Hi. ----- Original Message ----- > From: "Fabiano Fidêncio" <fabiano@xxxxxxxxxxxx> > To: "Sandy Stutsman" <sstutsma@xxxxxxxxxx> > Cc: spice-devel@xxxxxxxxxxxxxxxxxxxxx > Sent: Thursday, June 25, 2015 6:50:11 AM > Subject: Re: [spice-gtk PATCH v2] This adds reference counting to cached images. > > On Wed, Jun 24, 2015 at 7:09 PM, Sandy Stutsman <sstutsma@xxxxxxxxxx> wrote: > > > > Windows guests with multi-monitors will often send down the same image > > via different channels. If these instances are not counted, one channel > > can delete an image before all the rest of the channels are finished with > > it. In this case, the client will hang. > > > > This can happen, for instance, when the Windows guest is updating the > > monitor's wallpaper. There is a driver instance for each monitor, so each > > one is sending down its own copy of the same image with the same id. As > > one channel may be busier than another, the order that the client executes > > commands may not be the same order as the server issued them. Here's what > > can happen: > > > > On the server side: > > Monitor 1 sends image A > > Monitor 1 sends multiple rendering commands for image A > > Monitor 1 removes image A > > Monitor 2 sends image A > > Monitor 2 sends rendering commands for image A > > On the client side: > > Monitor 1 adds image A to the cache > > Monitor 1 starts rendering with image A > > Monitor 2 adds image A to the cache - has same id, so image is replaced > > Monitor 1 removes image A - image A is completely removed from cache > > Monitor 2 render command hangs waiting for image A > > > > Addresses bug: https://bugzilla.redhat.com/show_bug.cgi?id=1194354 > > --- > > Change since v1 > > *Add to commit log > > --- > > src/spice-channel-cache.h | 60 > > ++++++++++++++++++++++++++++++++++++----------- > > src/spice-session.c | 2 +- > > 2 files changed, 47 insertions(+), 15 deletions(-) > > > > diff --git a/src/spice-channel-cache.h b/src/spice-channel-cache.h > > index 17775e6..968e661 100644 > > --- a/src/spice-channel-cache.h > > +++ b/src/spice-channel-cache.h > > @@ -27,15 +27,20 @@ G_BEGIN_DECLS > > typedef struct display_cache_item { > > guint64 id; > > gboolean lossy; > > + uint32_t ref_count; > > Could be guint32, right? Yep. > > > } display_cache_item; > > > > -typedef GHashTable display_cache; > > +typedef struct display_cache { > > + GHashTable *table; > > + gboolean ref_counted; > > +}display_cache; > > > > static inline display_cache_item* cache_item_new(guint64 id, gboolean > > lossy) > > { > > display_cache_item *self = g_slice_new(display_cache_item); > > self->id = id; > > self->lossy = lossy; > > + self->ref_count = 1; > > return self; > > } > > > > @@ -46,18 +51,24 @@ static inline void cache_item_free(display_cache_item > > *self) > > > > static inline display_cache* cache_new(GDestroyNotify value_destroy) > > { > > - GHashTable* self; > > - > > - self = g_hash_table_new_full(g_int64_hash, g_int64_equal, > > - (GDestroyNotify)cache_item_free, > > - value_destroy); > > - > > + display_cache * self = g_slice_new(display_cache); > > + self->table = g_hash_table_new_full(g_int64_hash, g_int64_equal, > > + (GDestroyNotify) cache_item_free, > > + value_destroy); > > + self->ref_counted = FALSE; > > return self; > > } > > > > +static inline display_cache * cache_image_new(GDestroyNotify > > value_destroy) > > +{ > > + display_cache * self = cache_new(value_destroy); > > + self->ref_counted = TRUE; > > + return self; > > +}; > > + > > static inline gpointer cache_find(display_cache *cache, uint64_t id) > > { > > - return g_hash_table_lookup(cache, &id); > > + return g_hash_table_lookup(cache->table, &id); > > } > > > > static inline gpointer cache_find_lossy(display_cache *cache, uint64_t id, > > gboolean *lossy) > > @@ -65,7 +76,7 @@ static inline gpointer cache_find_lossy(display_cache > > *cache, uint64_t id, gbool > > gpointer value; > > display_cache_item *item; > > > > - if (!g_hash_table_lookup_extended(cache, &id, (gpointer*)&item, > > &value)) > > + if (!g_hash_table_lookup_extended(cache->table, &id, (gpointer*)&item, > > &value)) > > return NULL; > > > > *lossy = item->lossy; > > @@ -77,8 +88,17 @@ static inline void cache_add_lossy(display_cache *cache, > > uint64_t id, > > gpointer value, gboolean lossy) > > { > > display_cache_item *item = cache_item_new(id, lossy); > > - > > - g_hash_table_replace(cache, item, value); > > + display_cache_item *current_item; > > + gpointer current_image; > > + > > + //If image is currently in the table add its reference count before > > replacing it > > + if(cache->ref_counted) { > > + if(g_hash_table_lookup_extended(cache->table, &id, (gpointer*) > > ¤t_item, > > + (gpointer*) ¤t_image)) { > > + item->ref_count = current_item->ref_count + 1; > > + } > > + } > > + g_hash_table_replace(cache->table, item, value); > > } > > > > static inline void cache_add(display_cache *cache, uint64_t id, gpointer > > value) > > @@ -88,17 +108,29 @@ static inline void cache_add(display_cache *cache, > > uint64_t id, gpointer value) > > > > static inline gboolean cache_remove(display_cache *cache, uint64_t id) > > { > > - return g_hash_table_remove(cache, &id); > > + display_cache_item * item; > > + gpointer value; > > + > > + if( g_hash_table_lookup_extended(cache->table, &id, (gpointer*) &item, > > &value)) { > > + --item->ref_count; > > + if(!cache->ref_counted || !item->ref_count ) { > > I really would prefer to have comparisons (when not booleans) in the > explicit way, like: > if(!cache->ref_counted || item->ref_count > 0) { ... } > actually changed to if(!cache->ref_counted || item->ref_count == 0) { ... } > > + return g_hash_table_remove(cache->table, &id); > > + } > > + } > > + else { > > + return FALSE; > > + } > > + return TRUE; > > } > > > > static inline void cache_clear(display_cache *cache) > > { > > - g_hash_table_remove_all(cache); > > + g_hash_table_remove_all(cache->table); > > } > > > > static inline void cache_unref(display_cache *cache) > > { > > - g_hash_table_unref(cache); > > + g_hash_table_unref(cache->table); > > } > > > > G_END_DECLS > > diff --git a/src/spice-session.c b/src/spice-session.c > > index 778d82a..a252448 100644 > > --- a/src/spice-session.c > > +++ b/src/spice-session.c > > @@ -257,7 +257,7 @@ static void spice_session_init(SpiceSession *session) > > g_free(channels); > > > > ring_init(&s->channels); > > - s->images = cache_new((GDestroyNotify)pixman_image_unref); > > + s->images = cache_image_new((GDestroyNotify)pixman_image_unref); > > s->glz_window = glz_decoder_window_new(); > > update_proxy(session, NULL); > > } > > -- > > 1.9.5.msysgit.0 > > > > _______________________________________________ > > Spice-devel mailing list > > Spice-devel@xxxxxxxxxxxxxxxxxxxxx > > http://lists.freedesktop.org/mailman/listinfo/spice-devel > > > Apart from the minors comments, that can or cannot be addressed (up to > Sandy), the patch looks good to me. > -- > Fabiano Fidêncio > _______________________________________________ Spice-devel mailing list Spice-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/spice-devel