tui: Refactor for running in another thread

src/nvim/tui/input.c

@@ -15,42 +15,46 @@
 # include "tui/input.c.generated.h"
 #endif
 
-TermInput *term_input_new(void)
+void term_input_init(TermInput *input, Loop *loop)
 {
-  TermInput *rv = xmalloc(sizeof(TermInput));
+  input->loop = loop;
-  rv->paste_enabled = false;
+  input->paste_enabled = false;
-  rv->in_fd = 0;
+  input->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);
+  input->tk = termkey_new_abstract(term, 0);
-  int curflags = termkey_get_canonflags(rv->tk);
+  int curflags = termkey_get_canonflags(input->tk);
-  termkey_set_canonflags(rv->tk, curflags | TERMKEY_CANON_DELBS);
+  termkey_set_canonflags(input->tk, curflags | TERMKEY_CANON_DELBS);
   // setup input handle
-  rstream_init_fd(&loop, &rv->read_stream, rv->in_fd, 0xfff, rv);
+  rstream_init_fd(loop, &input->read_stream, input->in_fd, 0xfff, input);
-  rstream_start(&rv->read_stream, read_cb);
   // initialize a timer handle for handling ESC with libtermkey
-  time_watcher_init(&loop, &rv->timer_handle, rv);
+  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);
-  return rv;
 }
 
 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);
+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)
@@ -60,6 +64,24 @@ void term_input_set_encoding(TermInput *input, char* enc)
   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)
 {
   size_t len = 0;
@@ -76,7 +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)
@@ -91,7 +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)
@@ -142,7 +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)
@@ -218,16 +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;
   }
@@ -270,9 +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;
   }
@@ -318,6 +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);
 }

src/nvim/tui/input.h

@@ -12,6 +12,7 @@ typedef struct term_input {
   bool paste_enabled;
   TermKey *tk;
   TimeWatcher timer_handle;
+  Loop *loop;
   Stream read_stream;
 } TermInput;
 

src/nvim/tui/tui.c

@@ -22,6 +22,7 @@
 #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.
@@ -33,14 +34,21 @@ typedef struct {
 } Rect;
 
 typedef struct {
+  UIBridgeData *bridge;
+  Loop *loop;
+  bool stop;
   unibi_var_t params[9];
   char buf[OUTBUF_SIZE];
   size_t bufpos, bufsize;
-  TermInput *input;
+  TermInput input;
-  uv_loop_t *write_loop;
+  uv_loop_t write_loop;
   unibi_term *ut;
   uv_tty_t output_handle;
-  SignalWatcher winch_handle;
+  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 out_fd;
@@ -66,59 +74,9 @@ static bool volatile got_winch = false;
 
 UI *tui_start(void)
 {
-  TUIData *data = xcalloc(1, sizeof(TUIData));
   UI *ui = xcalloc(1, sizeof(UI));
-  ui->data = data;
-  data->print_attrs = EMPTY_ATTRS;
-  ugrid_init(&data->grid);
-  data->can_use_terminal_scroll = true;
-  data->bufpos = 0;
-  data->bufsize = sizeof(data->buf) - CNORM_COMMAND_MAX_SIZE;
-  data->showing_mode = 0;
-  data->unibi_ext.enable_mouse = -1;
-  data->unibi_ext.disable_mouse = -1;
-  data->unibi_ext.enable_bracketed_paste = -1;
-  data->unibi_ext.disable_bracketed_paste = -1;
-  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) {
-    // For some reason could not read terminfo file, use a dummy entry that
-    // will be populated with common values by fix_terminfo below
-    data->ut = unibi_dummy();
-  }
-  fix_terminfo(data);
-  // Enter alternate screen and clear
-  unibi_out(ui, unibi_enter_ca_mode);
-  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_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;
@@ -142,21 +100,46 @@ UI *tui_start(void)
   ui->set_title = tui_set_title;
   ui->set_icon = tui_set_icon;
   ui->set_encoding = tui_set_encoding;
-  // Attach
+  return ui_bridge_attach(ui, tui_main, tui_scheduler);
-  ui_attach(ui);
-  return ui;
 }
 
