[libcamera-devel] [PATCH 2/5] test: timer: Add a 32 bit wraparound test

Kieran Bingham kieran.bingham at ideasonboard.com
Thu Jan 17 21:20:40 CET 2019


Add a test which catches a timer running longer than the nanosecond
resolution of 32 bits.

Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
---
 test/timer.cpp | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/test/timer.cpp b/test/timer.cpp
index 3d1a78ac2768..c6a6ede73486 100644
--- a/test/timer.cpp
+++ b/test/timer.cpp
@@ -81,6 +81,19 @@ protected:
 			return TestFail;
 		}
 
+		/*
+		 * 32 bit wrap test
+		 * Nanosecond resolution in a 32 bit value wraps at 4.294967
+		 * seconds (0xFFFFFFFF / 1000000)
+		 */
+		timer.start(4295);
+		dispatcher->processEvents();
+
+		if (timer.isRunning() || timer.jitter() > 50) {
+			cout << "Timer expiration test failed" << endl;
+			return TestFail;
+		}
+
 		/* Timer restart. */
 		timer.start(500);
 
-- 
2.17.1



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