diff --git a/CMakeLists.txt b/CMakeLists.txt
index a764f3d3d..d730861cd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -813,9 +813,9 @@ target_include_directories(tdcore SYSTEM PRIVATE ${OPENSSL_INCLUDE_DIR})
 target_link_libraries(tdcore PUBLIC tdapi tdactor tdutils tdnet tddb PRIVATE ${OPENSSL_CRYPTO_LIBRARY} ${CMAKE_DL_LIBS} ${ZLIB_LIBRARIES})
 if (WIN32)
   if (MINGW)
-    target_link_libraries(tdcore PRIVATE ws2_32 mswsock)
+    target_link_libraries(tdcore PRIVATE ws2_32 mswsock crypt32)
   else()
-    target_link_libraries(tdcore PRIVATE ws2_32 Mswsock)
+    target_link_libraries(tdcore PRIVATE ws2_32 Mswsock Crypt32)
   endif()
 endif()
 
diff --git a/benchmark/CMakeLists.txt b/benchmark/CMakeLists.txt
index e175ee414..78bb649f5 100644
--- a/benchmark/CMakeLists.txt
+++ b/benchmark/CMakeLists.txt
@@ -10,9 +10,9 @@ add_executable(bench_crypto bench_crypto.cpp)
 target_link_libraries(bench_crypto PRIVATE tdutils ${OPENSSL_CRYPTO_LIBRARY} ${CMAKE_DL_LIBS} ${ZLIB_LIBRARIES})
 if (WIN32)
   if (MINGW)
-    target_link_libraries(bench_crypto PRIVATE ws2_32 mswsock)
+    target_link_libraries(bench_crypto PRIVATE ws2_32 mswsock crypt32)
   else()
-    target_link_libraries(bench_crypto PRIVATE ws2_32 Mswsock)
+    target_link_libraries(bench_crypto PRIVATE ws2_32 Mswsock Crypt32)
   endif()
 endif()
 target_include_directories(bench_crypto SYSTEM PRIVATE ${OPENSSL_INCLUDE_DIR})
diff --git a/build.html b/build.html
index cc4910b6b..289fd2823 100644
--- a/build.html
+++ b/build.html
@@ -28,6 +28,7 @@ select.large { font-size: large; }
         <option>C++</option>
         <option>Swift</option>
         <option>Objective-C</option>
+        <option>Object Pascal</option>
         <option>Dart</option>
         <option>Rust</option>
         <option>Erlang</option>
@@ -202,6 +203,8 @@ function getExampleAnchor(language) {
     case 'Elixir':
     case 'C':
       return language.toLowerCase();
+    case 'Object Pascal':
+      return 'object-pascal';
     case 'C#':
       return 'csharp';
     case 'C++':
diff --git a/example/README.md b/example/README.md
index 44090b565..d9081f9b8 100644
--- a/example/README.md
+++ b/example/README.md
@@ -18,6 +18,7 @@ Choose your preferred programming language to see examples of usage and a detail
 - [C++](#cxx)
 - [Swift](#swift)
 - [Objective-C](#objective-c)
+- [Object Pascal](#object-pascal)
 - [Dart](#dart)
 - [Rust](#rust)
 - [Erlang](#erlang)
@@ -135,6 +136,15 @@ TDLib can be used from the Objective-C programming language through [JSON](https
 
 See [example/ios](https://github.com/tdlib/td/tree/master/example/ios) for an example of building TDLib for iOS, watchOS, tvOS, and macOS.
 
+<a name="object-pascal"></a>
+## Using TDLib in Object Pascal projects with Delphi and Lazarus
+
+TDLib can be used from the Object Pascal programming language through the [JSON](https://github.com/tdlib/td#using-json).
+
+See [tdlib-delphi](https://github.com/dieletro/tdlib-delphi) for an example of TDLib usage from Delphi.
+
+See [tdlib-lazarus](https://github.com/dieletro/tdlib-lazarus) for an example of TDLib usage from Lazarus.
+
 <a name="dart"></a>
 ## Using TDLib in Dart projects
 
diff --git a/example/cpp/tdjson_example.cpp b/example/cpp/tdjson_example.cpp
index c22320ee8..5d69c4e21 100644
--- a/example/cpp/tdjson_example.cpp
+++ b/example/cpp/tdjson_example.cpp
@@ -13,32 +13,32 @@
 
 int main() {
   // disable TDLib logging
-  td_json_client_execute(nullptr, "{\"@type\":\"setLogVerbosityLevel\", \"new_verbosity_level\":0}");
+  td_execute("{\"@type\":\"setLogVerbosityLevel\", \"new_verbosity_level\":0}");
 
-  void *client = td_json_client_create();
-  // somehow share the client with other threads, which will be able to send requests via td_json_client_send
+  int client_id = td_create_client();
+  // somehow share the client_id with other threads, which will be able to send requests via td_send
 
   const bool test_incorrect_queries = false;
   if (test_incorrect_queries) {
-    td_json_client_execute(nullptr, "{\"@type\":\"setLogVerbosityLevel\", \"new_verbosity_level\":3}");
-    td_json_client_execute(nullptr, "");
-    td_json_client_execute(nullptr, "test");
-    td_json_client_execute(nullptr, "\"test\"");
-    td_json_client_execute(nullptr, "{\"@type\":\"test\", \"@extra\":1}");
+    td_execute("{\"@type\":\"setLogVerbosityLevel\", \"new_verbosity_level\":1}");
+    td_execute("");
+    td_execute("test");
+    td_execute("\"test\"");
+    td_execute("{\"@type\":\"test\", \"@extra\":1}");
 
-    td_json_client_send(client, "{\"@type\":\"getFileMimeType\"}");
-    td_json_client_send(client, "{\"@type\":\"getFileMimeType\", \"@extra\":1}");
-    td_json_client_send(client, "{\"@type\":\"getFileMimeType\", \"@extra\":null}");
-    td_json_client_send(client, "{\"@type\":\"test\"}");
-    td_json_client_send(client, "[]");
-    td_json_client_send(client, "{\"@type\":\"test\", \"@extra\":1}");
-    td_json_client_send(client, "{\"@type\":\"sendMessage\", \"chat_id\":true, \"@extra\":1}");
-    td_json_client_send(client, "test");
+    td_send(client_id, "{\"@type\":\"getFileMimeType\"}");
+    td_send(client_id, "{\"@type\":\"getFileMimeType\", \"@extra\":1}");
+    td_send(client_id, "{\"@type\":\"getFileMimeType\", \"@extra\":null}");
+    td_send(client_id, "{\"@type\":\"test\"}");
+    td_send(client_id, "[]");
+    td_send(client_id, "{\"@type\":\"test\", \"@extra\":1}");
+    td_send(client_id, "{\"@type\":\"sendMessage\", \"chat_id\":true, \"@extra\":1}");
+    td_send(client_id, "test");
   }
 
   const double WAIT_TIMEOUT = 10.0;  // seconds
   while (true) {
-    const char *result = td_json_client_receive(client, WAIT_TIMEOUT);
+    const char *result = td_receive(WAIT_TIMEOUT);
     if (result != nullptr) {
       // parse the result as a JSON object and process it as an incoming update or an answer to a previously sent request
 
@@ -49,6 +49,4 @@ int main() {
       std::cout << result << std::endl;
     }
   }
-
-  td_json_client_destroy(client);
 }
diff --git a/example/csharp/TdExample.cs b/example/csharp/TdExample.cs
index eb5c0c0f5..7c5b4d255 100644
--- a/example/csharp/TdExample.cs
+++ b/example/csharp/TdExample.cs
@@ -23,7 +23,8 @@ namespace TdExample
 
         private static TdApi.AuthorizationState _authorizationState = null;
         private static volatile bool _haveAuthorization = false;
-        private static volatile bool _quiting = false;
+        private static volatile bool _needQuit = false;
+        private static volatile bool _canQuit = false;
 
         private static volatile AutoResetEvent _gotAuthorization = new AutoResetEvent(false);
 
