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awslabs / amazon-kinesis-video-streams-webrtc-sdk-c

Amazon Kinesis Video Streams Webrtc SDK is for developers to install and customize realtime communication between devices and enable secure streaming of video, audio to Kinesis Video Streams.
https://awslabs.github.io/amazon-kinesis-video-streams-webrtc-sdk-c/group__PublicMemberFunctions.html
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[Bug]: signalingClientSendMessageSync delay #1918

Closed AndreaPetrelli closed 8 months ago

AndreaPetrelli commented 9 months ago

Please confirm you have already done the following

Describe the bug

We are using the sdk in master mode with no problems with Trickle ICE enabled clients.

Working with Alexa (that does not support Trickle ICE) we discovered a random delay (from 0 to 10 seconds) waiting for the reply of function signalingClientSendMessageSync.

After some investigations we noted that this delay is produced by this code: https://github.com/awslabs/amazon-kinesis-video-streams-webrtc-sdk-c/blob/74e7f6856b2d3bd71bf7f57374e009af9881ba70/src/source/Signaling/LwsApiCalls.c#L1929

Playing around the defined constants we found that lowering the constant SIGNALING_SERVICE_WSS_PING_PONG_INTERVAL_IN_SECONDS from 10 to 3 seconds, we experiment that the random delay never exceeds 3 seconds.

Expected Behavior

We expect that message is sent as soon as the function signalingClientSendMessageSync has been raised.

Current Behavior

The message is not sent immediatly but with a random delay between 0 and 10 seconds.

Reproduction Steps

For some reason this issue is not relevant when Trickle ICE is enabled. We have discovered this issue working with Alexa because Trickle ICE is not supported and the required 6 seconds timeout if often unsatisfied.

WebRTC C SDK version being used

branch release-1.10.0

Compiler and Version used

gcc (GCC) 12.3.0

Operating System and version

Linux 6.1.54-v7l

Platform being used

Raspberry CM4

AndreaPetrelli commented 9 months ago

Working on the issue we found that wakeLwsServiceEventLoop is called before the wait of the reply.

https://github.com/awslabs/amazon-kinesis-video-streams-webrtc-sdk-c/blob/74e7f6856b2d3bd71bf7f57374e009af9881ba70/src/source/Signaling/LwsApiCalls.c#L1918

The problem is that the lwsHttpCallbackRoutine is not called immediatly but only at the next pong.

https://github.com/awslabs/amazon-kinesis-video-streams-webrtc-sdk-c/blob/74e7f6856b2d3bd71bf7f57374e009af9881ba70/src/source/Signaling/LwsApiCalls.h#L21

Can we add more information?

AndreaPetrelli commented 8 months ago

My fault, i used lws from meta-openembedded and it use libuv as a default. Removing libuv solve the issue.

niyatim23 commented 8 months ago

Closing assuming resolved. Feel free to reopen / open a new issue if problem persists