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 #include "base/barrier_closure.h" 6 7 #include <utility> 8 9 #include "base/atomic_ref_count.h" 10 #include "base/bind.h" 11 #include "base/memory/ptr_util.h" 12 13 namespace base { 14 namespace { 15 16 // Maintains state for a BarrierClosure. 17 class BarrierInfo { 18 public: 19 BarrierInfo(int num_callbacks_left, OnceClosure done_closure); 20 void Run(); 21 22 private: 23 AtomicRefCount num_callbacks_left_; 24 OnceClosure done_closure_; 25 }; 26 BarrierInfo(int num_callbacks,OnceClosure done_closure)27BarrierInfo::BarrierInfo(int num_callbacks, OnceClosure done_closure) 28 : num_callbacks_left_(num_callbacks), 29 done_closure_(std::move(done_closure)) {} 30 Run()31void BarrierInfo::Run() { 32 DCHECK(!num_callbacks_left_.IsZero()); 33 if (!num_callbacks_left_.Decrement()) 34 std::move(done_closure_).Run(); 35 } 36 37 } // namespace 38 BarrierClosure(int num_callbacks_left,OnceClosure done_closure)39RepeatingClosure BarrierClosure(int num_callbacks_left, 40 OnceClosure done_closure) { 41 DCHECK_GE(num_callbacks_left, 0); 42 43 if (num_callbacks_left == 0) 44 std::move(done_closure).Run(); 45 46 return BindRepeating( 47 &BarrierInfo::Run, 48 Owned(new BarrierInfo(num_callbacks_left, std::move(done_closure)))); 49 } 50 51 } // namespace base 52