blob: 1132d5160e501ecc79a47411a20ee20d4791be81 [file] [log] [blame]
/*
* Copyright 2017 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
*
* http://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.
*/
// Interface for getting the current ThreadIdentity, creating one if necessary.
// See thread_identity.h.
//
// This file is separate from thread_identity.h because creating a new
// ThreadIdentity requires slightly higher level libraries (per_thread_sem
// and low_level_alloc) than accessing an existing one. This separation allows
// us to have a smaller //absl/base:base.
#ifndef ABSL_SYNCHRONIZATION_INTERNAL_CREATE_THREAD_IDENTITY_H_
#define ABSL_SYNCHRONIZATION_INTERNAL_CREATE_THREAD_IDENTITY_H_
#include "absl/base/internal/thread_identity.h"
#include "absl/base/port.h"
namespace absl {
inline namespace lts_2018_12_18 {
namespace synchronization_internal {
// Allocates and attaches a ThreadIdentity object for the calling thread.
// For private use only.
base_internal::ThreadIdentity* CreateThreadIdentity();
// Returns the ThreadIdentity object representing the calling thread; guaranteed
// to be unique for its lifetime. The returned object will remain valid for the
// program's lifetime; although it may be re-assigned to a subsequent thread.
// If one does not exist for the calling thread, allocate it now.
inline base_internal::ThreadIdentity* GetOrCreateCurrentThreadIdentity() {
base_internal::ThreadIdentity* identity =
base_internal::CurrentThreadIdentityIfPresent();
if (ABSL_PREDICT_FALSE(identity == nullptr)) {
return CreateThreadIdentity();
}
return identity;
}
} // namespace synchronization_internal
} // inline namespace lts_2018_12_18
} // namespace absl
#endif // ABSL_SYNCHRONIZATION_INTERNAL_CREATE_THREAD_IDENTITY_H_