mojo/system/simple_dispatcher.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_SYSTEM_SIMPLE_DISPATCHER_H_
   6 #define MOJO_SYSTEM_SIMPLE_DISPATCHER_H_
   7
   8 #include <list>
   9
  10 #include "base/basictypes.h"
  11 #include "mojo/system/dispatcher.h"
  12 #include "mojo/system/system_impl_export.h"
  13 #include "mojo/system/waiter_list.h"
  14
  15 namespace mojo {
  16 namespace system {
  17
  18 // A base class for simple dispatchers. "Simple" means that there's a one-to-one
  19 // correspondence between handles and dispatchers (see the explanatory comment
  20 // in core.cc). This class implements the standard waiter-signalling mechanism
  21 // in that case.
  22 class MOJO_SYSTEM_IMPL_EXPORT SimpleDispatcher : public Dispatcher {
  23  protected:
  24   SimpleDispatcher();
  25   virtual ~SimpleDispatcher();
  26
  27   // To be called by subclasses when the state changes (so
  28   // |SatisfiedFlagsNoLock()| and |SatisfiableFlagsNoLock()| should be checked
  29   // again). Must be called under lock.
  30   void StateChangedNoLock();
  31
  32   // These should return the wait flags that are satisfied by the object's
  33   // current state and those that may eventually be satisfied by this object's
  34   // state, respectively. They should be overridden by subclasses to reflect
  35   // their notion of state. They are never called after the dispatcher has been
  36   // closed. They are called under |lock_|.
  37   virtual MojoWaitFlags SatisfiedFlagsNoLock() const = 0;
  38   virtual MojoWaitFlags SatisfiableFlagsNoLock() const = 0;
  39
  40   // |Dispatcher| protected methods:
  41   virtual void CancelAllWaitersNoLock() OVERRIDE;
  42   virtual MojoResult AddWaiterImplNoLock(Waiter* waiter,
  43                                          MojoWaitFlags flags,
  44                                          MojoResult wake_result) OVERRIDE;
  45   virtual void RemoveWaiterImplNoLock(Waiter* waiter) OVERRIDE;
  46
  47  private:
  48   // Protected by |lock()|:
  49   WaiterList waiter_list_;
  50
  51   DISALLOW_COPY_AND_ASSIGN(SimpleDispatcher);
  52 };
  53
  54 }  // namespace system
  55 }  // namespace mojo
  56
  57 #endif  // MOJO_SYSTEM_SIMPLE_DISPATCHER_H_