Add cc::Surface ref counting.

cc/surfaces/surface_manager_ref_unittest.cc

Index: cc/surfaces/surface_manager_ref_unittest.cc
diff --git a/cc/surfaces/surface_manager_ref_unittest.cc b/cc/surfaces/surface_manager_ref_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0b8172dcdbdbc8b6389444f934c37e5bc7cecabb
--- /dev/null
+++ b/cc/surfaces/surface_manager_ref_unittest.cc
@@ -0,0 +1,293 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <stddef.h>
+
+#include <unordered_map>
+#include <vector>
+
+#include "base/memory/ptr_util.h"
+#include "cc/surfaces/surface.h"
+#include "cc/surfaces/surface_factory.h"
+#include "cc/surfaces/surface_id.h"
+#include "cc/surfaces/surface_manager.h"
+#include "cc/surfaces/surface_sequence_generator.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace cc {
+namespace {
+
+constexpr FrameSinkId kFrameSink1(1, 0);
+constexpr FrameSinkId kFrameSink2(2, 0);
+constexpr FrameSinkId kFrameSink3(3, 0);
+constexpr LocalFrameId kLocalFrame1(1, 0);
+constexpr LocalFrameId kLocalFrame2(2, 0);
+
+// Tests for reference tracking in SurfaceManager.
+class SurfaceManagerRefTest : public testing::Test {
+ public:
+  SurfaceManager& manager() { return *manager_; }
+
+  // Creates a new Surface with the provided SurfaceId. Will first create the
+  // SurfaceFactory for |frame_sink_id| if necessary.
+  SurfaceId CreateSurface(const FrameSinkId& frame_sink_id,
+                          const LocalFrameId& local_frame_id) {
+    GetFactory(frame_sink_id).Create(local_frame_id);
+    return SurfaceId(frame_sink_id, local_frame_id);
+  }
+
+  // Destroy Surface with |surface_id|.
+  void DestroySurface(const SurfaceId& surface_id) {
+    GetFactory(surface_id.frame_sink_id()).Destroy(surface_id.local_frame_id());
+  }
+
+ protected:
+  SurfaceFactory& GetFactory(const FrameSinkId& frame_sink_id) {
+    auto& factory_ptr = factories_[frame_sink_id];
+    if (!factory_ptr)
+      factory_ptr = base::MakeUnique<SurfaceFactory>(frame_sink_id,
+                                                     manager_.get(), nullptr);
+    return *factory_ptr;
+  }
+
+  // testing::Test:
+  void SetUp() override {
+    // Start each test with a fresh SurfaceManager instance.
+    manager_ = base::MakeUnique<SurfaceManager>();
+  }
+  void TearDown() override {
+    factories_.clear();
+    manager_.reset();
+  }
+
+  std::unordered_map<FrameSinkId,
+                     std::unique_ptr<SurfaceFactory>,
+                     FrameSinkIdHash>
+      factories_;
+  std::unique_ptr<SurfaceManager> manager_;
+};
+
+}  // namespace
+
+TEST_F(SurfaceManagerRefTest, AddReference) {
+  SurfaceId id1 = CreateSurface(kFrameSink1, kLocalFrame1);
+  manager().AddSurfaceReference(SurfaceManager::kRootSurfaceId, id1);
+
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id1), 1u);
+  EXPECT_EQ(manager().GetSurfaceRefereeCount(id1), 0u);
+}
+
+TEST_F(SurfaceManagerRefTest, AddRemoveReference) {
+  SurfaceId id1 = CreateSurface(kFrameSink1, kLocalFrame1);
+  SurfaceId id2 = CreateSurface(kFrameSink2, kLocalFrame1);
+  manager().AddSurfaceReference(SurfaceManager::kRootSurfaceId, id1);
+  manager().AddSurfaceReference(id1, id2);
+
