core/state/snapshot, tests: sync snap gen + snaps in consensus tests

core/blockchain.go

@@ -121,6 +121,8 @@ type CacheConfig struct {
 	TrieDirtyDisabled   bool          // Whether to disable trie write caching and GC altogether (archive node)
 	TrieTimeLimit       time.Duration // Time limit after which to flush the current in-memory trie to disk
 	SnapshotLimit       int           // Memory allowance (MB) to use for caching snapshot entries in memory
+
+	SnapshotWait bool // Wait for snapshot construction on startup. TODO(karalabe): This is a dirty hack for testing, nuke it
 }
 
 // BlockChain represents the canonical chain given a database with a genesis
@@ -303,7 +305,7 @@ func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, chainConfig *par
 	}
 	// Load any existing snapshot, regenerating it if loading failed
 	if bc.cacheConfig.SnapshotLimit > 0 {
-		bc.snaps = snapshot.New(bc.db, bc.stateCache.TrieDB(), bc.cacheConfig.SnapshotLimit, bc.CurrentBlock().Root())
+		bc.snaps = snapshot.New(bc.db, bc.stateCache.TrieDB(), bc.cacheConfig.SnapshotLimit, bc.CurrentBlock().Root(), !bc.cacheConfig.SnapshotWait)
 	}
 	// Take ownership of this particular state
 	go bc.update()