travis: enable test suite on ARM64 (#20219)

* travis: Enable ARM support

* Include fixes from 20039

* Add a trace to debug the invalid lookup issue

* Try increasing the timeout to see if the arm test passes

* Investigate the resolver issue

* Increase arm64 timeout for clique test

* increase timeout in tests for arm64

* Only test the failing tests

* Review feedback: don't export epsilon

* Remove investigation tricks+include fjl's feeback

* Revert the retry ahead of using the mock resolver

* Fix rebase errors

.travis.yml

@@ -34,6 +34,16 @@ jobs:
     # These are the latest Go versions.
     - stage: build
       os: linux
+      arch: amd64
+      dist: xenial
+      go: 1.13.x
+      script:
+        - go run build/ci.go install
+        - go run build/ci.go test -coverage $TEST_PACKAGES
+
+    - stage: build
+      os: linux
+      arch: arm64
       dist: xenial
       go: 1.13.x
       script:

consensus/ethash/ethash_test.go

@@ -49,7 +49,7 @@ func TestTestMode(t *testing.T) {
 		if err := ethash.VerifySeal(nil, header); err != nil {
 			t.Fatalf("unexpected verification error: %v", err)
 		}
-	case <-time.NewTimer(time.Second).C:
+	case <-time.NewTimer(2 * time.Second).C:
 		t.Error("sealing result timeout")
 	}
 }

eth/handler_test.go

@@ -608,7 +608,7 @@ func testBroadcastBlock(t *testing.T, totalPeers, broadcastExpected int) {
 			}
 		}(peer)
 	}
-	timeout := time.After(300 * time.Millisecond)
+	timeout := time.After(time.Second)
 	var receivedCount int
 outer:
 	for {

metrics/doc.go

+package metrics
+
+const epsilon = 0.0000000000000001
+const epsilonPercentile = .00000000001

metrics/sample_test.go

 package metrics
 
 import (
+	"math"
 	"math/rand"
 	"runtime"
 	"testing"
@@ -326,7 +327,7 @@ func testUniformSampleStatistics(t *testing.T, s Sample) {
 	if 7380.5 != ps[1] {
 		t.Errorf("75th percentile: 7380.5 != %v\n", ps[1])
 	}
-	if 9986.429999999998 != ps[2] {
+	if math.Abs(9986.429999999998-ps[2]) > epsilonPercentile {
 		t.Errorf("99th percentile: 9986.429999999998 != %v\n", ps[2])
 	}
 }

miner/worker_test.go

@@ -340,7 +340,9 @@ func testEmptyWork(t *testing.T, chainConfig *params.ChainConfig, engine consens
 		}
 	}
 	w.fullTaskHook = func() {
-		time.Sleep(100 * time.Millisecond)
+		// Aarch64 unit tests are running in a VM on travis, they must
+		// be given more time to execute.
+		time.Sleep(time.Second)
 	}
 
 	// Ensure worker has finished initialization
@@ -355,7 +357,7 @@ func testEmptyWork(t *testing.T, chainConfig *params.ChainConfig, engine consens
 	for i := 0; i < 2; i += 1 {
 		select {
 		case <-taskCh:
-		case <-time.NewTimer(2 * time.Second).C:
+		case <-time.NewTimer(4 * time.Second).C:
 			t.Error("new task timeout")
 		}
 	}