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tdlib-fork/tdutils/td/utils/port/detail/EventFdLinux.cpp

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//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2018
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include "td/utils/port/detail/EventFdLinux.h"
char disable_linker_warning_about_empty_file_event_fd_linux_cpp TD_UNUSED;
#ifdef TD_EVENTFD_LINUX
#include "td/utils/logging.h"
#include "td/utils/Slice.h"
#include <sys/eventfd.h>
namespace td {
namespace detail {
void EventFdLinux::init() {
int fd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
auto eventfd_errno = errno;
LOG_IF(FATAL, fd == -1) << Status::PosixError(eventfd_errno, "eventfd call failed");
fd_ = Fd(fd, Fd::Mode::Owner);
}
bool EventFdLinux::empty() {
return fd_.empty();
}
void EventFdLinux::close() {
fd_.close();
}
Status EventFdLinux::get_pending_error() {
return Status::OK();
}
const Fd &EventFdLinux::get_fd() const {
return fd_;
}
Fd &EventFdLinux::get_fd() {
return fd_;
}
void EventFdLinux::release() {
const uint64 value = 1;
// NB: write_unsafe is used, because release will be called from multiple threads
auto result = fd_.write_unsafe(Slice(reinterpret_cast<const char *>(&value), sizeof(value)));
if (result.is_error()) {
LOG(FATAL) << "EventFdLinux write failed: " << result.error();
}
size_t size = result.ok();
if (size != sizeof(value)) {
LOG(FATAL) << "EventFdLinux write returned " << value << " instead of " << sizeof(value);
}
}
void EventFdLinux::acquire() {
uint64 res;
auto result = fd_.read(MutableSlice(reinterpret_cast<char *>(&res), sizeof(res)));
if (result.is_error()) {
LOG(FATAL) << "EventFdLinux read failed: " << result.error();
}
fd_.clear_flags(Fd::Read);
}
} // namespace detail
} // namespace td
#endif