[master] Fix timing issue with GetVCFinalBlock

[sandipbhoir]

Description

This fixes the timing issue with syncing of extseed which uses pubkey whitelisting.

• Basically flag m_vcFinalBlockProcessed can remains unset in some corner case with timing issue in GetVCFinalBlockFromL2lDataProvider.
• Same also applies for GetDSBlockFromL2lDataProvider

Backward Compatibility

• This is not a breaking change
• This is a breaking change

Review Suggestion

Status

Implementation

• ready for review

Integration Test (Core Team)

• local machine test

• small-scale cloud test

[chetan-zilliqa]

Hi @sandipbhoir , One question about the fix, Maybe I'm missing somewhere.
Imagine the flow when the block is received and timeout happens.

1. Initially received flag is set to false and we go into a while loop.
2. Both timeouts happened and the final block is received. so m_vcFinalBlockProcessed= true now.
3. next time it will not go into a loop and we set m_vcFinalBlockProcessed=false and return received which is set to false.
4. But since we returned false from GetVCFinalBlockFromL2lDataProvider function, it will not go to fetch FetchMbTxPendingTxMessageFromL2l ?

[sandipbhoir]

Hi @sandipbhoir , One question about the fix, Maybe I'm missing somewhere.
Imagine the flow when the block is received and timeout happens.

1. Initially received flag is set to `false` and we go into a while loop.

2. Both timeouts happened and the final block is received. so `m_vcFinalBlockProcessed= true` now.

3. next time it will not go into a loop and we set `m_vcFinalBlockProcessed=false` and return received which is set to `false`.

4. But since we returned `false` from `GetVCFinalBlockFromL2lDataProvider` function, it will not go to fetch `FetchMbTxPendingTxMessageFromL2l` ?

Good valid point.