1 //===-- Implementation of sched_rr_get_interval ---------------------------===// 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/sched/sched_rr_get_interval.h" 10 11 #include "src/__support/OSUtil/syscall.h" // For internal syscall function. 12 #include "src/__support/common.h" 13 #include "src/__support/macros/config.h" 14 #include "src/errno/libc_errno.h" 15 16 #include <sys/syscall.h> // For syscall numbers. 17 18 #ifdef SYS_sched_rr_get_interval_time64 19 #include <linux/time_types.h> // For __kernel_timespec. 20 #endif 21 22 namespace LIBC_NAMESPACE_DECL { 23 24 LLVM_LIBC_FUNCTION(int, sched_rr_get_interval, 25 (pid_t tid, struct timespec *tp)) { 26 #ifdef SYS_sched_rr_get_interval 27 int ret = 28 LIBC_NAMESPACE::syscall_impl<int>(SYS_sched_rr_get_interval, tid, tp); 29 #elif defined(SYS_sched_rr_get_interval_time64) 30 // The difference between the and SYS_sched_rr_get_interval 31 // SYS_sched_rr_get_interval_time64 syscalls is the data type used for the 32 // time interval parameter: the latter takes a struct __kernel_timespec 33 int ret; 34 if (tp) { 35 struct __kernel_timespec ts32; 36 ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_sched_rr_get_interval_time64, 37 tid, &ts32); 38 if (ret == 0) { 39 tp->tv_sec = ts32.tv_sec; 40 tp->tv_nsec = static_cast<long int>(ts32.tv_nsec); 41 } 42 } else 43 // When tp is a nullptr, we still do the syscall to set ret and errno 44 ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_sched_rr_get_interval_time64, 45 tid, nullptr); 46 #else 47 #error \ 48 "sched_rr_get_interval and sched_rr_get_interval_time64 syscalls not available." 49 #endif 50 if (ret < 0) { 51 libc_errno = -ret; 52 return -1; 53 } 54 return 0; 55 } 56 57 } // namespace LIBC_NAMESPACE_DECL 58