From 040efa2820e45675fc4ebc54648e288eefed9827 Mon Sep 17 00:00:00 2001
From: Dzmitry Malyshau <kvarkus@gmail.com>
Date: Tue, 31 Dec 2019 18:57:09 -0500
Subject: [PATCH] Fix refcount use of the texture view source

---
 wgpu-core/src/command/mod.rs | 33 ++++++++++++++++++---------------
 wgpu-core/src/device/mod.rs  | 11 +++++++----
 wgpu-core/src/swap_chain.rs  |  4 ++--
 3 files changed, 27 insertions(+), 21 deletions(-)

diff --git a/wgpu-core/src/command/mod.rs b/wgpu-core/src/command/mod.rs
index 9b5fa00e41..c88319c56d 100644
--- a/wgpu-core/src/command/mod.rs
+++ b/wgpu-core/src/command/mod.rs
@@ -252,7 +252,11 @@ impl<F: IdentityFilter<RenderPassId>> Global<F> {
             );
 
             const MAX_TOTAL_ATTACHMENTS: usize = 10;
-            type OutputAttachment<'a> = (TextureId, &'a hal::image::SubresourceRange, Option<TextureUsage>);
+            type OutputAttachment<'a> = (
+                &'a Stored<TextureId>,
+                &'a hal::image::SubresourceRange,
+                Option<TextureUsage>,
+            );
             let mut output_attachments = ArrayVec::<[OutputAttachment; MAX_TOTAL_ATTACHMENTS]>::new();
 
             log::trace!(
@@ -271,8 +275,8 @@ impl<F: IdentityFilter<RenderPassId>> Global<F> {
                         } else {
                             extent = Some(view.extent);
                         }
-                        let texture_id = match view.inner {
-                            TextureViewInner::Native { ref source_id, .. } => source_id.value,
+                        let source_id = match view.inner {
+                            TextureViewInner::Native { ref source_id, .. } => source_id,
                             TextureViewInner::SwapChain { .. } => {
                                 panic!("Unexpected depth/stencil use of swapchain image!")
                             }
@@ -280,10 +284,10 @@ impl<F: IdentityFilter<RenderPassId>> Global<F> {
 
                         // Using render pass for transition.
                         let consistent_usage = cmb.trackers.textures.query(
-                            texture_id,
+                            source_id.value,
                             view.range.clone(),
                         );
-                        output_attachments.push((texture_id, &view.range, consistent_usage));
+                        output_attachments.push((source_id, &view.range, consistent_usage));
 
                         let old_layout = match consistent_usage {
                             Some(usage) => conv::map_texture_state(
@@ -333,7 +337,7 @@ impl<F: IdentityFilter<RenderPassId>> Global<F> {
                                 source_id.value,
                                 view.range.clone(),
                             );
-                            output_attachments.push((source_id.value, &view.range, consistent_usage));
+                            output_attachments.push((source_id, &view.range, consistent_usage));
 
                             let old_layout = match consistent_usage {
                                 Some(usage) => conv::map_texture_state(usage, hal::format::Aspects::COLOR).1,
@@ -393,7 +397,7 @@ impl<F: IdentityFilter<RenderPassId>> Global<F> {
                                 source_id.value,
                                 view.range.clone(),
                             );
-                            output_attachments.push((source_id.value, &view.range, consistent_usage));
+                            output_attachments.push((source_id, &view.range, consistent_usage));
 
                             let old_layout = match consistent_usage {
                                 Some(usage) => conv::map_texture_state(usage, hal::format::Aspects::COLOR).1,
@@ -442,27 +446,26 @@ impl<F: IdentityFilter<RenderPassId>> Global<F> {
             };
 
             let mut trackers = TrackerSet::new(B::VARIANT);
-            for (texture_id, view_range, consistent_usage) in output_attachments {
-                let texture = &texture_guard[texture_id];
+            for (source_id, view_range, consistent_usage) in output_attachments {
+                let texture = &texture_guard[source_id.value];
                 assert!(texture.usage.contains(TextureUsage::OUTPUT_ATTACHMENT));
 
                 let usage = consistent_usage.unwrap_or(TextureUsage::OUTPUT_ATTACHMENT);
-                let ref_count = texture.life_guard.ref_count.as_ref().unwrap();
                 match trackers.textures.init(
-                    texture_id,
-                    ref_count.clone(),
+                    source_id.value,
+                    source_id.ref_count.clone(),
                     &texture.full_range,
                 ) {
                     Some(mut init) => init.set(view_range.clone(), usage),
-                    None => panic!("Your texture {:?} is in the another attachment!", texture_id),
+                    None => panic!("Your texture {:?} is in the another attachment!", source_id.value),
                 };
 
                 if consistent_usage.is_some() {
                     // If we expect the texture to be transited to a new state by the
                     // render pass configuration, make the tracker aware of that.
                     let _ = trackers.textures.change_replace(
-                        texture_id,
-                        ref_count,
+                        source_id.value,
+                        &source_id.ref_count,
                         view_range.clone(),
                         TextureUsage::OUTPUT_ATTACHMENT,
                         &texture.full_range,
diff --git a/wgpu-core/src/device/mod.rs b/wgpu-core/src/device/mod.rs
index cbf2e639dd..05ddb28b66 100644
--- a/wgpu-core/src/device/mod.rs
+++ b/wgpu-core/src/device/mod.rs
@@ -1069,13 +1069,16 @@ impl<F: IdentityFilter<id::BindGroupId>> Global<F> {
                                 ref raw,
                                 ref source_id,
                             } => {
-                                let texture = used
-                                    .textures
-                                    .use_extend(
-                                        &*texture_guard,
+                                // Careful here: the texture may no longer have its own ref count,
+                                // if it was deleted by the user.
+                                let texture = &texture_guard[source_id.value];
+                                used.textures
+                                    .change_extend(
                                         source_id.value,
+                                        &source_id.ref_count,
                                         view.range.clone(),
                                         usage,
+                                        &texture.full_range,
                                     )
                                     .unwrap();
                                 assert!(texture.usage.contains(usage));
diff --git a/wgpu-core/src/swap_chain.rs b/wgpu-core/src/swap_chain.rs
index 757a82a471..b760de378a 100644
--- a/wgpu-core/src/swap_chain.rs
+++ b/wgpu-core/src/swap_chain.rs
@@ -167,7 +167,7 @@ impl<F: IdentityFilter<TextureViewId>> Global<F> {
                 image,
                 source_id: Stored {
                     value: swap_chain_id,
-                    ref_count: sc.life_guard.ref_count.clone().unwrap(),
+                    ref_count: sc.life_guard.add_ref(),
                 },
                 framebuffers: SmallVec::new(),
             },
@@ -185,7 +185,7 @@ impl<F: IdentityFilter<TextureViewId>> Global<F> {
             },
             life_guard: LifeGuard::new(),
         };
-        let ref_count = view.life_guard.ref_count.clone().unwrap();
+        let ref_count = view.life_guard.add_ref();
         let view_id = hub
             .texture_views
             .register_identity(view_id_in, view, &mut token);