Merge PR #3246 'Run builtin TUI in a another thread'

15 files changed, 975 insertions, 312 deletions

diff --git a/src/nvim/CMakeLists.txt b/src/nvim/CMakeLists.txt
index 5e547ed290..ba08ed1c82 100644
--- a/src/nvim/CMakeLists.txt
+++ b/src/nvim/CMakeLists.txt
@@ -2,12 +2,15 @@ include(CheckLibraryExists)
 
 option(USE_GCOV "Enable gcov support" OFF)
 
+if(NOT CLANG_TSAN)
+# GCOV and TSAN results in false data race reports
 if(USE_GCOV)
   message(STATUS "Enabling gcov support")
   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} --coverage")
   set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} --coverage")
   set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} --coverage")
 endif()
+endif()
 
 set(GENERATED_DIR ${PROJECT_BINARY_DIR}/src/nvim/auto)
 set(DISPATCH_GENERATOR ${PROJECT_SOURCE_DIR}/scripts/msgpack-gen.lua)
diff --git a/src/nvim/event/defs.h b/src/nvim/event/defs.h
index 5126d52241..b802866a3d 100644
--- a/src/nvim/event/defs.h
+++ b/src/nvim/event/defs.h
@@ -4,7 +4,7 @@
 #include <assert.h>
 #include <stdarg.h>
 
-#define EVENT_HANDLER_MAX_ARGC 4
+#define EVENT_HANDLER_MAX_ARGC 6
 
 typedef void (*argv_callback)(void **argv);
 typedef struct message {
@@ -12,6 +12,7 @@ typedef struct message {
   argv_callback handler;
   void *argv[EVENT_HANDLER_MAX_ARGC];
 } Event;
+typedef void(*event_scheduler)(Event event, void *data);
 
 #define VA_EVENT_INIT(event, p, h, a)                   \
   do {                                                  \
diff --git a/src/nvim/event/loop.c b/src/nvim/event/loop.c
index 3d3288f858..088e059d19 100644
--- a/src/nvim/event/loop.c
+++ b/src/nvim/event/loop.c
@@ -10,20 +10,19 @@
 # include "event/loop.c.generated.h"
 #endif
 
-typedef struct idle_event {
-  uv_idle_t idle;
-  Event event;
-} IdleEvent;
-
 
 void loop_init(Loop *loop, void *data)
 {
   uv_loop_init(&loop->uv);
+  loop->recursive = 0;
   loop->uv.data = loop;
   loop->children = kl_init(WatcherPtr);
   loop->children_stop_requests = 0;
   loop->events = queue_new_parent(loop_on_put, loop);
   loop->fast_events = queue_new_child(loop->events);
+  loop->thread_events = queue_new_parent(NULL, NULL);
+  uv_mutex_init(&loop->mutex);
+  uv_async_init(&loop->uv, &loop->async, async_cb);
   uv_signal_init(&loop->uv, &loop->children_watcher);
   uv_timer_init(&loop->uv, &loop->children_kill_timer);
   uv_timer_init(&loop->uv, &loop->poll_timer);
@@ -31,9 +30,7 @@ void loop_init(Loop *loop, void *data)
 
 void loop_poll_events(Loop *loop, int ms)
 {
-  static int recursive = 0;
-
-  if (recursive++) {
+  if (loop->recursive++) {
     abort();  // Should not re-enter uv_run
   }
 
@@ -55,10 +52,19 @@ void loop_poll_events(Loop *loop, int ms)
     uv_timer_stop(&loop->poll_timer);
   }
 
-  recursive--;  // Can re-enter uv_run now
+  loop->recursive--;  // Can re-enter uv_run now
   queue_process_events(loop->fast_events);
 }
 
+// Schedule an event from another thread
+void loop_schedule(Loop *loop, Event event)
+{
+  uv_mutex_lock(&loop->mutex);
+  queue_put_event(loop->thread_events, event);
+  uv_async_send(&loop->async);
+  uv_mutex_unlock(&loop->mutex);
+}
+
 void loop_on_put(Queue *queue, void *data)
 {
   Loop *loop = data;
@@ -72,14 +78,32 @@ void loop_on_put(Queue *queue, void *data)
 
