CJSON_CDECL declaration in cJSON.h file in sample asset_tracker_v2 application

[mexco]

We have added custom code to default asset_tracker_v2 using SDK1.9.1,  MFW version :- mfw_nrf9160_1.3.1. The data is successfully uploaded to the cloud. After reaching the heap limit APP hangs up.

It is observed that memory stack is not cleared in Azure_iot_hub_codec.c file by function cJSON_delete(root_obj), which has internal hooks with  constant CJSON_CDECL used as member pointer.

 In cJSON.h file, though CJSON_CDECL is defined, how does it helps to free the stack and buffer without pointing to a physical memory location? In order to free the memory, how to modify CJSON_CDECL so that the cjson_delete() works properly.

See the images for cjson_delete() function and CJSON_CDECL below.

     

[Maria Gilje]

Hello mexco,

Thank you for your patience. The DevZone team is currently short staffed because of summer holiday in Norway. Some delays are expected.

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I am looking into your case.

Could you please share the relevant code from Azure_iot_hub_codec.c?

I will be able to help you further after the weekend.

Best regards,

Maria

[mexco]

HI, you can see the files cjson.c and cjson.h used in .../nrf/applications/asset_tracker_v2 from ../v1.7.1/modules/lib/cjson, attached here also. The cjson_delet(). CJSON Structur, CJSON_DECL etc all are in these files.

cJSON.c cJSON.h

[Maria Gilje]

Thank you.

I have asked about this internally, and will get back to you when I have more information.

BR,

Maria

[Maria Gilje]

Hello,

Your issue is most likely not caused by CJSON_DECL, as it will evaluate to be empty in your case.

You should investigate what fills up the heap, and try to avoid using heap where you can.

CONFIG_HEAP_MEM_POOL_SIZE can also be increased where you need it.

BR,

Maria

[mexco]

Maria Gilje said:

CONFIG_HEAP_MEM_POOL_SIZE

increasing the heap size just delays the hang up, but does not clear the heap. So, the system will hang up after longer duration. How the use of heap can be avoided ? Please may you give hint ?

[Maria Gilje]

Hello,

mexco said:

How the use of heap can be avoided ? Please may you give hint ?

Limit use of malloc() in your application. Also make sure to free() allocated memory after use.

More information on dynamic memory allocation can be found on various programming forums, i.e. Stack Overflow or by searching the web.

BR,

Maria