1 files changed, 175 insertions, 0 deletions
diff --git a/gfx/layers/client/TextureClientPool.h b/gfx/layers/client/TextureClientPool.h
new file mode 100644
index 0000000000..d557ca9a03
--- /dev/null
+++ b/gfx/layers/client/TextureClientPool.h
@@ -0,0 +1,175 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+#ifndef MOZILLA_GFX_TEXTURECLIENTPOOL_H
+#define MOZILLA_GFX_TEXTURECLIENTPOOL_H
+
+#include "mozilla/gfx/Types.h"
+#include "mozilla/gfx/Point.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/layers/KnowsCompositor.h"
+#include "TextureClient.h"
+#include "nsITimer.h"
+#include <stack>
+#include <list>
+
+namespace mozilla {
+namespace layers {
+
+class ISurfaceAllocator;
+class TextureForwarder;
+class TextureReadLock;
+
+class TextureClientAllocator {
+ protected:
+  virtual ~TextureClientAllocator() = default;
+
+ public:
+  NS_INLINE_DECL_REFCOUNTING(TextureClientAllocator)
+
+  virtual already_AddRefed<TextureClient> GetTextureClient() = 0;
+
+  /**
+   * Return a TextureClient that is not yet ready to be reused, but will be
+   * imminently.
+   */
+  virtual void ReturnTextureClientDeferred(TextureClient* aClient) = 0;
+
+  virtual void ReportClientLost() = 0;
+};
+
+class TextureClientPool final : public TextureClientAllocator {
+  virtual ~TextureClientPool();
+
+ public:
+  TextureClientPool(KnowsCompositor* aKnowsCompositor,
+                    gfx::SurfaceFormat aFormat, gfx::IntSize aSize,
+                    TextureFlags aFlags, uint32_t aShrinkTimeoutMsec,
+                    uint32_t aClearTimeoutMsec, uint32_t aInitialPoolSize,
+                    uint32_t aPoolUnusedSize, TextureForwarder* aAllocator);
+
+  /**
+   * Gets an allocated TextureClient of size and format that are determined
+   * by the initialisation parameters given to the pool. This will either be
+   * a cached client that was returned to the pool, or a newly allocated
+   * client if one isn't available.
+   *
+   * All clients retrieved by this method should be returned using the return
+   * functions, or reported lost so that the pool can manage its size correctly.
+   */
+  already_AddRefed<TextureClient> GetTextureClient() override;
+
+  /**
+   * Return a TextureClient that is no longer being used and is ready for
+   * immediate re-use or destruction.
+   */
+  void ReturnTextureClient(TextureClient* aClient);
+
+  /**
+   * Return a TextureClient that is not yet ready to be reused, but will be
+   * imminently.
+   */
+  void ReturnTextureClientDeferred(TextureClient* aClient) override;
+
+  /**
+   * Return any clients to the pool that were previously returned in
+   * ReturnTextureClientDeferred.
+   */
+  void ReturnDeferredClients();
+
+  /**
+   * Attempt to shrink the pool so that there are no more than
+   * mInitialPoolSize outstanding.
+   */
+  void ShrinkToMaximumSize();
+
+  /**
+   * Report that a client retrieved via GetTextureClient() has become
+   * unusable, so that it will no longer be tracked.
+   */
+  void ReportClientLost() override;
+
+  /**
+   * Calling this will cause the pool to attempt to relinquish any unused
+   * clients.
+   */
+  void Clear();
+
+  LayersBackend GetBackend() const {
+    return mKnowsCompositor->GetCompositorBackendType();
+  }
+  int32_t GetMaxTextureSize() const {
+    return mKnowsCompositor->GetMaxTextureSize();
+  }
+  gfx::SurfaceFormat GetFormat() { return mFormat; }
+  TextureFlags GetFlags() const { return mFlags; }
+
+  /**
+   * Clear the pool and put it in a state where it won't recycle any new
+   * texture.
+   */
+  void Destroy();
+
+ private:
+  void ReturnUnlockedClients();
+
+  /// Allocate a single TextureClient to be returned from the pool.
+  void AllocateTextureClient();
+
+  /// Reset and/or initialise timers for shrinking/clearing the pool.
+  void ResetTimers();
+
+  /// KnowsCompositor passed to the TextureClient for buffer creation.
+  RefPtr<KnowsCompositor> mKnowsCompositor;
+
+  /// Format is passed to the TextureClient for buffer creation.
+  gfx::SurfaceFormat mFormat;
+
+  /// The width and height of the tiles to be used.
+  gfx::IntSize mSize;
+
+  /// Flags passed to the TextureClient for buffer creation.
+  const TextureFlags mFlags;
+
+  /// How long to wait after a TextureClient is returned before trying
+  /// to shrink the pool to its maximum size of mPoolUnusedSize.
+  uint32_t mShrinkTimeoutMsec;
+
+  /// How long to wait after a TextureClient is returned before trying
+  /// to clear the pool.
+  uint32_t mClearTimeoutMsec;
+
+  // The initial number of unused texture clients to seed the pool with
+  // on construction
+  uint32_t mInitialPoolSize;
+
+  // How many unused texture clients to try and keep around if we go over
+  // the initial allocation
+  uint32_t mPoolUnusedSize;
+
+  /// This is a total number of clients in the wild and in the stack of
+  /// deferred clients (see below).  So, the total number of clients in
+  /// existence is always mOutstandingClients + the size of mTextureClients.
+  uint32_t mOutstandingClients;
+
+  std::stack<RefPtr<TextureClient>> mTextureClients;
+
+  std::list<RefPtr<TextureClient>> mTextureClientsDeferred;
+  RefPtr<nsITimer> mShrinkTimer;
+  RefPtr<nsITimer> mClearTimer;
+  // This mSurfaceAllocator owns us, so no need to hold a ref to it
+  TextureForwarder* mSurfaceAllocator;
+
+  // Keep track of whether this pool has been destroyed or not. If it has,
+  // we won't accept returns of TextureClients anymore, and the refcounting
+  // should take care of their destruction.
+  bool mDestroyed;
+};
+
+}  // namespace layers
+}  // namespace mozilla
+
+#endif /* MOZILLA_GFX_TEXTURECLIENTPOOL_H */