 void loop_close(Loop *loop)
 {
+  uv_mutex_destroy(&loop->mutex);
   uv_close((uv_handle_t *)&loop->children_watcher, NULL);
   uv_close((uv_handle_t *)&loop->children_kill_timer, NULL);
   uv_close((uv_handle_t *)&loop->poll_timer, NULL);
+  uv_close((uv_handle_t *)&loop->async, NULL);
   do {
     uv_run(&loop->uv, UV_RUN_DEFAULT);
   } while (uv_loop_close(&loop->uv));
+  queue_free(loop->events);
+  queue_free(loop->fast_events);
+  queue_free(loop->thread_events);
+  kl_destroy(WatcherPtr, loop->children);
+}
+
+static void async_cb(uv_async_t *handle)
+{
+  Loop *l = handle->loop->data;
+  uv_mutex_lock(&l->mutex);
+  while (!queue_empty(l->thread_events)) {
+    Event ev = queue_get(l->thread_events);
+    queue_put_event(l->fast_events, ev);
+  }
+  uv_mutex_unlock(&l->mutex);
 }
 
 static void timer_cb(uv_timer_t *handle)
 {
 }
+
diff --git a/src/nvim/event/loop.h b/src/nvim/event/loop.h
index 9212a45aa4..0c1fcb5ed9 100644
--- a/src/nvim/event/loop.h
+++ b/src/nvim/event/loop.h
@@ -16,11 +16,14 @@ KLIST_INIT(WatcherPtr, WatcherPtr, _noop)
 
 typedef struct loop {
   uv_loop_t uv;
-  Queue *events, *fast_events;
+  Queue *events, *fast_events, *thread_events;
   klist_t(WatcherPtr) *children;
   uv_signal_t children_watcher;
   uv_timer_t children_kill_timer, poll_timer;
   size_t children_stop_requests;
+  uv_async_t async;
+  uv_mutex_t mutex;
+  int recursive;
 } Loop;
 
 #define CREATE_EVENT(queue, handler, argc, ...)                  \
diff --git a/src/nvim/event/queue.c b/src/nvim/event/queue.c
index 19eca14144..c5ef22d426 100644
--- a/src/nvim/event/queue.c
+++ b/src/nvim/event/queue.c
@@ -105,16 +105,15 @@ static Queue *queue_new(Queue *parent, put_callback put_cb, void *data)
 void queue_free(Queue *queue)
 {
   assert(queue);
-  if (queue->parent) {
-    while (!QUEUE_EMPTY(&queue->headtail)) {
-      QUEUE *q = QUEUE_HEAD(&queue->headtail);
-      QueueItem *item = queue_node_data(q);
-      assert(!item->link);
+  while (!QUEUE_EMPTY(&queue->headtail)) {
+    QUEUE *q = QUEUE_HEAD(&queue->headtail);
+    QueueItem *item = queue_node_data(q);
+    if (queue->parent) {
       QUEUE_REMOVE(&item->data.item.parent->node);
       xfree(item->data.item.parent);
-      QUEUE_REMOVE(q);
-      xfree(item);
     }
+    QUEUE_REMOVE(q);
+    xfree(item);
   }
 
   xfree(queue);
@@ -128,9 +127,8 @@ Event queue_get(Queue *queue)
 void queue_put_event(Queue *queue, Event event)
 {
   assert(queue);
-  assert(queue->parent);  // don't push directly to the parent queue
   queue_push(queue, event);
-  if (queue->parent->put_cb) {
+  if (queue->parent && queue->parent->put_cb) {
     queue->parent->put_cb(queue->parent, queue->parent->data);
   }
 }
@@ -177,11 +175,11 @@ static Event queue_remove(Queue *queue)
     rv = child->data.item.event;
     xfree(child);
   } else {
-    assert(queue->parent);
-    assert(!queue_empty(queue->parent));
-    // remove the corresponding link node in the parent queue
-    QUEUE_REMOVE(&item->data.item.parent->node);
-    xfree(item->data.item.parent);
+    if (queue->parent) {
+      // remove the corresponding link node in the parent queue
+      QUEUE_REMOVE(&item->data.item.parent->node);
+      xfree(item->data.item.parent);
+    }
     rv = item->data.item.event;
   }
 
@@ -195,11 +193,13 @@ static void queue_push(Queue *queue, Event event)
   item->link = false;
   item->data.item.event = event;
   QUEUE_INSERT_TAIL(&queue->headtail, &item->node);
-  // push link node to the parent queue
-  item->data.item.parent = xmalloc(sizeof(QueueItem));
-  item->data.item.parent->link = true;
-  item->data.item.parent->data.queue = queue;
-  QUEUE_INSERT_TAIL(&queue->parent->headtail, &item->data.item.parent->node);
+  if (queue->parent) {
+    // push link node to the parent queue
+    item->data.item.parent = xmalloc(sizeof(QueueItem));
+    item->data.item.parent->link = true;
+    item->data.item.parent->data.queue = queue;
+    QUEUE_INSERT_TAIL(&queue->parent->headtail, &item->data.item.parent->node);
+  }
 }
 
 static QueueItem *queue_node_data(QUEUE *q)
diff --git a/src/nvim/log.c b/src/nvim/log.c
index 3575f49e78..08b6d0483e 100644
--- a/src/nvim/log.c
+++ b/src/nvim/log.c
@@ -16,29 +16,49 @@
 
