gpu/command_buffer/service/mailbox_manager.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef GPU_COMMAND_BUFFER_SERVICE_MAILBOX_MANAGER_H_
   6 #define GPU_COMMAND_BUFFER_SERVICE_MAILBOX_MANAGER_H_
   7
   8 #include <functional>
   9 #include <map>
  10
  11 #include "base/memory/linked_ptr.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "crypto/hmac.h"
  14 #include "gpu/command_buffer/common/constants.h"
  15 #include "gpu/gpu_export.h"
  16
  17 // From gl2/gl2ext.h.
  18 #ifndef GL_MAILBOX_SIZE_CHROMIUM
  19 #define GL_MAILBOX_SIZE_CHROMIUM 64
  20 #endif
  21
  22 typedef signed char GLbyte;
  23
  24 namespace gpu {
  25 namespace gles2 {
  26
  27 class Texture;
  28 class TextureManager;
  29
  30 // Identifies a mailbox where a texture definition can be stored for
  31 // transferring textures between contexts that are not in the same context
  32 // group. It is a random key signed with a hash of a private key.
  33 struct GPU_EXPORT MailboxName {
  34   MailboxName();
  35   GLbyte key[GL_MAILBOX_SIZE_CHROMIUM / 2];
  36   GLbyte signature[GL_MAILBOX_SIZE_CHROMIUM / 2];
  37 };
  38
  39 // Manages resources scoped beyond the context or context group level.
  40 class GPU_EXPORT MailboxManager : public base::RefCounted<MailboxManager> {
  41  public:
  42   MailboxManager();
  43
  44   // Generate a unique mailbox name signed with the manager's private key.
  45   void GenerateMailboxName(MailboxName* name);
  46
  47   // Look up the texture definition from the named mailbox.
  48   Texture* ConsumeTexture(unsigned target, const MailboxName& name);
  49
  50   // Put the texture into the named mailbox.
  51   bool ProduceTexture(unsigned target,
  52                       const MailboxName& name,
  53                       Texture* texture);
  54
  55   // Destroy any mailbox that reference the given texture.
  56   void TextureDeleted(Texture* texture);
  57
  58   std::string private_key() {
  59     return std::string(private_key_, sizeof(private_key_));
  60   }
  61
  62  private:
  63   friend class base::RefCounted<MailboxManager>;
  64
  65   ~MailboxManager();
  66
  67   void SignMailboxName(MailboxName* name);
  68   bool IsMailboxNameValid(const MailboxName& name);
  69
  70   struct TargetName {
  71     TargetName(unsigned target, const MailboxName& name);
  72     unsigned target;
  73     MailboxName name;
  74   };
  75
  76   static bool TargetNameLess(const TargetName& lhs, const TargetName& rhs);
  77
  78   // This is a bidirectional map between mailbox and textures. We can have
  79   // multiple mailboxes per texture, but one texture per mailbox. We keep an
  80   // iterator in the MailboxToTextureMap to be able to manage changes to
  81   // the TextureToMailboxMap efficiently.
  82   typedef std::multimap<Texture*, TargetName> TextureToMailboxMap;
  83   typedef std::map<
  84       TargetName,
  85       TextureToMailboxMap::iterator,
  86       std::pointer_to_binary_function<
  87           const TargetName&, const TargetName&, bool> > MailboxToTextureMap;
  88
  89   char private_key_[GL_MAILBOX_SIZE_CHROMIUM / 2];
  90   crypto::HMAC hmac_;
  91   MailboxToTextureMap mailbox_to_textures_;
  92   TextureToMailboxMap textures_to_mailboxes_;
  93
  94   DISALLOW_COPY_AND_ASSIGN(MailboxManager);
  95 };
  96 }  // namespage gles2
  97 }  // namespace gpu
  98
  99 #endif  // GPU_COMMAND_BUFFER_SERVICE_MAILBOX_MANAGER_H_
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