@@ -133,9 +134,11 @@ namespace TdExample
             {
                 Print("Closed");
                 _client.Dispose(); // _client is closed and native resources can be disposed now
-                if (!_quiting)
+                if (!_needQuit)
                 {
                     _client = CreateTdClient(); // recreate _client after previous has closed
+                } else {
+                    _canQuit = true;
                 }
             }
             else
@@ -187,7 +190,7 @@ namespace TdExample
                         _client.Send(new TdApi.Close(), _defaultHandler);
                         break;
                     case "q":
-                        _quiting = true;
+                        _needQuit = true;
                         _haveAuthorization = false;
                         _client.Send(new TdApi.Close(), _defaultHandler);
                         break;
@@ -228,7 +231,7 @@ namespace TdExample
             _defaultHandler.OnResult(Td.Client.Execute(new TdApi.GetTextEntities("@telegram /test_command https://telegram.org telegram.me @gif @test")));
 
             // main loop
-            while (!_quiting)
+            while (!_needQuit)
             {
                 // await authorization
                 _gotAuthorization.Reset();
@@ -240,6 +243,9 @@ namespace TdExample
                     GetCommand();
                 }
             }
+            while (!_canQuit) {
+                Thread.Sleep(1);
+            }
         }
 
         private class DefaultHandler : Td.ClientResultHandler
diff --git a/example/java/org/drinkless/tdlib/Client.java b/example/java/org/drinkless/tdlib/Client.java
index 986d5b3c7..d95196f17 100644
--- a/example/java/org/drinkless/tdlib/Client.java
+++ b/example/java/org/drinkless/tdlib/Client.java
@@ -8,14 +8,11 @@ package org.drinkless.tdlib;
 
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicLong;
-import java.util.concurrent.locks.Lock;
-import java.util.concurrent.locks.ReadWriteLock;
-import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 /**
  * Main class for interaction with the TDLib.
  */
-public final class Client implements Runnable {
+public final class Client {
     /**
      * Interface for handler for results of queries to TDLib and incoming updates from TDLib.
      */
@@ -55,25 +52,11 @@ public final class Client implements Runnable {
      * @throws NullPointerException if query is null.
      */
     public void send(TdApi.Function query, ResultHandler resultHandler, ExceptionHandler exceptionHandler) {
-        if (query == null) {
-            throw new NullPointerException("query is null");
-        }
-
-        readLock.lock();
-        try {
-            if (isClientDestroyed) {
-                if (resultHandler != null) {
-                    handleResult(new TdApi.Error(500, "Client is closed"), resultHandler, exceptionHandler);
-                }
-                return;
-            }
-
-            long queryId = currentQueryId.incrementAndGet();
+        long queryId = currentQueryId.incrementAndGet();
+        if (resultHandler != null) {
             handlers.put(queryId, new Handler(resultHandler, exceptionHandler));
-            nativeClientSend(nativeClientId, queryId, query);
-        } finally {
-            readLock.unlock();
         }
+        nativeClientSend(nativeClientId, queryId, query);
     }
 
     /**
@@ -97,22 +80,9 @@ public final class Client implements Runnable {
      * @throws NullPointerException if query is null.
      */
     public static TdApi.Object execute(TdApi.Function query) {
-        if (query == null) {
-            throw new NullPointerException("query is null");
-        }
         return nativeClientExecute(query);
     }
 
-    /**
-     * Overridden method from Runnable, do not call it directly.
-     */
-    @Override
-    public void run() {
-        while (!stopFlag) {
-            receiveQueries(300.0 /*seconds*/);
-        }
-    }
-
     /**
      * Creates new Client.
      *
@@ -123,54 +93,79 @@ public final class Client implements Runnable {
      */
     public static Client create(ResultHandler updateHandler, ExceptionHandler updateExceptionHandler, ExceptionHandler defaultExceptionHandler) {
         Client client = new Client(updateHandler, updateExceptionHandler, defaultExceptionHandler);
-        new Thread(client, "TDLib thread").start();
+        synchronized (responseReceiver) {
+            if (!responseReceiver.isRun) {
+                responseReceiver.isRun = true;
+
+                Thread receiverThread = new Thread(responseReceiver, "TDLib thread");
+                receiverThread.setDaemon(true);
+                receiverThread.start();
+            }
+        }
         return client;
     }
 
-    /**
-     * Closes Client.
-     */
-    public void close() {
-        writeLock.lock();
-        try {
-            if (isClientDestroyed) {
-                return;
+    private static class ResponseReceiver implements Runnable {
+        public boolean isRun = false;
+
+        @Override
+        public void run() {
+            while (true) {
+                int resultN = nativeClientReceive(clientIds, eventIds, events, 100000.0 /*seconds*/);
+                for (int i = 0; i < resultN; i++) {
+                    processResult(clientIds[i], eventIds[i], events[i]);
+                    events[i] = null;
+                }
             }
-            if (!stopFlag) {
-                send(new TdApi.Close(), null);
-            }
-            isClientDestroyed = true;
-            while (!stopFlag) {
-                Thread.yield();
-            }
-            while (!handlers.isEmpty()) {
-                receiveQueries(300.0);
-            }
-            updateHandlers.remove(nativeClientId);
-            defaultExceptionHandlers.remove(nativeClientId);
-            destroyNativeClient(nativeClientId);
-        } finally {
-            writeLock.unlock();
         }
+
+        private void processResult(int clientId, long id, TdApi.Object object) {
+            boolean isClosed = false;
+            if (id == 0 && object instanceof TdApi.UpdateAuthorizationState) {
+                TdApi.AuthorizationState authorizationState = ((TdApi.UpdateAuthorizationState) object).authorizationState;
+                if (authorizationState instanceof TdApi.AuthorizationStateClosed) {
+                    isClosed = true;
+                }
+            }
+
+            Handler handler = id == 0 ? updateHandlers.get(clientId) : handlers.remove(id);
+            if (handler != null) {
+                try {
+                    handler.resultHandler.onResult(object);
+                } catch (Throwable cause) {
+                    ExceptionHandler exceptionHandler = handler.exceptionHandler;
+                    if (exceptionHandler == null) {
+                        exceptionHandler = defaultExceptionHandlers.get(clientId);
+                    }
+                    if (exceptionHandler != null) {
+                        try {
+                            exceptionHandler.onException(cause);
+                        } catch (Throwable ignored) {
+                        }
+                    }
+                }
+            }
+
+            if (isClosed) {
+                updateHandlers.remove(clientId);           // there will be no more updates
+                defaultExceptionHandlers.remove(clientId); // ignore further exceptions
+            }
+        }
+
+        private static final int MAX_EVENTS = 1000;
+        private final int[] clientIds = new int[MAX_EVENTS];
+        private final long[] eventIds = new long[MAX_EVENTS];
+        private final TdApi.Object[] events = new TdApi.Object[MAX_EVENTS];
     }
 
-    private final ReadWriteLock readWriteLock = new ReentrantReadWriteLock();
-    private final Lock readLock = readWriteLock.readLock();
-    private final Lock writeLock = readWriteLock.writeLock();
+    private final int nativeClientId;
 
-    private volatile boolean stopFlag = false;
-    private volatile boolean isClientDestroyed = false;
-    private final long nativeClientId;
+    private static final ConcurrentHashMap<Integer, ExceptionHandler> defaultExceptionHandlers = new ConcurrentHashMap<Integer, ExceptionHandler>();
+    private static final ConcurrentHashMap<Integer, Handler> updateHandlers = new ConcurrentHashMap<Integer, Handler>();
+    private static final ConcurrentHashMap<Long, Handler> handlers = new ConcurrentHashMap<Long, Handler>();
+    private static final AtomicLong currentQueryId = new AtomicLong();
 