 #define USR_LOG_FILE "$HOME/.nvimlog"
 
+static uv_mutex_t mutex;
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "log.c.generated.h"
 #endif
 
+void log_init(void)
+{
+  uv_mutex_init(&mutex);
+}
+
+void log_lock(void)
+{
+  uv_mutex_lock(&mutex);
+}
+
+void log_unlock(void)
+{
+  uv_mutex_unlock(&mutex);
+}
+
 bool do_log(int log_level, const char *func_name, int line_num, bool eol,
             const char* fmt, ...) FUNC_ATTR_UNUSED
 {
+  log_lock();
+  bool ret = false;
   FILE *log_file = open_log_file();
 
   if (log_file == NULL) {
-    return false;
+    goto end;
   }
 
   va_list args;
   va_start(args, fmt);
-  bool ret = v_do_log_to_file(log_file, log_level, func_name, line_num, eol,
+  ret = v_do_log_to_file(log_file, log_level, func_name, line_num, eol,
                               fmt, args);
   va_end(args);
 
   if (log_file != stderr && log_file != stdout) {
     fclose(log_file);
   }
+end:
+  log_unlock();
   return ret;
 }
 
diff --git a/src/nvim/main.c b/src/nvim/main.c
index 3e096ee190..dd2b813b1c 100644
--- a/src/nvim/main.c
+++ b/src/nvim/main.c
@@ -177,6 +177,7 @@ void event_teardown(void)
 /// Needed for unit tests. Must be called after `time_init()`.
 void early_init(void)
 {
+  log_init();
   fs_init();
   handle_init();
 
diff --git a/src/nvim/msgpack_rpc/channel.c b/src/nvim/msgpack_rpc/channel.c
index 45e78d6e79..34ff7c6374 100644
--- a/src/nvim/msgpack_rpc/channel.c
+++ b/src/nvim/msgpack_rpc/channel.c
@@ -825,6 +825,7 @@ static void log_server_msg(uint64_t channel_id,
   msgpack_unpack_next(&unpacked, packed->data, packed->size, NULL);
   uint64_t type = unpacked.data.via.array.ptr[0].via.u64;
   DLOGN("[msgpack-rpc] nvim -> client(%" PRIu64 ") ", channel_id);
+  log_lock();
   FILE *f = open_log_file();
   fprintf(f, type ? (type == 1 ? RES : NOT) : REQ);
   log_msg_close(f, unpacked.data);
@@ -836,6 +837,7 @@ static void log_client_msg(uint64_t channel_id,
                            msgpack_object msg)
 {
   DLOGN("[msgpack-rpc] client(%" PRIu64 ") -> nvim ", channel_id);
+  log_lock();
   FILE *f = open_log_file();
   fprintf(f, is_request ? REQ : RES);
   log_msg_close(f, msg);
@@ -847,6 +849,7 @@ static void log_msg_close(FILE *f, msgpack_object msg)
   fputc('\n', f);
   fflush(f);
   fclose(f);
+  log_unlock();
 }
 #endif
 
diff --git a/src/nvim/tui/term_input.inl b/src/nvim/tui/input.c
index c396557160..b680e885df 100644
--- a/src/nvim/tui/term_input.inl
+++ b/src/nvim/tui/input.c
@@ -1,21 +1,86 @@
-#include <termkey.h>
 
+#include "nvim/tui/input.h"
+#include "nvim/vim.h"
+#include "nvim/api/vim.h"
+#include "nvim/api/private/helpers.h"
 #include "nvim/ascii.h"
 #include "nvim/misc2.h"
 #include "nvim/os/os.h"
 #include "nvim/os/input.h"
 #include "nvim/event/rstream.h"
-#include "nvim/event/time.h"
 
 #define PASTETOGGLE_KEY "<f37>"
 
