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