cc/surfaces/surface_id_allocator.h

   1 // Copyright 2014 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 CC_SURFACES_SURFACE_ID_ALLOCATOR_H_
   6 #define CC_SURFACES_SURFACE_ID_ALLOCATOR_H_
   7
   8 #include "cc/surfaces/surface_id.h"
   9 #include "cc/surfaces/surfaces_export.h"
  10
  11 namespace cc {
  12
  13 class SurfaceManager;
  14
  15 // This is a helper class for generating surface IDs within a specified
  16 // namespace.  This is not threadsafe, to use from multiple threads wrap this
  17 // class in a mutex.
  18 class CC_SURFACES_EXPORT SurfaceIdAllocator {
  19  public:
  20   explicit SurfaceIdAllocator(uint32_t id_namespace);
  21   ~SurfaceIdAllocator();
  22
  23   SurfaceId GenerateId();
  24
  25   static uint32_t NamespaceForId(SurfaceId id);
  26
  27   // This needs to be called before any sequences with this allocator's
  28   // namespace will be used to enforce destruction dependencies.
  29   // When this SurfaceIdAllocator is destroyed, its namespace is
  30   // automatically invalidated and any remaining sequences with that
  31   // namespace will be ignored. This method does not need to be called in
  32   // contexts where there is no SurfaceManager (e.g. a renderer process).
  33   void RegisterSurfaceIdNamespace(SurfaceManager* manager);
  34
  35   uint32_t id_namespace() const { return id_namespace_; }
  36
  37  private:
  38   const uint32_t id_namespace_;
  39   uint32_t next_id_;
  40   SurfaceManager* manager_;
  41
  42   DISALLOW_COPY_AND_ASSIGN(SurfaceIdAllocator);
  43 };
  44
  45 }  // namespace cc
  46
  47 #endif  // CC_SURFACES_SURFACE_ID_ALLOCATOR_H_