diff --git a/tdutils/CMakeLists.txt b/tdutils/CMakeLists.txt
index 0e98a4d0d..414e3d3c5 100644
--- a/tdutils/CMakeLists.txt
+++ b/tdutils/CMakeLists.txt
@@ -37,6 +37,7 @@ set(TDUTILS_SOURCE
   td/utils/port/FileFd.cpp
   td/utils/port/IPAddress.cpp
   td/utils/port/path.cpp
+  td/utils/port/PollFlags.cpp
   td/utils/port/ServerSocketFd.cpp
   td/utils/port/signals.cpp
   td/utils/port/sleep.cpp
@@ -54,7 +55,6 @@ set(TDUTILS_SOURCE
   td/utils/port/detail/KQueue.cpp
   td/utils/port/detail/NativeFd.cpp
   td/utils/port/detail/Poll.cpp
-  td/utils/port/detail/PollableFd.cpp
   td/utils/port/detail/Select.cpp
   td/utils/port/detail/ThreadIdGuard.cpp
   td/utils/port/detail/WineventPoll.cpp
@@ -100,6 +100,7 @@ set(TDUTILS_SOURCE
   td/utils/port/platform.h
   td/utils/port/Poll.h
   td/utils/port/PollBase.h
+  td/utils/port/PollFlags.h
   td/utils/port/RwMutex.h
   td/utils/port/ServerSocketFd.h
   td/utils/port/signals.h
diff --git a/tdutils/td/utils/port/detail/PollableFd.cpp b/tdutils/td/utils/port/PollFlags.cpp
similarity index 79%
rename from tdutils/td/utils/port/detail/PollableFd.cpp
rename to tdutils/td/utils/port/PollFlags.cpp
index d2e91d048..4aaffce46 100644
--- a/tdutils/td/utils/port/detail/PollableFd.cpp
+++ b/tdutils/td/utils/port/PollFlags.cpp
@@ -4,13 +4,10 @@
 // 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/PollableFd.h"
-
-#if TD_POSIX_PORT
-#include <unistd.h>
-#endif
+#include "td/utils/port/PollFlags.h"
 
 namespace td {
+
 bool PollFlagsSet::write_flags(PollFlags flags) {
   if (flags.empty()) {
     return false;
@@ -18,9 +15,11 @@ bool PollFlagsSet::write_flags(PollFlags flags) {
   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;
@@ -33,19 +32,40 @@ bool PollFlagsSet::flush() const {
   }
   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
diff --git a/tdutils/td/utils/port/PollFlags.h b/tdutils/td/utils/port/PollFlags.h
new file mode 100644
index 000000000..cbea2cc0d
--- /dev/null
+++ b/tdutils/td/utils/port/PollFlags.h
@@ -0,0 +1,122 @@
+//
+// 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)
+//
+#pragma once
+
+#include "td/utils/StringBuilder.h"
+
+#include <atomic>
+
+namespace td {
+
+class PollFlags {
+ public:
+  using Raw = int32;
+  bool can_read() const {
+    return has_flags(Read());
+  }
+  bool can_write() const {
+    return has_flags(Write());
+  }
+  bool can_close() const {
+    return has_flags(Close());
+  }
+  bool has_pending_error() const {
+    return has_flags(Error());
+  }
+  void remove_flags(PollFlags flags) {
+    remove_flags(flags.raw());
+  }
+  bool add_flags(PollFlags flags) {
+    auto old_flags = flags_;
+    add_flags(flags.raw());
+    return old_flags != flags_;
+  }
+  bool has_flags(PollFlags flags) const {
+    return has_flags(flags.raw());
+  }
+
+  bool empty() const {
+    return flags_ == 0;
+  }
+  Raw raw() const {
+    return flags_;
+  }
+  static PollFlags from_raw(Raw raw) {
+    return PollFlags(raw);
+  }
+  PollFlags() = default;
+
+  bool operator==(const PollFlags &other) const {
+    return flags_ == other.flags_;
+  }
+  bool operator!=(const PollFlags &other) const {
+    return !(*this == other);
+  }
+  PollFlags operator|(const PollFlags other) const {
+    return from_raw(raw() | other.raw());
+  }
+
+  static PollFlags Write() {
+    return PollFlags(Flag::Write);
+  }
+  static PollFlags Error() {
+    return PollFlags(Flag::Error);
+  }
+  static PollFlags Close() {
+    return PollFlags(Flag::Close);
+  }
+  static PollFlags Read() {
+    return PollFlags(Flag::Read);
+  }
+  static PollFlags ReadWrite() {
+    return Read() | Write();
+  }
+
+ private:
+  enum class Flag : Raw { Write = 0x001, Read = 0x002, Close = 0x004, Error = 0x008, None = 0 };
+  Raw flags_{static_cast<Raw>(Flag::None)};
+
+  explicit PollFlags(Raw raw) : flags_(raw) {
+  }
+  explicit PollFlags(Flag flag) : PollFlags(static_cast<Raw>(flag)) {
+  }
+
+  PollFlags &add_flags(Raw flags) {
+    flags_ |= flags;
+    return *this;
+  }
+  PollFlags &remove_flags(Raw flags) {
+    flags_ &= ~flags;
+    return *this;
+  }
+  bool has_flags(Raw flags) const {
+    return (flags_ & flags) == flags;
+  }
+};
+
+StringBuilder &operator<<(StringBuilder &sb, PollFlags flags);
+
+class PollFlagsSet {
+ public:
+  // write flags from any thread
+  // this is the only function that should be called from other threads
+  bool write_flags(PollFlags flags);
+
+  bool write_flags_local(PollFlags flags);
+  bool flush() const;
+
+  PollFlags read_flags() const;
+  PollFlags read_flags_local() const;
+  void clear_flags(PollFlags flags);
+  void clear();
+
+ private:
+  mutable std::atomic<PollFlags::Raw> to_write_{0};
+  mutable PollFlags flags_;
+};
+
+}  // namespace td
diff --git a/tdutils/td/utils/port/detail/PollableFd.h b/tdutils/td/utils/port/detail/PollableFd.h
index 3982667ca..eb7ec8fd0 100644
--- a/tdutils/td/utils/port/detail/PollableFd.h
+++ b/tdutils/td/utils/port/detail/PollableFd.h
@@ -8,138 +8,14 @@
 
