Re: [Qemu-devel] [RFC] Ensure SIGALRM causes a cpu_loop_exit

[Thiemo Seufer]

andrzej zaborowski wrote:
> On 24/11/2007, Paul Brook <address@hidden> wrote:
> > > There is a chance that when using "unix" or "dynticks" clock, the
> > > signal arrives when no cpu is executing.
> 
> How about this version, this one touches vl.c only:

Any reason why this isn't in CVS?


Thiemo

> --- a/vl.c
> +++ b/vl.c
> @@ -236,6 +236,10 @@ const char *prom_envs[MAX_PROM_ENVS];
>  struct bt_piconet_s *local_piconet;
>  struct modem_ops_s modem_ops;
> 
> +static CPUState *cur_cpu;
> +static CPUState *next_cpu;
> +static int event_pending;
> +
>  #define TFR(expr) do { if ((expr) != -1) break; } while (errno == EINTR)
> 
>  /***********************************************************/
> @@ -1183,16 +1187,16 @@ static void host_alarm_handler(int host_signum)
>          struct qemu_alarm_win32 *data = ((struct
> qemu_alarm_timer*)dwUser)->priv;
>          SetEvent(data->host_alarm);
>  #endif
> -        CPUState *env = cpu_single_env;
> -        if (env) {
> -            /* stop the currently executing cpu because a timer occured */
> -            cpu_interrupt(env, CPU_INTERRUPT_EXIT);
> +        CPUState *env = next_cpu;
> +
> +        /* stop the currently executing cpu because a timer occured */
> +        cpu_interrupt(env, CPU_INTERRUPT_EXIT);
>  #ifdef USE_KQEMU
> -            if (env->kqemu_enabled) {
> -                kqemu_cpu_interrupt(env);
> -            }
> -#endif
> +        if (env->kqemu_enabled) {
> +            kqemu_cpu_interrupt(env);
>          }
> +#endif
> +        event_pending = 1;
>      }
>  }
> 
> @@ -7168,8 +7172,6 @@ void main_loop_wait(int timeout)
> 
>  }
> 
> -static CPUState *cur_cpu;
> -
>  static int main_loop(void)
>  {
>      int ret, timeout;
> @@ -7179,15 +7181,13 @@ static int main_loop(void)
>      CPUState *env;
> 
>      cur_cpu = first_cpu;
> +    next_cpu = cur_cpu->next_cpu ?: first_cpu;
>      for(;;) {
>          if (vm_running) {
> 
> -            env = cur_cpu;
>              for(;;) {
>                  /* get next cpu */
> -                env = env->next_cpu;
> -                if (!env)
> -                    env = first_cpu;
> +                env = next_cpu;
>  #ifdef CONFIG_PROFILER
>                  ti = profile_getclock();
>  #endif
> @@ -7195,6 +7195,12 @@ static int main_loop(void)
>  #ifdef CONFIG_PROFILER
>                  qemu_time += profile_getclock() - ti;
>  #endif
> +                next_cpu = env->next_cpu ?: first_cpu;
> +                if (event_pending) {
> +                    ret = EXCP_INTERRUPT;
> +                    event_pending = 0;
> +                    break;
> +                }
>                  if (ret == EXCP_HLT) {
>                      /* Give the next CPU a chance to run.  */
>                      cur_cpu = env;
> 
> 
>