ui: Implement module for thread-safe communication with U

The ui_bridge.c module implements a surrogate UI that forwards calls to another
thread.

2 files changed, 387 insertions, 0 deletions

diff --git a/src/nvim/ui_bridge.c b/src/nvim/ui_bridge.c
new file mode 100644
index 0000000000..6e1a27cc9c
--- /dev/null
+++ b/src/nvim/ui_bridge.c
@@ -0,0 +1,347 @@
+// FIXME(tarruda): This module is very repetitive. It might be a good idea to
+// automatically generate it with a lua script during build
+#include <assert.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <limits.h>
+
+#include "nvim/vim.h"
+#include "nvim/ui.h"
+#include "nvim/memory.h"
+#include "nvim/ui_bridge.h"
+
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "ui_bridge.c.generated.h"
+#endif
+
+#define UI(b) (((UIBridgeData *)b)->ui)
+
+// Call a function in the UI thread
+#define UI_CALL(ui, name, argc, ...)                                      \
+  ((UIBridgeData *)ui)->scheduler(                                        \
+    event_create(1, ui_bridge_##name##_event, argc, __VA_ARGS__), UI(ui))
+
+#define INT2PTR(i) ((void *)(uintptr_t)i)
+#define PTR2INT(p) ((int)(uintptr_t)p)
+
+UI *ui_bridge_attach(UI *ui, ui_main_fn ui_main, event_scheduler scheduler)
+{
+  UIBridgeData *rv = xcalloc(1, sizeof(UIBridgeData));
+  rv->ui = ui;
+  rv->bridge.rgb = ui->rgb;
+  rv->bridge.stop = ui_bridge_stop;
+  rv->bridge.resize = ui_bridge_resize;
+  rv->bridge.clear = ui_bridge_clear;
+  rv->bridge.eol_clear = ui_bridge_eol_clear;
+  rv->bridge.cursor_goto = ui_bridge_cursor_goto;
+  rv->bridge.update_menu = ui_bridge_update_menu;
+  rv->bridge.busy_start = ui_bridge_busy_start;
+  rv->bridge.busy_stop = ui_bridge_busy_stop;
+  rv->bridge.mouse_on = ui_bridge_mouse_on;
+  rv->bridge.mouse_off = ui_bridge_mouse_off;
+  rv->bridge.mode_change = ui_bridge_mode_change;
+  rv->bridge.set_scroll_region = ui_bridge_set_scroll_region;
+  rv->bridge.scroll = ui_bridge_scroll;
+  rv->bridge.highlight_set = ui_bridge_highlight_set;
+  rv->bridge.put = ui_bridge_put;
+  rv->bridge.bell = ui_bridge_bell;
+  rv->bridge.visual_bell = ui_bridge_visual_bell;
+  rv->bridge.update_fg = ui_bridge_update_fg;
+  rv->bridge.update_bg = ui_bridge_update_bg;
+  rv->bridge.flush = ui_bridge_flush;
+  rv->bridge.suspend = ui_bridge_suspend;
+  rv->bridge.set_title = ui_bridge_set_title;
+  rv->bridge.set_icon = ui_bridge_set_icon;
+  rv->bridge.set_encoding = ui_bridge_set_encoding;
+  rv->scheduler = scheduler;
+
+  rv->ui_main = ui_main;
+  uv_mutex_init(&rv->mutex);
+  uv_cond_init(&rv->cond);
+  uv_mutex_lock(&rv->mutex);
+  rv->ready = false;
+
+  if (uv_thread_create(&rv->ui_thread, ui_thread_run, rv)) {
+    abort();
+  }
+
+  while (!rv->ready) {
+    uv_cond_wait(&rv->cond, &rv->mutex);
+  }
+  uv_mutex_unlock(&rv->mutex);
+
+  ui_attach(&rv->bridge);
+  return &rv->bridge;
+}
+
+static void ui_thread_run(void *data)
+{
+  UIBridgeData *bridge = data;
+  bridge->ui_main(bridge, bridge->ui);
+}
+
+static void ui_bridge_stop(UI *b)
+{
+  UI_CALL(b, stop, 1, b);
+  UIBridgeData *bridge = (UIBridgeData *)b;
+  uv_thread_join(&bridge->ui_thread);
+  uv_mutex_destroy(&bridge->mutex);
+  uv_cond_destroy(&bridge->cond);
+  ui_detach(b);
+  xfree(b);
+}
+static void ui_bridge_stop_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->stop(ui);
+}
+
+static void ui_bridge_resize(UI *b, int width, int height)
+{
+  UI_CALL(b, resize, 3, b, INT2PTR(width), INT2PTR(height));
+}
