xref: /aosp_15_r20/external/cronet/base/synchronization/atomic_flag.cc (revision 6777b5387eb2ff775bb5750e3f5d96f37fb7352b)
1*6777b538SAndroid Build Coastguard Worker // Copyright 2011 The Chromium Authors
2*6777b538SAndroid Build Coastguard Worker // Use of this source code is governed by a BSD-style license that can be
3*6777b538SAndroid Build Coastguard Worker // found in the LICENSE file.
4*6777b538SAndroid Build Coastguard Worker 
5*6777b538SAndroid Build Coastguard Worker #include "base/synchronization/atomic_flag.h"
6*6777b538SAndroid Build Coastguard Worker 
7*6777b538SAndroid Build Coastguard Worker #include "base/check_op.h"
8*6777b538SAndroid Build Coastguard Worker 
9*6777b538SAndroid Build Coastguard Worker namespace base {
10*6777b538SAndroid Build Coastguard Worker 
AtomicFlag()11*6777b538SAndroid Build Coastguard Worker AtomicFlag::AtomicFlag() {
12*6777b538SAndroid Build Coastguard Worker   // It doesn't matter where the AtomicFlag is built so long as it's always
13*6777b538SAndroid Build Coastguard Worker   // Set() from the same sequence after. Note: the sequencing requirements are
14*6777b538SAndroid Build Coastguard Worker   // necessary for IsSet()'s callers to know which sequence's memory operations
15*6777b538SAndroid Build Coastguard Worker   // they are synchronized with.
16*6777b538SAndroid Build Coastguard Worker   DETACH_FROM_SEQUENCE(set_sequence_checker_);
17*6777b538SAndroid Build Coastguard Worker }
18*6777b538SAndroid Build Coastguard Worker 
19*6777b538SAndroid Build Coastguard Worker AtomicFlag::~AtomicFlag() = default;
20*6777b538SAndroid Build Coastguard Worker 
Set()21*6777b538SAndroid Build Coastguard Worker void AtomicFlag::Set() {
22*6777b538SAndroid Build Coastguard Worker   DCHECK_CALLED_ON_VALID_SEQUENCE(set_sequence_checker_);
23*6777b538SAndroid Build Coastguard Worker   flag_.store(1, std::memory_order_release);
24*6777b538SAndroid Build Coastguard Worker }
25*6777b538SAndroid Build Coastguard Worker 
UnsafeResetForTesting()26*6777b538SAndroid Build Coastguard Worker void AtomicFlag::UnsafeResetForTesting() {
27*6777b538SAndroid Build Coastguard Worker   DETACH_FROM_SEQUENCE(set_sequence_checker_);
28*6777b538SAndroid Build Coastguard Worker   flag_.store(0, std::memory_order_release);
29*6777b538SAndroid Build Coastguard Worker }
30*6777b538SAndroid Build Coastguard Worker 
31*6777b538SAndroid Build Coastguard Worker }  // namespace base
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