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