56 lines · cpp
1//===-- Implementation of poll --------------------------------------------===//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-exception6//7//===----------------------------------------------------------------------===//8 9#include "src/poll/poll.h"10 11#include "hdr/types/nfds_t.h"12#include "hdr/types/struct_pollfd.h"13#include "hdr/types/struct_timespec.h"14#include "src/__support/OSUtil/syscall.h" // syscall_impl15#include "src/__support/common.h"16#include "src/__support/libc_errno.h"17#include "src/__support/macros/config.h"18 19#include <sys/syscall.h> // SYS_poll, SYS_ppoll20 21namespace LIBC_NAMESPACE_DECL {22 23LLVM_LIBC_FUNCTION(int, poll, (pollfd * fds, nfds_t nfds, int timeout)) {24 int ret = 0;25 26#if defined(SYS_poll)27 ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_poll, fds, nfds, timeout);28#else // no SYS_poll29 timespec ts, *tsp;30 if (timeout >= 0) {31 ts.tv_sec = timeout / 1000;32 ts.tv_nsec = (timeout % 1000) * 1000000;33 tsp = &ts;34 } else {35 tsp = nullptr;36 }37#if defined(SYS_ppoll)38 ret =39 LIBC_NAMESPACE::syscall_impl<int>(SYS_ppoll, fds, nfds, tsp, nullptr, 0);40#elif defined(SYS_ppoll_time64)41 ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_ppoll_time64, fds, nfds, tsp,42 nullptr, 0);43#else44#error "poll, ppoll, ppoll_time64 syscalls not available."45#endif // defined(SYS_ppoll) || defined(SYS_ppoll_time64)46#endif // defined(SYS_poll)47 48 if (ret < 0) {49 libc_errno = -ret;50 return -1;51 }52 return ret;53}54 55} // namespace LIBC_NAMESPACE_DECL56