Re: [Qemu-devel] [PATCH v2 3/3] slirp: set mainloop timeout with more precise value

[liu ping fan]

On Wed, Aug 14, 2013 at 4:35 PM, Jan Kiszka <address@hidden> wrote:
> On 2013-08-14 05:02, Liu Ping Fan wrote:
>> If slirp needs to emulate tcp timeout, then the timeout value
>> for mainloop should be more precise, which is determined by
>> slirp's fasttimo or slowtimo. Achieve this by swap the logic
>> sequence of slirp_pollfds_fill and slirp_update_timeout.
>>
>> Signed-off-by: Liu Ping Fan <address@hidden>
>> ---
>>  main-loop.c      |  3 +--
>>  slirp/libslirp.h |  3 +--
>>  slirp/slirp.c    | 28 ++++++++++++++++++++++++----
>>  stubs/slirp.c    |  6 +-----
>>  4 files changed, 27 insertions(+), 13 deletions(-)
>>
>> diff --git a/main-loop.c b/main-loop.c
>> index a44fff6..e258567 100644
>> --- a/main-loop.c
>> +++ b/main-loop.c
>> @@ -458,8 +458,7 @@ int main_loop_wait(int nonblocking)
>>      g_array_set_size(gpollfds, 0); /* reset for new iteration */
>>      /* XXX: separate device handlers from system ones */
>>  #ifdef CONFIG_SLIRP
>> -    slirp_update_timeout(&timeout);
>> -    slirp_pollfds_fill(gpollfds);
>> +    slirp_pollfds_fill(gpollfds, &timeout);
>>  #endif
>>      qemu_iohandler_fill(gpollfds);
>>      ret = os_host_main_loop_wait(timeout);
>> diff --git a/slirp/libslirp.h b/slirp/libslirp.h
>> index ceabff8..5bdcbd5 100644
>> --- a/slirp/libslirp.h
>> +++ b/slirp/libslirp.h
>> @@ -16,8 +16,7 @@ Slirp *slirp_init(int restricted, struct in_addr vnetwork,
>>                    void *opaque);
>>  void slirp_cleanup(Slirp *slirp);
>>
>> -void slirp_update_timeout(uint32_t *timeout);
>> -void slirp_pollfds_fill(GArray *pollfds);
>> +void slirp_pollfds_fill(GArray *pollfds, uint32_t *timeout);
>>
>>  void slirp_pollfds_poll(GArray *pollfds, int select_error);
>>
>> diff --git a/slirp/slirp.c b/slirp/slirp.c
>> index c224523..da759a7 100644
>> --- a/slirp/slirp.c
>> +++ b/slirp/slirp.c
>> @@ -260,18 +260,37 @@ void slirp_cleanup(Slirp *slirp)
>>  #define CONN_CANFSEND(so) (((so)->so_state & 
>> (SS_FCANTSENDMORE|SS_ISFCONNECTED)) == SS_ISFCONNECTED)
>>  #define CONN_CANFRCV(so) (((so)->so_state & 
>> (SS_FCANTRCVMORE|SS_ISFCONNECTED)) == SS_ISFCONNECTED)
>>
>> -void slirp_update_timeout(uint32_t *timeout)
>> +static void slirp_update_timeout(uint32_t *timeout)
>>  {
>> -    if (!QTAILQ_EMPTY(&slirp_instances)) {
>> -        *timeout = MIN(1000, *timeout);
>> +    Slirp *slirp;
>> +    uint32_t t;
>> +
>> +    if (*timeout <= TIMEOUT_FAST) {
>> +        return;
>> +    }
>> +    t = *timeout;
>> +
>> +    /* If we have tcp timeout with slirp, then we will fill @timeout with
>> +     * more precise value.
>> +     */
>> +    QTAILQ_FOREACH(slirp, &slirp_instances, entry) {
>> +        if (slirp->time_fasttimo) {
>> +            *timeout = TIMEOUT_FAST;
>> +            return;
>> +        }
>> +        if (slirp->do_slowtimo) {
>> +            t = MIN(TIMEOUT_SLOW, t);
>> +        }
>>      }
>> +    *timeout = t;
>>  }
>>
>> -void slirp_pollfds_fill(GArray *pollfds)
>> +void slirp_pollfds_fill(GArray *pollfds, uint32_t *timeout)
>>  {
>>      Slirp *slirp;
>>      struct socket *so, *so_next;
>>
>> +    *timeout = MIN(1000, *timeout);
>
> This should come after the QTAILQ_EMPTY check: no slirps, no timeout
> modifications.
>
Will fix.

Thx,
Pingfan

>>      if (QTAILQ_EMPTY(&slirp_instances)) {
>>          return;
>>      }
>> @@ -437,6 +456,7 @@ void slirp_pollfds_fill(GArray *pollfds)
>>              }
>>          }
>>      }
>> +    slirp_update_timeout(timeout);
>>  }
>>
>>  void slirp_pollfds_poll(GArray *pollfds, int select_error)
>> diff --git a/stubs/slirp.c b/stubs/slirp.c
>> index f1fc833..bd0ac7f 100644
>> --- a/stubs/slirp.c
>> +++ b/stubs/slirp.c
>> @@ -1,11 +1,7 @@
>>  #include "qemu-common.h"
>>  #include "slirp/slirp.h"
>>
>> -void slirp_update_timeout(uint32_t *timeout)
>> -{
>> -}
>> -
>> -void slirp_pollfds_fill(GArray *pollfds)
>> +void slirp_pollfds_fill(GArray *pollfds, uint32_t *timeout)
>>  {
>>  }
>>
>>
>
> The rest looks good!
>
> Jan
>
> --
> Siemens AG, Corporate Technology, CT RTC ITP SES-DE
> Corporate Competence Center Embedded Linux