engines/engine_v2: refactor verifyQC by errgroup, close XFN-09 (#1740)

consensus/XDPoS/engines/engine_v2/engine.go

@@ -1,12 +1,14 @@
 package engine_v2
 
 import (
+	"context"
 	"encoding/json"
 	"errors"
 	"fmt"
 	"math/big"
 	"os"
 	"path/filepath"
+	"runtime"
 	"strconv"
 	"sync"
 	"time"
@@ -25,6 +27,7 @@ import (
 	"github.com/XinFinOrg/XDPoSChain/log"
 	"github.com/XinFinOrg/XDPoSChain/params"
 	"github.com/XinFinOrg/XDPoSChain/trie"
+	"golang.org/x/sync/errgroup"
 )
 
 type XDPoS_v2 struct {
@@ -756,34 +759,36 @@ func (x *XDPoS_v2) verifyQC(blockChainReader consensus.ChainReader, quorumCert *
 	}
 	start := time.Now()
 
-	var wg sync.WaitGroup
+	eg, ctx := errgroup.WithContext(context.Background())
-	wg.Add(len(signatures))
+	eg.SetLimit(runtime.NumCPU())
-	sigErrChan := make(chan error, len(signatures))
+	for _, sig := range signatures {
-
+		eg.Go(func() error {
-	for _, signature := range signatures {
+			select {
-		go func(sig types.Signature) {
+			case <-ctx.Done():
-			defer wg.Done()
+				return ctx.Err()
+			default:
 				verified, _, err := x.verifyMsgSignature(types.VoteSigHash(&types.VoteForSign{
 					ProposedBlockInfo: quorumCert.ProposedBlockInfo,
 					GapNumber:         quorumCert.GapNumber,
 				}), sig, epochInfo.Masternodes)
 				if err != nil {
 					log.Error("[verifyQC] Error while verfying QC message signatures", "Error", err)
-				sigErrChan <- errors.New("error while verfying QC message signatures")
+					return errors.New("error while verfying QC message signatures")
-				return
 				}
 				if !verified {
 					log.Warn("[verifyQC] Signature not verified doing QC verification", "QC", quorumCert)
-				sigErrChan <- errors.New("fail to verify QC due to signature mis-match")
+					return errors.New("fail to verify QC due to signature mis-match")
-				return
 				}
-		}(signature)
+				return nil
 			}
-	wg.Wait()
+		})
+	}
+	err = eg.Wait()
+
 	elapsed := time.Since(start)
 	log.Debug("[verifyQC] time verify message signatures of qc", "elapsed", elapsed)
-	if len(sigErrChan) > 0 {
+	if err != nil {
-		return <-sigErrChan
+		return err
 	}
 	epochSwitchNumber := epochInfo.EpochSwitchBlockInfo.Number.Uint64()
 	gapNumber := epochSwitchNumber - epochSwitchNumber%x.config.Epoch