How Foundry verifies a block

The order of verification

1. Receive a block from block sync or Tendermint consensus.
2. Verify the block
   • Verify the block without history in the verification queue
     • Call Client::import_block function
     • Verify block without history in the verification queue
     • If blocks are verified, client::import_verified_blocks is called
   • Verify the block using history
     • Call check_and_close_block in the import_verified_blocks
     • Call verify_block_family, verify_block_external, and verify_block_final in the check_and_close_block function
3. The verified block will be saved in the disk of the commit_block function.

Why we need verification queues

Verification queues verify signatures in a block using threads.