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id1), 1u);
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id2), 1u);
+  EXPECT_EQ(manager().GetSurfaceRefereeCount(id1), 1u);
+  EXPECT_EQ(manager().GetSurfaceRefereeCount(id2), 0u);
+
+  manager().RemoveSurfaceReference(id1, id2);
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id1), 1u);
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id2), 0u);
+  EXPECT_EQ(manager().GetSurfaceRefereeCount(id1), 0u);
+  EXPECT_EQ(manager().GetSurfaceRefereeCount(id2), 0u);
+}
+
+TEST_F(SurfaceManagerRefTest, AddRemoveReferenceRecursive) {
+  SurfaceId id1 = CreateSurface(kFrameSink1, kLocalFrame1);
+  SurfaceId id2 = CreateSurface(kFrameSink2, kLocalFrame1);
+  SurfaceId id3 = CreateSurface(kFrameSink3, kLocalFrame1);
+
+  manager().AddSurfaceReference(SurfaceManager::kRootSurfaceId, id1);
+  manager().AddSurfaceReference(id1, id2);
+  manager().AddSurfaceReference(id2, id3);
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id1), 1u);
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id2), 1u);
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id3), 1u);
+  EXPECT_EQ(manager().GetSurfaceRefereeCount(id1), 1u);
+  EXPECT_EQ(manager().GetSurfaceRefereeCount(id2), 1u);
+  EXPECT_EQ(manager().GetSurfaceRefereeCount(id3), 0u);
+
+  // Should remove reference from id1 -> id2 and then since id2 has zero
+  // references all references it holds should be removed.
+  manager().RemoveSurfaceReference(id1, id2);
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id1), 1u);
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id2), 0u);
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id3), 0u);
+  EXPECT_EQ(manager().GetSurfaceRefereeCount(id1), 0u);
+  EXPECT_EQ(manager().GetSurfaceRefereeCount(id2), 0u);
+  EXPECT_EQ(manager().GetSurfaceRefereeCount(id3), 0u);
+}
+
+TEST_F(SurfaceManagerRefTest, NewSurfaceFromFrameSink) {
+  SurfaceId id1 = CreateSurface(kFrameSink1, kLocalFrame1);
+  SurfaceId id2 = CreateSurface(kFrameSink2, kLocalFrame1);
+  SurfaceId id3 = CreateSurface(kFrameSink3, kLocalFrame1);
+
+  manager().AddSurfaceReference(SurfaceManager::kRootSurfaceId, id1);
+  manager().AddSurfaceReference(id1, id2);
+  manager().AddSurfaceReference(id2, id3);
+
+  // |kFramesink2| received a CompositorFrame with a new size, so it destroys
+  // |id2| and creates |id2_next|. No reference have been removed yet.
+  DestroySurface(id2);
+  SurfaceId id2_next = CreateSurface(kFrameSink2, kLocalFrame2);
+  EXPECT_NE(manager().GetSurfaceForId(id2), nullptr);
+  EXPECT_NE(manager().GetSurfaceForId(id2_next), nullptr);
+
+  // Add references to and from |id2_next|.
+  manager().AddSurfaceReference(id1, id2_next);
+  manager().AddSurfaceReference(id2_next, id3);
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id2), 1u);
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id2_next), 1u);
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id3), 2u);
+
+  manager().RemoveSurfaceReference(id1, id2);
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id2), 0u);
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id2_next), 1u);
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id3), 1u);
+
