Don't try to modify image in-place in python operator dataflow example

phil-opp · phil-opp · commit aee051284e66 · 2023-06-21T12:24:19.000+02:00
The shared memory image must not be modified because it might be sent to other receivers too. Trying to modify it will result in a SEGFAULT now that we map the shared memory region as read-only.
diff --git a/examples/python-operator-dataflow/plot.py b/examples/python-operator-dataflow/plot.py
@@ -58,6 +58,7 @@ def on_input(
                 dora_input["value"]
                 .to_numpy()
                 .reshape((CAMERA_HEIGHT, CAMERA_WIDTH, 3))
+                .copy() # copy the image because we want to modify it below
             )
             self.image = frame
 

Original file line number	Diff line number	Diff line change
`@@ -58,6 +58,7 @@ def on_input(`
`58`	`58`	`dora_input["value"]`
`59`	`59`	`.to_numpy()`
`60`	`60`	`.reshape((CAMERA_HEIGHT, CAMERA_WIDTH, 3))`
	`61`	`+ .copy() # copy the image because we want to modify it below`
`61`	`62`	`)`
`62`	`63`	`self.image = frame`
`63`	`64`