-struct term_input {
-  int in_fd;
-  bool paste_enabled;
-  TermKey *tk;
-  TimeWatcher timer_handle;
-  Stream read_stream;
-};
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "tui/input.c.generated.h"
+#endif
+
+void term_input_init(TermInput *input, Loop *loop)
+{
+  input->loop = loop;
+  input->paste_enabled = false;
+  input->in_fd = 0;
+
+  const char *term = os_getenv("TERM");
+  if (!term) {
+    term = "";  // termkey_new_abstract assumes non-null (#2745)
+  }
+  input->tk = termkey_new_abstract(term, 0);
+  int curflags = termkey_get_canonflags(input->tk);
+  termkey_set_canonflags(input->tk, curflags | TERMKEY_CANON_DELBS);
+  // setup input handle
+  rstream_init_fd(loop, &input->read_stream, input->in_fd, 0xfff, input);
+  // initialize a timer handle for handling ESC with libtermkey
+  time_watcher_init(loop, &input->timer_handle, input);
+  // Set the pastetoggle option to a special key that will be sent when
+  // \e[20{0,1}~/ are received
+  Error err = ERROR_INIT;
+  vim_set_option(cstr_as_string("pastetoggle"),
+      STRING_OBJ(cstr_as_string(PASTETOGGLE_KEY)), &err);
+}
+
+void term_input_destroy(TermInput *input)
+{
+  time_watcher_close(&input->timer_handle, NULL);
+  stream_close(&input->read_stream, NULL);
+  termkey_destroy(input->tk);
+}
+
+void term_input_start(TermInput *input)
+{
+  rstream_start(&input->read_stream, read_cb);
+}
+
+void term_input_stop(TermInput *input)
+{
+  rstream_stop(&input->read_stream);
+  time_watcher_stop(&input->timer_handle);
+}
+
+void term_input_set_encoding(TermInput *input, char* enc)
+{
+  int enc_flag = strcmp(enc, "utf-8") == 0 ? TERMKEY_FLAG_UTF8
+                                           : TERMKEY_FLAG_RAW;
+  termkey_set_flags(input->tk, enc_flag);
+}
+
+static void input_enqueue_event(void **argv)
+{
+  char *buf = argv[0];
+  input_enqueue(cstr_as_string(buf));
+  xfree(buf);
+}
+
+static void input_done_event(void **argv)
+{
+  input_done();
+}
+
+static void enqueue_input(char *buf, size_t size)
+{
+  loop_schedule(&loop, event_create(1, input_enqueue_event, 1,
+        xstrndup(buf, size)));
+}
 
 static void forward_simple_utf8(TermKeyKey *key)
 {
@@ -33,7 +98,7 @@ static void forward_simple_utf8(TermKeyKey *key)
   }
 
   buf[len] = 0;
-  input_enqueue((String){.data = buf, .size = len});
+  enqueue_input(buf, len);
 }
 
 static void forward_modified_utf8(TermKey *tk, TermKeyKey *key)
@@ -48,7 +113,7 @@ static void forward_modified_utf8(TermKey *tk, TermKeyKey *key)
     len = termkey_strfkey(tk, buf, sizeof(buf), key, TERMKEY_FORMAT_VIM);
   }
 
-  input_enqueue((String){.data = buf, .size = len});
+  enqueue_input(buf, len);
 }
 
 static void forward_mouse_event(TermKey *tk, TermKeyKey *key)
@@ -99,7 +164,7 @@ static void forward_mouse_event(TermKey *tk, TermKeyKey *key)
   }
 
   len += (size_t)snprintf(buf + len, sizeof(buf) - len, "><%d,%d>", col, row);
-  input_enqueue((String){.data = buf, .size = len});
+  enqueue_input(buf, len);
 }
 
