server: refactor processElectraPayload

server/service.go

@@ -687,18 +687,20 @@ func (m *BoostService) processElectraPayload(w http.ResponseWriter, req *http.Re
 	}
 
 	// Prepare for requests
-	var wg sync.WaitGroup
-	var mu sync.Mutex
-	result := new(builderApi.VersionedSubmitBlindedBlockResponse)
+	resultCh := make(chan *builderApi.VersionedSubmitBlindedBlockResponse, len(m.relays))
+	var received atomic.Bool
+	go func() {
+		// Make sure we receive a response within the timeout
+		time.Sleep(m.httpClientGetPayload.Timeout)
+		resultCh <- nil
+	}()
 
 	// Prepare the request context, which will be cancelled after the first successful response from a relay
 	requestCtx, requestCtxCancel := context.WithCancel(context.Background())
 	defer requestCtxCancel()
 
 	for _, relay := range m.relays {
-		wg.Add(1)
 		go func(relay types.RelayEntry) {
-			defer wg.Done()
 			url := relay.GetURI(params.PathGetPayload)
 			log := log.WithField("url", url)
 			log.Debug("calling getPayload")
@@ -759,26 +761,21 @@ func (m *BoostService) processElectraPayload(w http.ResponseWriter, req *http.Re
 				}
 			}
 
-			// Lock before accessing the shared payload
-			mu.Lock()
-			defer mu.Unlock()
-
-			if requestCtx.Err() != nil { // request has been cancelled (or deadline exceeded)
-				return
-			}
-
-			// Received successful response. Now cancel other requests and return immediately
 			requestCtxCancel()
-			*result = *responsePayload
-			log.Info("received payload from relay")
+			if received.CompareAndSwap(false, true) {
+				resultCh <- responsePayload
+				log.Info("received payload from relay")
+			} else {
+				log.Trace("Discarding response, already received a correct response")
+			}
 		}(relay)
 	}
 
-	// Wait for all requests to complete...
-	wg.Wait()
+	// Wait for the first request to complete
+	result := <-resultCh
 
 	// If no payload has been received from relay, log loudly about withholding!
-	if getPayloadResponseIsEmpty(result) {
+	if result == nil || getPayloadResponseIsEmpty(result) {
 		originRelays := types.RelayEntriesToStrings(originalBid.relays)
 		log.WithField("relaysWithBid", strings.Join(originRelays, ", ")).Error("no payload received from relay!")
 		m.respondError(w, http.StatusBadGateway, errNoSuccessfulRelayResponse.Error())

server/service_test.go

@@ -19,6 +19,7 @@ import (
 	builderApiV1 "github.com/attestantio/go-builder-client/api/v1"
 	builderSpec "github.com/attestantio/go-builder-client/spec"
 	eth2ApiV1Deneb "github.com/attestantio/go-eth2-client/api/v1/deneb"
+	eth2ApiV1Electra "github.com/attestantio/go-eth2-client/api/v1/electra"
 	"github.com/attestantio/go-eth2-client/spec"
 	"github.com/attestantio/go-eth2-client/spec/altair"
 	"github.com/attestantio/go-eth2-client/spec/bellatrix"
@@ -125,6 +126,41 @@ func blindedBlockContentsToPayloadDeneb(signedBlindedBlockContents *eth2ApiV1Den
 	}
 }
 