+static void ui_bridge_resize_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->resize(ui, PTR2INT(argv[1]), PTR2INT(argv[2]));
+}
+
+static void ui_bridge_clear(UI *b)
+{
+  UI_CALL(b, clear, 1, b);
+}
+static void ui_bridge_clear_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->clear(ui);
+}
+
+static void ui_bridge_eol_clear(UI *b)
+{
+  UI_CALL(b, eol_clear, 1, b);
+}
+static void ui_bridge_eol_clear_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->eol_clear(ui);
+}
+
+static void ui_bridge_cursor_goto(UI *b, int row, int col)
+{
+  UI_CALL(b, cursor_goto, 3, b, INT2PTR(row), INT2PTR(col));
+}
+static void ui_bridge_cursor_goto_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->cursor_goto(ui, PTR2INT(argv[1]), PTR2INT(argv[2]));
+}
+
+static void ui_bridge_update_menu(UI *b)
+{
+  UI_CALL(b, update_menu, 1, b);
+}
+static void ui_bridge_update_menu_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->update_menu(ui);
+}
+
+static void ui_bridge_busy_start(UI *b)
+{
+  UI_CALL(b, busy_start, 1, b);
+}
+static void ui_bridge_busy_start_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->busy_start(ui);
+}
+
+static void ui_bridge_busy_stop(UI *b)
+{
+  UI_CALL(b, busy_stop, 1, b);
+}
+static void ui_bridge_busy_stop_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->busy_stop(ui);
+}
+
+static void ui_bridge_mouse_on(UI *b)
+{
+  UI_CALL(b, mouse_on, 1, b);
+}
+static void ui_bridge_mouse_on_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->mouse_on(ui);
+}
+
+static void ui_bridge_mouse_off(UI *b)
+{
+  UI_CALL(b, mouse_off, 1, b);
+}
+static void ui_bridge_mouse_off_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->mouse_off(ui);
+}
+
+static void ui_bridge_mode_change(UI *b, int mode)
+{
+  UI_CALL(b, mode_change, 2, b, INT2PTR(mode));
+}
+static void ui_bridge_mode_change_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->mode_change(ui, PTR2INT(argv[1]));
+}
+
+static void ui_bridge_set_scroll_region(UI *b, int top, int bot, int left,
+    int right)
+{
+  UI_CALL(b, set_scroll_region, 5, b, INT2PTR(top), INT2PTR(bot),
+      INT2PTR(left), INT2PTR(right));
+}
+static void ui_bridge_set_scroll_region_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->set_scroll_region(ui, PTR2INT(argv[1]), PTR2INT(argv[2]),
+      PTR2INT(argv[3]), PTR2INT(argv[4]));
+}
+
+static void ui_bridge_scroll(UI *b, int count)
+{
+  UI_CALL(b, scroll, 2, b, INT2PTR(count));
+}
+static void ui_bridge_scroll_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->scroll(ui, PTR2INT(argv[1]));
+}
+
+static void ui_bridge_highlight_set(UI *b, HlAttrs attrs)
+{
+  HlAttrs *a = xmalloc(sizeof(HlAttrs));
+  *a = attrs;
+  UI_CALL(b, highlight_set, 2, b, a);
+}
+static void ui_bridge_highlight_set_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->highlight_set(ui, *((HlAttrs *)argv[1]));
+  xfree(argv[1]);
+}
+
+static void ui_bridge_put(UI *b, uint8_t *text, size_t size)
+{
+  uint8_t *t = xmalloc(8);
+  memcpy(t, text, size);
+  UI_CALL(b, put, 3, b, t, INT2PTR(size));
+}
+static void ui_bridge_put_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->put(ui, (uint8_t *)argv[1], (size_t)(uintptr_t)argv[2]);
+  xfree(argv[1]);
+}
+
+static void ui_bridge_bell(UI *b)
+{
+  UI_CALL(b, bell, 1, b);
+}
+static void ui_bridge_bell_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->bell(ui);
+}
+
+static void ui_bridge_visual_bell(UI *b)
+{
+  UI_CALL(b, visual_bell, 1, b);
+}
+static void ui_bridge_visual_bell_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->visual_bell(ui);
