mosquitto_connect_bind_v5() and mosquitto_loop_forever() not working in detached thread

[luismigb]

Hi,

I am working with version 2.0.18 cross compiling for ARM (Raspberry Pi).

I want to run a detached thread with any of mosquitto_loop... APIs (to be able to execute other application threads), but I am not able to get it working, only when it is called from the main thread.

I have created a class with a Start method which initialize required fields from mosq_config struct and call all mosquitto APIs to configure TLS and callbacks.
Then, if I call mosquitto_connect_bind_v5 and then mosquitto_loop_forever (inside Start method), this connects and subscribe to broker correctly.
But if I move those two functions to a detached thread run from Start method, mosquitto_connect_bind_v5 fails (sometimes) with "Bad file descriptor" or most of the time with "A TLS error occurred".

Debugging this I get:

4063442928 [ERROR] [MosquittoClient::LogCallback] Error: Unable to load CA certificates, check cafile "▒3▒▒".
4063442929 [ERROR] [MosquittoClient::LogCallback] OpenSSL Error[0]: error:02001002:system library:fopen:No such file or directory
4063442929 [ERROR] [MosquittoClient::LogCallback] OpenSSL Error[1]: error:2006D080:BIO routines:BIO_new_file:no such file
4063442930 [ERROR] [MosquittoClient::LogCallback] OpenSSL Error[2]: error:0B084002:x509 certificate routines:X509_load_cert_crl_file:system lib

Which means that mqttClient->tls_cafile lost its content after the thread creation and because of that the connection is never established.

Attached there is a reduced sample of the class I have created.

MosquittoClient.log