Initial in-process implementation of some Mojo primitives.

mojo/system/simple_dispatcher.h

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef MOJO_SYSTEM_SIMPLE_DISPATCHER_H_
+#define MOJO_SYSTEM_SIMPLE_DISPATCHER_H_
+
+#include <list>
+
+#include "base/basictypes.h"
+#include "mojo/system/dispatcher.h"
+#include "mojo/system/waiter_list.h"
+
+namespace mojo {
+namespace system {
+
+// A base class for simple dispatchers. "Simple" means that there's a one-to-one
+// correspondence between handles and dispatchers (see the explanatory comment
+// in core_impl.cc). This class implements the standard waiter-signalling
+// mechanism in that case.
+class SimpleDispatcher : public Dispatcher {
+ protected:
+  SimpleDispatcher();
+
+  friend class base::RefCountedThreadSafe<SimpleDispatcher>;
+  virtual ~SimpleDispatcher();
+
+  // To be called by subclasses when the state changes (so
+  // |SatisfiedFlagsNoLock()| and |SatisfiableFlagsNoLock()| should be checked
+  // again). Must be called under lock.
+  void StateChangedNoLock();
+
+  // These should return the wait flags that are satisfied by the object's
+  // current state and those that may eventually be satisfied by this object's
+  // state, respectively. They should be overridden by subclasses to reflect
+  // their notion of state. They are never called after the dispatcher has been
+  // closed. They are called under |lock_|.
+  virtual MojoWaitFlags SatisfiedFlagsNoLock() const = 0;
+  virtual MojoWaitFlags SatisfiableFlagsNoLock() const = 0;
+
+  // |Dispatcher| implementation/overrides:
+  virtual void CancelAllWaitersNoLock() OVERRIDE;
+  virtual MojoResult AddWaiterImplNoLock(Waiter* waiter,
+                                         MojoWaitFlags flags,
+                                         MojoResult wake_result) OVERRIDE;
+  virtual void RemoveWaiterImplNoLock(Waiter* waiter) OVERRIDE;
+
+ private:
+  // Protected by |lock()|:
+  WaiterList waiter_list_;
+
+  DISALLOW_COPY_AND_ASSIGN(SimpleDispatcher);
+};
+
+}  // namespace system
+}  // namespace mojo
+
+#endif  // MOJO_SYSTEM_SIMPLE_DISPATCHER_H_