| // 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 BASE_BARRIER_CLOSURE_H_ | 
 | #define BASE_BARRIER_CLOSURE_H_ | 
 |  | 
 | #include "base/base_export.h" | 
 | #include "base/callback.h" | 
 |  | 
 | namespace base { | 
 |  | 
 | // BarrierClosure executes |done_closure| after it has been invoked | 
 | // |num_closures| times. | 
 | // | 
 | // If |num_closures| is 0, |done_closure| is executed immediately. | 
 | // | 
 | // BarrierClosure is thread-safe - the count of remaining closures is | 
 | // maintained as a base::AtomicRefCount. |done_closure| will be run on | 
 | // the thread that calls the final Run() on the returned closures. | 
 | // | 
 | // |done_closure| is also cleared on the final calling thread. | 
 | BASE_EXPORT RepeatingClosure BarrierClosure(int num_closures, | 
 |                                             OnceClosure done_closure); | 
 |  | 
 | }  // namespace base | 
 |  | 
 | #endif  // BASE_BARRIER_CLOSURE_H_ |