/src/abseil-cpp/absl/synchronization/internal/create_thread_identity.h
Line | Count | Source |
1 | | /* |
2 | | * Copyright 2017 The Abseil Authors. |
3 | | * |
4 | | * Licensed under the Apache License, Version 2.0 (the "License"); |
5 | | * you may not use this file except in compliance with the License. |
6 | | * You may obtain a copy of the License at |
7 | | * |
8 | | * https://www.apache.org/licenses/LICENSE-2.0 |
9 | | * |
10 | | * Unless required by applicable law or agreed to in writing, software |
11 | | * distributed under the License is distributed on an "AS IS" BASIS, |
12 | | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
13 | | * See the License for the specific language governing permissions and |
14 | | * limitations under the License. |
15 | | */ |
16 | | |
17 | | // Interface for getting the current ThreadIdentity, creating one if necessary. |
18 | | // See thread_identity.h. |
19 | | // |
20 | | // This file is separate from thread_identity.h because creating a new |
21 | | // ThreadIdentity requires slightly higher level libraries (per_thread_sem |
22 | | // and low_level_alloc) than accessing an existing one. This separation allows |
23 | | // us to have a smaller //absl/base:base. |
24 | | |
25 | | #ifndef ABSL_SYNCHRONIZATION_INTERNAL_CREATE_THREAD_IDENTITY_H_ |
26 | | #define ABSL_SYNCHRONIZATION_INTERNAL_CREATE_THREAD_IDENTITY_H_ |
27 | | |
28 | | #include "absl/base/internal/thread_identity.h" |
29 | | #include "absl/base/port.h" |
30 | | |
31 | | namespace absl { |
32 | | ABSL_NAMESPACE_BEGIN |
33 | | namespace synchronization_internal { |
34 | | |
35 | | // Allocates and attaches a ThreadIdentity object for the calling thread. |
36 | | // For private use only. |
37 | | base_internal::ThreadIdentity* CreateThreadIdentity(); |
38 | | |
39 | | // Returns the ThreadIdentity object representing the calling thread; guaranteed |
40 | | // to be unique for its lifetime. The returned object will remain valid for the |
41 | | // program's lifetime; although it may be re-assigned to a subsequent thread. |
42 | | // If one does not exist for the calling thread, allocate it now. |
43 | 9.72M | inline base_internal::ThreadIdentity* GetOrCreateCurrentThreadIdentity() { |
44 | 9.72M | base_internal::ThreadIdentity* identity = |
45 | 9.72M | base_internal::CurrentThreadIdentityIfPresent(); |
46 | 9.72M | if (ABSL_PREDICT_FALSE(identity == nullptr)) { |
47 | 2 | return CreateThreadIdentity(); |
48 | 2 | } |
49 | 9.72M | return identity; |
50 | 9.72M | } |
51 | | |
52 | | } // namespace synchronization_internal |
53 | | ABSL_NAMESPACE_END |
54 | | } // namespace absl |
55 | | |
56 | | #endif // ABSL_SYNCHRONIZATION_INTERNAL_CREATE_THREAD_IDENTITY_H_ |