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tdutils/td/utils/port/detail/Poll.cpp

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+/*
+    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 2017-2019 Telegram Systems LLP
+*/
+#include "td/utils/port/detail/Poll.h"
+
+char disable_linker_warning_about_empty_file_poll_cpp TD_UNUSED;
+
+#ifdef TD_POLL_POLL
+
+#include "td/utils/format.h"
+#include "td/utils/logging.h"
+#include "td/utils/misc.h"
+#include "td/utils/ScopeGuard.h"
+#include "td/utils/Status.h"
+
+namespace td {
+namespace detail {
+
+void Poll::init() {
+}
+
+void Poll::clear() {
+  pollfds_.clear();
+}
+
+void Poll::subscribe(PollableFd fd, PollFlags flags) {
+  unsubscribe(fd.ref());
+  struct pollfd pollfd;
+  pollfd.fd = fd.native_fd().fd();
+  pollfd.events = 0;
+  if (flags.can_read()) {
+    pollfd.events |= POLLIN;
+  }
+  if (flags.can_write()) {
+    pollfd.events |= POLLOUT;
+  }
+  pollfd.revents = 0;
+  pollfds_.push_back(pollfd);
+  fds_.push_back(std::move(fd));
+}
+
+void Poll::unsubscribe(PollableFdRef fd_ref) {
+  auto fd = fd_ref.lock();
+  SCOPE_EXIT {
+    fd.release_as_list_node();
+  };
+  for (auto it = pollfds_.begin(); it != pollfds_.end(); ++it) {
+    if (it->fd == fd.native_fd().fd()) {
+      pollfds_.erase(it);
+      fds_.erase(fds_.begin() + (it - pollfds_.begin()));
+      return;
+    }
+  }
+}
+
+void Poll::unsubscribe_before_close(PollableFdRef fd) {
+  unsubscribe(fd);
+}
+
+void Poll::run(int timeout_ms) {
+  int err = poll(pollfds_.data(), narrow_cast<int>(pollfds_.size()), timeout_ms);
+  auto poll_errno = errno;
+  LOG_IF(FATAL, err == -1 && poll_errno != EINTR) << Status::PosixError(poll_errno, "poll failed");
+
+  for (size_t i = 0; i < pollfds_.size(); i++) {
+    auto &pollfd = pollfds_[i];
+    auto &fd = fds_[i];
+
+    PollFlags flags;
+    if (pollfd.revents & POLLIN) {
+      pollfd.revents &= ~POLLIN;
+      flags = flags | PollFlags::Read();
+    }
+    if (pollfd.revents & POLLOUT) {
+      pollfd.revents &= ~POLLOUT;
+      flags = flags | PollFlags::Write();
+    }
+    if (pollfd.revents & POLLHUP) {
+      pollfd.revents &= ~POLLHUP;
+      flags = flags | PollFlags::Close();
+    }
+    if (pollfd.revents & POLLERR) {
+      pollfd.revents &= ~POLLERR;
+      flags = flags | PollFlags::Error();
+    }
+    if (pollfd.revents & POLLNVAL) {
+      LOG(FATAL) << "Unexpected POLLNVAL " << tag("fd", pollfd.fd);
+    }
+    if (pollfd.revents) {
+      LOG(FATAL) << "Unsupported poll events: " << pollfd.revents;
+    }
+    fd.add_flags(flags);
+  }
+}
+
+}  // namespace detail
+}  // namespace td
+
+#endif