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   // NOTE: a value of 0 for |deadline| indicates an indefinite timeout.
  35   void AddHandler(MessagePumpMojoHandler* handler,
  36                   const Handle& handle,
  37                   MojoHandleSignals wait_signals,
  38                   base::TimeTicks deadline);
  39
  40   void RemoveHandler(const Handle& handle);
  41
  42   // MessagePump:
  43   virtual void Run(Delegate* delegate) OVERRIDE;
  44   virtual void Quit() OVERRIDE;
  45   virtual void ScheduleWork() OVERRIDE;
  46   virtual void ScheduleDelayedWork(
  47       const base::TimeTicks& delayed_work_time) OVERRIDE;
  48
  49  private:
  50   struct RunState;
  51   struct WaitState;
  52
  53   // Contains the data needed to track a request to AddHandler().
  54   struct Handler {
  55     Handler() : handler(NULL), wait_signals(MOJO_HANDLE_SIGNAL_NONE), id(0) {}
  56
  57     MessagePumpMojoHandler* handler;
  58     MojoHandleSignals wait_signals;
  59     base::TimeTicks deadline;
  60     // See description of |MessagePumpMojo::next_handler_id_| for details.
  61     int id;
  62   };
  63
  64   typedef std::map<Handle, Handler> HandleToHandler;
  65
  66   // Implementation of Run().
  67   void DoRunLoop(RunState* run_state, Delegate* delegate);
  68
  69   // Services the set of handles ready. If |block| is true this waits for a
  70   // handle to become ready, otherwise this does not block.
  71   void DoInternalWork(const RunState& run_state, bool block);
  72
  73   // Removes the first invalid handle. This is called if MojoWaitMany finds an
  74   // invalid handle.
  75   void RemoveFirstInvalidHandle(const WaitState& wait_state);
  76
  77   void SignalControlPipe(const RunState& run_state);
  78
  79   WaitState GetWaitState(const RunState& run_state) const;
  80
  81   // Returns the deadline for the call to MojoWaitMany().
  82   MojoDeadline GetDeadlineForWait(const RunState& run_state) const;
  83
  84   // If non-NULL we're running (inside Run()). Member is reference to value on
  85   // stack.
  86   RunState* run_state_;
  87
  88   // Lock for accessing |run_state_|. In general the only method that we have to
  89   // worry about is ScheduleWork(). All other methods are invoked on the same
  90   // thread.
  91   base::Lock run_state_lock_;
  92
  93   HandleToHandler handlers_;
  94
  95   // An ever increasing value assigned to each Handler::id. Used to detect
  96   // uniqueness while notifying. That is, while notifying expired timers we copy
  97   // |handlers_| and only notify handlers whose id match. If the id does not
  98   // match it means the handler was removed then added so that we shouldn't
  99   // notify it.
 100   int next_handler_id_;
 101
 102   DISALLOW_COPY_AND_ASSIGN(MessagePumpMojo);
 103 };
 104
 105 }  // namespace common
 106 }  // namespace mojo
 107
 108 #endif  // MOJO_COMMON_MESSAGE_PUMP_MOJO_H_