ppapi/proxy/plugin_resource_tracker.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 PPAPI_PROXY_PLUGIN_RESOURCE_TRACKER_H_
   6 #define PPAPI_PROXY_PLUGIN_RESOURCE_TRACKER_H_
   7
   8 #include <map>
   9 #include <utility>
  10
  11 #include "base/compiler_specific.h"
  12 #include "base/containers/hash_tables.h"
  13 #include "ppapi/c/pp_completion_callback.h"
  14 #include "ppapi/c/pp_instance.h"
  15 #include "ppapi/c/pp_stdint.h"
  16 #include "ppapi/c/pp_resource.h"
  17 #include "ppapi/c/pp_var.h"
  18 #include "ppapi/proxy/ppapi_proxy_export.h"
  19 #include "ppapi/shared_impl/host_resource.h"
  20 #include "ppapi/shared_impl/resource_tracker.h"
  21
  22 namespace base {
  23 template<typename T> struct DefaultSingletonTraits;
  24 }
  25
  26 namespace ppapi {
  27
  28 namespace proxy {
  29
  30 class PPAPI_PROXY_EXPORT PluginResourceTracker : public ResourceTracker {
  31  public:
  32   PluginResourceTracker();
  33   ~PluginResourceTracker() override;
  34
  35   // Given a host resource, maps it to an existing plugin resource ID if it
  36   // exists, or returns 0 on failure.
  37   PP_Resource PluginResourceForHostResource(
  38       const HostResource& resource) const;
  39
  40   // "Abandons" a PP_Resource on the plugin side. This releases a reference to
  41   // the resource and allows the plugin side of the resource (the proxy
  42   // resource) to be destroyed without sending a message to the renderer
  43   // notifing it that the plugin has released the resource. This is useful when
  44   // the plugin sends a resource to the renderer in reply to a sync IPC. The
  45   // plugin would want to release its reference to the reply resource straight
  46   // away but doing so can sometimes cause the resource to be deleted in the
  47   // renderer before the sync IPC reply has been received giving the renderer a
  48   // chance to add a ref to it. (see e.g. crbug.com/490611). Instead the
  49   // renderer assumes responsibility for the ref that the plugin created and
  50   // this function can be called.
  51   void AbandonResource(PP_Resource res);
  52
  53  protected:
  54   // ResourceTracker overrides.
  55   PP_Resource AddResource(Resource* object) override;
  56   void RemoveResource(Resource* object) override;
  57
  58  private:
  59   // Map of host instance/resource pairs to a plugin resource ID.
  60   typedef std::map<HostResource, PP_Resource> HostResourceMap;
  61   HostResourceMap host_resource_map_;
  62
  63   base::hash_set<PP_Resource> abandoned_resources_;
  64
  65   DISALLOW_COPY_AND_ASSIGN(PluginResourceTracker);
  66 };
  67
  68 }  // namespace proxy
  69 }  // namespace ppapi
  70
  71 #endif  // PPAPI_PROXY_PLUGIN_RESOURCE_TRACKER_H_