-    private static final ConcurrentHashMap<Long, ExceptionHandler> defaultExceptionHandlers = new ConcurrentHashMap<Long, ExceptionHandler>();
-    private static final ConcurrentHashMap<Long, Handler> updateHandlers = new ConcurrentHashMap<Long, Handler>();
-
-    private final ConcurrentHashMap<Long, Handler> handlers = new ConcurrentHashMap<Long, Handler>();
-    private final AtomicLong currentQueryId = new AtomicLong();
-
-    private static final int MAX_EVENTS = 1000;
-    private final long[] eventIds = new long[MAX_EVENTS];
-    private final TdApi.Object[] events = new TdApi.Object[MAX_EVENTS];
+    private static final ResponseReceiver responseReceiver = new ResponseReceiver();
 
     private static class Handler {
         final ResultHandler resultHandler;
@@ -184,76 +179,24 @@ public final class Client implements Runnable {
 
     private Client(ResultHandler updateHandler, ExceptionHandler updateExceptionHandler, ExceptionHandler defaultExceptionHandler) {
         nativeClientId = createNativeClient();
-        updateHandlers.put(nativeClientId, new Handler(updateHandler, updateExceptionHandler));
+        if (updateHandler != null) {
+            updateHandlers.put(nativeClientId, new Handler(updateHandler, updateExceptionHandler));
+        }
         if (defaultExceptionHandler != null) {
-          defaultExceptionHandlers.put(nativeClientId, defaultExceptionHandler);
+            defaultExceptionHandlers.put(nativeClientId, defaultExceptionHandler);
         }
     }
 
     @Override
     protected void finalize() throws Throwable {
-        try {
-            close();
-        } finally {
-            super.finalize();
-        }
+        send(new TdApi.Close(), null, null);
     }
 
-    private void processResult(long id, TdApi.Object object) {
-        if (object instanceof TdApi.UpdateAuthorizationState) {
-            if (((TdApi.UpdateAuthorizationState) object).authorizationState instanceof TdApi.AuthorizationStateClosed) {
-                stopFlag = true;
-            }
-        }
-        Handler handler;
-        if (id == 0) {
-            // update handler stays forever
-            handler = updateHandlers.get(nativeClientId);
-        } else {
-            handler = handlers.remove(id);
-        }
-        if (handler == null) {
-            return;
-        }
+    private static native int createNativeClient();
 
-        handleResult(object, handler.resultHandler, handler.exceptionHandler);
-    }
+    private static native void nativeClientSend(int nativeClientId, long eventId, TdApi.Function function);
 
-    private void handleResult(TdApi.Object object, ResultHandler resultHandler, ExceptionHandler exceptionHandler) {
-        if (resultHandler == null) {
-            return;
-        }
-
-        try {
-            resultHandler.onResult(object);
-        } catch (Throwable cause) {
-            if (exceptionHandler == null) {
-                exceptionHandler = defaultExceptionHandlers.get(nativeClientId);
-            }
-            if (exceptionHandler != null) {
-                try {
-                    exceptionHandler.onException(cause);
-                } catch (Throwable ignored) {
-                }
-            }
-        }
-    }
-
-    private void receiveQueries(double timeout) {
-        int resultN = nativeClientReceive(nativeClientId, eventIds, events, timeout);
-        for (int i = 0; i < resultN; i++) {
-            processResult(eventIds[i], events[i]);
-            events[i] = null;
-        }
-    }
-
-    private static native long createNativeClient();
-
-    private static native void nativeClientSend(long nativeClientId, long eventId, TdApi.Function function);
-
-    private static native int nativeClientReceive(long nativeClientId, long[] eventIds, TdApi.Object[] events, double timeout);
+    private static native int nativeClientReceive(int[] clientIds, long[] eventIds, TdApi.Object[] events, double timeout);
 
     private static native TdApi.Object nativeClientExecute(TdApi.Function function);
-
-    private static native void destroyNativeClient(long nativeClientId);
 }
diff --git a/example/java/org/drinkless/tdlib/example/Example.java b/example/java/org/drinkless/tdlib/example/Example.java
index 8e52fda92..7c2e5649e 100644
--- a/example/java/org/drinkless/tdlib/example/Example.java
+++ b/example/java/org/drinkless/tdlib/example/Example.java
@@ -29,7 +29,8 @@ public final class Example {
 
     private static TdApi.AuthorizationState authorizationState = null;
     private static volatile boolean haveAuthorization = false;
-    private static volatile boolean quiting = false;
+    private static volatile boolean needQuit = false;
+    private static volatile boolean canQuit = false;
 
     private static final Client.ResultHandler defaultHandler = new DefaultHandler();
 
@@ -160,8 +161,10 @@ public final class Example {
                 break;
             case TdApi.AuthorizationStateClosed.CONSTRUCTOR:
                 print("Closed");
-                if (!quiting) {
+                if (!needQuit) {
                     client = Client.create(new UpdateHandler(), null, null); // recreate client after previous has closed
+                } else {
+                    canQuit = true;
                 }
                 break;
             default:
@@ -230,7 +233,7 @@ public final class Example {
                     client.send(new TdApi.LogOut(), defaultHandler);
                     break;
                 case "q":
-                    quiting = true;
+                    needQuit = true;
                     haveAuthorization = false;
                     client.send(new TdApi.Close(), defaultHandler);
                     break;
@@ -316,7 +319,7 @@ public final class Example {
         defaultHandler.onResult(Client.execute(new TdApi.GetTextEntities("@telegram /test_command https://telegram.org telegram.me @gif @test")));
 
         // main loop
-        while (!quiting) {
+        while (!needQuit) {
             // await authorization
             authorizationLock.lock();
             try {
@@ -331,6 +334,9 @@ public final class Example {
                 getCommand();
             }
         }
+        while (!canQuit) {
+            Thread.sleep(1);
+        }
     }
 
     private static class OrderedChat implements Comparable<OrderedChat> {
diff --git a/example/java/td_jni.cpp b/example/java/td_jni.cpp
index 34ad9c836..e0106e258 100644
--- a/example/java/td_jni.cpp
+++ b/example/java/td_jni.cpp
@@ -26,31 +26,35 @@ static td::td_api::object_ptr<td::td_api::Function> fetch_function(JNIEnv *env,
   return result;
 }
 
-static td::Client *get_client(jlong client_id) {
-  return reinterpret_cast<td::Client *>(static_cast<std::uintptr_t>(client_id));
+static td::ClientManager *get_manager() {
+  return td::ClientManager::get_manager_singleton();
 }
 
-static jlong Client_createNativeClient(JNIEnv *env, jclass clazz) {
-  return static_cast<jlong>(reinterpret_cast<std::uintptr_t>(new td::Client()));
+static jint Client_createNativeClient(JNIEnv *env, jclass clazz) {
+  return static_cast<jint>(get_manager()->create_client());
 }
 
-static void Client_nativeClientSend(JNIEnv *env, jclass clazz, jlong client_id, jlong id, jobject function) {
-  get_client(client_id)->send({static_cast<std::uint64_t>(id), fetch_function(env, function)});
+static void Client_nativeClientSend(JNIEnv *env, jclass clazz, jint client_id, jlong id, jobject function) {
+  get_manager()->send(static_cast<std::int32_t>(client_id), static_cast<std::uint64_t>(id),
+                      fetch_function(env, function));
 }
 
-static jint Client_nativeClientReceive(JNIEnv *env, jclass clazz, jlong client_id, jlongArray ids, jobjectArray events,
-                                       jdouble timeout) {
-  auto client = get_client(client_id);
-  jsize events_size = env->GetArrayLength(ids);  // ids and events size must be of equal size
+static jint Client_nativeClientReceive(JNIEnv *env, jclass clazz, jintArray client_ids, jlongArray ids,
+                                       jobjectArray events, jdouble timeout) {
+  jsize events_size = env->GetArrayLength(ids);  // client_ids, ids and events must be of equal size
   if (events_size == 0) {
     return 0;
   }
   jsize result_size = 0;
 
-  auto response = client->receive(timeout);
+  auto *manager = get_manager();
+  auto response = manager->receive(timeout);
   while (response.object) {
-    jlong result_id = static_cast<jlong>(response.id);
-    env->SetLongArrayRegion(ids, result_size, 1, &result_id);
+    jint client_id = static_cast<jint>(response.client_id);
+    env->SetIntArrayRegion(client_ids, result_size, 1, &client_id);
+
+    jlong request_id = static_cast<jlong>(response.request_id);
+    env->SetLongArrayRegion(ids, result_size, 1, &request_id);
 
     jobject object;
     response.object->store(env, object);
@@ -62,21 +66,17 @@ static jint Client_nativeClientReceive(JNIEnv *env, jclass clazz, jlong client_i
       break;
     }
 
