connections=%d (select bad socket)",
i,
num_connections);
pthread_mutex_unlock(num_connections_mutex);
log_err(-1, id, tmpLine);
}
}
else
pthread_mutex_unlock(svr_conn[i].cn_mutex);
} /* END for i */
/* NOTE: break out if shutdown request received */
if ((SState != NULL) && (OrigState != *SState))
return(0);
/* have any connections timed out ?? */
now = time((time_t *)0);
for (i = 0;i < max_connection;i++)
{
struct connection *cp;
pthread_mutex_lock(svr_conn[i].cn_mutex);
cp = &svr_conn[i];
if (cp->cn_active != FromClientDIS)
{
pthread_mutex_unlock(svr_conn[i].cn_mutex);
continue;
}
if ((now - cp->cn_lasttime) <= PBS_NET_MAXCONNECTIDLE)
{
pthread_mutex_unlock(svr_conn[i].cn_mutex);
continue;
}
if (cp->cn_authen & PBS_NET_CONN_NOTIMEOUT)
{
pthread_mutex_unlock(svr_conn[i].cn_mutex);
continue; /* do not time-out this connection */
}
/* NOTE: add info about node associated with connection - NYI */
snprintf(tmpLine, sizeof(tmpLine), "connection %d to host %s has timed out after %d seconds - closing stale connection\n",
i,
PAddrToString(&cp->cn_addr),
PBS_NET_MAXCONNECTIDLE);
log_err(-1, "wait_request", tmpLine);
/* locate node associated with interface, mark node as down until node responds */
/* NYI */
close_conn(i, TRUE);
pthread_mutex_unlock(svr_conn[i].cn_mutex);
} /* END for (i) */
return(0);
}
注意:我没有写这段代码。
最佳答案
有没有可能你搞砸了,在程序的其他地方你试图关闭同一个句柄两次?
那可以很容易地对你做到这一点。
提示:systrace 可以确定这是否正在发生。
关于c - 带运行程序的 SIGPIPE,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/8040945/