text: /*
      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/PollFlags.h"
  
  namespace td {
  
  bool PollFlagsSet::write_flags(PollFlags flags) {
    if (flags.empty()) {
      return false;
    }
    auto old_flags = to_write_.fetch_or(flags.raw(), std::memory_order_relaxed);
    return (flags.raw() & ~old_flags) != 0;
  }
  
  bool PollFlagsSet::write_flags_local(PollFlags flags) {
    return flags_.add_flags(flags);
  }
  
  bool PollFlagsSet::flush() const {
    if (to_write_.load(std::memory_order_relaxed) == 0) {
      return false;
    }
    auto to_write = to_write_.exchange(0, std::memory_order_relaxed);
    auto old_flags = flags_;
    flags_.add_flags(PollFlags::from_raw(to_write));
    if (flags_.can_close()) {
      flags_.remove_flags(PollFlags::Write());
    }
    return flags_ != old_flags;
  }
  
  PollFlags PollFlagsSet::read_flags() const {
    flush();
    return flags_;
  }
  
  PollFlags PollFlagsSet::read_flags_local() const {
    return flags_;
  }
  
  void PollFlagsSet::clear_flags(PollFlags flags) {
    flags_.remove_flags(flags);
  }
  
  void PollFlagsSet::clear() {
    to_write_ = 0;
    flags_ = {};
  }
  
  StringBuilder &operator<<(StringBuilder &sb, PollFlags flags) {
    sb << '[';
    if (flags.can_read()) {
      sb << 'R';
    }
    if (flags.can_write()) {
      sb << 'W';
    }
    if (flags.can_close()) {
      sb << 'C';
    }
    if (flags.has_pending_error()) {
      sb << 'E';
    }
    return sb << ']';
  }
  
  }  // namespace td
  