Re: [Qemu-devel] [PATCH v16 13/14] migration: Remove not needed semaphore and quit

[Dr. David Alan Gilbert]

* Juan Quintela (address@hidden) wrote:
> We know quit with shutdwon in the QIO.
> 
> Signed-off-by: Juan Quintela <address@hidden>

Reviewed-by: Dr. David Alan Gilbert <address@hidden>

> --
> Add comment
> Use shutdown() instead of unref()
> ---
>  migration/ram.c | 14 +++++---------
>  1 file changed, 5 insertions(+), 9 deletions(-)
> 
> diff --git a/migration/ram.c b/migration/ram.c
> index 5d38d699f3..61f7313093 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -594,14 +594,10 @@ typedef struct {
>      QemuThread thread;
>      /* communication channel */
>      QIOChannel *c;
> -    /* sem where to wait for more work */
> -    QemuSemaphore sem;
>      /* this mutex protects the following parameters */
>      QemuMutex mutex;
>      /* is this channel thread running */
>      bool running;
> -    /* should this thread finish */
> -    bool quit;
>      /* array of pages to receive */
>      MultiFDPages_t *pages;
>      /* packet allocated len */
> @@ -1144,8 +1140,11 @@ static void multifd_recv_terminate_threads(Error *err)
>          MultiFDRecvParams *p = &multifd_recv_state->params[i];
>  
>          qemu_mutex_lock(&p->mutex);
> -        p->quit = true;
> -        qemu_sem_post(&p->sem);
> +        /* We could arrive here for two reasons:
> +           - normal quit, i.e. everything went fine, just finished
> +           - error quit: We close the channels so the channel threads
> +             finish the qio_channel_read_all_eof() */
> +        qio_channel_shutdown(p->c, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
>          qemu_mutex_unlock(&p->mutex);
>      }
>  }
> @@ -1168,7 +1167,6 @@ int multifd_load_cleanup(Error **errp)
>          object_unref(OBJECT(p->c));
>          p->c = NULL;
>          qemu_mutex_destroy(&p->mutex);
> -        qemu_sem_destroy(&p->sem);
>          qemu_sem_destroy(&p->sem_sync);
>          g_free(p->name);
>          p->name = NULL;
> @@ -1291,9 +1289,7 @@ int multifd_load_setup(void)
>          MultiFDRecvParams *p = &multifd_recv_state->params[i];
>  
>          qemu_mutex_init(&p->mutex);
> -        qemu_sem_init(&p->sem, 0);
>          qemu_sem_init(&p->sem_sync, 0);
> -        p->quit = false;
>          p->id = i;
>          p->pages = multifd_pages_init(page_count);
>          p->packet_len = sizeof(MultiFDPacket_t)
> -- 
> 2.17.1
> 
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK