[Spice-devel] [PATCH 2/2] RedChannel: Add FOREACH_CHANNELL and use it to iterate

[Jonathon Jongsma]

Typo in commit summary (CHANNELL -> CHANNEL)

Also: do we really need an unsafe version of the loop? why not just have a
single version that's always safe?


On Mon, 2016-05-23 at 12:42 +0100, Frediano Ziglio wrote:
> Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> ---
>  server/red-channel.c | 44 ++++++++++++++++++++++++--------------------
>  1 file changed, 24 insertions(+), 20 deletions(-)
> 
> diff --git a/server/red-channel.c b/server/red-channel.c
> index 2b37fed..9ec9a26 100644
> --- a/server/red-channel.c
> +++ b/server/red-channel.c
> @@ -59,6 +59,21 @@ typedef struct MarkerPipeItem {
>  
>  #define CHANNEL_BLOCKED_SLEEP_DURATION 10000 //micro
>  
> +#define FOREACH_CHANNEL(client, _link, _data)                   \
> +    for (_link = (client ? (client)->channels : NULL); \
> +         (_data = (_link ? _link->data : NULL), \
> +         _link) != NULL; \
> +         _link = _link->next)
> +
> +#define FOREACH_CHANNEL_SAFE(client, _link, _next, _data)                   \
> +    for (_link = (client ? (client)->channels : NULL), \
> +         _next = (_link ? _link->next : NULL), \
> +         _data = (_link ? _link->data : NULL); \
> +         _link; \
> +         _link = _next, \
> +         _next = (_link ? _link->next : NULL), \
> +         _data = (_link ? _link->data : NULL))
> +
>  enum QosPingState {
>      PING_STATE_NONE,
>      PING_STATE_TIMER,
> @@ -2053,13 +2068,15 @@ static gboolean
> red_channel_client_set_migration_seamless(RedChannelClient *rcc)
>  void red_client_set_migration_seamless(RedClient *client) // dest
>  {
>      GList *link;
> +    RedChannelClient *rcc;
> +
>      spice_assert(client->during_target_migrate);
>      pthread_mutex_lock(&client->lock);
>      client->seamless_migrate = TRUE;
>      /* update channel clients that got connected before the migration
>       * type was set. red_client_add_channel will handle newer channel clients
> */
> -    for (link = client->channels; link != NULL; link = link->next) {
> -        if (red_channel_client_set_migration_seamless(link->data))
> +    FOREACH_CHANNEL(client, link, rcc) {
> +        if (red_channel_client_set_migration_seamless(rcc))
>              client->num_migrated_channels++;
>      }
>      pthread_mutex_unlock(&client->lock);
> @@ -2077,14 +2094,10 @@ void red_client_migrate(RedClient *client)
>                        " this might be a BUG",
>                        client->thread_id, pthread_self());
>      }
> -    link = client->channels;
> -    while (link) {
> -        next = link->next;
> -        rcc = link->data;
> +    FOREACH_CHANNEL_SAFE(client, link, next, rcc) {
>          if (red_channel_client_is_connected(rcc)) {
>              rcc->channel->client_cbs.migrate(rcc);
>          }
> -        link = next;
>      }
>  }
>  
> @@ -2101,12 +2114,9 @@ void red_client_destroy(RedClient *client)
>                        client->thread_id,
>                        pthread_self());
>      }
> -    link = client->channels;
> -    while (link) {
> -        next = link->next;
> +    FOREACH_CHANNEL_SAFE(client, link, next, rcc) {
>          // some channels may be in other threads, so disconnection
>          // is not synchronous.
> -        rcc = link->data;
>          rcc->destroying = 1;
>          // some channels may be in other threads. However we currently
>          // assume disconnect is synchronous (we changed the dispatcher
> @@ -2118,7 +2128,6 @@ void red_client_destroy(RedClient *client)
>          spice_assert(rcc->pipe_size == 0);
>          spice_assert(rcc->send_data.size == 0);
>          red_channel_client_destroy(rcc);
> -        link = next;
>      }
>      red_client_unref(client);
>  }
> @@ -2130,8 +2139,7 @@ static RedChannelClient
> *red_client_get_channel(RedClient *client, int type, int
>      RedChannelClient *rcc;
>      RedChannelClient *ret = NULL;
>  
> -    for (link = client->channels; link != NULL; link = link->next) {
> -        rcc = link->data;
> +    FOREACH_CHANNEL(client, link, rcc) {
>          if (rcc->channel->type == type && rcc->channel->id == id) {
>              ret = rcc;
>              break;
> @@ -2162,6 +2170,7 @@ void red_client_set_main(RedClient *client,
> MainChannelClient *mcc) {
>  void red_client_semi_seamless_migrate_complete(RedClient *client)
>  {
>      GList *link, *next;
> +    RedChannelClient *rcc;
>  
>      pthread_mutex_lock(&client->lock);
>      if (!client->during_target_migrate || client->seamless_migrate) {
> @@ -2170,15 +2179,10 @@ void
> red_client_semi_seamless_migrate_complete(RedClient *client)
>          return;
>      }
>      client->during_target_migrate = FALSE;
> -    link = client->channels;
> -    while (link) {
> -        next = link->next;
> -        RedChannelClient *rcc = link->data;
> -
> +    FOREACH_CHANNEL_SAFE(client, link, next, rcc) {
>          if (rcc->latency_monitor.timer) {
>              red_channel_client_start_ping_timer(rcc,
> PING_TEST_IDLE_NET_TIMEOUT_MS);
>          }
> -        link = next;
>      }
>      pthread_mutex_unlock(&client->lock);
>      reds_on_client_semi_seamless_migrate_complete(client->reds, client);