1 files changed, 246 insertions, 0 deletions
diff --git a/gfx/layers/SurfacePoolWayland.cpp b/gfx/layers/SurfacePoolWayland.cpp
new file mode 100644
index 0000000000..e1229fcaaa
--- /dev/null
+++ b/gfx/layers/SurfacePoolWayland.cpp
@@ -0,0 +1,246 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nullptr; c-basic-offset: 2
+ * -*- This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/layers/SurfacePoolWayland.h"
+
+#include "GLBlitHelper.h"
+#include "mozilla/gfx/DataSurfaceHelpers.h"
+
+namespace mozilla::layers {
+
+using gfx::IntSize;
+using gl::DepthAndStencilBuffer;
+using gl::GLContext;
+using gl::MozFramebuffer;
+using widget::WaylandBuffer;
+
+/* static */ RefPtr<SurfacePool> SurfacePool::Create(size_t aPoolSizeLimit) {
+  return new SurfacePoolWayland(aPoolSizeLimit);
+}
+
+SurfacePoolWayland::SurfacePoolWayland(size_t aPoolSizeLimit)
+    : mMutex("SurfacePoolWayland"), mPoolSizeLimit(aPoolSizeLimit) {}
+
+RefPtr<SurfacePoolHandle> SurfacePoolWayland::GetHandleForGL(GLContext* aGL) {
+  return new SurfacePoolHandleWayland(this, aGL);
+}
+
+template <typename F>
+void SurfacePoolWayland::ForEachEntry(F aFn) {
+  for (auto& iter : mInUseEntries) {
+    aFn(iter.second);
+  }
+  for (auto& entry : mPendingEntries) {
+    aFn(entry);
+  }
+  for (auto& entry : mAvailableEntries) {
+    aFn(entry);
+  }
+}
+
+void SurfacePoolWayland::DestroyGLResourcesForContext(GLContext* aGL) {
+  MutexAutoLock lock(mMutex);
+
+  ForEachEntry([&](SurfacePoolEntry& entry) {
+    if (entry.mGLResources && entry.mGLResources->mGL == aGL) {
+      entry.mGLResources = Nothing();
+      entry.mWaylandBuffer->DestroyGLResources();
+    }
+  });
+  mDepthBuffers.RemoveElementsBy(
+      [&](const DepthBufferEntry& entry) { return entry.mGL == aGL; });
+}
+
+bool SurfacePoolWayland::CanRecycleSurfaceForRequest(
+    const MutexAutoLock& aProofOfLock, const SurfacePoolEntry& aEntry,
+    const IntSize& aSize, GLContext* aGL) {
+  if (aEntry.mSize != aSize) {
+    return false;
+  }
+  if (aEntry.mGLResources) {
+    return aEntry.mGLResources->mGL == aGL;
+  }
+  return aGL == nullptr;
+}
+
+RefPtr<WaylandBuffer> SurfacePoolWayland::ObtainBufferFromPool(
+    const IntSize& aSize, GLContext* aGL) {
+  MutexAutoLock lock(mMutex);
+
+  auto iterToRecycle = std::find_if(
+      mAvailableEntries.begin(), mAvailableEntries.end(),
+      [&](const SurfacePoolEntry& aEntry) {
+        return CanRecycleSurfaceForRequest(lock, aEntry, aSize, aGL);
+      });
+  if (iterToRecycle != mAvailableEntries.end()) {
+    RefPtr<WaylandBuffer> buffer = iterToRecycle->mWaylandBuffer;
+    mInUseEntries.insert({buffer.get(), std::move(*iterToRecycle)});
+    mAvailableEntries.RemoveElementAt(iterToRecycle);
+    return buffer;
+  }
+
+  RefPtr<WaylandBuffer> buffer;
+  if (aGL) {
+    buffer = widget::WaylandBufferDMABUF::Create(
+        LayoutDeviceIntSize::FromUnknownSize(aSize), aGL);
+  } else {
+    buffer = widget::WaylandBufferSHM::Create(
+        LayoutDeviceIntSize::FromUnknownSize(aSize));
+  }
+  if (buffer) {
+    mInUseEntries.insert({buffer.get(), SurfacePoolEntry{aSize, buffer, {}}});
+  }
+
+  return buffer;
+}
+
+void SurfacePoolWayland::ReturnBufferToPool(
+    const RefPtr<WaylandBuffer>& aBuffer) {
+  MutexAutoLock lock(mMutex);
+
+  auto inUseEntryIter = mInUseEntries.find(aBuffer);
+  MOZ_RELEASE_ASSERT(inUseEntryIter != mInUseEntries.end());
+
+  if (aBuffer->IsAttached()) {
+    mPendingEntries.AppendElement(std::move(inUseEntryIter->second));
+    mInUseEntries.erase(inUseEntryIter);
+  } else {
+    mAvailableEntries.AppendElement(std::move(inUseEntryIter->second));
+    mInUseEntries.erase(inUseEntryIter);
+  }
+}
+
+void SurfacePoolWayland::EnforcePoolSizeLimit() {
+  MutexAutoLock lock(mMutex);
+
+  // Enforce the pool size limit, removing least-recently-used entries as
+  // necessary.
