Document concurrency model about esp-homekit-sdk HOT 2 OPEN

Yes this is super helpful - thank you.

Is it safe for me to call hap_ functions from multiple tasks?

from esp-homekit-sdk.

Since entire HomeKit communication happens over HTTP, all the read/write callbacks are invoked in the context of the esp_http_server. The various events (like HAP_EVENT_CTRL_PAIRED) are invoked using the esp_event_loop. Whenever application calls hap_char_update_val(), the value change event is queued and notification sent to controllers, again in the esp_http_server task's context. There is also another hap-loop task for some internal operations and state machine.

The app_main() function itself is invoked in the context of the main task, about which, you can read here.

Ideally, the hap_char_update_val() API would need some protection, since it can get invoked from multiple task contexts, but currently it is missing. Other APIs can also have protection, but a lot of those aren't really required to be invoked from different tasks .

I hope this answers your question.

from esp-homekit-sdk.