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