1 files changed, 137 insertions, 0 deletions
diff --git a/src/nvim/event/loop.c b/src/nvim/event/loop.c
new file mode 100644
index 0000000000..c467ae8b96
--- /dev/null
+++ b/src/nvim/event/loop.c
@@ -0,0 +1,137 @@
+#include <stdint.h>
+
+#include <uv.h>
+
+#include "nvim/event/loop.h"
+
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "event/loop.c.generated.h"
+#endif
+
+
+void loop_init(Loop *loop, void *data)
+{
+  uv_loop_init(&loop->uv);
+  loop->uv.data = loop;
+  loop->deferred_events = kl_init(Event);
+  loop->immediate_events = kl_init(Event);
+}
+
+void loop_poll_events(Loop *loop, int ms)
+{
+  static int recursive = 0;
+
+  if (recursive++) {
+    abort();  // Should not re-enter uv_run
+  }
+
+  bool wait = true;
+  uv_timer_t timer;
+
+  if (ms > 0) {
+    uv_timer_init(&loop->uv, &timer);
+    // Use a repeating timeout of ms milliseconds to make sure
+    // we do not block indefinitely for I/O.
+    uv_timer_start(&timer, timer_cb, (uint64_t)ms, (uint64_t)ms);
+  } else if (ms == 0) {
+    // For ms == 0, we need to do a non-blocking event poll by
+    // setting the run mode to UV_RUN_NOWAIT.
+    wait = false;
+  }
+
+  if (wait) {
+    loop_run_once(loop);
+  } else {
+    loop_run_nowait(loop);
+  }
+
+  if (ms > 0) {
+    // Ensure the timer handle is closed and run the event loop
+    // once more to let libuv perform it's cleanup
+    uv_timer_stop(&timer);
+    uv_close((uv_handle_t *)&timer, NULL);
+    loop_run_nowait(loop);
+  }
+
+  recursive--;  // Can re-enter uv_run now
+  process_events_from(loop->immediate_events);
+}
+
+bool loop_has_deferred_events(Loop *loop)
+{
+  return loop->deferred_events_allowed && !kl_empty(loop->deferred_events);
+}
+
+void loop_enable_deferred_events(Loop *loop)
+{
+  ++loop->deferred_events_allowed;
+}
+
+void loop_disable_deferred_events(Loop *loop)
+{
+  --loop->deferred_events_allowed;
+}
+
+// Queue an event
+void loop_push_event(Loop *loop, Event event, bool deferred)
+{
+  // Sometimes libuv will run pending callbacks(timer for example) before
+  // blocking for a poll. If this happens and the callback pushes a event to one
+  // of the queues, the event would only be processed after the poll
+  // returns(user hits a key for example). To avoid this scenario, we call
+  // uv_stop when a event is enqueued.
+  loop_stop(loop);
+  kl_push(Event, deferred ? loop->deferred_events : loop->immediate_events,
+      event);
+}
+
+void loop_process_event(Loop *loop)
+{
+  process_events_from(loop->deferred_events);
+}
+
+
+void loop_run(Loop *loop)
+{
+  uv_run(&loop->uv, UV_RUN_DEFAULT);
+}
+
+void loop_run_once(Loop *loop)
+{
+  uv_run(&loop->uv, UV_RUN_ONCE);
+}
+
+void loop_run_nowait(Loop *loop)
+{
+  uv_run(&loop->uv, UV_RUN_NOWAIT);
+}
+
+void loop_stop(Loop *loop)
+{
+  uv_stop(&loop->uv);
+}
+
+void loop_close(Loop *loop)
+{
+  do {
+    uv_run(&loop->uv, UV_RUN_DEFAULT);
+  } while (uv_loop_close(&loop->uv));
+}
+
+void loop_process_all_events(Loop *loop)
+{
+  process_events_from(loop->immediate_events);
+  process_events_from(loop->deferred_events);
+}
+
+static void process_events_from(klist_t(Event) *queue)
+{
+  while (!kl_empty(queue)) {
+    Event event = kl_shift(Event, queue);
+    event.handler(event);
+  }
+}
+
+static void timer_cb(uv_timer_t *handle)
+{
+}