diff --git a/src/dialogs.cc b/src/dialogs.cc
index 9eb7ba4..be57184 100644
--- a/src/dialogs.cc
+++ b/src/dialogs.cc
@@ -23,7 +23,7 @@ Dialog::Message::Message(const std::string &text) : Gtk::Window(Gtk::WindowType:
   show_now();
 
   while(Gtk::Main::events_pending())
-    Gtk::Main::iteration(false);
+    Gtk::Main::iteration();
 }
 
 bool Dialog::Message::on_delete_event(GdkEventAny *event) {
diff --git a/src/juci.cc b/src/juci.cc
index 15f9ba7..4b50c38 100644
--- a/src/juci.cc
+++ b/src/juci.cc
@@ -105,7 +105,7 @@ void Application::on_activate() {
   }
 
   while(Gtk::Main::events_pending())
-    Gtk::Main::iteration(false);
+    Gtk::Main::iteration();
   for(auto view : Notebook::get().get_views())
     view->scroll_to(view->get_buffer()->get_insert(), 0.0, 1.0, 0.5);
 }
diff --git a/src/notebook.cc b/src/notebook.cc
index c9eb343..b23c3c2 100644
--- a/src/notebook.cc
+++ b/src/notebook.cc
@@ -168,7 +168,7 @@ void Notebook::open(const boost::filesystem::path &file_path_, size_t notebook_i
     if(!show_tooltips)
       view->hide_tooltips();
     while(Gtk::Main::events_pending())
-      Gtk::Main::iteration(false);
+      Gtk::Main::iteration();
     if(get_current_view() == view) {
       if(center)
         view->scroll_to(view->get_buffer()->get_insert(), 0.0, 1.0, 0.5);
diff --git a/src/selection_dialog.cc b/src/selection_dialog.cc
index a94cd06..5ef5709 100644
--- a/src/selection_dialog.cc
+++ b/src/selection_dialog.cc
@@ -166,7 +166,7 @@ void SelectionDialogBase::show() {
     }
     else if(list_view_text.get_model()->children().begin() != list_view_text.get_selection()->get_selected()) {
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       if(is_visible())
         list_view_text.scroll_to_row(list_view_text.get_model()->get_path(list_view_text.get_selection()->get_selected()), 0.5);
     }
diff --git a/src/source_clang.cc b/src/source_clang.cc
index 87ee1fc..6202c37 100644
--- a/src/source_clang.cc
+++ b/src/source_clang.cc
@@ -1793,7 +1793,7 @@ void Source::ClangViewRefactor::wait_parsing() {
   if(message) {
     for(;;) {
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       bool all_parsed = true;
       for(auto &clang_view : clang_views) {
         if(!clang_view->parsed) {
@@ -1927,7 +1927,7 @@ void Source::ClangView::async_delete() {
   }
 
   auto before_parse_time = std::time(nullptr);
-  delete_thread = std::thread([this, before_parse_time, project_paths_in_use = std::move(project_paths_in_use)] {
+  delete_thread = std::thread([this, before_parse_time, project_paths_in_use = std::move(project_paths_in_use), buffer_modified = get_buffer()->get_modified()] {
     while(!parsed)
       std::this_thread::sleep_for(std::chrono::milliseconds(10));
 
@@ -1935,7 +1935,7 @@ void Source::ClangView::async_delete() {
     parse_state = ParseState::STOP;
     dispatcher.disconnect();
 
-    if(get_buffer()->get_modified()) {
+    if(buffer_modified) {
       std::ifstream stream(file_path.string(), std::ios::binary);
       if(stream) {
         std::string buffer;
@@ -1953,6 +1953,8 @@ void Source::ClangView::async_delete() {
       auto build = Project::Build::create(file_path);
       Usages::Clang::cache(build->project_path, build->get_default_path(), file_path, before_parse_time, project_paths_in_use, clang_tu.get(), clang_tokens.get());
     }
+    else
+      Usages::Clang::cancel_cache_in_progress();
 
     if(full_reparse_thread.joinable())
       full_reparse_thread.join();
diff --git a/src/usages_clang.cc b/src/usages_clang.cc
index 592d096..6cd86a0 100644
--- a/src/usages_clang.cc
+++ b/src/usages_clang.cc
@@ -165,7 +165,7 @@ std::vector<Usages::Clang::Usages> Usages::Clang::get_usages(const boost::filesy
     message = std::make_unique<Dialog::Message>(message_string);
     while(cache_in_progress_count != 0) {
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
     }
   }
 