-    response = client->receive(0);
+    response = manager->receive(0);
   }
   return result_size;
 }
 
 static jobject Client_nativeClientExecute(JNIEnv *env, jclass clazz, jobject function) {
   jobject result;
-  td::Client::execute({0, fetch_function(env, function)}).object->store(env, result);
+  td::ClientManager::execute(fetch_function(env, function))->store(env, result);
   return result;
 }
 
-static void Client_destroyNativeClient(JNIEnv *env, jclass clazz, jlong client_id) {
-  delete get_client(client_id);
-}
-
 static void Log_setVerbosityLevel(JNIEnv *env, jclass clazz, jint new_log_verbosity_level) {
   td::Log::set_verbosity_level(static_cast<int>(new_log_verbosity_level));
 }
@@ -103,8 +103,11 @@ static jclass log_class;
 
 static void on_fatal_error(const char *error_message) {
   auto env = td::jni::get_jni_env(java_vm, JAVA_VERSION);
+  if (env == nullptr) {
+    return;
+  }
   jmethodID on_fatal_error_method = env->GetStaticMethodID(log_class, "onFatalError", "(Ljava/lang/String;)V");
-  if (env && on_fatal_error_method) {
+  if (on_fatal_error_method) {
     jstring error_str = td::jni::to_jstring(env.get(), error_message);
     env->CallStaticVoidMethod(log_class, on_fatal_error_method, error_str);
     if (error_str) {
@@ -133,11 +136,10 @@ static jint register_native(JavaVM *vm) {
 
 #define TD_OBJECT "L" PACKAGE_NAME "/TdApi$Object;"
 #define TD_FUNCTION "L" PACKAGE_NAME "/TdApi$Function;"
-  register_method(client_class, "createNativeClient", "()J", Client_createNativeClient);
-  register_method(client_class, "nativeClientSend", "(JJ" TD_FUNCTION ")V", Client_nativeClientSend);
-  register_method(client_class, "nativeClientReceive", "(J[J[" TD_OBJECT "D)I", Client_nativeClientReceive);
+  register_method(client_class, "createNativeClient", "()I", Client_createNativeClient);
+  register_method(client_class, "nativeClientSend", "(IJ" TD_FUNCTION ")V", Client_nativeClientSend);
+  register_method(client_class, "nativeClientReceive", "([I[J[" TD_OBJECT "D)I", Client_nativeClientReceive);
   register_method(client_class, "nativeClientExecute", "(" TD_FUNCTION ")" TD_OBJECT, Client_nativeClientExecute);
-  register_method(client_class, "destroyNativeClient", "(J)V", Client_destroyNativeClient);
 
   register_method(log_class, "setVerbosityLevel", "(I)V", Log_setVerbosityLevel);
   register_method(log_class, "setFilePath", "(Ljava/lang/String;)Z", Log_setFilePath);
diff --git a/example/web/README.md b/example/web/README.md
index 6f137ec9c..15a4964db 100644
--- a/example/web/README.md
+++ b/example/web/README.md
@@ -6,7 +6,7 @@ You need a Unix shell with `sed`, `tar` and `wget` utilities to run the provided
 
 ## Building tdweb NPM package
 
-* Install the 1.39.5 [emsdk](https://kripken.github.io/emscripten-site/docs/getting_started/downloads.html), which is known to work. Do not use the system-provided `emscripten` package, because it contains a version that is too old.
+* Install the 2.0.6 [emsdk](https://kripken.github.io/emscripten-site/docs/getting_started/downloads.html), which is known to work. Do not use the system-provided `emscripten` package, because it contains a too old emsdk version.
 * Install all `TDLib` build dependencies as described in [Building](https://github.com/tdlib/td#building).
 * Run `source ./emsdk_env.sh` from `emsdk` directory to set up the correct build environment.
 * On `macOS`, install the `coreutils` [Homebrew](https://brew.sh) package and replace `realpath` in scripts with `grealpath`:
diff --git a/sqlite/CMakeLists.txt b/sqlite/CMakeLists.txt
index 0d90f3330..131facb48 100644
--- a/sqlite/CMakeLists.txt
+++ b/sqlite/CMakeLists.txt
@@ -22,9 +22,9 @@ target_include_directories(tdsqlite SYSTEM PRIVATE ${OPENSSL_INCLUDE_DIR})
 target_link_libraries(tdsqlite PRIVATE ${OPENSSL_CRYPTO_LIBRARY} ${CMAKE_DL_LIBS} ${ZLIB_LIBRARIES})
 if (WIN32)
   if (MINGW)
-    target_link_libraries(tdsqlite PRIVATE ws2_32 mswsock)
+    target_link_libraries(tdsqlite PRIVATE ws2_32 mswsock crypt32)
   else()
-    target_link_libraries(tdsqlite PRIVATE ws2_32 Mswsock)
+    target_link_libraries(tdsqlite PRIVATE ws2_32 Mswsock Crypt32)
   endif()
 endif()
 
diff --git a/td/telegram/Client.cpp b/td/telegram/Client.cpp
index 0de42e12f..474bb8868 100644
--- a/td/telegram/Client.cpp
+++ b/td/telegram/Client.cpp
@@ -13,6 +13,7 @@
 
 #include "td/utils/common.h"
 #include "td/utils/crypto.h"
+#include "td/utils/ExitGuard.h"
 #include "td/utils/logging.h"
 #include "td/utils/misc.h"
 #include "td/utils/MpscPollableQueue.h"
@@ -203,10 +204,12 @@ class ClientManager::Impl final {
         td.second.reset();
       }
     }
-    while (!tds_.empty()) {
-      receive(10, false, true);
+    while (!tds_.empty() && !ExitGuard::is_exited()) {
+      receive(0.1, false, true);
+    }
+    if (!ExitGuard::is_exited()) {  // prevent closing of schedulers from already killed by OS threads
+      concurrent_scheduler_->finish();
     }
-    concurrent_scheduler_->finish();
   }
 
  private:
@@ -475,7 +478,9 @@ class MultiImpl {
       Scheduler::instance()->finish();
     }
     scheduler_thread_.join();
-    concurrent_scheduler_->finish();
+    if (!ExitGuard::is_exited()) {  // prevent closing of schedulers from already killed by OS threads
+      concurrent_scheduler_->finish();
+    }
   }
 
  private:
@@ -618,11 +623,14 @@ class ClientManager::Impl final {
   Impl(Impl &&) = delete;
   Impl &operator=(Impl &&) = delete;
   ~Impl() {
+    if (ExitGuard::is_exited()) {
+      return;
+    }
     for (auto &it : impls_) {
       close_impl(it.first);
     }
-    while (!impls_.empty()) {
-      receive(10, false, true);
+    while (!impls_.empty() && !ExitGuard::is_exited()) {
+      receive(0.1, false, true);
     }
   }
 
@@ -673,8 +681,8 @@ class Client::Impl final {
   Impl &operator=(Impl &&) = delete;
   ~Impl() {
     multi_impl_->close(td_id_);
-    while (true) {
-      auto response = receiver_.receive(10.0, false, true);
+    while (!ExitGuard::is_exited()) {
+      auto response = receiver_.receive(0.1, false, true);
       if (response.object == nullptr && response.client_id != 0 && response.request_id == 0) {
         break;
       }
@@ -742,4 +750,10 @@ ClientManager::~ClientManager() = default;
 ClientManager::ClientManager(ClientManager &&other) = default;
 ClientManager &ClientManager::operator=(ClientManager &&other) = default;
 
+ClientManager *ClientManager::get_manager_singleton() {
+  static ClientManager client_manager;
+  static ExitGuard exit_guard;
+  return &client_manager;
+}
+
 }  // namespace td
diff --git a/td/telegram/Client.h b/td/telegram/Client.h
index 8254d0cd8..34eecfb79 100644
--- a/td/telegram/Client.h
+++ b/td/telegram/Client.h
@@ -260,6 +260,12 @@ class ClientManager final {
    */
   ClientManager &operator=(ClientManager &&other);
 
