mojo/common/message_pump_mojo.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 MOJO_COMMON_MESSAGE_PUMP_MOJO_H_
   6 #define MOJO_COMMON_MESSAGE_PUMP_MOJO_H_
   7
   8 #include <map>
   9
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/message_loop/message_pump.h"
  12 #include "base/synchronization/lock.h"
  13 #include "base/time/time.h"
  14 #include "mojo/common/mojo_common_export.h"
  15 #include "mojo/public/cpp/system/core.h"
  16
  17 namespace mojo {
  18 namespace common {
  19
  20 class MessagePumpMojoHandler;
  21
  22 // Mojo implementation of MessagePump.
  23 class MOJO_COMMON_EXPORT MessagePumpMojo : public base::MessagePump {
  24  public:
  25   MessagePumpMojo();
  26   virtual ~MessagePumpMojo();
  27
  28   // Static factory function (for using with |base::Thread::Options|, wrapped
  29   // using |base::Bind()|).
  30   static scoped_ptr<base::MessagePump> Create();
  31
  32   // Registers a MessagePumpMojoHandler for the specified handle. Only one
  33   // handler can be registered for a specified handle.
  34   void AddHandler(MessagePumpMojoHandler* handler,
  35                   const Handle& handle,
  36                   MojoHandleSignals wait_signals,
  37                   base::TimeTicks deadline);
  38
  39   void RemoveHandler(const Handle& handle);
  40
  41   // MessagePump:
  42   virtual void Run(Delegate* delegate) OVERRIDE;
  43   virtual void Quit() OVERRIDE;
  44   virtual void ScheduleWork() OVERRIDE;
  45   virtual void ScheduleDelayedWork(
  46       const base::TimeTicks& delayed_work_time) OVERRIDE;
  47
  48  private:
  49   struct RunState;
  50   struct WaitState;
  51
  52   // Contains the data needed to track a request to AddHandler().
  53   struct Handler {
  54     Handler() : handler(NULL), wait_signals(MOJO_HANDLE_SIGNAL_NONE), id(0) {}
  55
  56     MessagePumpMojoHandler* handler;
  57     MojoHandleSignals wait_signals;
  58     base::TimeTicks deadline;
  59     // See description of |MessagePumpMojo::next_handler_id_| for details.
  60     int id;
  61   };
  62
  63   typedef std::map<Handle, Handler> HandleToHandler;
  64
  65   // Implementation of Run().
  66   void DoRunLoop(RunState* run_state, Delegate* delegate);
  67
  68   // Services the set of handles ready. If |block| is true this waits for a
  69   // handle to become ready, otherwise this does not block.
  70   void DoInternalWork(const RunState& run_state, bool block);
  71
  72   // Removes the first invalid handle. This is called if MojoWaitMany finds an
  73   // invalid handle.
  74   void RemoveFirstInvalidHandle(const WaitState& wait_state);
  75
  76   void SignalControlPipe(const RunState& run_state);
  77
  78   WaitState GetWaitState(const RunState& run_state) const;
  79
  80   // Returns the deadline for the call to MojoWaitMany().
  81   MojoDeadline GetDeadlineForWait(const RunState& run_state) const;
  82
  83   // If non-NULL we're running (inside Run()). Member is reference to value on
  84   // stack.
  85   RunState* run_state_;
  86
  87   // Lock for accessing |run_state_|. In general the only method that we have to
  88   // worry about is ScheduleWork(). All other methods are invoked on the same
  89   // thread.
  90   base::Lock run_state_lock_;
  91
  92   HandleToHandler handlers_;
  93
  94   // An ever increasing value assigned to each Handler::id. Used to detect
  95   // uniqueness while notifying. That is, while notifying expired timers we copy
  96   // |handlers_| and only notify handlers whose id match. If the id does not
  97   // match it means the handler was removed then added so that we shouldn't
  98   // notify it.
  99   int next_handler_id_;
 100
 101   DISALLOW_COPY_AND_ASSIGN(MessagePumpMojo);
 102 };
 103
 104 }  // namespace common
 105 }  // namespace mojo
 106
 107 #endif  // MOJO_COMMON_MESSAGE_PUMP_MOJO_H_