 static TermKeyResult tk_getkey(TermKey *tk, TermKeyKey *key, bool force)
@@ -175,16 +240,16 @@ static bool handle_bracketed_paste(TermInput *input)
       int state = get_real_state();
       if (state & NORMAL) {
         // Enter insert mode
-        input_enqueue(cstr_as_string("i"));
+        enqueue_input("i", 1);
       } else if (state & VISUAL) {
         // Remove the selected text and enter insert mode
-        input_enqueue(cstr_as_string("c"));
+        enqueue_input("c", 1);
       } else if (!(state & INSERT)) {
         // Don't mess with the paste option
         return true;
       }
     }
-    input_enqueue(cstr_as_string(PASTETOGGLE_KEY));
+    enqueue_input(PASTETOGGLE_KEY, sizeof(PASTETOGGLE_KEY) - 1);
     input->paste_enabled = enable;
     return true;
   }
@@ -227,9 +292,9 @@ static void read_cb(Stream *stream, RBuffer *buf, size_t c, void *data,
       // ls *.md | xargs nvim
       input->in_fd = 2;
       stream_close(&input->read_stream, NULL);
-      queue_put(loop.fast_events, restart_reading, 1, input);
+      queue_put(input->loop->fast_events, restart_reading, 1, input);
     } else {
-      input_done();
+      loop_schedule(&loop, event_create(1, input_done_event, 0));
     }
     return;
   }
@@ -275,51 +340,6 @@ static void read_cb(Stream *stream, RBuffer *buf, size_t c, void *data,
 static void restart_reading(void **argv)
 {
   TermInput *input = argv[0];
-  rstream_init_fd(&loop, &input->read_stream, input->in_fd, 0xfff, input);
+  rstream_init_fd(input->loop, &input->read_stream, input->in_fd, 0xfff, input);
   rstream_start(&input->read_stream, read_cb);
 }
-
-static TermInput *term_input_new(void)
-{
-  TermInput *rv = xmalloc(sizeof(TermInput));
-  rv->paste_enabled = false;
-  rv->in_fd = 0;
-
-  const char *term = os_getenv("TERM");
-  if (!term) {
-    term = "";  // termkey_new_abstract assumes non-null (#2745)
-  }
-  rv->tk = termkey_new_abstract(term, 0);
-  int curflags = termkey_get_canonflags(rv->tk);
-  termkey_set_canonflags(rv->tk, curflags | TERMKEY_CANON_DELBS);
-  // setup input handle
-  rstream_init_fd(&loop, &rv->read_stream, rv->in_fd, 0xfff, rv);
-  rstream_start(&rv->read_stream, read_cb);
-  // initialize a timer handle for handling ESC with libtermkey
-  time_watcher_init(&loop, &rv->timer_handle, rv);
-  // Set the pastetoggle option to a special key that will be sent when
-  // \e[20{0,1}~/ are received
-  Error err = ERROR_INIT;
-  vim_set_option(cstr_as_string("pastetoggle"),
-      STRING_OBJ(cstr_as_string(PASTETOGGLE_KEY)), &err);
-  return rv;
-}
-
-static void term_input_destroy(TermInput *input)
-{
-  time_watcher_stop(&input->timer_handle);
-  time_watcher_close(&input->timer_handle, NULL);
-  rstream_stop(&input->read_stream);
-  stream_close(&input->read_stream, NULL);
-  termkey_destroy(input->tk);
-  // Run once to remove references to input/timer handles
-  loop_poll_events(&loop, 0);
-  xfree(input);
-}
-
-static void term_input_set_encoding(TermInput *input, char* enc)
-{
-  int enc_flag = strcmp(enc, "utf-8") == 0 ? TERMKEY_FLAG_UTF8
-                                           : TERMKEY_FLAG_RAW;
-  termkey_set_flags(input->tk, enc_flag);
-}
diff --git a/src/nvim/tui/input.h b/src/nvim/tui/input.h
new file mode 100644
index 0000000000..033f53b4e2
--- /dev/null
+++ b/src/nvim/tui/input.h
@@ -0,0 +1,23 @@
+#ifndef NVIM_TUI_INPUT_H
+#define NVIM_TUI_INPUT_H
+
+#include <stdbool.h>
+
+#include <termkey.h>
+#include "nvim/event/stream.h"
+#include "nvim/event/time.h"
+
+typedef struct term_input {
+  int in_fd;
+  bool paste_enabled;
+  TermKey *tk;
+  TimeWatcher timer_handle;
+  Loop *loop;
+  Stream read_stream;
+} TermInput;
+
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "tui/input.h.generated.h"
+#endif
+
+#endif  // NVIM_TUI_INPUT_H
diff --git a/src/nvim/tui/tui.c b/src/nvim/tui/tui.c
index acc2ccc682..b2bb80a092 100644
--- a/src/nvim/tui/tui.c
+++ b/src/nvim/tui/tui.c
@@ -17,46 +17,45 @@
 #include "nvim/event/loop.h"
 #include "nvim/event/signal.h"
 #include "nvim/tui/tui.h"
+#include "nvim/tui/input.h"
+#include "nvim/os/input.h"
+#include "nvim/os/os.h"
 #include "nvim/strings.h"
+#include "nvim/ugrid.h"
+#include "nvim/ui_bridge.h"
 
 // Space reserved in the output buffer to restore the cursor to normal when
 // flushing. No existing terminal will require 32 bytes to do that.
 #define CNORM_COMMAND_MAX_SIZE 32
 #define OUTBUF_SIZE 0xffff
 
