xref: /aosp_15_r20/external/llvm-libc/src/__support/threads/linux/futex_word.h (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
1 //===--- Definition of a type for a futex word ------------------*- 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___SUPPORT_THREADS_LINUX_FUTEX_WORD_H
10 #define LLVM_LIBC_SRC___SUPPORT_THREADS_LINUX_FUTEX_WORD_H
11 
12 #include "src/__support/macros/config.h"
13 #include <stdint.h>
14 #include <sys/syscall.h>
15 namespace LIBC_NAMESPACE_DECL {
16 
17 // Futexes are 32 bits in size on all platforms, including 64-bit platforms.
18 using FutexWordType = uint32_t;
19 
20 #if SYS_futex
21 constexpr auto FUTEX_SYSCALL_ID = SYS_futex;
22 #elif defined(SYS_futex_time64)
23 constexpr auto FUTEX_SYSCALL_ID = SYS_futex_time64;
24 #else
25 #error "futex and futex_time64 syscalls not available."
26 #endif
27 
28 } // namespace LIBC_NAMESPACE_DECL
29 
30 #endif // LLVM_LIBC_SRC___SUPPORT_THREADS_LINUX_FUTEX_WORD_H
31