+func blindedBlockContentsToPayloadElectra(signedBlindedBlockContents *eth2ApiV1Electra.SignedBlindedBeaconBlock) *builderApiDeneb.ExecutionPayloadAndBlobsBundle {
+	header := signedBlindedBlockContents.Message.Body.ExecutionPayloadHeader
+	numBlobs := len(signedBlindedBlockContents.Message.Body.BlobKZGCommitments)
+	commitments := make([]deneb.KZGCommitment, numBlobs)
+	copy(commitments, signedBlindedBlockContents.Message.Body.BlobKZGCommitments)
+	proofs := make([]deneb.KZGProof, numBlobs)
+	blobs := make([]deneb.Blob, numBlobs)
+	return &builderApiDeneb.ExecutionPayloadAndBlobsBundle{
+		ExecutionPayload: &deneb.ExecutionPayload{
+			ParentHash:    header.ParentHash,
+			FeeRecipient:  header.FeeRecipient,
+			StateRoot:     header.StateRoot,
+			ReceiptsRoot:  header.ReceiptsRoot,
+			LogsBloom:     header.LogsBloom,
+			PrevRandao:    header.PrevRandao,
+			BlockNumber:   header.BlockNumber,
+			GasLimit:      header.GasLimit,
+			GasUsed:       header.GasUsed,
+			Timestamp:     header.Timestamp,
+			ExtraData:     header.ExtraData,
+			BaseFeePerGas: header.BaseFeePerGas,
+			BlockHash:     header.BlockHash,
+			Transactions:  make([]bellatrix.Transaction, 0),
+			Withdrawals:   make([]*capella.Withdrawal, 0),
+			BlobGasUsed:   header.BlobGasUsed,
+			ExcessBlobGas: header.ExcessBlobGas,
+		},
+		BlobsBundle: &builderApiDeneb.BlobsBundle{
+			Commitments: commitments,
+			Proofs:      proofs,
+			Blobs:       blobs,
+		},
+	}
+}
+
 func TestNewBoostServiceErrors(t *testing.T) {
 	t.Run("errors when no relays", func(t *testing.T) {
 		_, err := NewBoostService(BoostServiceOpts{
@@ -787,6 +823,34 @@ func TestGetPayloadDeneb(t *testing.T) {
 	require.Equal(t, signedBlindedBlock.Message.Body.ExecutionPayloadHeader.BlockHash, resp.Deneb.ExecutionPayload.BlockHash)
 }
 
+func TestGetPayloadElectra(t *testing.T) {
+	// Load the signed blinded beacon block used for getPayload
+	jsonFile, err := os.Open("../testdata/signed-blinded-beacon-block-electra.json")
+	require.NoError(t, err)
+	defer jsonFile.Close()
+	signedBlindedBlock := new(eth2ApiV1Electra.SignedBlindedBeaconBlock)
+	require.NoError(t, DecodeJSON(jsonFile, &signedBlindedBlock))
+
+	backend := newTestBackend(t, 1, time.Second)
+
+	// Prepare getPayload response
+	backend.relays[0].GetPayloadResponse = &builderApi.VersionedSubmitBlindedBlockResponse{
+		Version: spec.DataVersionElectra,
+		Electra: blindedBlockContentsToPayloadElectra(signedBlindedBlock),
+	}
+
+	// call getPayload, ensure it's only called on relay 0 (origin of the bid)
+	getPayloadPath := "/eth/v1/builder/blinded_blocks"
+	rr := backend.request(t, http.MethodPost, getPayloadPath, signedBlindedBlock)
+	require.Equal(t, http.StatusOK, rr.Code, rr.Body.String())
+	require.Equal(t, 1, backend.relays[0].GetRequestCount(getPayloadPath))
+
+	resp := new(builderApi.VersionedSubmitBlindedBlockResponse)
+	err = json.Unmarshal(rr.Body.Bytes(), resp)
+	require.NoError(t, err)
+	require.Equal(t, signedBlindedBlock.Message.Body.ExecutionPayloadHeader.BlockHash, resp.Electra.ExecutionPayload.BlockHash)
+}
+
 func TestGetPayloadToAllRelays(t *testing.T) {
 	// Load the signed blinded beacon block used for getPayload
 	jsonFile, err := os.Open("../testdata/signed-blinded-beacon-block-deneb.json")

