50 lines · cpp
1//===---------- Linux implementation of the epoll_wait 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-exception6//7//===----------------------------------------------------------------------===//8 9#include "src/sys/epoll/epoll_wait.h"10 11#include "hdr/signal_macros.h" // for NSIG12#include "hdr/types/sigset_t.h"13#include "hdr/types/struct_epoll_event.h"14#include "src/__support/OSUtil/syscall.h" // For internal syscall function.15#include "src/__support/common.h"16#include "src/__support/libc_errno.h"17#include "src/__support/macros/config.h"18#include "src/__support/macros/sanitizer.h"19 20#include <sys/syscall.h> // For syscall numbers.21 22namespace LIBC_NAMESPACE_DECL {23 24LLVM_LIBC_FUNCTION(int, epoll_wait,25 (int epfd, struct epoll_event *events, int maxevents,26 int timeout)) {27#ifdef SYS_epoll_wait28 int ret = LIBC_NAMESPACE::syscall_impl<int>(29 SYS_epoll_wait, epfd, reinterpret_cast<long>(events), maxevents, timeout);30#elif defined(SYS_epoll_pwait)31 int ret = LIBC_NAMESPACE::syscall_impl<int>(32 SYS_epoll_pwait, epfd, reinterpret_cast<long>(events), maxevents, timeout,33 reinterpret_cast<long>(nullptr), NSIG / 8);34#else35#error "epoll_wait and epoll_pwait are unavailable. Unable to build epoll_wait."36#endif37 // A negative return value indicates an error with the magnitude of the38 // value being the error code.39 if (ret < 0) {40 libc_errno = -ret;41 return -1;42 }43 44 MSAN_UNPOISON(events, ret * sizeof(struct epoll_event));45 46 return ret;47}48 49} // namespace LIBC_NAMESPACE_DECL50