From a90b14239198996798586e07b68d4e2f71916078 Mon Sep 17 00:00:00 2001
From: Jim Huang <jserv@ccns.ncku.edu.tw>
Date: Thu, 5 Dec 2024 11:05:41 +0800
Subject: [PATCH] Manipulate the delay only when it is positive

The return value of '_twin_timeout_delay' might be negative, and the
polling should be aware of it; otherwise, an unbounded delay occurs.
---
 src/dispatch.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/dispatch.c b/src/dispatch.c
index d1f8aa4..4864ab0 100644
--- a/src/dispatch.c
+++ b/src/dispatch.c
@@ -17,7 +17,9 @@ void twin_dispatch(twin_context_t *ctx)
         _twin_run_timeout();
         _twin_run_work();
         if (g_twin_backend.poll && !g_twin_backend.poll(ctx)) {
-            usleep(_twin_timeout_delay() * 1000);
+            twin_time_t delay = _twin_timeout_delay();
+            if (delay > 0)
+                usleep(delay * 1000);
             break;
         }
     }