+  // |id2| should be deleted during GC but other surfaces shouldn't.
+  EXPECT_EQ(manager().GetSurfaceForId(id2), nullptr);
+  EXPECT_NE(manager().GetSurfaceForId(id2_next), nullptr);
+  EXPECT_NE(manager().GetSurfaceForId(id3), nullptr);
+}
+
+TEST_F(SurfaceManagerRefTest, CheckGC) {
+  SurfaceId id1 = CreateSurface(kFrameSink1, kLocalFrame1);
+  SurfaceId id2 = CreateSurface(kFrameSink2, kLocalFrame1);
+
+  manager().AddSurfaceReference(SurfaceManager::kRootSurfaceId, id1);
+  manager().AddSurfaceReference(id1, id2);
+
+  EXPECT_NE(manager().GetSurfaceForId(id1), nullptr);
+  EXPECT_NE(manager().GetSurfaceForId(id2), nullptr);
+
+  // Destroying the surfaces shouldn't delete them yet, since there is still an
+  // active reference on all surfaces.
+  DestroySurface(id1);
+  DestroySurface(id2);
+  EXPECT_NE(manager().GetSurfaceForId(id1), nullptr);
+  EXPECT_NE(manager().GetSurfaceForId(id2), nullptr);
+
+  // Should delete |id2| when the only reference to it is removed.
+  manager().RemoveSurfaceReference(id1, id2);
+  EXPECT_EQ(manager().GetSurfaceForId(id2), nullptr);
+
+  // Should delete |id1| when the only reference to it is removed.
+  manager().RemoveSurfaceReference(SurfaceManager::kRootSurfaceId, id1);
+  EXPECT_EQ(manager().GetSurfaceForId(id1), nullptr);
+}
+
+TEST_F(SurfaceManagerRefTest, CheckGCRecusiveFull) {
+  SurfaceId id1 = CreateSurface(kFrameSink1, kLocalFrame1);
+  SurfaceId id2 = CreateSurface(kFrameSink2, kLocalFrame1);
+  SurfaceId id3 = CreateSurface(kFrameSink3, kLocalFrame1);
+
+  manager().AddSurfaceReference(SurfaceManager::kRootSurfaceId, id1);
+  manager().AddSurfaceReference(id1, id2);
+  manager().AddSurfaceReference(id2, id3);
+
+  DestroySurface(id3);
+  DestroySurface(id2);
+  DestroySurface(id1);
+
+  // Destroying the surfaces shouldn't delete them yet, since there is still an
+  // active reference on all surfaces.
+  EXPECT_NE(manager().GetSurfaceForId(id3), nullptr);
+  EXPECT_NE(manager().GetSurfaceForId(id2), nullptr);
+  EXPECT_NE(manager().GetSurfaceForId(id1), nullptr);
+
+  manager().RemoveSurfaceReference(SurfaceManager::kRootSurfaceId, id1);
+
+  // Removing the reference from the root to id1 should allow all three surfaces
+  // to be deleted during GC.
+  EXPECT_EQ(manager().GetSurfaceForId(id1), nullptr);
+  EXPECT_EQ(manager().GetSurfaceForId(id2), nullptr);
+  EXPECT_EQ(manager().GetSurfaceForId(id3), nullptr);
+}
+
+TEST_F(SurfaceManagerRefTest, CheckGCWithSequences) {
+  SurfaceId id1 = CreateSurface(kFrameSink1, kLocalFrame1);
+  SurfaceId id2 = CreateSurface(kFrameSink2, kLocalFrame1);
+
+  manager().AddSurfaceReference(SurfaceManager::kRootSurfaceId, id1);
+  manager().AddSurfaceReference(id1, id2);
+
+  SurfaceId id3 = CreateSurface(kFrameSink3, kLocalFrame1);
+  Surface* surface3 = manager().GetSurfaceForId(id3);
+
+  // Add destruction dependency from |id2| to |id3|.
+  manager().RegisterFrameSinkId(kFrameSink2);
+  SurfaceSequence sequence(kFrameSink2, 1u);
+  surface3->AddDestructionDependency(sequence);
+  EXPECT_EQ(surface3->GetDestructionDependencyCount(), 1u);
+
+  // Surface for |id3| isn't delete yet because it has a valid destruction
+  // dependency from |kFrameSink2|