@@ -359,8 +359,14 @@ void Usages::Clang::erase_all_caches_for_project(const boost::filesystem::path &
   if(project_path.empty())
     return;
 
-  if(cache_in_progress_count != 0)
-    std::this_thread::sleep_for(std::chrono::milliseconds(10));
+  if(cache_in_progress_count != 0) {
+    Dialog::Message message("Please wait while clearing project parse cache");
+    while(cache_in_progress_count != 0) {
+      while(Gtk::Main::events_pending())
+        Gtk::Main::iteration();
+    }
+    message.hide();
+  }
 
   LockGuard lock(caches_mutex);
   boost::system::error_code ec;
@@ -384,6 +390,10 @@ void Usages::Clang::cache_in_progress() {
   ++cache_in_progress_count;
 }
 
+void Usages::Clang::cancel_cache_in_progress() {
+  --cache_in_progress_count;
+}
+
 void Usages::Clang::add_usages(const boost::filesystem::path &project_path, const boost::filesystem::path &build_path, const boost::filesystem::path &path_,
                                std::vector<Usages> &usages, PathSet &visited, const std::string &spelling, clangmm::Cursor cursor,
                                clangmm::TranslationUnit *translation_unit, bool store_in_cache) {
diff --git a/src/usages_clang.h b/src/usages_clang.h
index 7fe60db..0ecd960 100644
--- a/src/usages_clang.h
+++ b/src/usages_clang.h
@@ -117,6 +117,7 @@ namespace Usages {
     static void erase_cache(const boost::filesystem::path &path);
     static void erase_all_caches_for_project(const boost::filesystem::path &project_path, const boost::filesystem::path &build_path);
     static void cache_in_progress();
+    static void cancel_cache_in_progress();
 
   private:
     static void add_usages(const boost::filesystem::path &project_path, const boost::filesystem::path &build_path, const boost::filesystem::path &path_,
diff --git a/src/window.cc b/src/window.cc
index a0b92f3..3bb0d07 100644
--- a/src/window.cc
+++ b/src/window.cc
@@ -105,13 +105,19 @@ Window::Window() {
     return false;
   });
 
-  signal_hide().connect([] {
-    while(!Source::View::non_deleted_views.empty()) {
-      while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+  signal_delete_event().connect([](GdkEventAny *) {
+    if(!Source::View::non_deleted_views.empty()) {
+      Dialog::Message message("Please wait while completing background processes");
+      while(!Source::View::non_deleted_views.empty()) {
+        while(Gtk::Main::events_pending())
+          Gtk::Main::iteration();
+      }
+      message.hide();
     }
     // TODO 2022 (after Debian Stretch LTS has ended, see issue #354): remove:
     Project::current = nullptr;
+
+    return false;
   });
 
   Gtk::Settings::get_default()->connect_property_changed("gtk-theme-name", [] {
diff --git a/tests/source_clang_test.cc b/tests/source_clang_test.cc
index 6fbaf38..170c4fd 100644
--- a/tests/source_clang_test.cc
+++ b/tests/source_clang_test.cc
@@ -16,7 +16,7 @@ std::string main_error = R"(int main() {
 
 void flush_events() {
   while(Gtk::Main::events_pending())
-    Gtk::Main::iteration(false);
+    Gtk::Main::iteration();
 }
 