testdata/signed-blinded-beacon-block-electra.json

@@ -0,0 +1,72 @@
+{
+  "message": {
+    "slot": "252288",
+    "proposer_index": "4295",
+    "parent_root": "0x9a8eef2096477e645150fee1a2ce13190382179a0ea843f31173715a1a14e074",
+    "state_root": "0x4c033e0b4a34c0eb8e0caba126fae3ed303a83254fe39f8daaa673125f4042cc",
+    "body": {
+      "randao_reveal": "0xa7a74e03d8ef909abc75b9452d167e15869180fb4b19db79a1136b510495f02d6ae480ee4ad6a2a9e41af866a9a54c681601a3a1dee30f676e93e6c6b3eb3e880c2cb8d32bd730ca9e7def92877c70da09bfc52a531f1be15619c8a3bb38bdf6",
+      "eth1_data": {
+        "deposit_root": "0x0cacd599c9cdcee8398b40ef045baf2c137bed4d2b02a465a0414b04015f861d",
+        "deposit_count": "216773",
+        "block_hash": "0xd75a680056c50b4e339eda2f91ccd33badc5d59feab830526e342c5ec68d8dce"
+      },
+      "graffiti": "0x6c69676874686f7573652d6e65746865726d696e642d33000000000000000000",
+      "proposer_slashings": [],
+      "attester_slashings": [],
+      "attestations": [
+        {
+          "aggregation_bits": "0xf8fbff9093195acfebcff69cdfef71fbd9eaf19777f7dfb1f9233faf08be7e463a675cefef2d9e03",
+          "data": {
+            "slot": "252287",
+            "index": "0",
+            "beacon_block_root": "0x9a8eef2096477e645150fee1a2ce13190382179a0ea843f31173715a1a14e074",
+            "source": {
+              "epoch": "7682",
+              "root": "0x83900465836d88fbd48a829ca207db86e32aa7797966df1b0c886128c72a1a0b"
+            },
+            "target": {
+              "epoch": "7883",
+              "root": "0x6e20c4503b853781327d750ee818651e5493b04f5ea0f2699725eecb1e0c3ddf"
+            }
+          },
+          "signature": "0xb8fb8248ce16152eb41f88803445ef64c33da86de7bfd398b12e745a449013f9454c38b42a658291e344e3eb11d1c3ec03d692b9ed299aff0f599ea9145596b5195d11ff49f83a573519616c8b76c9459a1ed5f869e1c5c6bad176adbd3b689c",
+          "committee_bits": "0x0300000000000000"
+        }
+      ],
+      "deposits": [],
+      "voluntary_exits": [],
+      "sync_aggregate": {
+        "sync_committee_bits": "0xde98bcde844ff76e87b94cfff1cbcc3dfbf93fdf3ee9b994764fafe484f762eb1562e7fa28e96f5d7a887bff689ffb932d5eff467e668d137bc565d37e3fa7fd",
+        "sync_committee_signature": "0x93a611fb577d17674242e42de06958513013b0cb07d1f284e993ed7d63ac43bbc234e54a886ca9cb979e76eabeeb6ee603556234b7d661bdb7a7ac98813028faf8060e5e9271d4f25de199ce5e2ecc2a6762a49c41bf366b1c4c54bc185c62f9"
+      },
+      "execution_payload_header": {
+        "parent_hash": "0x98b62322edaa4d91ecc0847fe2f7debc89dec5e808d7e369aa9b535543227f60",
+        "fee_recipient": "0xf97e180c050e5ab072211ad2c213eb5aee4df134",
+        "state_root": "0x3b6b594d5cbe7ff4c8bdca04f080c57a18fffdaf1c8e700e69b86f7425ed8d73",
+        "receipts_root": "0x04deb4be6955e1a300123be48007597f67e4229f8ce70f4f10388de6fd3fa267",
+        "logs_bloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+        "prev_randao": "0x83612b3de54001f74bf36234e373c1fca95dab5e4645bc3faf7108345cf82e34",
+        "block_number": "220275",
+        "gas_limit": "30000000",
+        "gas_used": "84000",
+        "timestamp": "1732296378",
+        "extra_data": "0x4e65746865726d696e64",
+        "base_fee_per_gas": "7",
+        "block_hash": "0xb65b77e52407ff25f7fcd3f455c991ae67be1bc10cb7ec992a659698cf88870f",
+        "transactions_root": "0xb1fcd304d8ba402be6e76346395ea7641fbb4c83663b697a0e88ab115d859d3f",
+        "withdrawals_root": "0x792930bbd5baac43bcc798ee49aa8185ef76bb3b44ba62b91d86ae569e4bb535",
+        "blob_gas_used": "0",
+        "excess_blob_gas": "0"
+      },
+      "bls_to_execution_changes": [],
+      "blob_kzg_commitments": [],
+      "execution_requests": {
+        "deposits": [],
+        "withdrawals": [],
+        "consolidations": []
+      }
+    }
+  },
+  "signature": "0x94cd72a70a0b424f68145115a9a52f6c8557fb40ec8b67c26cbb9b324b72756624a59e8bbe11b78acbbb8e9c606035d10c0dab9a3f4177d7e6954f8ea1863d0b0b00007fb420b4b4cf52e065bda0ad32af0d3a71bd6938180bab6dd1af754d2f"
+}