1 // Copyright 2013 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #include "base/barrier_closure.h"
9 #include "base/atomic_ref_count.h"
10 #include "base/functional/bind.h"
11 #include "base/memory/ptr_util.h"
12 #include "base/numerics/safe_conversions.h"
17 // Maintains state for a BarrierClosure.
20 BarrierInfo(size_t num_callbacks_left, OnceClosure done_closure);
21 BarrierInfo(const BarrierInfo&) = delete;
22 BarrierInfo& operator=(const BarrierInfo&) = delete;
26 AtomicRefCount num_callbacks_left_;
27 OnceClosure done_closure_;
30 BarrierInfo::BarrierInfo(size_t num_callbacks, OnceClosure done_closure)
31 : num_callbacks_left_(checked_cast<int>(num_callbacks)),
32 done_closure_(std::move(done_closure)) {}
34 void BarrierInfo::Run() {
35 DCHECK(!num_callbacks_left_.IsZero());
36 if (!num_callbacks_left_.Decrement())
37 std::move(done_closure_).Run();
40 void ShouldNeverRun() {
46 RepeatingClosure BarrierClosure(size_t num_callbacks_left,
47 OnceClosure done_closure) {
48 if (num_callbacks_left == 0) {
49 std::move(done_closure).Run();
50 return BindRepeating(&ShouldNeverRun);
53 return BindRepeating(&BarrierInfo::Run,
54 std::make_unique<BarrierInfo>(num_callbacks_left,
55 std::move(done_closure)));