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Diffstat (limited to 'third_party/abseil-cpp/absl/strings/internal/cordz_update_scope.h')
-rw-r--r-- | third_party/abseil-cpp/absl/strings/internal/cordz_update_scope.h | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/third_party/abseil-cpp/absl/strings/internal/cordz_update_scope.h b/third_party/abseil-cpp/absl/strings/internal/cordz_update_scope.h new file mode 100644 index 0000000000..57ba75de93 --- /dev/null +++ b/third_party/abseil-cpp/absl/strings/internal/cordz_update_scope.h @@ -0,0 +1,71 @@ +// 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 +// +// https://www.apache.org/licenses/LICENSE-2.0 +// +// 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_ |