CEventLoop: Don't bother looking through fds when select() returns 0.

If it returns 0 that just means we hit the timeout. I suppose we could skip
the timer checks if there are a non-zero number of fds marked as well, but
I'm not sure that's a great idea since it will add some latency.

1 files changed, 5 insertions, 2 deletions

diff --git a/LibCore/CEventLoop.cpp b/LibCore/CEventLoop.cpp
index d84a45fe16..3fca8b9239 100644
--- a/LibCore/CEventLoop.cpp
+++ b/LibCore/CEventLoop.cpp
@@ -199,8 +199,8 @@ void CEventLoop::wait_for_event(WaitMode mode)
         should_wait_forever = false;
     }
 
-    int rc = select(max_fd + 1, &rfds, &wfds, nullptr, should_wait_forever ? nullptr : &timeout);
-    if (rc < 0) {
+    int marked_fd_count = select(max_fd + 1, &rfds, &wfds, nullptr, should_wait_forever ? nullptr : &timeout);
+    if (marked_fd_count < 0) {
         ASSERT_NOT_REACHED();
     }
 
@@ -224,6 +224,9 @@ void CEventLoop::wait_for_event(WaitMode mode)
         }
     }
 
+    if (!marked_fd_count)
+        return;
+
     for (auto& notifier : *s_notifiers) {
         if (FD_ISSET(notifier->fd(), &rfds)) {
             if (notifier->on_ready_to_read)