+  /**
+   * Returns a pointer to a singleton ClientManager instance.
+   * \return A unique singleton ClientManager instance.
+   */
+  static ClientManager *get_manager_singleton();
+
  private:
   friend class Client;
   class Impl;
diff --git a/td/telegram/ClientJson.cpp b/td/telegram/ClientJson.cpp
index d5beab12d..80ef8450b 100644
--- a/td/telegram/ClientJson.cpp
+++ b/td/telegram/ClientJson.cpp
@@ -115,8 +115,7 @@ const char *ClientJson::execute(Slice request) {
 }
 
 static ClientManager *get_manager() {
-  static ClientManager client_manager;
-  return &client_manager;
+  return ClientManager::get_manager_singleton();
 }
 
 static std::mutex extra_mutex;
diff --git a/td/telegram/ContactsManager.cpp b/td/telegram/ContactsManager.cpp
index a9849bd37..49709f40d 100644
--- a/td/telegram/ContactsManager.cpp
+++ b/td/telegram/ContactsManager.cpp
@@ -12825,6 +12825,14 @@ bool ContactsManager::get_chat_is_active(ChatId chat_id) const {
   return c->is_active;
 }
 
+ChannelId ContactsManager::get_chat_migrated_to_channel_id(ChatId chat_id) const {
+  auto c = get_chat(chat_id);
+  if (c == nullptr) {
+    return ChannelId();
+  }
+  return c->migrated_to_channel_id;
+}
+
 DialogParticipantStatus ContactsManager::get_chat_status(ChatId chat_id) const {
   auto c = get_chat(chat_id);
   if (c == nullptr) {
diff --git a/td/telegram/ContactsManager.h b/td/telegram/ContactsManager.h
index 665948167..74b075194 100644
--- a/td/telegram/ContactsManager.h
+++ b/td/telegram/ContactsManager.h
@@ -467,6 +467,7 @@ class ContactsManager : public Actor {
   void reload_chat_full(ChatId chat_id, Promise<Unit> &&promise);
 
   bool get_chat_is_active(ChatId chat_id) const;
+  ChannelId get_chat_migrated_to_channel_id(ChatId chat_id) const;
   DialogParticipantStatus get_chat_status(ChatId chat_id) const;
   DialogParticipantStatus get_chat_permissions(ChatId chat_id) const;
   bool is_appointed_chat_administrator(ChatId chat_id) const;
diff --git a/td/telegram/Logging.cpp b/td/telegram/Logging.cpp
index 8694ab498..131303a67 100644
--- a/td/telegram/Logging.cpp
+++ b/td/telegram/Logging.cpp
@@ -29,6 +29,7 @@
 
 #include "td/actor/actor.h"
 
+#include "td/utils/ExitGuard.h"
 #include "td/utils/FileLog.h"
 #include "td/utils/logging.h"
 #include "td/utils/misc.h"
@@ -44,6 +45,7 @@ static std::mutex logging_mutex;
 static FileLog file_log;
 static TsLog ts_log(&file_log);
 static NullLog null_log;
+static ExitGuard exit_guard;
 
 #define ADD_TAG(tag) \
   { #tag, &VERBOSITY_NAME(tag) }
diff --git a/td/telegram/MessageReplyInfo.h b/td/telegram/MessageReplyInfo.h
index d1c3a75da..0c1b4e8d9 100644
--- a/td/telegram/MessageReplyInfo.h
+++ b/td/telegram/MessageReplyInfo.h
@@ -9,7 +9,7 @@
 #include "td/telegram/ChannelId.h"
 #include "td/telegram/DialogId.h"
 #include "td/telegram/MessageId.h"
-#include "Td/telegram/td_api.h"
+#include "td/telegram/td_api.h"
 #include "td/telegram/telegram_api.h"
 
 #include "td/utils/common.h"
diff --git a/td/telegram/MessagesManager.cpp b/td/telegram/MessagesManager.cpp
index e6404c61c..4ba626ae1 100644
--- a/td/telegram/MessagesManager.cpp
+++ b/td/telegram/MessagesManager.cpp
@@ -15424,6 +15424,9 @@ std::pair<int32, vector<DialogId>> MessagesManager::search_dialogs(const string
     }
 
     promise.set_value(Unit());
+
+    update_recently_found_dialogs();
+
     size_t result_size = min(static_cast<size_t>(limit), recently_found_dialog_ids_.size());
     return {narrow_cast<int32>(recently_found_dialog_ids_.size()),
             vector<DialogId>(recently_found_dialog_ids_.begin(), recently_found_dialog_ids_.begin() + result_size)};
@@ -23734,6 +23737,26 @@ bool MessagesManager::is_broadcast_channel(DialogId dialog_id) const {
   return td_->contacts_manager_->get_channel_type(dialog_id.get_channel_id()) == ChannelType::Broadcast;
 }
 
+bool MessagesManager::is_deleted_secret_chat(const Dialog *d) const {
+  if (d == nullptr) {
+    return true;
+  }
+  if (d->dialog_id.get_type() != DialogType::SecretChat) {
+    return false;
+  }
+
+  if (d->order != DEFAULT_ORDER || d->messages != nullptr) {
+    return false;
+  }
+
+  auto state = td_->contacts_manager_->get_secret_chat_state(d->dialog_id.get_secret_chat_id());
+  if (state != SecretChatState::Closed) {
+    return false;
+  }
+
+  return true;
+}
+
 int32 MessagesManager::get_message_schedule_date(const Message *m) {
   if (!m->message_id.is_scheduled()) {
     return 0;
@@ -28934,7 +28957,7 @@ void MessagesManager::send_dialog_action(DialogId dialog_id, MessageId top_threa
 
   auto &query_ref = set_typing_query_[dialog_id];
   if (!query_ref.empty() && !td_->auth_manager_->is_bot()) {
-    LOG(INFO) << "Cancel previous set typing query";
+    LOG(INFO) << "Cancel previous send chat action query";
     cancel_query(query_ref);
   }
   query_ref = td_->create_handler<SetTypingQuery>(std::move(promise))
@@ -28942,7 +28965,7 @@ void MessagesManager::send_dialog_action(DialogId dialog_id, MessageId top_threa
 }
 
 void MessagesManager::on_send_dialog_action_timeout(DialogId dialog_id) {
-  LOG(INFO) << "Receive send_dialog_action timeout in " << dialog_id;
+  LOG(INFO) << "Receive send_chat_action timeout in " << dialog_id;
   Dialog *d = get_dialog(dialog_id);
   CHECK(d != nullptr);
 
@@ -30778,7 +30801,7 @@ MessagesManager::Message *MessagesManager::add_message_to_dialog(Dialog *d, uniq
     if (queue_id & 1) {
       LOG(INFO) << "Add " << message_id << " from " << source << " to queue " << queue_id;
       yet_unsent_media_queues_[queue_id][message_id.get()];  // reserve place for promise
-      if (!td_->auth_manager_->is_bot() && !is_dialog_action_unneeded(dialog_id)) {
+      if (!td_->auth_manager_->is_bot()) {
         pending_send_dialog_action_timeout_.add_timeout_in(dialog_id.get(), 1.0);
       }
     }
@@ -32890,11 +32913,8 @@ void MessagesManager::update_dialog_pos(Dialog *d, const char *source, bool need
       }
     }
     if (dialog_type == DialogType::SecretChat) {
-      auto secret_chat_id = d->dialog_id.get_secret_chat_id();
-      auto date = td_->contacts_manager_->get_secret_chat_date(secret_chat_id);
-      auto state = td_->contacts_manager_->get_secret_chat_state(secret_chat_id);
-      // do not return removed from the chat list closed secret chats
-      if (date != 0 && (d->order != DEFAULT_ORDER || state != SecretChatState::Closed || d->messages != nullptr)) {
+      auto date = td_->contacts_manager_->get_secret_chat_date(d->dialog_id.get_secret_chat_id());
+      if (date != 0 && !is_deleted_secret_chat(d)) {
         LOG(INFO) << "Creation of secret chat at " << date << " found";
         int64 creation_order = get_dialog_order(MessageId(), date);
         if (creation_order > new_order) {
@@ -35195,6 +35215,7 @@ void MessagesManager::save_recently_found_dialogs() {
     }
     value += to_string(dialog_id.get());
   }
+  LOG(DEBUG) << "Save recently found chats " << value;
   G()->td_db()->get_binlog_pmc()->set("recently_found_dialog_usernames_and_ids", value);
 }
 
