From aff2f6d422d01d01e1314622a7ce2f5e88d70aad Mon Sep 17 00:00:00 2001
From: Bartok9 <259807879+Bartok9@users.noreply.github.com>
Date: Wed, 12 Aug 2026 13:25:17 -0400
Subject: [PATCH] fix(ros2): reject non-positive waiters time_interval

Prevent busy-spin when time_interval is 0 and reject negative poll gaps.
---
 src/rai_core/rai/communication/ros2/waiters.py |  2 ++
 tests/communication/ros2/test_waiters.py       | 14 ++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/src/rai_core/rai/communication/ros2/waiters.py b/src/rai_core/rai/communication/ros2/waiters.py
index 6effa109d..ec7530a1e 100644
--- a/src/rai_core/rai/communication/ros2/waiters.py
+++ b/src/rai_core/rai/communication/ros2/waiters.py
@@ -46,6 +46,8 @@ def wait_for_ros2_entities(
 
     if timeout < 0:
         raise ValueError("Timeout must be 0 (wait forever) or a positive value.")
+    if time_interval <= 0:
+        raise ValueError("time_interval must be positive.")
     start_time = time.time()
 
     while timeout == 0 or time.time() - start_time < timeout:
diff --git a/tests/communication/ros2/test_waiters.py b/tests/communication/ros2/test_waiters.py
index 06dc5957b..c00fdf2dc 100644
--- a/tests/communication/ros2/test_waiters.py
+++ b/tests/communication/ros2/test_waiters.py
@@ -168,3 +168,17 @@ def test_wait_for_ros2_entities_negative_timeout():
             get_entities=lambda: [],
             timeout=-1,
         )
+
+
+def test_wait_for_entities_rejects_non_positive_time_interval():
+    import pytest
+    from rai.communication.ros2 import waiters
+
+    with pytest.raises(ValueError, match="time_interval"):
+        waiters.wait_for_ros2_entities(
+            ["/x"], lambda: [], time_interval=0, timeout=1.0
+        )
+    with pytest.raises(ValueError, match="time_interval"):
+        waiters.wait_for_ros2_entities(
+            ["/x"], lambda: [], time_interval=-0.5, timeout=1.0
+        )