1 //===-- Linux implementation of nanosleep function ------------------------===// 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 #include "src/time/nanosleep.h" 10 #include "hdr/time_macros.h" 11 #include "src/__support/OSUtil/syscall.h" // For syscall functions. 12 #include "src/__support/common.h" 13 #include "src/__support/macros/config.h" 14 #include "src/errno/libc_errno.h" 15 16 #include <stdint.h> // For int64_t. 17 #include <sys/syscall.h> // For syscall numbers. 18 19 namespace LIBC_NAMESPACE_DECL { 20 21 LLVM_LIBC_FUNCTION(int, nanosleep, 22 (const struct timespec *req, struct timespec *rem)) { 23 #if SYS_nanosleep 24 int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_nanosleep, req, rem); 25 #elif defined(SYS_clock_nanosleep_time64) 26 static_assert( 27 sizeof(time_t) == sizeof(int64_t), 28 "SYS_clock_gettime64 requires struct timespec with 64-bit members."); 29 int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_clock_nanosleep_time64, 30 CLOCK_REALTIME, 0, req, rem); 31 #else 32 #error "SYS_nanosleep and SYS_clock_nanosleep_time64 syscalls not available." 33 #endif 34 35 if (ret < 0) { 36 libc_errno = -ret; 37 return -1; 38 } 39 return ret; 40 } 41 42 } // namespace LIBC_NAMESPACE_DECL 43