1 //===-- Linux futex related definitions -------------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef LLVM_LIBC_SRC_THREADS_LINUX_FUTEX_H 10 #define LLVM_LIBC_SRC_THREADS_LINUX_FUTEX_H 11 12 #include "src/__support/macros/config.h" 13 #include "src/__support/macros/properties/architectures.h" // Architecture macros 14 15 namespace LIBC_NAMESPACE_DECL { 16 17 #if (defined(LIBC_TARGET_ARCH_IS_AARCH64) || \ 18 defined(LIBC_TARGET_ARCH_IS_X86_64)) 19 // The futex data has to be exactly 4 bytes long. However, we use a uint type 20 // here as we do not want to use `uint32_t` type to match the public definitions 21 // of types which include a field for a futex word. With public definitions, we 22 // cannot include <stdint.h> so we stick to the `unsigned int` type for x86_64 23 // and aarch64 24 using FutexWordType = unsigned int; 25 static_assert(sizeof(FutexWordType) == 4, 26 "Unexpected size of unsigned int type."); 27 #else 28 #error "Futex word base type not defined for the target architecture." 29 #endif 30 31 } // namespace LIBC_NAMESPACE_DECL 32 33 #endif // LLVM_LIBC_SRC_THREADS_LINUX_FUTEX_H 34