gpu: Mailbox emulation with EGLImage

gpu/command_buffer/service/mailbox_synchronizer.h

+// Copyright (c) 2014 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.
+
+#ifndef GPU_COMMAND_BUFFER_SERVICE_MAILBOX_SYNCHRONIZER_H_
+#define GPU_COMMAND_BUFFER_SERVICE_MAILBOX_SYNCHRONIZER_H_
+
+#include "gpu/command_buffer/common/mailbox.h"
+
+#include <map>
+#include <set>
+
+#include "base/memory/linked_ptr.h"
+#include "base/synchronization/lock.h"
+#include "gpu/command_buffer/service/texture_definition.h"
+#include "gpu/gpu_export.h"
+
+namespace gpu {
+namespace gles2 {
+
+class MailboxManager;
+class Texture;
+
+// A thread-safe proxy that can be used to emulate texture sharing across
+// share-groups.
+class MailboxSynchronizer {
+ public:
+  ~MailboxSynchronizer();
+
+  GPU_EXPORT static bool Initialize();
+  GPU_EXPORT static void Terminate();
+  static MailboxSynchronizer* GetInstance();
+
+  // Create a texture from a globally visible mailbox.
+  Texture* CreateTextureFromMailbox(unsigned target, const Mailbox& mailbox);
+
+  void PushTextureUpdates(MailboxManager* manager);
+  void PullTextureUpdates(MailboxManager* manager);
+
+  void TextureDeleted(Texture* texture);
+
+ private:
+  MailboxSynchronizer();
+
+  struct TargetName {
+    TargetName(unsigned target, const Mailbox& mailbox);
+    bool operator<(const TargetName& rhs) const {
+      return memcmp(this, &rhs, sizeof(rhs)) < 0;
+    }
+    bool operator!=(const TargetName& rhs) const {
+      return memcmp(this, &rhs, sizeof(rhs)) != 0;
+    }
+    bool operator==(const TargetName& rhs) const {
+      return !operator!=(rhs);
+    }
+    unsigned target;
+    Mailbox mailbox;
+  };
+
+  base::Lock lock_;
+
+  struct TextureGroup {
+    explicit TextureGroup(const TextureDefinition& definition);
+    ~TextureGroup();
+
+    TextureDefinition definition;
+    std::set<TargetName> mailboxes;
+   private:
+    DISALLOW_COPY_AND_ASSIGN(TextureGroup);
+  };
+
+  struct TextureVersion {
+    explicit TextureVersion(linked_ptr<TextureGroup> group);
+    ~TextureVersion();
+
+    unsigned int version;
+    linked_ptr<TextureGroup> group;
+  };
+  typedef std::map<Texture*, TextureVersion> TextureMap;
+  TextureMap textures_;
+
+  linked_ptr<TextureGroup> GetGroupForMailboxLocked(
+      const TargetName& target_name);
+  void ReassociateMailboxLocked(
+      const TargetName& target_name,
+      TextureGroup* group);
+  void UpdateTextureLocked(Texture* texture, TextureVersion& texture_version);
+
+  DISALLOW_COPY_AND_ASSIGN(MailboxSynchronizer);
+};
+
+}  // namespage gles2
+}  // namespace gpu
+
+#endif  // GPU_COMMAND_BUFFER_SERVICE_MAILBOX_SYNCHRONIZER_H_
+