 #include "td/utils/format.h"
 #include "td/utils/List.h"
-#include "td/utils/MovableValue.h"
 #include "td/utils/Observer.h"
 #include "td/utils/port/detail/NativeFd.h"
+#include "td/utils/port/PollFlags.h"
 #include "td/utils/SpinLock.h"
-#include "td/utils/Status.h"
 
 #include <atomic>
 
 namespace td {
-class ObserverBase;
-
-class PollFlags {
- public:
-  using Raw = int32;
-  bool can_read() const {
-    return has_flags(Read());
-  }
-  bool can_write() const {
-    return has_flags(Write());
-  }
-  bool can_close() const {
-    return has_flags(Close());
-  }
-  bool has_pending_error() const {
-    return has_flags(Error());
-  }
-  void remove_flags(PollFlags flags) {
-    remove_flags(flags.raw());
-  }
-  bool add_flags(PollFlags flags) {
-    auto old_flags = flags_;
-    add_flags(flags.raw());
-    return old_flags != flags_;
-  }
-  bool has_flags(PollFlags flags) const {
-    return has_flags(flags.raw());
-  }
-
-  bool empty() const {
-    return flags_ == 0;
-  }
-  Raw raw() const {
-    return flags_;
-  }
-  static PollFlags from_raw(Raw raw) {
-    return PollFlags(raw);
-  }
-  PollFlags() = default;
-
-  bool operator==(const PollFlags &other) const {
-    return flags_ == other.flags_;
-  }
-  bool operator!=(const PollFlags &other) const {
-    return !(*this == other);
-  }
-  PollFlags operator|(const PollFlags other) const {
-    return from_raw(raw() | other.raw());
-  }
-
-  static PollFlags Write() {
-    return PollFlags(Flag::Write);
-  }
-  static PollFlags Error() {
-    return PollFlags(Flag::Error);
-  }
-  static PollFlags Close() {
-    return PollFlags(Flag::Close);
-  }
-  static PollFlags Read() {
-    return PollFlags(Flag::Read);
-  }
-  static PollFlags ReadWrite() {
-    return Read() | Write();
-  }
-
- private:
-  enum class Flag : Raw { Write = 0x001, Read = 0x002, Close = 0x004, Error = 0x008, None = 0 };
-  Raw flags_{static_cast<Raw>(Flag::None)};
-
-  explicit PollFlags(Raw raw) : flags_(raw) {
-  }
-  explicit PollFlags(Flag flag) : PollFlags(static_cast<Raw>(flag)) {
-  }
-
-  PollFlags &add_flags(Raw flags) {
-    flags_ |= flags;
-    return *this;
-  }
-  PollFlags &remove_flags(Raw flags) {
-    flags_ &= ~flags;
-    return *this;
-  }
-  bool has_flags(Raw flags) const {
-    return (flags_ & flags) == flags;
-  }
-};
-
-inline 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 << "]";
-}
-
-class PollFlagsSet {
- public:
-  // write flags from any thread
-  // this is the only function that should be called from other threads
-  bool write_flags(PollFlags flags);
-
-  bool write_flags_local(PollFlags flags);
-  bool flush() const;
-
-  PollFlags read_flags() const;
-  PollFlags read_flags_local() const;
-  void clear_flags(PollFlags flags);
-  void clear();
-
- private:
-  mutable std::atomic<PollFlags::Raw> to_write_{0};
-  mutable PollFlags flags_;
-};
 
 class PollableFdInfo;
 class PollableFdInfoUnlock {