[Sheepdog] [PATCH] fix a bug in rx() when read() returns 0 but connection is not marked as closed.

[levin li]

Yes, we met this problem, when read() returns zero, but errno is EAGAIN,
I suppose the EAGAIN was created by previous read()

thanks
levin

On 2012年04月24日 17:20, MORITA Kazutaka wrote:
> On Tue, Apr 24, 2012 at 5:40 PM, Huxinwei<huxinwei at huawei.com>  wrote:
>> I proposed something similar a while ago.
>> The connection is actually staying in CLOSE_WAIT status while this happens. I'd suggest you consider something more reliable.
> Is there any case that read() returns zero but the connection is not closed?
>
> Thanks,
>
> Kazutaka
>
>> +               else if (!ret) { //FIXME: is this the best place to check?
>> +                       int r;
>> +                       struct tcp_info ti;
>> +                       socklen_t l = sizeof(struct tcp_info);
>> +                       r = getsockopt(conn->fd, SOL_TCP, TCP_INFO, (void*)&ti,&l);
>> +                       if (r<  0) panic("this is really wired");
>> +                       if (ti.tcpi_state == TCP_CLOSE_WAIT) {
>> +                               conn->c_rx_state = C_IO_CLOSED;
>> +                               conn->c_tx_state = C_IO_CLOSED;
>> +                       }
>> +               }
>>
>> FYI.
>>
>>> -----Original Message-----
>>> From: sheepdog-bounces at lists.wpkg.org
>>> [mailto:sheepdog-bounces at lists.wpkg.org] On Behalf Of Li Wenpeng
>>> Sent: Tuesday, April 24, 2012 4:00 PM
>>> To: sheepdog at lists.wpkg.org
>>> Subject: [Sheepdog] [PATCH] fix a bug in rx() when read() returns 0 but
>>> connection is not marked as closed.
>>>
>>> From: levin li<xingke.lwp at taobao.com>
>>>
>>> if read() returns 0，it means connection closed, but previous
>>> read() may set errno to EAGAIN, in which case rx() would just
>>> return 0 without set connection state as C_IO_CLOSED
>>>
>>> Signed-off-by: levin li<xingke.lwp at taobao.com>
>>> ---
>>>   lib/net.c |    7 ++++++-
>>>   1 files changed, 6 insertions(+), 1 deletions(-)
>>>
>>> diff --git a/lib/net.c b/lib/net.c
>>> index 260ae38..8ac7c9e 100644
>>> --- a/lib/net.c
>>> +++ b/lib/net.c
>>> @@ -70,7 +70,12 @@ int rx(struct connection *conn, enum conn_state
>>> next_state)
>>>        int ret;
>>>
>>>        ret = read(conn->fd, conn->rx_buf, conn->rx_length);
>>> -     if (!ret || ret<  0) {
>>> +     if (!ret) {
>>> +             conn->c_rx_state = C_IO_CLOSED;
>>> +             return 0;
>>> +     }
>>> +
>>> +     if (ret<  0) {
>>>                if (errno != EAGAIN)
>>>                        conn->c_rx_state = C_IO_CLOSED;
>>>                return 0;
>>> --
>>> 1.7.1
>>>
>>> --
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>>> sheepdog at lists.wpkg.org
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