ppapi/proxy/host_dispatcher.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_HOST_DISPATCHER_H_
   6 #define PPAPI_PROXY_HOST_DISPATCHER_H_
   7
   8 #include <map>
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/compiler_specific.h"
  13 #include "base/memory/ref_counted.h"
  14 #include "base/process.h"
  15 #include "ipc/ipc_channel_proxy.h"
  16 #include "ppapi/c/pp_instance.h"
  17 #include "ppapi/proxy/dispatcher.h"
  18
  19 struct PPB_Proxy_Private;
  20
  21 namespace ppapi {
  22
  23 struct Preferences;
  24
  25 namespace proxy {
  26
  27 class PPAPI_PROXY_EXPORT HostDispatcher : public Dispatcher {
  28  public:
  29   // This interface receives notifications about sync messages being sent by
  30   // the dispatcher to the plugin process. It is used to detect a hung plugin.
  31   //
  32   // Note that there can be nested sync messages, so the begin/end status
  33   // actually represents a stack of blocking messages.
  34   class SyncMessageStatusReceiver : public IPC::ChannelProxy::MessageFilter {
  35    public:
  36     // Notification that a sync message is about to be sent out.
  37     virtual void BeginBlockOnSyncMessage() = 0;
  38
  39     // Notification that a sync message reply was received and the dispatcher
  40     // is no longer blocked on a sync message.
  41     virtual void EndBlockOnSyncMessage() = 0;
  42
  43    protected:
  44     virtual ~SyncMessageStatusReceiver() {}
  45   };
  46
  47   // Constructor for the renderer side. This will take a reference to the
  48   // SyncMessageStatusReceiver.
  49   //
  50   // You must call InitHostWithChannel after the constructor.
  51   HostDispatcher(PP_Module module,
  52                  PP_GetInterface_Func local_get_interface,
  53                  SyncMessageStatusReceiver* sync_status,
  54                  const PpapiPermissions& permissions);
  55   ~HostDispatcher();
  56
  57   // You must call this function before anything else. Returns true on success.
  58   // The delegate pointer must outlive this class, ownership is not
  59   // transferred.
  60   virtual bool InitHostWithChannel(Delegate* delegate,
  61                                    const IPC::ChannelHandle& channel_handle,
  62                                    bool is_client,
  63                                    const Preferences& preferences);
  64
  65   // The host side maintains a mapping from PP_Instance to Dispatcher so
  66   // that we can send the messages to the right channel.
  67   static HostDispatcher* GetForInstance(PP_Instance instance);
  68   static void SetForInstance(PP_Instance instance,
  69                              HostDispatcher* dispatcher);
  70   static void RemoveForInstance(PP_Instance instance);
  71
  72   // Returns the host's notion of our PP_Module. This will be different than
  73   // the plugin's notion of its PP_Module because the plugin process may be
  74   // used by multiple renderer processes.
  75   //
  76   // Use this value instead of a value from the plugin whenever talking to the
  77   // host.
  78   PP_Module pp_module() const { return pp_module_; }
  79
  80   // Dispatcher overrides.
  81   virtual bool IsPlugin() const;
  82   virtual bool Send(IPC::Message* msg);
  83
  84   // IPC::Listener.
  85   virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
  86   virtual void OnChannelError() OVERRIDE;
  87
  88   // Proxied version of calling GetInterface on the plugin. This will check
  89   // if the plugin supports the given interface (with caching) and returns the
  90   // pointer to the proxied interface if it is supported. Returns NULL if the
  91   // given interface isn't supported by the plugin or the proxy.
  92   const void* GetProxiedInterface(const std::string& iface_name);
  93
  94   // See the value below. Call this when processing a scripting message from
  95   // the plugin that can be reentered. This is set to false at the beginning
  96   // of processing of each message from the plugin.
  97   void set_allow_plugin_reentrancy() {
  98     allow_plugin_reentrancy_ = true;
  99   }
 100
 101   // Returns the proxy interface for talking to the implementation.
 102   const PPB_Proxy_Private* ppb_proxy() const { return ppb_proxy_; }
 103
 104  protected:
 105   // Overridden from Dispatcher.
 106   virtual void OnInvalidMessageReceived();
 107
 108  private:
 109   void OnHostMsgLogWithSource(PP_Instance instance,
 110                               int int_log_level,
 111                               const std::string& source,
 112                               const std::string& value);
 113
 114   scoped_refptr<SyncMessageStatusReceiver> sync_status_;
 115
 116   PP_Module pp_module_;
 117
 118   // Maps interface name to whether that interface is supported. If an interface
 119   // name is not in the map, that implies that we haven't queried for it yet.
 120   typedef base::hash_map<std::string, bool> PluginSupportedMap;
 121   PluginSupportedMap plugin_supported_;
 122
 123   // Guaranteed non-NULL.
 124   const PPB_Proxy_Private* ppb_proxy_;
 125
 126   // Set to true when the plugin is in a state that it can be reentered by a
 127   // sync message from the host. We allow reentrancy only when we're processing
 128   // a sync message from the renderer that is a scripting command. When the
 129   // plugin is in this state, it needs to accept reentrancy since scripting may
 130   // ultimately call back into the plugin.
 131   bool allow_plugin_reentrancy_;
 132
 133   DISALLOW_COPY_AND_ASSIGN(HostDispatcher);
 134 };
 135
 136 // Create this object on the stack to prevent the module (and hence the
 137 // dispatcher) from being deleted out from under you. This is necessary when
 138 // calling some scripting functions that may delete the plugin.
 139 //
 140 // This class does nothing if used on the plugin side.
 141 class ScopedModuleReference {
 142  public:
 143   explicit ScopedModuleReference(Dispatcher* dispatcher);
 144   ~ScopedModuleReference();
 145
 146  private:
 147   HostDispatcher* dispatcher_;
 148
 149   DISALLOW_COPY_AND_ASSIGN(ScopedModuleReference);
 150 };
 151
 152 }  // namespace proxy
 153 }  // namespace ppapi
 154
 155 #endif  // PPAPI_PROXY_HOST_DISPATCHER_H_