-typedef struct term_input TermInput;
-
-#include "term_input.inl"
-
 typedef struct {
   int top, bot, left, right;
 } Rect;
 
 typedef struct {
-  char data[7];
-  HlAttrs attrs;
-} Cell;
-
-typedef struct {
+  UIBridgeData *bridge;
+  Loop *loop;
+  bool stop;
   unibi_var_t params[9];
   char buf[OUTBUF_SIZE];
   size_t bufpos, bufsize;
-  TermInput *input;
-  uv_loop_t *write_loop;
+  TermInput input;
+  uv_loop_t write_loop;
   unibi_term *ut;
   uv_tty_t output_handle;
-  SignalWatcher winch_handle;
-  Rect scroll_region;
+  SignalWatcher winch_handle, cont_handle;
+  bool cont_received;
+  // Event scheduled by the ui bridge. Since the main thread suspends until
+  // the event is handled, it is fine to use a single field instead of a queue
+  Event scheduled_event;
+  UGrid grid;
   kvec_t(Rect) invalid_regions;
-  int row, col;
-  int bg, fg;
   int out_fd;
-  int old_height;
   bool can_use_terminal_scroll;
   bool mouse_enabled;
   bool busy;
-  HlAttrs attrs, print_attrs;
-  Cell **screen;
+  HlAttrs print_attrs;
   int showing_mode;
   struct {
     int enable_mouse, disable_mouse;
@@ -72,32 +71,41 @@ static bool volatile got_winch = false;
 # include "tui/tui.c.generated.h"
 #endif
 
-#define EMPTY_ATTRS ((HlAttrs){false, false, false, false, false, -1, -1})
-
-#define FOREACH_CELL(ui, top, bot, left, right, go, code)               \
-  do {                                                                  \
-    TUIData *data = ui->data;                                           \
-    for (int row = top; row <= bot; ++row) {                            \
-      Cell *cells = data->screen[row];                                  \
-      if (go) {                                                         \
-        unibi_goto(ui, row, left);                                      \
-      }                                                                 \
-      for (int col = left; col <= right; ++col) {                       \
-        Cell *cell = cells + col;                                       \
-        (void)(cell);                                                   \
-        code;                                                           \
-      }                                                                 \
-    }                                                                   \
-  } while (0)
-
 
