xref: /aosp_15_r20/external/llvm-libc/src/sys/epoll/linux/epoll_pwait2.cpp (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
1 //===---------- Linux implementation of the epoll_pwait2 function ---------===//
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/epoll/epoll_pwait2.h"
10 
11 #include "hdr/signal_macros.h" // for NSIG
12 #include "hdr/types/sigset_t.h"
13 #include "hdr/types/struct_epoll_event.h"
14 #include "hdr/types/struct_timespec.h"
15 #include "src/__support/OSUtil/syscall.h" // For internal syscall function.
16 #include "src/__support/common.h"
17 #include "src/__support/macros/config.h"
18 #include "src/__support/macros/sanitizer.h"
19 #include "src/errno/libc_errno.h"
20 
21 #include <sys/syscall.h> // For syscall numbers.
22 
23 namespace LIBC_NAMESPACE_DECL {
24 
25 LLVM_LIBC_FUNCTION(int, epoll_pwait2,
26                    (int epfd, struct epoll_event *events, int maxevents,
27                     const struct timespec *timeout, const sigset_t *sigmask)) {
28   int ret = LIBC_NAMESPACE::syscall_impl<int>(
29       SYS_epoll_pwait2, epfd, reinterpret_cast<long>(events), maxevents,
30       reinterpret_cast<long>(timeout), reinterpret_cast<long>(sigmask),
31       NSIG / 8);
32 
33   // A negative return value indicates an error with the magnitude of the
34   // value being the error code.
35   if (ret < 0) {
36     libc_errno = -ret;
37     return -1;
38   }
39 
40   MSAN_UNPOISON(events, ret * sizeof(struct epoll_event));
41 
42   return ret;
43 }
44 
45 } // namespace LIBC_NAMESPACE_DECL
46