The coverage of SDLBackgroundTaskManager is not enough

[t-yoshii]

Bug Report

The new SDLBackgroundTaskManager stops background task when transport is connected.

We found that RAI is not sent because the app become Suspended before sending RAI. App does not wakeup anymore because no message will be sent from SDL Core.

Also, SDLBackgroundTaskManager does not start background task when it receives a data from EA session, is it OK?
Till v6.2.3, SDLIAPTransport start background task when it receives data.
https://github.com/smartdevicelink/sdl_ios/blob/6.2.3/SmartDeviceLink/SDLIAPTransport.m#L640

Jul  1 10:56:53 iPhoneSE-M00235 CTSMediaApp1_ms(SmartDeviceLink)[257] <Notice>: 10:56:53:390 \M-p\M^_\M^T\M-5 (SDL)Lifecycle:SDLLifecycleManager:709 - Transport connected
// Background task ended
Jul  1 10:56:53 iPhoneSE-M00235 CTSMediaApp1_ms(SmartDeviceLink)[257] <Notice>: 10:56:53:390 \M-p\M^_\M^T\M-5 (SDL):SDLBackgroundTaskManager:57 - Ending background task with id: 11
Jul  1 10:56:53 iPhoneSE-M00235 CTSMediaApp1_ms(SmartDeviceLink)[257] <Notice>: 10:56:53:390 \M-b\M^Z\M-* (SDL)Utilities:SDLStateMachine:84 - State machine for class SDLLifecycleManager will transition from state Started to state Connected
Jul  1 10:56:53 iPhoneSE-M00235 CTSMediaApp1_ms(SmartDeviceLink)[257] <Notice>: 10:56:53:391 \M-b\M^Z\M-* (SDL)Protocol:SDLProtocol:280 - Send RPC RegisterAppInterface (request)
// Proxy tries to send data, however, this RAI is not received at SDL Core.
Jul  1 10:56:53 iPhoneSE-M00235 CTSMediaApp1_ms(SmartDeviceLink)[257] <Notice>: 10:56:53:392 \M-b\M^Z\M-* (SDL)Protocol:SDLProtocol:343 - Sending protocol message: Version:5, encrypted:0, frameType:Single(1), serviceType:7, frameData:Reserved(0), sessionID:1, dataSize:558, messageID:1  RPC Info: RegisterAppInterface Request
Jul  1 10:56:53 iPhoneSE-M00235 assertiond[66] <Notice>: [CTSMediaApp1_ms:257] Deactivate assertion: <BKProcessAssertion: 0x10fd345d0; "com.sdl.transport.backgroundTask" (finishTask:180s); id:\M-b\M^@\M-&C0EE4CEE27BB>
Jul  1 10:56:53 iPhoneSE-M00235 assertiond[66] <Notice>: [CTSMediaApp1_ms:257] no more active assertions, resetting _timedAssertionPermittedDuration, _timedAssertionReferenceTime, _timedAssertionDeadlineActive: NO
Jul  1 10:56:53 iPhoneSE-M00235 assertiond[66] <Notice>: [CTSMediaApp1_ms:257] New process assertion state; (none) (assertion 0x10fd345d0 added: (none); removed: preventSuspend, preventIdleSleep, preventSuspendOnSleep)
Jul  1 10:56:53 iPhoneSE-M00235 assertiond[66] <Notice>: [CTSMediaApp1_ms:257] suspend success
Jul  1 10:56:53 iPhoneSE-M00235 assertiond[66] <Notice>: [CTSMediaApp1_ms:257] Setting jetsam priority to 0 [0]
Jul  1 10:56:53 iPhoneSE-M00235 assertiond[66] <Notice>: [CTSMediaApp1_ms:257] pid_shutdown_sockets(1) success
Jul  1 10:56:53 iPhoneSE-M00235 assertiond[66] <Notice>: Releasing PowerAssertion on CTSMediaApp1_ms:257 from update
Jul  1 10:56:53 iPhoneSE-M00235 assertiond[66] <Notice>: [CTSMediaApp1_ms:257] Remove assertion: <BKProcessAssertion: 0x10fd345d0; "com.sdl.transport.backgroundTask" (finishTask:180s); id:\M-b\M^@\M-&C0EE4CEE27BB>
Jul  1 10:56:53 iPhoneSE-M00235 SpringBoard[55] <Notice>: Application process state changed for UIEvolution.Media-Test-App: <SBApplicationProcessState: 0x1c0c28de0; pid: 257; taskState: Suspended; visibility: Background>
    ACCPlatformApplicationStateProcessIDKey = 257;
    ACCPlatformApplicationStateProcessIDKey = 257;
Jul  1 10:56:53 iPhoneSE-M00235 mediaserverd(CoreMedia)[27] <Notice>: -CMSessionMgr- CMSessionMgrHandleApplicationStateChange: CMSession: Client UIEvolution.Media-Test-App with pid '257' is now Background Suspended. Background entitlement: YES
Jul  1 10:56:53 iPhoneSE-M00235 mediaserverd(AudioToolbox)[27] <Notice>: 3351: { "action":"application_state_changed", "session":{"ID":"0x1b063","PID":257,"name":"CTSMediaApp1_ms","type":"Fig"}, "details":{"new_state":"Background Task Suspended"} }
Jul  1 10:56:53 iPhoneSE-M00235 mediaserverd(AudioToolbox)[27] <Notice>: 1170: pid 257(CTSMediaApp1_ms)
Jul  1 10:56:53 iPhoneSE-M00235 mediaserverd(AudioToolbox)[27] <Notice>: 3351: { "action":"application_state_changed", "session":{"ID":"0x1b060","PID":257,"name":"CTSMediaApp1_ms"}, "details":{"new_state":"Background Task Suspended"} }
Jul  1 10:56:53 iPhoneSE-M00235 powerd[36] <Notice>: Process assertiond.66 Released NoIdleSleepAssertion "CTSMediaApp1_ms:257:257-6E9F34BE-A081-40D9-8D1A-C0EE4CEE27BB [com.sdl.transport.backgroundTask] [0x10fd345d0]" age:00:00:32  id:4295000956 [System: PrevIdle]
Jul  1 10:56:53 iPhoneSE-M00235 symptomsd(SymptomEvaluator)[123] <Notice>: 257 UIEvolution.Media-Test-App: BackgroundTaskSuspended (most elevated: BackgroundTaskSuspended)

Reproduction Steps

1. Repeadedly connect and disconnect SDL apps in background.

Expected Behavior

2. SDL app registers

Observed Behavior

2. SDL app fails to register

OS & Version Information

• iOS Version: iOS11, iPhone SE
• SDL iOS Version: 6.3.0
• Testing Against: Our internal devboard

Test Case, Sample Code, and / or Example App

none

[NicoleYarroch]

@t-yoshii Does PR #1333 fix this issue for you?

[t-yoshii]

@NicoleYarroch Thanks. We will test the fix #1333

[theresalech]

@t-yoshii have you been able to confirm the fix? We'd like to move forward with releasing the hotfix as soon as possible. Thanks!

[t-yoshii]

Hi @theresalech @NicoleYarroch ,

Thanks for the ping. We are running the repeat test, so, please give us some more time.

So far, It seems connection stability is greatly improved by this fix!. However, some connection failures are observed. So I am also analyzing these issues.

[t-yoshii]

Hi @theresalech @NicoleYarroch,

We tried to reproduce above issues, however, it did not reproduce after >100 attempts. So we think the above failures were temporary problems.

Please merge #1333.
We appreciate your efforts on the connection stability improvement since v6.2.0.

Thanks.