Avoid iterating over all handles in MessagePumpMojo on every iteration to calculate deadlines.

mojo/message_pump/message_pump_mojo.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_MESSAGE_PUMP_MESSAGE_PUMP_MOJO_H_
 #define MOJO_MESSAGE_PUMP_MESSAGE_PUMP_MOJO_H_
 
 #include <map>
+#include <set>
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_pump.h"
 #include "base/observer_list.h"
 #include "base/synchronization/lock.h"
 #include "base/time/time.h"
 #include "mojo/message_pump/mojo_message_pump_export.h"
 #include "mojo/public/cpp/system/core.h"
 
@@ skipping 91 matching lines @@
   // If non-NULL we're running (inside Run()). Member is reference to value on
   // stack.
   RunState* run_state_;
 
   // Lock for accessing |run_state_|. In general the only method that we have to
   // worry about is ScheduleWork(). All other methods are invoked on the same
   // thread.
   base::Lock run_state_lock_;
 
   HandleToHandler handlers_;
+  // Set of handles that have a deadline set. Avoids iterating over all elements
+  // in |handles_| in the common case (no deadline set).
+  // TODO(amistry): Make this better and avoid special-casing deadlines.
+  std::set<Handle> deadline_handles_;
 
   // An ever increasing value assigned to each Handler::id. Used to detect
   // uniqueness while notifying. That is, while notifying expired timers we copy
   // |handlers_| and only notify handlers whose id match. If the id does not
   // match it means the handler was removed then added so that we shouldn't
   // notify it.
   int next_handler_id_;
 
   base::ObserverList<Observer> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(MessagePumpMojo);
 };
 
 }  // namespace common
 }  // namespace mojo
 
 #endif  // MOJO_MESSAGE_PUMP_MESSAGE_PUMP_MOJO_H_