sequenceDiagram
  autonumber

  participant S as Synchronizer
  participant BP as BlockProcess
  participant C as ChainService


  box crate:ckb_sync
    participant S
    participant BP
  end


  box crate:ckb_chain
    participant C
  end

  Note left of S: synchronizer received <br>Block(122) from remote peer

  Note over S: try_process SyncMessageUnionReader::SendBlock


  S->>+BP: BlockProcess::execute(Block(122))
  BP->>+C: process_block(Block(122))
  Note over BP: waiting ChainService to return<br>the result of process_block(Block(123))
  Note over C: insert_block(Block(122))
  C->>-BP: return result of process_block(Block(122))
  BP->>-S: return result of BlockProcess::execute(Block(122))

  alt block is Valid
    Note over S: going on
  else block is Invalid
    Note over S: punish the malicious peer
  end

  Note left of S: synchronizer received <br>Block(123) from remote peer
  Note over S: try_process SyncMessageUnionReader::SendBlock
  S->>+BP: BlockProcess::execute(Block(123))
  BP->>+C: process_block(Block(123))
  Note over BP: waiting ChainService to return<br>the result of process_block(Block(123))
  Note over C: insert_block(Block(123))
  C->>-BP: return result of process_block(Block(123))
  BP->>-S: return result of BlockProcess::execute(Block(123))

  alt block is Valid
    Note over S: going on
  else block is Invalid
    Note over S: punish the malicious peer
  end