1 | //===---------- Linux implementation of the POSIX posix_madvise function --===// |
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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/sys/mman/posix_madvise.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 | |
15 | #include <sys/syscall.h> // For syscall numbers. |
16 | |
17 | namespace LIBC_NAMESPACE_DECL { |
18 | |
19 | // This function is currently linux only. It has to be refactored suitably if |
20 | // posix_madvise is to be supported on non-linux operating systems also. |
21 | LLVM_LIBC_FUNCTION(int, posix_madvise, (void *addr, size_t size, int advice)) { |
22 | // POSIX_MADV_DONTNEED does nothing because the default MADV_DONTNEED may |
23 | // cause data loss, which the posix madvise does not allow. |
24 | if (advice == POSIX_MADV_DONTNEED) { |
25 | return 0; |
26 | } |
27 | int ret = LIBC_NAMESPACE::syscall_impl<int>( |
28 | SYS_madvise, reinterpret_cast<long>(addr), size, advice); |
29 | return ret < 0 ? -ret : 0; |
30 | } |
31 | |
32 | } // namespace LIBC_NAMESPACE_DECL |
33 |