53 lines
2.1 KiB
C++
53 lines
2.1 KiB
C++
/*
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* Copyright 2017 The Abseil Authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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// Interface for getting the current ThreadIdentity, creating one if necessary.
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// See thread_identity.h.
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//
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// This file is separate from thread_identity.h because creating a new
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// ThreadIdentity requires slightly higher level libraries (per_thread_sem
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// and low_level_alloc) than accessing an existing one. This separation allows
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// us to have a smaller //absl/base:base.
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#ifndef ABSL_SYNCHRONIZATION_INTERNAL_CREATE_THREAD_IDENTITY_H_
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#define ABSL_SYNCHRONIZATION_INTERNAL_CREATE_THREAD_IDENTITY_H_
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#include "absl/base/internal/thread_identity.h"
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#include "absl/base/port.h"
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namespace absl {
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namespace synchronization_internal {
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// Allocates and attaches a ThreadIdentity object for the calling thread.
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// For private use only.
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base_internal::ThreadIdentity* CreateThreadIdentity();
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// Returns the ThreadIdentity object representing the calling thread; guaranteed
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// to be unique for its lifetime. The returned object will remain valid for the
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// program's lifetime; although it may be re-assigned to a subsequent thread.
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// If one does not exist for the calling thread, allocate it now.
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inline base_internal::ThreadIdentity* GetOrCreateCurrentThreadIdentity() {
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base_internal::ThreadIdentity* identity =
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base_internal::CurrentThreadIdentityIfPresent();
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if (ABSL_PREDICT_FALSE(identity == nullptr)) {
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return CreateThreadIdentity();
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}
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return identity;
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}
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} // namespace synchronization_internal
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} // namespace absl
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#endif // ABSL_SYNCHRONIZATION_INTERNAL_CREATE_THREAD_IDENTITY_H_
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