ppapi/proxy/resource_reply_thread_registrar.h

   1 // Copyright 2013 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_RESOURCE_REPLY_THREAD_REGISTRAR_H_
   6 #define PPAPI_PROXY_RESOURCE_REPLY_THREAD_REGISTRAR_H_
   7
   8 #include <map>
   9 #include <set>
  10
  11 #include "base/basictypes.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "base/synchronization/lock.h"
  14 #include "ppapi/c/pp_resource.h"
  15 #include "ppapi/proxy/ppapi_proxy_export.h"
  16
  17
  18 namespace base {
  19 class SingleThreadTaskRunner;
  20 }
  21
  22 namespace IPC {
  23 class Message;
  24 }
  25
  26 namespace ppapi {
  27
  28 class TrackedCallback;
  29
  30 namespace proxy {
  31
  32 class ResourceMessageReplyParams;
  33
  34 // ResourceReplyThreadRegistrar records the handling thread for
  35 // PpapiPluginMsg_ResourceReply messages.
  36 // This class is thread safe.
  37 class PPAPI_PROXY_EXPORT ResourceReplyThreadRegistrar
  38     : public base::RefCountedThreadSafe<ResourceReplyThreadRegistrar> {
  39  public:
  40   explicit ResourceReplyThreadRegistrar(
  41       scoped_refptr<base::SingleThreadTaskRunner> main_thread);
  42
  43   // This method can only be called while holding the Pepper proxy lock; the
  44   // other methods can be called with/without the Pepper proxy lock.
  45   void Register(PP_Resource resource,
  46                 int32_t sequence_number,
  47                 scoped_refptr<TrackedCallback> reply_thread_hint);
  48   void Unregister(PP_Resource resource);
  49
  50   scoped_refptr<base::SingleThreadTaskRunner> GetTargetThread(
  51       const ResourceMessageReplyParams& reply_params,
  52       const IPC::Message& nested_msg);
  53
  54  private:
  55   friend class base::RefCountedThreadSafe<ResourceReplyThreadRegistrar>;
  56
  57   typedef std::map<int32_t, scoped_refptr<base::SingleThreadTaskRunner>>
  58       SequenceThreadMap;
  59   typedef std::map<PP_Resource, SequenceThreadMap> ResourceMap;
  60
  61   ~ResourceReplyThreadRegistrar();
  62
  63   // The lock that protects the data members below.
  64   // Please note that we should never try to acquire the Pepper proxy lock while
  65   // holding |lock_|, otherwise we will cause deadlock.
  66   base::Lock lock_;
  67   ResourceMap map_;
  68   scoped_refptr<base::SingleThreadTaskRunner> main_thread_;
  69
  70   DISALLOW_COPY_AND_ASSIGN(ResourceReplyThreadRegistrar);
  71 };
  72
  73 }  // namespace proxy
  74 }  // namespace ppapi
  75
  76 #endif   // PPAPI_PROXY_RESOURCE_REPLY_THREAD_REGISTRAR_H_