1 //===-- Implementation of sched_getaffinity -------------------------------===// 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_getaffinity.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 <sched.h> 17 #include <stdint.h> 18 #include <sys/syscall.h> // For syscall numbers. 19 20 namespace LIBC_NAMESPACE_DECL { 21 22 LLVM_LIBC_FUNCTION(int, sched_getaffinity, 23 (pid_t tid, size_t cpuset_size, cpu_set_t *mask)) { 24 int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_sched_getaffinity, tid, 25 cpuset_size, mask); 26 if (ret < 0) { 27 libc_errno = -ret; 28 return -1; 29 } 30 if (size_t(ret) < cpuset_size) { 31 // This means that only |ret| bytes in |mask| have been set. We will have to 32 // zero out the remaining bytes. 33 auto *mask_bytes = reinterpret_cast<uint8_t *>(mask); 34 for (size_t i = size_t(ret); i < cpuset_size; ++i) 35 mask_bytes[i] = 0; 36 } 37 return 0; 38 } 39 40 } // namespace LIBC_NAMESPACE_DECL 41