[Fady Samuel, 2016/11/02 03:10:36]

nit: period at the end of the sentence.

[kylechar, 2016/11/02 13:58:59]

Done.

+  DestroySurface(id3);
+  EXPECT_NE(manager().GetSurfaceForId(id3), nullptr);
+
+  // Surface for |id2| isn't deleted because it has a reference.
+  DestroySurface(id2);
+  EXPECT_NE(manager().GetSurfaceForId(id2), nullptr);
+
+  // Satisfy destruction dependency on |id3| and delete during GC.
+  std::vector<uint32_t> satisfied({sequence.sequence});
+  manager().DidSatisfySequences(kFrameSink2, &satisfied);
+  EXPECT_EQ(manager().GetSurfaceForId(id3), nullptr);
+
+  // Remove ref on |id2| and delete during GC.
+  manager().RemoveSurfaceReference(id1, id2);
+  EXPECT_EQ(manager().GetSurfaceForId(id2), nullptr);
+}
+
+TEST_F(SurfaceManagerRefTest, TryAddReferenceToBadSurface) {
+  // Not creating an accompanying Surface and SurfaceFactory.
+  SurfaceId id(FrameSinkId(100u, 200u), LocalFrameId(1u, 123123u));
+
+  // Adding reference from root to the Surface should do nothing because
+  // SurfaceManager doesn't know Surface for |id| exists.
+  manager().AddSurfaceReference(SurfaceManager::kRootSurfaceId, id);
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id), 0u);
+}
+
+TEST_F(SurfaceManagerRefTest, TryDoubleAddReference) {
+  SurfaceId id1 = CreateSurface(kFrameSink1, kLocalFrame1);
+  SurfaceId id2 = CreateSurface(kFrameSink2, kLocalFrame1);
+
+  manager().AddSurfaceReference(SurfaceManager::kRootSurfaceId, id1);
+  manager().AddSurfaceReference(id1, id2);
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id2), 1u);
+  EXPECT_EQ(manager().GetSurfaceRefereeCount(id1), 1u);
+
+  // The second request should be ignored without crashing.
+  manager().AddSurfaceReference(id1, id2);
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id2), 1u);
+  EXPECT_EQ(manager().GetSurfaceRefereeCount(id1), 1u);
+}
+
+TEST_F(SurfaceManagerRefTest, TryAddSelfReference) {
+  SurfaceId id1 = CreateSurface(kFrameSink1, kLocalFrame1);
+
+  // Adding a self reference should be ignored without crashing.
+  manager().AddSurfaceReference(id1, id1);
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id1), 0u);
+  EXPECT_EQ(manager().GetSurfaceRefereeCount(id1), 0u);
+}
+
+TEST_F(SurfaceManagerRefTest, TryRemoveBadReference) {
+  SurfaceId id1 = CreateSurface(kFrameSink1, kLocalFrame1);
+  SurfaceId id2 = CreateSurface(kFrameSink2, kLocalFrame1);
+
+  // Removing non-existent reference should be ignored.
+  manager().AddSurfaceReference(id1, id2);
+  manager().RemoveSurfaceReference(id2, id1);
+  EXPECT_EQ(manager().GetSurfaceRefereeCount(id1), 1u);
+  EXPECT_EQ(manager().GetSurfaceReferenceCount(id2), 1u);
+}

[Fady Samuel, 2016/11/02 03:10:36]

This is a very comprehensive set of tests! Thanks! What about a test that has a
cycle? This shouldn't happen on valid input, but it's possible we end up with
invalid input (compromised renderer) and we don't want to break the display
compositor.

[kylechar, 2016/11/02 13:58:59]

Huh. Interesting. Fixing that would require the GC to be changed a bit, which
I'm not sure is possible with the mix of sequences/references, but would be the
end goal 

I think it makes the most sense to do a mark and sweep starting from
kRootSurfaceId, anything that isn't reachable from there is destroyed. A bad
renderer could make cycles all day with surfaces it knows about but once it's
killed there is no way to reach the cycles and all the surfaces will be
destroyed. So it's no different than a bad renderer refusing to give up
references.

Since we aren't using references for all (as of this CL any) surfaces that
doesn't work yet...

+
+}  // namespace cc