 int main() {
diff --git a/tests/source_key_test.cc b/tests/source_key_test.cc
index a56bf4b..e0e339e 100644
--- a/tests/source_key_test.cc
+++ b/tests/source_key_test.cc
@@ -27,7 +27,7 @@ int main() {
     {
       buffer->set_text("  ''\n");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       auto iter = buffer->get_iter_at_line(0);
       iter.forward_chars(3);
       assert(view.is_spellcheck_iter(iter));
@@ -36,7 +36,7 @@ int main() {
     {
       buffer->set_text("  \"\"\n");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       auto iter = buffer->get_iter_at_line(0);
       iter.forward_chars(3);
       assert(view.is_spellcheck_iter(iter));
@@ -45,7 +45,7 @@ int main() {
     {
       buffer->set_text("  'test\n");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       auto iter = buffer->get_iter_at_line(0);
       iter.forward_to_line_end();
       assert(view.is_spellcheck_iter(iter));
@@ -54,7 +54,7 @@ int main() {
     {
       buffer->set_text("  \"test'\n");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       auto iter = buffer->get_iter_at_line(0);
       iter.forward_to_line_end();
       iter.backward_char();
@@ -67,7 +67,7 @@ int main() {
     {
       buffer->set_text("  'test'\n");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       auto iter = buffer->get_iter_at_line(0);
       iter.forward_chars(2);
       assert(!view.is_spellcheck_iter(iter));
@@ -85,7 +85,7 @@ int main() {
     {
       buffer->set_text("  \"test\"\n");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       auto iter = buffer->get_iter_at_line(0);
       iter.forward_chars(2);
       assert(!view.is_spellcheck_iter(iter));
@@ -103,7 +103,7 @@ int main() {
     {
       buffer->set_text("  '\\''\n");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       auto iter = buffer->get_iter_at_line(0);
       iter.forward_chars(2);
       assert(!view.is_spellcheck_iter(iter));
@@ -124,7 +124,7 @@ int main() {
     {
       buffer->set_text("  /**/\n");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       auto iter = buffer->get_iter_at_line(0);
       iter.forward_chars(2);
       assert(!view.is_spellcheck_iter(iter));
@@ -145,7 +145,7 @@ int main() {
     {
       buffer->set_text("  //t\n");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       auto iter = buffer->get_iter_at_line(0);
       iter.forward_chars(2);
       assert(!view.is_spellcheck_iter(iter));
@@ -474,7 +474,7 @@ int main() {
     {
       buffer->set_text("  int main() {//comment");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "  int main() {//comment\n"
                                      "    \n"
@@ -511,7 +511,7 @@ int main() {
       iter.backward_chars(4);
       buffer->place_cursor(iter);
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "  int main() {//comment\n"
                                      "    \n"
@@ -578,7 +578,7 @@ int main() {
       iter.backward_chars(1);
       buffer->place_cursor(iter);
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "  int main()\n"
                                      "  {/*comment*/\n"
@@ -598,7 +598,7 @@ int main() {
     {
       buffer->set_text("  else // comment");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "  else // comment\n"
                                      "    ");
@@ -614,7 +614,7 @@ int main() {
     {
       buffer->set_text("  else;//comment");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "  else;//comment\n"
                                      "  ");
@@ -630,7 +630,7 @@ int main() {
     {
       buffer->set_text("  else {}//comment");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "  else {}//comment\n"
                                      "  ");
@@ -654,7 +654,7 @@ int main() {
     {
       buffer->set_text("  } else if(true)//comment");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "  } else if(true)//comment\n"
                                      "    ");
@@ -673,7 +673,7 @@ int main() {
       buffer->set_text("  } else if(true)//comment\n"
                        "    ;//comment");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "  } else if(true)//comment\n"
                                      "    ;//comment\n"
@@ -694,7 +694,7 @@ int main() {
       buffer->set_text("  if(true) { /*comment*/\n"
                        "    ;");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "  if(true) { /*comment*/\n"
                                      "    ;\n"
@@ -745,7 +745,7 @@ int main() {
       buffer->set_text("  if(true && // comment\n"
                        "     false) { // comment");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "  if(true && // comment\n"
                                      "     false) { // comment\n"
@@ -771,7 +771,7 @@ int main() {
                        "     false)//comment\n"
                        "    ;//comment");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "  if(true &&\n"
                                      "     false)//comment\n"
@@ -828,7 +828,7 @@ int main() {
       buffer->set_text("  int a = 2 + // test\n"
                        "    2;");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "  int a = 2 + // test\n"
                                      "    2;\n"
@@ -1085,7 +1085,7 @@ int main() {
     {
       buffer->set_text("  auto func=[] {//comment");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "  auto func=[] {//comment\n"
                                      "    \n"
@@ -1193,7 +1193,7 @@ int main() {
       buffer->set_text("  class Class : BaseClass {\n"
                        "    public://comment");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "  class Class : BaseClass {\n"
                                      "  public://comment\n"
@@ -1285,7 +1285,7 @@ int main() {
     {
       buffer->set_text("  /*");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "  /*\n"
                                      "   * ");
@@ -1295,7 +1295,7 @@ int main() {
       buffer->set_text("  /*\n"
                        "   */");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "  /*\n"
                                      "   */\n"
@@ -1305,7 +1305,7 @@ int main() {
     {
       buffer->set_text("   //comment");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "   //comment\n"
                                      "   ");
@@ -1315,7 +1315,7 @@ int main() {
       buffer->set_text("   //comment\n"
                        "   //comment");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "   //comment\n"
                                      "   //comment\n"
@@ -1326,7 +1326,7 @@ int main() {
       buffer->set_text("#test\n"
                        "  test();");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       auto iter = buffer->get_iter_at_line(0);
       iter.forward_to_line_end();
       buffer->place_cursor(iter);
@@ -1342,7 +1342,7 @@ int main() {
       buffer->set_text("  #test\n"
                        "    test();");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       auto iter = buffer->get_iter_at_line(0);
       iter.forward_to_line_end();
       buffer->place_cursor(iter);
@@ -1361,7 +1361,7 @@ int main() {
       iter.backward_char();
       buffer->place_cursor(iter);
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "if('a'=='a'\n"
                                      "   )");
@@ -1392,7 +1392,7 @@ int main() {
       buffer->set_text("  else if(true)//comment\n"
                        "    ");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "  else if(true)//comment\n"
                                      "  {");
@@ -1516,7 +1516,7 @@ int main() {
     {
       buffer->set_text("  {} //}");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       auto iter = buffer->begin();
       iter.forward_chars(3);
       buffer->place_cursor(iter);
@@ -1624,7 +1624,7 @@ int main() {
       buffer->set_text("  else if(true)//comment\n"
                        "    ");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "  else if(true)//comment\n"
                                      "  {}");
@@ -1704,7 +1704,7 @@ int main() {
       buffer->set_text("  if(true)  // test\n"
                        "  ;");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       auto iter = buffer->get_iter_at_line(0);
       iter.forward_chars(11);
       buffer->place_cursor(iter);
@@ -1719,7 +1719,7 @@ int main() {
       buffer->set_text("  if(true)  // test\n"
                        "    ;");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       auto iter = buffer->get_iter_at_line(0);
       iter.forward_chars(11);
       buffer->place_cursor(iter);
@@ -1847,7 +1847,7 @@ int main() {
       buffer->set_text("  int main() {//comment\n"
                        "    ");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "  int main() {//comment\n"
                                      "  }");
@@ -2076,7 +2076,7 @@ int main() {
                        "\n"
                        "    test");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       auto iter = buffer->get_iter_at_line(2);
       buffer->place_cursor(iter);
       view.on_key_press_event(&event);
@@ -2110,7 +2110,7 @@ int main() {
                        "\n"
                        "    test");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       auto iter = buffer->get_iter_at_line(2);
       buffer->place_cursor(iter);
       view.on_key_press_event(&event);
@@ -2489,7 +2489,7 @@ int main() {
       buffer->set_text("\n"
                        "    * [test](https://test.org)\n");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       auto iter = buffer->get_iter_at_line(1);
       iter.forward_to_line_end();
       buffer->place_cursor(iter);
@@ -2505,7 +2505,7 @@ int main() {
       buffer->set_text("\n"
                        "    * [test](https://test.org)");
       while(Gtk::Main::events_pending())
-        Gtk::Main::iteration(false);
+        Gtk::Main::iteration();
       view.on_key_press_event(&event);
       g_assert(buffer->get_text() == "\n"
                                      "    * [test](https://test.org)\n"
diff --git a/tests/usages_clang_test.cc b/tests/usages_clang_test.cc
index d7f2301..61c7076 100644
--- a/tests/usages_clang_test.cc
+++ b/tests/usages_clang_test.cc
@@ -5,10 +5,17 @@
 #include "usages_clang.h"
 #include <cassert>
 #include <fstream>
+#include <gtksourceviewmm.h>
 