@@ -35213,6 +35234,7 @@ bool MessagesManager::load_recently_found_dialogs(Promise<Unit> &promise) {
     return true;
   }
 
+  LOG(DEBUG) << "Loaded recently found chats " << found_dialogs_str;
   auto found_dialogs = full_split(found_dialogs_str, ',');
   if (recently_found_dialogs_loaded_ == 1 && resolve_recently_found_dialogs_multipromise_.promise_count() == 0) {
     // queries was sent and have already been finished
@@ -35318,7 +35340,7 @@ bool MessagesManager::add_recently_found_dialog_internal(DialogId dialog_id) {
   // TODO create function
   auto it = std::find(recently_found_dialog_ids_.begin(), recently_found_dialog_ids_.end(), dialog_id);
   if (it == recently_found_dialog_ids_.end()) {
-    if (narrow_cast<int32>(recently_found_dialog_ids_.size()) == MAX_RECENT_FOUND_DIALOGS) {
+    if (narrow_cast<int32>(recently_found_dialog_ids_.size()) == MAX_RECENTLY_FOUND_DIALOGS) {
       CHECK(!recently_found_dialog_ids_.empty());
       recently_found_dialog_ids_.back() = dialog_id;
     } else {
@@ -35335,6 +35357,48 @@ bool MessagesManager::remove_recently_found_dialog_internal(DialogId dialog_id)
   return td::remove(recently_found_dialog_ids_, dialog_id);
 }
 
+void MessagesManager::update_recently_found_dialogs() {
+  vector<DialogId> dialog_ids;
+  for (auto dialog_id : recently_found_dialog_ids_) {
+    const Dialog *d = get_dialog(dialog_id);
+    if (d == nullptr) {
+      continue;
+    }
+    switch (dialog_id.get_type()) {
+      case DialogType::User:
+        // always keep
+        break;
+      case DialogType::Chat: {
+        auto channel_id = td_->contacts_manager_->get_chat_migrated_to_channel_id(dialog_id.get_chat_id());
+        if (channel_id.is_valid() && get_dialog(DialogId(channel_id)) != nullptr) {
+          dialog_id = DialogId(channel_id);
+        }
+        break;
+      }
+      case DialogType::Channel:
+        // always keep
+        break;
+      case DialogType::SecretChat:
+        if (is_deleted_secret_chat(d)) {
+          dialog_id = DialogId();
+        }
+        break;
+      case DialogType::None:
+      default:
+        UNREACHABLE();
+        break;
+    }
+    if (dialog_id.is_valid()) {
+      dialog_ids.push_back(dialog_id);
+    }
+  }
+
+  if (dialog_ids != recently_found_dialog_ids_) {
+    recently_found_dialog_ids_ = std::move(dialog_ids);
+    save_recently_found_dialogs();
+  }
+}
+
 void MessagesManager::suffix_load_loop(Dialog *d) {
   if (d->suffix_load_has_query_) {
     return;
diff --git a/td/telegram/MessagesManager.h b/td/telegram/MessagesManager.h
index 2b2fbb28e..6ee4299a4 100644
--- a/td/telegram/MessagesManager.h
+++ b/td/telegram/MessagesManager.h
@@ -1644,7 +1644,7 @@ class MessagesManager : public Actor {
   static constexpr int32 MIN_CHANNEL_DIFFERENCE = 10;
   static constexpr int32 MAX_CHANNEL_DIFFERENCE = 100;
   static constexpr int32 MAX_BOT_CHANNEL_DIFFERENCE = 100000;   // server side limit
-  static constexpr int32 MAX_RECENT_FOUND_DIALOGS = 20;         // some reasonable value
+  static constexpr int32 MAX_RECENTLY_FOUND_DIALOGS = 30;       // some reasonable value
   static constexpr size_t MAX_TITLE_LENGTH = 128;               // server side limit for chat title
   static constexpr size_t MAX_DESCRIPTION_LENGTH = 255;         // server side limit for chat description
   static constexpr size_t MAX_DIALOG_FILTER_TITLE_LENGTH = 12;  // server side limit for dialog filter title
@@ -2831,7 +2831,10 @@ class MessagesManager : public Actor {
 
   bool remove_recently_found_dialog_internal(DialogId dialog_id);
 
+  void update_recently_found_dialogs();
+
   void save_recently_found_dialogs();
+
   bool load_recently_found_dialogs(Promise<Unit> &promise);
 
   void reget_message_from_server_if_needed(DialogId dialog_id, const Message *m);
@@ -2916,6 +2919,8 @@ class MessagesManager : public Actor {
 
   bool is_broadcast_channel(DialogId dialog_id) const;
 
+  bool is_deleted_secret_chat(const Dialog *d) const;
+
   static int32 get_message_schedule_date(const Message *m);
 
   int32 recently_found_dialogs_loaded_ = 0;  // 0 - not loaded, 1 - load request was sent, 2 - loaded
diff --git a/td/telegram/Photo.cpp b/td/telegram/Photo.cpp
index 98a7dd30f..5672aa5d5 100644
--- a/td/telegram/Photo.cpp
+++ b/td/telegram/Photo.cpp
@@ -581,13 +581,16 @@ static vector<td_api::object_ptr<td_api::photoSize>> get_photo_sizes_object(File
   auto sizes = transform(photo_sizes, [file_manager](const PhotoSize &photo_size) {
     return get_photo_size_object(file_manager, &photo_size);
   });
-  std::sort(sizes.begin(), sizes.end(), [](const auto &lhs, const auto &rhs) {
+  std::stable_sort(sizes.begin(), sizes.end(), [](const auto &lhs, const auto &rhs) {
     if (lhs->photo_->expected_size_ != rhs->photo_->expected_size_) {
       return lhs->photo_->expected_size_ < rhs->photo_->expected_size_;
     }
     return static_cast<uint32>(lhs->width_) * static_cast<uint32>(lhs->height_) <
            static_cast<uint32>(rhs->width_) * static_cast<uint32>(rhs->height_);
   });
+  td::remove_if(sizes, [](const auto &size) {
+    return !size->photo_->local_->can_be_downloaded_ && !size->photo_->local_->is_downloading_completed_;
+  });
   return sizes;
 }
 