-static void tui_stop(UI *ui)
+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;
+  data->showing_mode = 0;
+  data->unibi_ext.enable_mouse = -1;
+  data->unibi_ext.disable_mouse = -1;
+  data->unibi_ext.enable_bracketed_paste = -1;
+  data->unibi_ext.disable_bracketed_paste = -1;
+  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);
+  // setup unibilium
+  data->ut = unibi_from_env();
+  if (!data->ut) {
+    // For some reason could not read terminfo file, use a dummy entry that
+    // will be populated with common values by fix_terminfo below
+    data->ut = unibi_dummy();
+  }
+  fix_terminfo(data);
+  // Enter alternate screen and clear
+  unibi_out(ui, unibi_enter_ca_mode);
+  unibi_out(ui, unibi_clear_screen);
+  // Enable bracketed paste
+  unibi_out(ui, data->unibi_ext.enable_bracketed_paste);
+  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);
+}
+
+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);
@@ -169,24 +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);
+  uv_run(&data->write_loop, UV_RUN_DEFAULT);
-  if (uv_loop_close(data->write_loop)) {
+  if (uv_loop_close(&data->write_loop)) {
     abort();
   }
-  xfree(data->write_loop);
   unibi_destroy(data->ut);
+}
+
+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)
@@ -521,16 +579,34 @@ static void tui_flush(UI *ui)
   flush_buf(ui);
 }
 
-static void tui_suspend(UI *ui)
+static void suspend_event(void **argv)
 {
+  UI *ui = argv[0];
   TUIData *data = ui->data;
   bool enable_mouse = data->mouse_enabled;
-  tui_stop(ui);
+  tui_terminal_stop(ui);
+  data->cont_received = false;
   kill(0, SIGTSTP);
-  ui = tui_start();
+  while (!data->cont_received) {
+    // poll the event loop until SIGCONT is received
+    loop_poll_events(data->loop, -1);
+  }
+  tui_terminal_start(ui);
   if (enable_mouse) {
     tui_mouse_on(ui);
   }
+  // resume the main thread
+  CONTINUE(data->bridge);
+}
+
+static void tui_suspend(UI *ui)
+{
+  TUIData *data = ui->data;
+  // kill(0, SIGTSTP) won't stop the UI thread, so we must poll for SIGCONT
+  // before continuing. This is done in another callback to avoid
+  // loop_poll_events recursion
+  queue_put_event(data->loop->fast_events,
+      event_create(1, suspend_event, 1, ui));
 }
 
 static void tui_set_title(UI *ui, char *title)
@@ -552,7 +628,7 @@ static void tui_set_icon(UI *ui, char *icon)
 static void tui_set_encoding(UI *ui, char* enc)
 {
   TUIData *data = ui->data;
-  term_input_set_encoding(data->input, enc);
+  term_input_set_encoding(&data->input, enc);
 }
 
 static void invalidate(UI *ui, int top, int bot, int left, int right)
@@ -633,8 +709,8 @@ end:
     height = DFLT_ROWS;
   }
 
-  ui->width = width;
+  data->bridge->bridge.width = ui->width = width;
-  ui->height = height;
+  data->bridge->bridge.height = ui->height = height;
 }
 
 static void unibi_goto(UI *ui, int row, int col)
@@ -817,7 +893,7 @@ static void flush_buf(UI *ui)
   buf.base = data->buf;
   buf.len = data->bufpos;
   uv_write(&req, (uv_stream_t *)&data->output_handle, &buf, 1, NULL);
-  uv_run(data->write_loop, UV_RUN_DEFAULT);
+  uv_run(&data->write_loop, UV_RUN_DEFAULT);
   data->bufpos = 0;
 
   if (!data->busy) {