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Deserializing error for string type #234
Description
Describe the bug
String types in service types cause microROS on the MCU side to fail in the executor due to a deserializing error. Running it through a debugger it fails in ucdr_deserialize_sequence_header when parsing the nested message type.
Service calls with non-string types work as expected. I've verified it's not a buffer overflow since the buffer size >> bytes received. There is also no packet corruption in UDP traffic, the dest packet and src packet match 1:1.
To Reproduce
Steps to reproduce the behaviour:
- On MCU, init service with service type that has a string type
- On host side, call service
Expected behaviour
The MCU accepts the service call and handles accordingly.
Actual behaviour
Executor fails due to deserialization error.
System information (please complete the following information):
- OS: Ubuntu 22.04
- ROS 2 Humble
- MCU: STM32F767ZI
Activity
hr-ti commentedon Aug 23, 2024
Seems like this is an error with the nested message type's string member. As it fails in ucdr_deserialize_sequence_header, the length of the string member is greater than the capacity in rosidl_runtime_c__String, which is always 0.
Since there's no issue with UDP comms, this could be due to an error in generating the string type from the agent side.
[-]Deserializing error for nested message types [/-][+]Deserializing error for string types[/+][-]Deserializing error for string types[/-][+]Deserializing error for string type[/+]hr-ti commentedon Aug 26, 2024
This actually applies to any sequence type, like a byte array. Since capacity is always 0, any populated sequence simply just fails
gavanderhoorn commentedon Aug 27, 2024
Edit: apologies, confused
capacitywithsize.re:
capacity: how do you initialise your message/service structs? Are you using the appropriate_init(..)/_fini(..)pairs or are you usingmicro_ros_utilities?