diff --git a/td/telegram/cli.cpp b/td/telegram/cli.cpp
index 288232e45..cdd0b06b2 100644
--- a/td/telegram/cli.cpp
+++ b/td/telegram/cli.cpp
@@ -20,6 +20,7 @@
 #include "td/utils/buffer.h"
 #include "td/utils/common.h"
 #include "td/utils/crypto.h"
+#include "td/utils/ExitGuard.h"
 #include "td/utils/FileLog.h"
 #include "td/utils/format.h"
 #include "td/utils/JsonBuilder.h"
@@ -4450,6 +4451,8 @@ void main(int argc, char **argv) {
 #ifndef _WIN32
   Debug::DeathHandler dh;
 #endif
+
+  ExitGuard exit_guard;
   ignore_signal(SignalType::HangUp).ensure();
   ignore_signal(SignalType::Pipe).ensure();
   set_signal_handler(SignalType::Error, fail_signal).ensure();
diff --git a/td/tl/tl_jni_object.cpp b/td/tl/tl_jni_object.cpp
index 640635c32..31af7508d 100644
--- a/td/tl/tl_jni_object.cpp
+++ b/td/tl/tl_jni_object.cpp
@@ -85,7 +85,10 @@ std::unique_ptr<JNIEnv, JvmThreadDetacher> get_jni_env(JavaVM *java_vm, jint jni
 #else
     auto p_env = &env;
 #endif
-    java_vm->AttachCurrentThread(p_env, nullptr);
+    if (java_vm->AttachCurrentThread(p_env, nullptr) != JNI_OK) {
+      java_vm = nullptr;
+      env = nullptr;
+    }
   } else {
     java_vm = nullptr;
   }
diff --git a/tdactor/td/actor/impl/Scheduler.cpp b/tdactor/td/actor/impl/Scheduler.cpp
index 39cb4661e..ca8f58fb6 100644
--- a/tdactor/td/actor/impl/Scheduler.cpp
+++ b/tdactor/td/actor/impl/Scheduler.cpp
@@ -111,6 +111,7 @@ void Scheduler::ServiceActor::tear_down() {
 /*** SchedlerGuard ***/
 SchedulerGuard::SchedulerGuard(Scheduler *scheduler, bool lock) : scheduler_(scheduler) {
   if (lock) {
+    // the next check can fail if OS killed the scheduler's thread without releasing the guard
     CHECK(!scheduler_->has_guard_);
     scheduler_->has_guard_ = true;
   }
diff --git a/tdutils/CMakeLists.txt b/tdutils/CMakeLists.txt
index 067237508..728a6a0cb 100644
--- a/tdutils/CMakeLists.txt
+++ b/tdutils/CMakeLists.txt
@@ -318,6 +318,12 @@ target_include_directories(tdutils PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_SOUR
 if (OPENSSL_FOUND)
   target_link_libraries(tdutils PRIVATE ${OPENSSL_CRYPTO_LIBRARY} ${CMAKE_DL_LIBS} ${ZLIB_LIBRARIES})
   target_include_directories(tdutils SYSTEM PRIVATE ${OPENSSL_INCLUDE_DIR})
+
+  if (MINGW)
+    target_link_libraries(tdutils PRIVATE ws2_32 mswsock crypt32)
+  else()
+    target_link_libraries(tdutils PRIVATE ws2_32 Mswsock Crypt32)
+  endif()
 endif()
 
 if (ZLIB_FOUND)
diff --git a/tdutils/td/utils/ExitGuard.cpp b/tdutils/td/utils/ExitGuard.cpp
index 1c62dec5e..758f85f6d 100644
--- a/tdutils/td/utils/ExitGuard.cpp
+++ b/tdutils/td/utils/ExitGuard.cpp
@@ -6,8 +6,15 @@
 //
 #include "td/utils/ExitGuard.h"
 
+#include "td/utils/logging.h"
+
 namespace td {
 
 std::atomic<bool> ExitGuard::is_exited_{false};
 
+ExitGuard::~ExitGuard() {
+  is_exited_.store(true, std::memory_order_relaxed);
+  set_verbosity_level(VERBOSITY_NAME(FATAL));
+}
+
 }  // namespace td
diff --git a/tdutils/td/utils/ExitGuard.h b/tdutils/td/utils/ExitGuard.h
index 1a91a731f..62a5bdaa9 100644
--- a/tdutils/td/utils/ExitGuard.h
+++ b/tdutils/td/utils/ExitGuard.h
@@ -17,9 +17,7 @@ class ExitGuard {
   ExitGuard &operator=(ExitGuard &&) = delete;
   ExitGuard(const ExitGuard &) = delete;
   ExitGuard &operator=(const ExitGuard &) = delete;
-  ~ExitGuard() {
-    is_exited_.store(true, std::memory_order_relaxed);
-  }
+  ~ExitGuard();
 
   static bool is_exited() {
     return is_exited_.load(std::memory_order_relaxed);
diff --git a/tdutils/td/utils/format.h b/tdutils/td/utils/format.h
index a3b5b3a46..8798d0e49 100644
--- a/tdutils/td/utils/format.h
+++ b/tdutils/td/utils/format.h
@@ -11,7 +11,6 @@
 #include "td/utils/Slice.h"
 #include "td/utils/StringBuilder.h"
 
-#include <set>
 #include <tuple>
 #include <utility>
 
@@ -335,9 +334,5 @@ template <class T>
 StringBuilder &operator<<(StringBuilder &stream, const vector<T> &vec) {
   return stream << format::as_array(vec);
 }
-template <class T>
-StringBuilder &operator<<(StringBuilder &stream, const std::set<T> &vec) {
-  return stream << format::as_array(vec);
-}
 
 }  // namespace td
diff --git a/tdutils/td/utils/logging.cpp b/tdutils/td/utils/logging.cpp
index 255b2da27..937cc279c 100644
--- a/tdutils/td/utils/logging.cpp
+++ b/tdutils/td/utils/logging.cpp
@@ -6,6 +6,7 @@
 //
 #include "td/utils/logging.h"
 
+#include "td/utils/ExitGuard.h"
 #include "td/utils/port/Clocks.h"
 #include "td/utils/port/StdStreams.h"
 #include "td/utils/port/thread_local.h"
@@ -48,6 +49,9 @@ Logger::Logger(LogInterface &log, const LogOptions &options, int log_level, Slic
   if (!options_.add_info) {
     return;
   }
+  if (ExitGuard::is_exited()) {
+    return;
+  }
 
   // log level
   sb_ << '[';
@@ -109,6 +113,9 @@ Logger::Logger(LogInterface &log, const LogOptions &options, int log_level, Slic
 }
 
 Logger::~Logger() {
+  if (ExitGuard::is_exited()) {
+    return;
+  }
   if (options_.fix_newlines) {
     sb_ << '\n';
     auto slice = as_cslice();
@@ -157,7 +164,7 @@ TsCerr &TsCerr::operator<<(Slice slice) {
 }
 
 void TsCerr::enterCritical() {
-  while (lock_.test_and_set(std::memory_order_acquire)) {
+  while (lock_.test_and_set(std::memory_order_acquire) && !ExitGuard::is_exited()) {
     // spin
   }
 }
@@ -167,6 +174,16 @@ void TsCerr::exitCritical() {
 }
 TsCerr::Lock TsCerr::lock_ = ATOMIC_FLAG_INIT;
 
+void TsLog::enter_critical() {
+  while (lock_.test_and_set(std::memory_order_acquire) && !ExitGuard::is_exited()) {
+    // spin
+  }
+}
+
+void TsLog::exit_critical() {
+  lock_.clear(std::memory_order_release);
+}
+
 class DefaultLog : public LogInterface {
  public:
   void append(CSlice slice, int log_level) override {
@@ -304,4 +321,6 @@ ScopedDisableLog::~ScopedDisableLog() {
   }
 }
 
+static ExitGuard exit_guard;
+
 }  // namespace td
diff --git a/tdutils/td/utils/logging.h b/tdutils/td/utils/logging.h
index 1202f0083..00c62169b 100644
--- a/tdutils/td/utils/logging.h
+++ b/tdutils/td/utils/logging.h
@@ -321,14 +321,8 @@ class TsLog : public LogInterface {
  private:
   LogInterface *log_ = nullptr;
   std::atomic_flag lock_ = ATOMIC_FLAG_INIT;
-  void enter_critical() {
-    while (lock_.test_and_set(std::memory_order_acquire)) {
-      // spin
-    }
-  }
-  void exit_critical() {
-    lock_.clear(std::memory_order_release);
-  }
+  void enter_critical();
+  void exit_critical();
 };
 
 }  // namespace td
diff --git a/tdutils/td/utils/port/FileFd.cpp b/tdutils/td/utils/port/FileFd.cpp
index 1a6965eca..634dacb64 100644
--- a/tdutils/td/utils/port/FileFd.cpp
+++ b/tdutils/td/utils/port/FileFd.cpp
@@ -12,6 +12,7 @@
 #endif
 
