event loop: New abstraction layer with refactored time/signal API

- Add event loop abstraction module under src/nvim/event. The
  src/nvim/event/loop module replaces src/nvim/os/event
- Remove direct dependency on libuv signal/timer API and use the new abstraction
  instead.
- Replace all references to uv_default_loop() by &loop.uv, a new global variable
  that wraps libuv main event loop but allows the event loop functions to be
  reused in other contexts.

1 files changed, 52 insertions, 0 deletions

diff --git a/src/nvim/event/signal.c b/src/nvim/event/signal.c
new file mode 100644
index 0000000000..63133b4f57
--- /dev/null
+++ b/src/nvim/event/signal.c
@@ -0,0 +1,52 @@
+#include <uv.h>
+
+#include "nvim/event/loop.h"
+#include "nvim/event/signal.h"
+
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "event/signal.c.generated.h"
+#endif
+
+
+void signal_watcher_init(Loop *loop, SignalWatcher *watcher, void *data)
+  FUNC_ATTR_NONNULL_ARG(1) FUNC_ATTR_NONNULL_ARG(2)
+{
+  uv_signal_init(&loop->uv, &watcher->uv);
+  watcher->uv.data = watcher;
+  watcher->data = data;
+  watcher->cb = NULL;
+}
+
+void signal_watcher_start(SignalWatcher *watcher, signal_cb cb, int signum)
+  FUNC_ATTR_NONNULL_ALL
+{
+  watcher->cb = cb;
+  uv_signal_start(&watcher->uv, signal_watcher_cb, signum);
+}
+
+void signal_watcher_stop(SignalWatcher *watcher)
+  FUNC_ATTR_NONNULL_ALL
+{
+  uv_signal_stop(&watcher->uv);
+}
+
+void signal_watcher_close(SignalWatcher *watcher, signal_close_cb cb)
+  FUNC_ATTR_NONNULL_ARG(1)
+{
+  watcher->close_cb = cb;
+  uv_close((uv_handle_t *)&watcher->uv, close_cb);
+}
+
+static void signal_watcher_cb(uv_signal_t *handle, int signum)
+{
+  SignalWatcher *watcher = handle->data;
+  watcher->cb(watcher, signum, watcher->data);
+}
+
+static void close_cb(uv_handle_t *handle)
+{
+  SignalWatcher *watcher = handle->data;
+  if (watcher->close_cb) {
+    watcher->close_cb(watcher, watcher->data);
+  }
+}