+  while (mAvailableEntries.Length() > mPoolSizeLimit) {
+    mAvailableEntries.RemoveElementAt(0);
+  }
+
+  NS_WARNING_ASSERTION(mPendingEntries.Length() < mPoolSizeLimit * 2,
+                       "Are we leaking pending entries?");
+  NS_WARNING_ASSERTION(mInUseEntries.size() < mPoolSizeLimit * 2,
+                       "Are we leaking in-use entries?");
+}
+
+void SurfacePoolWayland::CollectPendingSurfaces() {
+  MutexAutoLock lock(mMutex);
+  mPendingEntries.RemoveElementsBy([&](auto& entry) {
+    if (!entry.mWaylandBuffer->IsAttached()) {
+      mAvailableEntries.AppendElement(std::move(entry));
+      return true;
+    }
+    return false;
+  });
+}
+
+Maybe<GLuint> SurfacePoolWayland::GetFramebufferForBuffer(
+    const RefPtr<WaylandBuffer>& aBuffer, GLContext* aGL,
+    bool aNeedsDepthBuffer) {
+  MutexAutoLock lock(mMutex);
+  MOZ_RELEASE_ASSERT(aGL);
+
+  auto inUseEntryIter = mInUseEntries.find(aBuffer);
+  MOZ_RELEASE_ASSERT(inUseEntryIter != mInUseEntries.end());
+
+  SurfacePoolEntry& entry = inUseEntryIter->second;
+  if (entry.mGLResources) {
+    // We have an existing framebuffer.
+    MOZ_RELEASE_ASSERT(entry.mGLResources->mGL == aGL,
+                       "Recycled surface that still had GL resources from a "
+                       "different GL context. "
+                       "This shouldn't happen.");
+    if (!aNeedsDepthBuffer || entry.mGLResources->mFramebuffer->HasDepth()) {
+      return Some(entry.mGLResources->mFramebuffer->mFB);
+    }
+  }
+
+  // No usable existing framebuffer, we need to create one.
+
+  if (!aGL->MakeCurrent()) {
+    // Context may have been destroyed.
+    return {};
+  }
+
+  const GLuint tex = aBuffer->GetTexture();
+  auto fb = CreateFramebufferForTexture(lock, aGL, entry.mSize, tex,
+                                        aNeedsDepthBuffer);
+  if (!fb) {
+    // Framebuffer completeness check may have failed.
+    return {};
+  }
+
+  GLuint fbo = fb->mFB;
+  entry.mGLResources = Some(GLResourcesForBuffer{aGL, std::move(fb)});
+  return Some(fbo);
+}
+
+RefPtr<gl::DepthAndStencilBuffer> SurfacePoolWayland::GetDepthBufferForSharing(
+    const MutexAutoLock& aProofOfLock, GLContext* aGL, const IntSize& aSize) {
+  // Clean out entries for which the weak pointer has become null.
+  mDepthBuffers.RemoveElementsBy(
+      [&](const DepthBufferEntry& entry) { return !entry.mBuffer; });
+
+  for (const auto& entry : mDepthBuffers) {
+    if (entry.mGL == aGL && entry.mSize == aSize) {
+      return entry.mBuffer.get();
+    }
+  }
+  return nullptr;
+}
+
+UniquePtr<MozFramebuffer> SurfacePoolWayland::CreateFramebufferForTexture(
+    const MutexAutoLock& aProofOfLock, GLContext* aGL, const IntSize& aSize,
+    GLuint aTexture, bool aNeedsDepthBuffer) {
+  if (aNeedsDepthBuffer) {
+    // Try to find an existing depth buffer of aSize in aGL and create a
+    // framebuffer that shares it.
+    if (auto buffer = GetDepthBufferForSharing(aProofOfLock, aGL, aSize)) {
+      return MozFramebuffer::CreateForBackingWithSharedDepthAndStencil(
+          aSize, 0, LOCAL_GL_TEXTURE_2D, aTexture, buffer);
+    }
+  }
+
+  // No depth buffer needed or we didn't find one. Create a framebuffer with a
+  // new depth buffer and store a weak pointer to the new depth buffer in
+  // mDepthBuffers.
+  UniquePtr<MozFramebuffer> fb = MozFramebuffer::CreateForBacking(
+      aGL, aSize, 0, aNeedsDepthBuffer, LOCAL_GL_TEXTURE_2D, aTexture);
+  if (fb && fb->GetDepthAndStencilBuffer()) {
+    mDepthBuffers.AppendElement(
+        DepthBufferEntry{aGL, aSize, fb->GetDepthAndStencilBuffer().get()});
+  }
+
+  return fb;
+}
+
+SurfacePoolHandleWayland::SurfacePoolHandleWayland(
+    RefPtr<SurfacePoolWayland> aPool, GLContext* aGL)
+    : mPool(std::move(aPool)), mGL(aGL) {}
+
+void SurfacePoolHandleWayland::OnBeginFrame() {
+  mPool->CollectPendingSurfaces();
+}
+
+void SurfacePoolHandleWayland::OnEndFrame() { mPool->EnforcePoolSizeLimit(); }
+
+RefPtr<WaylandBuffer> SurfacePoolHandleWayland::ObtainBufferFromPool(
+    const IntSize& aSize) {
+  return mPool->ObtainBufferFromPool(aSize, mGL);
+}
+
+void SurfacePoolHandleWayland::ReturnBufferToPool(
+    const RefPtr<WaylandBuffer>& aBuffer) {
+  mPool->ReturnBufferToPool(aBuffer);
+}
+
+Maybe<GLuint> SurfacePoolHandleWayland::GetFramebufferForBuffer(
+    const RefPtr<WaylandBuffer>& aBuffer, bool aNeedsDepthBuffer) {
+  return mPool->GetFramebufferForBuffer(aBuffer, mGL, aNeedsDepthBuffer);
+}
+
+}  // namespace mozilla::layers