per_thread_tls.h (1758B)
1 // Copyright 2017 The Abseil Authors. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 #ifndef ABSL_BASE_INTERNAL_PER_THREAD_TLS_H_ 16 #define ABSL_BASE_INTERNAL_PER_THREAD_TLS_H_ 17 18 // This header defines two macros: 19 // 20 // If the platform supports thread-local storage: 21 // 22 // * ABSL_PER_THREAD_TLS_KEYWORD is the C keyword needed to declare a 23 // thread-local variable 24 // * ABSL_PER_THREAD_TLS is 1 25 // 26 // Otherwise: 27 // 28 // * ABSL_PER_THREAD_TLS_KEYWORD is empty 29 // * ABSL_PER_THREAD_TLS is 0 30 // 31 // Microsoft C supports thread-local storage. 32 // GCC supports it if the appropriate version of glibc is available, 33 // which the programmer can indicate by defining ABSL_HAVE_TLS 34 35 #include "absl/base/port.h" // For ABSL_HAVE_TLS 36 37 #if defined(ABSL_PER_THREAD_TLS) 38 #error ABSL_PER_THREAD_TLS cannot be directly set 39 #elif defined(ABSL_PER_THREAD_TLS_KEYWORD) 40 #error ABSL_PER_THREAD_TLS_KEYWORD cannot be directly set 41 #elif defined(ABSL_HAVE_TLS) 42 #define ABSL_PER_THREAD_TLS_KEYWORD __thread 43 #define ABSL_PER_THREAD_TLS 1 44 #elif defined(_MSC_VER) 45 #define ABSL_PER_THREAD_TLS_KEYWORD __declspec(thread) 46 #define ABSL_PER_THREAD_TLS 1 47 #else 48 #define ABSL_PER_THREAD_TLS_KEYWORD 49 #define ABSL_PER_THREAD_TLS 0 50 #endif 51 52 #endif // ABSL_BASE_INTERNAL_PER_THREAD_TLS_H_