 #include "td/utils/common.h"
+#include "td/utils/ExitGuard.h"
 #include "td/utils/logging.h"
 #include "td/utils/misc.h"
 #include "td/utils/port/detail/PollableFd.h"
@@ -356,6 +357,7 @@ Result<size_t> FileFd::pread(MutableSlice slice, int64 offset) const {
 
 static std::mutex in_process_lock_mutex;
 static std::unordered_set<string> locked_files;
+static ExitGuard exit_guard;
 
 static Status create_local_lock(const string &path, int32 &max_tries) {
   while (true) {
@@ -469,12 +471,13 @@ Status FileFd::lock(const LockFlags flags, const string &path, int32 max_tries)
 }
 
 void FileFd::remove_local_lock(const string &path) {
-  if (!path.empty()) {
-    VLOG(fd) << "Unlock file \"" << path << '"';
-    std::unique_lock<std::mutex> lock(in_process_lock_mutex);
-    auto erased_count = locked_files.erase(path);
-    CHECK(erased_count > 0);
+  if (path.empty() || ExitGuard::is_exited()) {
+    return;
   }
+  VLOG(fd) << "Unlock file \"" << path << '"';
+  std::unique_lock<std::mutex> lock(in_process_lock_mutex);
+  auto erased_count = locked_files.erase(path);
+  CHECK(erased_count > 0 || ExitGuard::is_exited());
 }
 
 void FileFd::close() {
diff --git a/tdutils/test/bitmask.cpp b/tdutils/test/bitmask.cpp
index b3fa109c7..3729a2a46 100644
--- a/tdutils/test/bitmask.cpp
+++ b/tdutils/test/bitmask.cpp
@@ -4,11 +4,17 @@
 // 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/tests.h"
+#include "td/utils/common.h"
 #include "td/utils/misc.h"
+#include "td/utils/Slice.h"
+#include "td/utils/Status.h"
+#include "td/utils/tests.h"
 #include "td/utils/utf8.h"
 
+#include <algorithm>
+
 namespace td {
+
 class RangeSet {
   template <class T>
   static auto find(T &ranges, int64 begin) {
@@ -28,17 +34,14 @@ class RangeSet {
     int64 end;
   };
 
-  static constexpr int64 BitSize = 1024;
-  static constexpr int64 MaxPartSize = 16 * 1024 * 1024;
-
-  RangeSet() = default;
+  static constexpr int64 BIT_SIZE = 1024;
 
   static RangeSet create_one_range(int64 end, int64 begin = 0) {
     RangeSet res;
     res.ranges_.push_back({begin, end});
     return res;
   }
-  static td::Result<RangeSet> decode(CSlice data) {
+  static Result<RangeSet> decode(CSlice data) {
     if (!check_utf8(data)) {
       return Status::Error("Invalid encoding");
     }
@@ -50,7 +53,7 @@ class RangeSet {
       begin = next_utf8_unsafe(begin, &size, "RangeSet");
 
       if (!is_empty && size != 0) {
-        res.ranges_.push_back({curr * BitSize, (curr + size) * BitSize});
+        res.ranges_.push_back({curr * BIT_SIZE, (curr + size) * BIT_SIZE});
       }
       curr += size;
       is_empty = !is_empty;
@@ -58,12 +61,12 @@ class RangeSet {
     return res;
   }
 
-  std::string encode(int64 prefix_size = -1) const {
-    std::vector<uint32> sizes;
+  string encode(int64 prefix_size = -1) const {
+    vector<uint32> sizes;
     uint32 all_end = 0;
 
     if (prefix_size != -1) {
-      prefix_size = (prefix_size + BitSize - 1) / BitSize * BitSize;
+      prefix_size = (prefix_size + BIT_SIZE - 1) / BIT_SIZE * BIT_SIZE;
     }
     for (auto it : ranges_) {
       if (prefix_size != -1 && it.begin >= prefix_size) {
@@ -73,10 +76,10 @@ class RangeSet {
         it.end = prefix_size;
       }
 
-      CHECK(it.begin % BitSize == 0);
-      CHECK(it.end % BitSize == 0);
-      uint32 begin = narrow_cast<uint32>(it.begin / BitSize);
-      uint32 end = narrow_cast<uint32>(it.end / BitSize);
+      CHECK(it.begin % BIT_SIZE == 0);
+      CHECK(it.end % BIT_SIZE == 0);
+      uint32 begin = narrow_cast<uint32>(it.begin / BIT_SIZE);
+      uint32 end = narrow_cast<uint32>(it.end / BIT_SIZE);
       if (sizes.empty()) {
         if (begin != 0) {
           sizes.push_back(0);
@@ -89,7 +92,7 @@ class RangeSet {
       all_end = end;
     }
 
-    std::string res;
+    string res;
     for (auto c : sizes) {
       append_utf8_character(res, c);
     }
@@ -149,8 +152,8 @@ class RangeSet {
   }
 
   void set(int64 begin, int64 end) {
-    CHECK(begin % BitSize == 0);
-    CHECK(end % BitSize == 0);
+    CHECK(begin % BIT_SIZE == 0);
+    CHECK(end % BIT_SIZE == 0);
     // 1. skip all with r.end < begin
     auto it_begin = find(begin);
 
@@ -162,16 +165,16 @@ class RangeSet {
     if (it_begin == it_end) {
       ranges_.insert(it_begin, Range{begin, end});
     } else {
-      begin = std::min(begin, it_begin->begin);
+      begin = td::min(begin, it_begin->begin);
       --it_end;
-      end = std::max(end, it_end->end);
+      end = td::max(end, it_end->end);
       *it_end = Range{begin, end};
       ranges_.erase(it_begin, it_end);
     }
   }
 
-  std::vector<int32> as_vector(int32 part_size) const {
-    std::vector<int32> res;
+  vector<int32> as_vector(int32 part_size) const {
+    vector<int32> res;
     for (auto it : ranges_) {
       auto begin = narrow_cast<int32>((it.begin + part_size - 1) / part_size);
       auto end = narrow_cast<int32>(it.end / part_size);
@@ -183,13 +186,12 @@ class RangeSet {
   }
 
  private:
-  std::vector<Range> ranges_;
+  vector<Range> ranges_;
 };
 
 TEST(Bitmask, simple) {
   auto validate_encoding = [](auto &rs) {
     auto str = rs.encode();
-    LOG(ERROR) << str.size();
     RangeSet rs2 = RangeSet::decode(str).move_as_ok();
     auto str2 = rs2.encode();
     rs = std::move(rs2);
@@ -238,9 +240,10 @@ TEST(Bitmask, simple) {
     ASSERT_EQ(8, get(3));
 
     ASSERT_EQ(10, rs.get_ready_prefix_size(S * 3, S * 3 + 10));
-    ASSERT_TRUE(!rs.is_ready(S*11, S *12));
+    ASSERT_TRUE(!rs.is_ready(S * 11, S * 12));
     ASSERT_EQ(3, rs.get_ready_parts(2, S * 2));
-    ASSERT_EQ(std::vector<int32>({2, 3, 4, 7}), rs.as_vector(S * 2) );
+    ASSERT_EQ(vector<int32>({2, 3, 4, 7}), rs.as_vector(S * 2));
   }
 }
+
 }  // namespace td
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index dce6e85f6..6fab03211 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -26,13 +26,13 @@ set(TESTS_MAIN
   main.cpp
 )
 
-add_library(all_tests STATIC ${TD_TEST_SOURCE})
-target_include_directories(all_tests PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>)
-target_link_libraries(all_tests PRIVATE tdcore tdclient)
+#add_library(all_tests STATIC ${TD_TEST_SOURCE})
+#target_include_directories(all_tests PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>)
+#target_link_libraries(all_tests PRIVATE tdcore tdclient)
 
 if (NOT CMAKE_CROSSCOMPILING OR EMSCRIPTEN)
   #Tests
-  add_executable(test-tdutils ${TESTS_MAIN} ${TDUTILS_TEST_SOURCE})
+  add_executable(test-tdutils EXCLUDE_FROM_ALL ${TESTS_MAIN} ${TDUTILS_TEST_SOURCE})
   add_executable(run_all_tests ${TESTS_MAIN} ${TD_TEST_SOURCE})
   if (CLANG AND NOT CYGWIN AND NOT EMSCRIPTEN AND NOT (CMAKE_HOST_SYSTEM_NAME MATCHES "OpenBSD"))
     target_compile_options(test-tdutils PUBLIC -fsanitize=undefined -fno-sanitize=vptr)