| //===---------- Linux implementation of the POSIX posix_madvise function --===// | |
| // | |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | |
| // See https://llvm.org/LICENSE.txt for license information. | |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | |
| // | |
| //===----------------------------------------------------------------------===// | |
| #include "src/sys/mman/posix_madvise.h" | |
| #include "src/__support/OSUtil/syscall.h" // For internal syscall function. | |
| #include "src/__support/common.h" | |
| #include "src/__support/macros/config.h" | |
| #include <sys/syscall.h> // For syscall numbers. | |
| #include "hdr/sys_mman_macros.h" // For POSIX_MADV_DONTNEED. | |
| namespace LIBC_NAMESPACE_DECL { | |
| // This function is currently linux only. It has to be refactored suitably if | |
| // posix_madvise is to be supported on non-linux operating systems also. | |
| LLVM_LIBC_FUNCTION(int, posix_madvise, (void *addr, size_t size, int advice)) { | |
| // POSIX_MADV_DONTNEED does nothing because the default MADV_DONTNEED may | |
| // cause data loss, which the posix madvise does not allow. | |
| if (advice == POSIX_MADV_DONTNEED) { | |
| return 0; | |
| } | |
| int ret = LIBC_NAMESPACE::syscall_impl<int>( | |
| SYS_madvise, reinterpret_cast<long>(addr), size, advice); | |
| return ret < 0 ? -ret : 0; | |
| } | |
| } // namespace LIBC_NAMESPACE_DECL |