+}
+
+static void ui_bridge_update_fg(UI *b, int fg)
+{
+  UI_CALL(b, update_fg, 2, b, INT2PTR(fg));
+}
+static void ui_bridge_update_fg_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->update_fg(ui, PTR2INT(argv[1]));
+}
+
+static void ui_bridge_update_bg(UI *b, int bg)
+{
+  UI_CALL(b, update_bg, 2, b, INT2PTR(bg));
+}
+static void ui_bridge_update_bg_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->update_bg(ui, PTR2INT(argv[1]));
+}
+
+static void ui_bridge_flush(UI *b)
+{
+  UI_CALL(b, flush, 1, b);
+}
+static void ui_bridge_flush_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->flush(ui);
+}
+
+static void ui_bridge_suspend(UI *b)
+{
+  UIBridgeData *data = (UIBridgeData *)b;
+  uv_mutex_lock(&data->mutex);
+  UI_CALL(b, suspend, 1, b);
+  data->ready = false;
+  // suspend the main thread until CONTINUE is called by the UI thread
+  while (!data->ready) {
+    uv_cond_wait(&data->cond, &data->mutex);
+  }
+  uv_mutex_unlock(&data->mutex);
+}
+static void ui_bridge_suspend_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->suspend(ui);
+}
+
+static void ui_bridge_set_title(UI *b, char *title)
+{
+  UI_CALL(b, set_title, 2, b, title ? xstrdup(title) : NULL);
+}
+static void ui_bridge_set_title_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->set_title(ui, argv[1]);
+  xfree(argv[1]);
+}
+
+static void ui_bridge_set_icon(UI *b, char *icon)
+{
+  UI_CALL(b, set_icon, 2, b, icon ? xstrdup(icon) : NULL);
+}
+static void ui_bridge_set_icon_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->set_icon(ui, argv[1]);
+  xfree(argv[1]);
+}
+
+static void ui_bridge_set_encoding(UI *b, char* enc)
+{
+  UI_CALL(b, set_encoding, 2, b, xstrdup(enc));
+}
+static void ui_bridge_set_encoding_event(void **argv)
+{
+  UI *ui = UI(argv[0]);
+  ui->set_encoding(ui, argv[1]);
+  xfree(argv[1]);
+}
diff --git a/src/nvim/ui_bridge.h b/src/nvim/ui_bridge.h
new file mode 100644
index 0000000000..76e9e27989
--- /dev/null
+++ b/src/nvim/ui_bridge.h
@@ -0,0 +1,40 @@
+// Bridge used for communication between a builtin UI thread and nvim core
+#ifndef NVIM_UI_BRIDGE_H
+#define NVIM_UI_BRIDGE_H
+
+#include <uv.h>
+
+#include "nvim/ui.h"
+#include "nvim/event/defs.h"
+
+typedef struct ui_bridge_data UIBridgeData;
+typedef void(*ui_main_fn)(UIBridgeData *bridge, UI *ui);
+struct ui_bridge_data {
+  UI bridge;  // actual UI passed to ui_attach
+  UI *ui;     // UI pointer that will have it's callback called in
+              // another thread
+  event_scheduler scheduler;
+  uv_thread_t ui_thread;
+  ui_main_fn ui_main;
+  uv_mutex_t mutex;
+  uv_cond_t cond;
+  // When the UI thread is called, the main thread will suspend until
+  // the call returns. This flag is used as a condition for the main
+  // thread to continue.
+  bool ready;
+};
+
+#define CONTINUE(b)                                                    \
+  do {                                                                 \
+    UIBridgeData *d = (UIBridgeData *)b;                               \
+    uv_mutex_lock(&d->mutex);                                          \
+    d->ready = true;                                                   \
+    uv_cond_signal(&d->cond);                                          \
+    uv_mutex_unlock(&d->mutex);                                        \
+  } while (0)
+
+
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "ui_bridge.h.generated.h"
+#endif
+#endif  // NVIM_UI_BRIDGE_H