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// Copyright 2021 The Abseil Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef ABSL_STRINGS_INTERNAL_CORDZ_UPDATE_SCOPE_H_
#define ABSL_STRINGS_INTERNAL_CORDZ_UPDATE_SCOPE_H_
#include "absl/base/config.h"
#include "absl/base/optimization.h"
#include "absl/base/thread_annotations.h"
#include "absl/strings/internal/cord_internal.h"
#include "absl/strings/internal/cordz_info.h"
#include "absl/strings/internal/cordz_update_tracker.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace cord_internal {
// CordzUpdateScope scopes an update to the provided CordzInfo.
// The class invokes `info->Lock(method)` and `info->Unlock()` to guard
// cordrep updates. This class does nothing if `info` is null.
// See also the 'Lock`, `Unlock` and `SetCordRep` methods in `CordzInfo`.
class ABSL_SCOPED_LOCKABLE CordzUpdateScope {
public:
CordzUpdateScope(CordzInfo* info, CordzUpdateTracker::MethodIdentifier method)
ABSL_EXCLUSIVE_LOCK_FUNCTION(info)
: info_(info) {
if (ABSL_PREDICT_FALSE(info_)) {
info->Lock(method);
}
}
// CordzUpdateScope can not be copied or assigned to.
CordzUpdateScope(CordzUpdateScope&& rhs) = delete;
CordzUpdateScope(const CordzUpdateScope&) = delete;
CordzUpdateScope& operator=(CordzUpdateScope&& rhs) = delete;
CordzUpdateScope& operator=(const CordzUpdateScope&) = delete;
~CordzUpdateScope() ABSL_UNLOCK_FUNCTION() {
if (ABSL_PREDICT_FALSE(info_)) {
info_->Unlock();
}
}
void SetCordRep(CordRep* rep) const {
if (ABSL_PREDICT_FALSE(info_)) {
info_->SetCordRep(rep);
}
}
CordzInfo* info() const { return info_; }
private:
CordzInfo* info_;
};
} // namespace cord_internal
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_STRINGS_INTERNAL_CORDZ_UPDATE_SCOPE_H_