 UI *tui_start(void)
 {
-  TUIData *data = xcalloc(1, sizeof(TUIData));
   UI *ui = xcalloc(1, sizeof(UI));
-  ui->data = data;
-  data->attrs = data->print_attrs = EMPTY_ATTRS;
-  data->fg = data->bg = -1;
+  ui->stop = tui_stop;
+  ui->rgb = os_getenv("NVIM_TUI_ENABLE_TRUE_COLOR") != NULL;
+  ui->resize = tui_resize;
+  ui->clear = tui_clear;
+  ui->eol_clear = tui_eol_clear;
+  ui->cursor_goto = tui_cursor_goto;
+  ui->update_menu = tui_update_menu;
+  ui->busy_start = tui_busy_start;
+  ui->busy_stop = tui_busy_stop;
+  ui->mouse_on = tui_mouse_on;
+  ui->mouse_off = tui_mouse_off;
+  ui->mode_change = tui_mode_change;
+  ui->set_scroll_region = tui_set_scroll_region;
+  ui->scroll = tui_scroll;
+  ui->highlight_set = tui_highlight_set;
+  ui->put = tui_put;
+  ui->bell = tui_bell;
+  ui->visual_bell = tui_visual_bell;
+  ui->update_fg = tui_update_fg;
+  ui->update_bg = tui_update_bg;
+  ui->flush = tui_flush;
+  ui->suspend = tui_suspend;
+  ui->set_title = tui_set_title;
+  ui->set_icon = tui_set_icon;
+  ui->set_encoding = tui_set_encoding;
+  return ui_bridge_attach(ui, tui_main, tui_scheduler);
+}
+
+static void terminfo_start(UI *ui)
+{
+  TUIData *data = ui->data;
   data->can_use_terminal_scroll = true;
   data->bufpos = 0;
   data->bufsize = sizeof(data->buf) - CNORM_COMMAND_MAX_SIZE;
@@ -109,12 +117,8 @@ UI *tui_start(void)
   data->unibi_ext.enter_insert_mode = -1;
   data->unibi_ext.enter_replace_mode = -1;
   data->unibi_ext.exit_insert_mode = -1;
-
   // write output to stderr if stdout is not a tty
   data->out_fd = os_isatty(1) ? 1 : (os_isatty(2) ? 2 : 1);
-  kv_init(data->invalid_regions);
-  // setup term input
-  data->input = term_input_new();
   // setup unibilium
   data->ut = unibi_from_env();
   if (!data->ut) {
@@ -128,62 +132,14 @@ UI *tui_start(void)
   unibi_out(ui, unibi_clear_screen);
   // Enable bracketed paste
   unibi_out(ui, data->unibi_ext.enable_bracketed_paste);
-  // setup output handle in a separate event loop(we wanna do synchronous
-  // write to the tty)
-  data->write_loop = xmalloc(sizeof(uv_loop_t));
-  uv_loop_init(data->write_loop);
-  uv_tty_init(data->write_loop, &data->output_handle, data->out_fd, 0);
+  uv_loop_init(&data->write_loop);
+  uv_tty_init(&data->write_loop, &data->output_handle, data->out_fd, 0);
   uv_tty_set_mode(&data->output_handle, UV_TTY_MODE_RAW);
-
-  // Obtain screen dimensions
-  update_size(ui);
-
-  // listen for SIGWINCH
-  signal_watcher_init(&loop, &data->winch_handle, ui);
-  data->winch_handle.events = queue_new_child(loop.events);
-  signal_watcher_start(&data->winch_handle, sigwinch_cb, SIGWINCH);
-
-  ui->stop = tui_stop;
-  ui->rgb = os_getenv("NVIM_TUI_ENABLE_TRUE_COLOR") != NULL;
-  ui->data = data;
-  ui->resize = tui_resize;
-  ui->clear = tui_clear;
-  ui->eol_clear = tui_eol_clear;
-  ui->cursor_goto = tui_cursor_goto;
-  ui->update_menu = tui_update_menu;
-  ui->busy_start = tui_busy_start;
-  ui->busy_stop = tui_busy_stop;
-  ui->mouse_on = tui_mouse_on;
-  ui->mouse_off = tui_mouse_off;
-  ui->mode_change = tui_mode_change;
-  ui->set_scroll_region = tui_set_scroll_region;
-  ui->scroll = tui_scroll;
-  ui->highlight_set = tui_highlight_set;
-  ui->put = tui_put;
-  ui->bell = tui_bell;
-  ui->visual_bell = tui_visual_bell;
-  ui->update_fg = tui_update_fg;
-  ui->update_bg = tui_update_bg;
-  ui->flush = tui_flush;
-  ui->suspend = tui_suspend;
-  ui->set_title = tui_set_title;
-  ui->set_icon = tui_set_icon;
-  ui->set_encoding = tui_set_encoding;
-  // Attach
-  ui_attach(ui);
-  return ui;
 }
 
-static void tui_stop(UI *ui)
+static void terminfo_stop(UI *ui)
 {
   TUIData *data = ui->data;
-  // Destroy common stuff
-  kv_destroy(data->invalid_regions);
-  signal_watcher_stop(&data->winch_handle);
-  queue_free(data->winch_handle.events);
-  signal_watcher_close(&data->winch_handle, NULL);
-  // Destroy input stuff
-  term_input_destroy(data->input);
   // Destroy output stuff
   tui_mode_change(ui, NORMAL);
   tui_mouse_off(ui);
@@ -196,24 +152,99 @@ static void tui_stop(UI *ui)
   flush_buf(ui);
   uv_tty_reset_mode();
   uv_close((uv_handle_t *)&data->output_handle, NULL);
-  uv_run(data->write_loop, UV_RUN_DEFAULT);
-  if (uv_loop_close(data->write_loop)) {
+  uv_run(&data->write_loop, UV_RUN_DEFAULT);
+  if (uv_loop_close(&data->write_loop)) {
     abort();
   }
-  xfree(data->write_loop);
   unibi_destroy(data->ut);
-  destroy_screen(data);
+}
+
+static void tui_terminal_start(UI *ui)
+{
+  TUIData *data = ui->data;
+  data->print_attrs = EMPTY_ATTRS;
+  ugrid_init(&data->grid);
+  terminfo_start(ui);
+  update_size(ui);
+  signal_watcher_start(&data->winch_handle, sigwinch_cb, SIGWINCH);
+  term_input_start(&data->input);
+}
+
+static void tui_terminal_stop(UI *ui)
+{
+  TUIData *data = ui->data;
+  term_input_stop(&data->input);
+  signal_watcher_stop(&data->winch_handle);
+  terminfo_stop(ui);
+  ugrid_free(&data->grid);
+}
+
+static void tui_stop(UI *ui)
+{
+  tui_terminal_stop(ui);
+  TUIData *data = ui->data;
+  data->stop = true;
+}
+
+// Main function of the TUI thread
+static void tui_main(UIBridgeData *bridge, UI *ui)
+{
+  Loop tui_loop;
+  loop_init(&tui_loop, NULL);
+  TUIData *data = xcalloc(1, sizeof(TUIData));
+  ui->data = data;
+  data->bridge = bridge;
+  data->loop = &tui_loop;
+  kv_init(data->invalid_regions);
+  signal_watcher_init(data->loop, &data->winch_handle, ui);
+  signal_watcher_init(data->loop, &data->cont_handle, data);
+  signal_watcher_start(&data->cont_handle, sigcont_cb, SIGCONT);
+  // initialize input reading structures
+  term_input_init(&data->input, &tui_loop);
+  tui_terminal_start(ui);
+  data->stop = false;
+  // allow the main thread to continue, we are ready to start handling UI
+  // callbacks
+  CONTINUE(bridge);
+
+  while (!data->stop) {
+    loop_poll_events(&tui_loop, -1);
+  }
+
+  term_input_destroy(&data->input);
+  signal_watcher_stop(&data->cont_handle);
+  signal_watcher_close(&data->cont_handle, NULL);
+  signal_watcher_close(&data->winch_handle, NULL);
+  loop_close(&tui_loop);
+  kv_destroy(data->invalid_regions);
   xfree(data);
-  ui_detach(ui);
   xfree(ui);
 }
 
