# Async non blocking API calls **URL:** \ **Category:** Uncategorized\ **Created:** [November 28, 2023, 2:18pm UTC](https://forum.legato.io/t/async-non-blocking-api-calls/6649 "2023-11-28T14:18:04Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![gi1](https://avatars.discourse-cdn.com/v4/letter/g/e79b87/32.png) [@gi1](https://forum.legato.io/u/gi1)\ **Post date:** [November 28, 2023, 2:18pm UTC](https://forum.legato.io/t/async-non-blocking-api-calls/6649/1 "2023-11-28T14:18:04Z")
Hello, I’m in this case: Component A (use B api function) Component B (exposes api functions) Component B handle “Data Connection”, it open GPRS context and activate data. I use built in ` **le\_data\_ConnectService()** and then **le\_data\_Request()** for this. Naturally if connection is down, Component B can take time to ativate. Componet A, instead, watch for some events (motion) and if needed it call Componet B for connection. My question is, **how to avoid blocking A while calling B apis during works?** Sorry for my questin but i cant find a clear documenation on this. I’ve tried calling B methods from A using thread but got a problem here… cause the le\_data\_ConnectService(); needs to be called from the main thread. So i Receive an error. Thank you so much, Gian ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [November 28, 2023, 2:30pm UTC](https://forum.legato.io/t/async-non-blocking-api-calls/6649/2 "2023-11-28T14:30:50Z")
Then can you using other higher priority thread to handle motion event in component A? ---
**Author:** ![gi1](https://avatars.discourse-cdn.com/v4/letter/g/e79b87/32.png) [@gi1](https://forum.legato.io/u/gi1)\ **Post date:** [November 28, 2023, 2:31pm UTC](https://forum.legato.io/t/async-non-blocking-api-calls/6649/3 "2023-11-28T14:31:52Z")
Thanks for your answer… Can you be more clear? ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [November 28, 2023, 2:33pm UTC](https://forum.legato.io/t/async-non-blocking-api-calls/6649/4 "2023-11-28T14:33:46Z")
You say that “le\_data\_ConnectService(); needs to be called from the main thread” Then you can create other thread to handle motion event, right? ---
**Author:** ![gi1](https://avatars.discourse-cdn.com/v4/letter/g/e79b87/32.png) [@gi1](https://forum.legato.io/u/gi1)\ **Post date:** [November 28, 2023, 2:36pm UTC](https://forum.legato.io/t/async-non-blocking-api-calls/6649/5 "2023-11-28T14:36:25Z")
Yes, from component A i can create a Thread to alert Component B that “data connection” is needed, and i can set this to high priority. But anyway … when calling B api… (Connect)… in this function i call le\_data\_ConnectService(), and it goves me an error: **le\_data\_ConnectService** must be called from main thread… ---
**Author:** ![gi1](https://avatars.discourse-cdn.com/v4/letter/g/e79b87/32.png) [@gi1](https://forum.legato.io/u/gi1)\ **Post date:** [November 28, 2023, 2:38pm UTC](https://forum.legato.io/t/async-non-blocking-api-calls/6649/6 "2023-11-28T14:38:00Z")
The only way i found is using a Timer in B to check is something changes… and start actions based on some variable changed. I’m using this approach in another component… but this fill the code of timers… ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [November 28, 2023, 2:44pm UTC](https://forum.legato.io/t/async-non-blocking-api-calls/6649/7 "2023-11-28T14:44:55Z")
Then why don’t you call le\_data\_ConnectService() in the main thread? ---
**Author:** ![gi1](https://avatars.discourse-cdn.com/v4/letter/g/e79b87/32.png) [@gi1](https://forum.legato.io/u/gi1)\ **Post date:** [November 28, 2023, 2:49pm UTC](https://forum.legato.io/t/async-non-blocking-api-calls/6649/8 "2023-11-28T14:49:05Z")
if calling in main thread means calling a direct function from extern, via a method… then this will block until connection established. And I dont want this, cause this will block other part of code that must flow normally without wait… ☹ ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [November 28, 2023, 2:50pm UTC](https://forum.legato.io/t/async-non-blocking-api-calls/6649/9 "2023-11-28T14:50:40Z")
Other part of code should be run in another higher priority thread, not same main thread ---
**Author:** ![gi1](https://avatars.discourse-cdn.com/v4/letter/g/e79b87/32.png) [@gi1](https://forum.legato.io/u/gi1)\ **Post date:** [November 28, 2023, 2:52pm UTC](https://forum.legato.io/t/async-non-blocking-api-calls/6649/10 "2023-11-28T14:52:52Z")
will try to make some changes following your direction… thank so much … you really kind. Gian