mirror of
				https://github.com/ton-blockchain/ton
				synced 2025-03-09 15:40:10 +00:00 
			
		
		
		
	
		
			
				
	
	
		
			141 lines
		
	
	
	
		
			4.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			141 lines
		
	
	
	
		
			4.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
/*
 | 
						|
    This file is part of TON Blockchain Library.
 | 
						|
 | 
						|
    TON Blockchain Library is free software: you can redistribute it and/or modify
 | 
						|
    it under the terms of the GNU Lesser General Public License as published by
 | 
						|
    the Free Software Foundation, either version 2 of the License, or
 | 
						|
    (at your option) any later version.
 | 
						|
 | 
						|
    TON Blockchain Library is distributed in the hope that it will be useful,
 | 
						|
    but WITHOUT ANY WARRANTY; without even the implied warranty of
 | 
						|
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 | 
						|
    GNU Lesser General Public License for more details.
 | 
						|
 | 
						|
    You should have received a copy of the GNU Lesser General Public License
 | 
						|
    along with TON Blockchain Library.  If not, see <http://www.gnu.org/licenses/>.
 | 
						|
 | 
						|
    Copyright 2017-2020 Telegram Systems LLP
 | 
						|
*/
 | 
						|
#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/misc.h"
 | 
						|
#include "td/utils/port/detail/NativeFd.h"
 | 
						|
#include "td/utils/port/detail/skip_eintr.h"
 | 
						|
#include "td/utils/port/PollFlags.h"
 | 
						|
#include "td/utils/ScopeGuard.h"
 | 
						|
#include "td/utils/Slice.h"
 | 
						|
 | 
						|
#include <cerrno>
 | 
						|
 | 
						|
#include <poll.h>
 | 
						|
#include <sys/eventfd.h>
 | 
						|
#include <unistd.h>
 | 
						|
 | 
						|
namespace td {
 | 
						|
namespace detail {
 | 
						|
class EventFdLinuxImpl {
 | 
						|
 public:
 | 
						|
  PollableFdInfo info;
 | 
						|
};
 | 
						|
 | 
						|
EventFdLinux::EventFdLinux() = default;
 | 
						|
EventFdLinux::EventFdLinux(EventFdLinux &&) = default;
 | 
						|
EventFdLinux &EventFdLinux::operator=(EventFdLinux &&) = default;
 | 
						|
EventFdLinux::~EventFdLinux() = default;
 | 
						|
 | 
						|
void EventFdLinux::init() {
 | 
						|
  auto fd = NativeFd(eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC));
 | 
						|
  auto eventfd_errno = errno;
 | 
						|
  LOG_IF(FATAL, !fd) << Status::PosixError(eventfd_errno, "eventfd call failed");
 | 
						|
  impl_ = make_unique<EventFdLinuxImpl>();
 | 
						|
  impl_->info.set_native_fd(std::move(fd));
 | 
						|
}
 | 
						|
 | 
						|
bool EventFdLinux::empty() {
 | 
						|
  return !impl_;
 | 
						|
}
 | 
						|
 | 
						|
void EventFdLinux::close() {
 | 
						|
  impl_.reset();
 | 
						|
}
 | 
						|
 | 
						|
Status EventFdLinux::get_pending_error() {
 | 
						|
  return Status::OK();
 | 
						|
}
 | 
						|
 | 
						|
PollableFdInfo &EventFdLinux::get_poll_info() {
 | 
						|
  return impl_->info;
 | 
						|
}
 | 
						|
 | 
						|
// NB: will be called from multiple threads
 | 
						|
void EventFdLinux::release() {
 | 
						|
  const uint64 value = 1;
 | 
						|
  auto slice = Slice(reinterpret_cast<const char *>(&value), sizeof(value));
 | 
						|
  auto native_fd = impl_->info.native_fd().fd();
 | 
						|
 | 
						|
  auto result = [&]() -> Result<size_t> {
 | 
						|
    auto write_res = detail::skip_eintr([&] { return ::write(native_fd, slice.begin(), slice.size()); });
 | 
						|
    auto write_errno = errno;
 | 
						|
    if (write_res >= 0) {
 | 
						|
      return narrow_cast<size_t>(write_res);
 | 
						|
    }
 | 
						|
    return Status::PosixError(write_errno, PSLICE() << "Write to fd " << native_fd << " has failed");
 | 
						|
  }();
 | 
						|
 | 
						|
  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() {
 | 
						|
  impl_->info.get_flags();
 | 
						|
  SCOPE_EXIT {
 | 
						|
    // Clear flags without EAGAIN and EWOULDBLOCK
 | 
						|
    // Looks like it is safe thing to do with eventfd
 | 
						|
    get_poll_info().clear_flags(PollFlags::Read());
 | 
						|
  };
 | 
						|
  uint64 res;
 | 
						|
  auto slice = MutableSlice(reinterpret_cast<char *>(&res), sizeof(res));
 | 
						|
  auto native_fd = impl_->info.native_fd().fd();
 | 
						|
  auto result = [&]() -> Result<size_t> {
 | 
						|
    CHECK(slice.size() > 0);
 | 
						|
    auto read_res = detail::skip_eintr([&] { return ::read(native_fd, slice.begin(), slice.size()); });
 | 
						|
    auto read_errno = errno;
 | 
						|
    if (read_res >= 0) {
 | 
						|
      CHECK(read_res != 0);
 | 
						|
      return narrow_cast<size_t>(read_res);
 | 
						|
    }
 | 
						|
    if (read_errno == EAGAIN
 | 
						|
#if EAGAIN != EWOULDBLOCK
 | 
						|
        || read_errno == EWOULDBLOCK
 | 
						|
#endif
 | 
						|
    ) {
 | 
						|
      return 0;
 | 
						|
    }
 | 
						|
    return Status::PosixError(read_errno, PSLICE() << "Read from fd " << native_fd << " has failed");
 | 
						|
  }();
 | 
						|
  if (result.is_error()) {
 | 
						|
    LOG(FATAL) << "EventFdLinux read failed: " << result.error();
 | 
						|
  }
 | 
						|
}
 | 
						|
 | 
						|
void EventFdLinux::wait(int timeout_ms) {
 | 
						|
  pollfd fd;
 | 
						|
  fd.fd = get_poll_info().native_fd().fd();
 | 
						|
  fd.events = POLLIN;
 | 
						|
  poll(&fd, 1, timeout_ms);
 | 
						|
}
 | 
						|
 | 
						|
}  // namespace detail
 | 
						|
}  // namespace td
 | 
						|
 | 
						|
#endif
 |