-#include <iostream>
+//Requires display server to work
+//However, it is possible to use the Broadway backend if the test is run in a pure terminal environment:
+//broadwayd&
+//make test
 
 int main() {
+  auto app = Gtk::Application::create();
+  Gsv::init();
+
   auto tests_path = boost::filesystem::canonical(JUCI_TESTS_PATH);
   auto project_path = boost::filesystem::canonical(tests_path / "usages_clang_test_files");
   auto build_path = project_path / "build";
@@ -148,6 +155,7 @@ int main() {
     }
 
     Usages::Clang::erase_unused_caches({project_path});
+    Usages::Clang::cache_in_progress();
     Usages::Clang::cache(project_path, build_path, path, time(nullptr), {project_path}, &translation_unit, tokens.get());
     assert(Usages::Clang::caches.size() == 3);
     assert(Usages::Clang::caches.find(project_path / "main.cpp") != Usages::Clang::caches.end());
@@ -155,6 +163,7 @@ int main() {
     assert(Usages::Clang::caches.find(project_path / "test2.hpp") != Usages::Clang::caches.end());
 
     Usages::Clang::erase_unused_caches({});
+    Usages::Clang::cache_in_progress();
     Usages::Clang::cache(project_path, build_path, path, time(nullptr), {}, &translation_unit, tokens.get());
     assert(Usages::Clang::caches.size() == 0);