+static void tui_scheduler(Event event, void *d)
+{
+  UI *ui = d;
+  TUIData *data = ui->data;
+  loop_schedule(data->loop, event);
+}
+
+static void refresh_event(void **argv)
+{
+  ui_refresh();
+}
+
+static void sigcont_cb(SignalWatcher *watcher, int signum, void *data)
+{
+  ((TUIData *)data)->cont_received = true;
+}
+
 static void sigwinch_cb(SignalWatcher *watcher, int signum, void *data)
 {
   got_winch = true;
   UI *ui = data;
   update_size(ui);
-  ui_refresh();
+  // run refresh_event in nvim main loop
+  loop_schedule(&loop, event_create(1, refresh_event, 0));
 }
 
 static bool attrs_differ(HlAttrs a1, HlAttrs a2)
@@ -234,9 +265,10 @@ static void update_attrs(UI *ui, HlAttrs attrs)
 
   data->print_attrs = attrs;
   unibi_out(ui, unibi_exit_attribute_mode);
+  UGrid *grid = &data->grid;
 
-  int fg = attrs.foreground != -1 ? attrs.foreground : data->fg;
-  int bg = attrs.background != -1 ? attrs.background : data->bg;
+  int fg = attrs.foreground != -1 ? attrs.foreground : grid->fg;
+  int bg = attrs.background != -1 ? attrs.background : grid->bg;
 
   if (ui->rgb) {
     if (fg != -1) {
@@ -278,25 +310,25 @@ static void update_attrs(UI *ui, HlAttrs attrs)
   }
 }
 
-static void print_cell(UI *ui, Cell *ptr)
+static void print_cell(UI *ui, UCell *ptr)
 {
   update_attrs(ui, ptr->attrs);
   out(ui, ptr->data, strlen(ptr->data));
 }
 
-static void clear_region(UI *ui, int top, int bot, int left, int right,
-    bool refresh)
+static void clear_region(UI *ui, int top, int bot, int left, int right)
 {
   TUIData *data = ui->data;
-  HlAttrs clear_attrs = EMPTY_ATTRS;
-  clear_attrs.foreground = data->fg;
-  clear_attrs.background = data->bg;
-  update_attrs(ui, clear_attrs);
+  UGrid *grid = &data->grid;
 
   bool cleared = false;
-  if (refresh && data->bg == -1 && right == ui->width -1) {
+  if (grid->bg == -1 && right == ui->width -1) {
     // Background is set to the default color and the right edge matches the
     // screen end, try to use terminal codes for clearing the requested area.
+    HlAttrs clear_attrs = EMPTY_ATTRS;
+    clear_attrs.foreground = grid->fg;
+    clear_attrs.background = grid->bg;
+    update_attrs(ui, clear_attrs);
     if (left == 0) {
       if (bot == ui->height - 1) {
         if (top == 0) {
@@ -319,36 +351,26 @@ static void clear_region(UI *ui, int top, int bot, int left, int right,
     }
   }
 
-  bool clear = refresh && !cleared;
-  FOREACH_CELL(ui, t