Re: [Qemu-devel] [RFC] [PATCHv8 15/30] aio / timers: Convert mainloop to use timeout

[Paolo Bonzini <pbonzini@redhat.com>]

Il 08/08/2013 23:42, Alex Bligh ha scritto:
> Convert mainloop to use timeout from default timerlist group
> (i.e. the current 3 static timers)

And with two AioContexts in the main loop this patch disappears
completely, since the deadline is computed by the second AioContext.

Paolo

> Signed-off-by: Alex Bligh <alex@alex.org.uk>
> ---
>  main-loop.c |   45 ++++++++++++++++++++++++++++++++++-----------
>  1 file changed, 34 insertions(+), 11 deletions(-)
> 
> diff --git a/main-loop.c b/main-loop.c
> index a44fff6..00e54bd 100644
> --- a/main-loop.c
> +++ b/main-loop.c
> @@ -155,10 +155,11 @@ static int max_priority;
>  static int glib_pollfds_idx;
>  static int glib_n_poll_fds;
>  
> -static void glib_pollfds_fill(uint32_t *cur_timeout)
> +static void glib_pollfds_fill(int64_t *cur_timeout)
>  {
>      GMainContext *context = g_main_context_default();
>      int timeout = 0;
> +    int64_t timeout_ns;
>      int n;
>  
>      g_main_context_prepare(context, &max_priority);
> @@ -174,9 +175,13 @@ static void glib_pollfds_fill(uint32_t *cur_timeout)
>                                   glib_n_poll_fds);
>      } while (n != glib_n_poll_fds);
>  
> -    if (timeout >= 0 && timeout < *cur_timeout) {
> -        *cur_timeout = timeout;
> +    if (timeout < 0) {
> +        timeout_ns = -1;
> +    } else {
> +        timeout_ns = (int64_t)timeout * (int64_t)SCALE_MS;
>      }
> +
> +    *cur_timeout = qemu_soonest_timeout(timeout_ns, *cur_timeout);
>  }
>  
>  static void glib_pollfds_poll(void)
> @@ -191,7 +196,7 @@ static void glib_pollfds_poll(void)
>  
>  #define MAX_MAIN_LOOP_SPIN (1000)
>  
> -static int os_host_main_loop_wait(uint32_t timeout)
> +static int os_host_main_loop_wait(int64_t timeout)
>  {
>      int ret;
>      static int spin_counter;
> @@ -214,7 +219,7 @@ static int os_host_main_loop_wait(uint32_t timeout)
>              notified = true;
>          }
>  
> -        timeout = 1;
> +        timeout = SCALE_MS;
>      }
>  
>      if (timeout > 0) {
> @@ -224,7 +229,7 @@ static int os_host_main_loop_wait(uint32_t timeout)
>          spin_counter++;
>      }
>  
> -    ret = g_poll((GPollFD *)gpollfds->data, gpollfds->len, timeout);
> +    ret = qemu_poll_ns((GPollFD *)gpollfds->data, gpollfds->len, timeout);
>  
>      if (timeout > 0) {
>          qemu_mutex_lock_iothread();
> @@ -373,7 +378,7 @@ static void pollfds_poll(GArray *pollfds, int nfds, fd_set *rfds,
>      }
>  }
>  
> -static int os_host_main_loop_wait(uint32_t timeout)
> +static int os_host_main_loop_wait(int64_t timeout)
>  {
>      GMainContext *context = g_main_context_default();
>      GPollFD poll_fds[1024 * 2]; /* this is probably overkill */
> @@ -382,6 +387,7 @@ static int os_host_main_loop_wait(uint32_t timeout)
>      PollingEntry *pe;
>      WaitObjects *w = &wait_objects;
>      gint poll_timeout;
> +    int64_t poll_timeout_ns;
>      static struct timeval tv0;
>      fd_set rfds, wfds, xfds;
>      int nfds;
> @@ -419,12 +425,17 @@ static int os_host_main_loop_wait(uint32_t timeout)
>          poll_fds[n_poll_fds + i].events = G_IO_IN;
>      }
>  
> -    if (poll_timeout < 0 || timeout < poll_timeout) {
> -        poll_timeout = timeout;
> +    if (poll_timeout < 0) {
> +        poll_timeout_ns = -1;
> +    } else {
> +        poll_timeout_ns = (int64_t)poll_timeout * (int64_t)SCALE_MS;
>      }
>  
> +    poll_timeout_ns = qemu_soonest_timeout(poll_timeout_ns, timeout);
> +
>      qemu_mutex_unlock_iothread();
> -    g_poll_ret = g_poll(poll_fds, n_poll_fds + w->num, poll_timeout);
> +    g_poll_ret = qemu_poll_ns(poll_fds, n_poll_fds + w->num, poll_timeout_ns);
> +
>      qemu_mutex_lock_iothread();
>      if (g_poll_ret > 0) {
>          for (i = 0; i < w->num; i++) {
> @@ -449,6 +460,7 @@ int main_loop_wait(int nonblocking)
>  {
>      int ret;
>      uint32_t timeout = UINT32_MAX;
> +    int64_t timeout_ns;
>  
>      if (nonblocking) {
>          timeout = 0;
> @@ -462,7 +474,18 @@ int main_loop_wait(int nonblocking)
>      slirp_pollfds_fill(gpollfds);
>  #endif
>      qemu_iohandler_fill(gpollfds);
> -    ret = os_host_main_loop_wait(timeout);
> +
> +    if (timeout == UINT32_MAX) {
> +        timeout_ns = -1;
> +    } else {
> +        timeout_ns = (uint64_t)timeout * (int64_t)(SCALE_MS);
> +    }
> +
> +    timeout_ns = qemu_soonest_timeout(timeout_ns,
> +                                      timerlistgroup_deadline_ns(
> +                                          main_loop_tlg));
> +
> +    ret = os_host_main_loop_wait(timeout_ns);
>      qemu_iohandler_poll(gpollfds, ret);
>  #ifdef CONFIG_SLIRP
>      slirp_pollfds_poll(gpollfds, (ret < 0));
>