fix lifecycle of BlockMiner.

itests/api_test.go

@@ -17,18 +17,19 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+func TestAPI(t *testing.T) {
+	t.Run("direct", func(t *testing.T) {
+		runAPITest(t, kit.Builder)
+	})
+	t.Run("rpc", func(t *testing.T) {
+		runAPITest(t, kit.RPCBuilder)
+	})
+}
+
 type apiSuite struct {
 	makeNodes kit.APIBuilder
 }
 
-func TestAPI(t *testing.T) {
-	runAPITest(t, kit.Builder)
-}
-
-func TestAPIRPC(t *testing.T) {
-	runAPITest(t, kit.RPCBuilder)
-}
-
 // runAPITest is the entry point to API test suite
 func runAPITest(t *testing.T, b kit.APIBuilder) {
 	ts := apiSuite{

itests/kit/blockminer.go

@@ -2,6 +2,7 @@ package kit
 
 import (
 	"context"
+	"sync"
 	"sync/atomic"
 	"testing"
 	"time"
@@ -17,37 +18,45 @@ type BlockMiner struct {
 	miner TestMiner
 
 	nextNulls int64
-	stopCh    chan chan struct{}
+	wg        sync.WaitGroup
+	cancel    context.CancelFunc
 }
 
 func NewBlockMiner(t *testing.T, miner TestMiner) *BlockMiner {
 	return &BlockMiner{
 		t:      t,
 		miner:  miner,
-		stopCh: make(chan chan struct{}),
+		cancel: func() {},
 	}
 }
 
 func (bm *BlockMiner) MineBlocks(ctx context.Context, blocktime time.Duration) {
 	time.Sleep(time.Second)
 
+	// wrap context in a cancellable context.
+	ctx, bm.cancel = context.WithCancel(ctx)
+
+	bm.wg.Add(1)
 	go func() {
+		defer bm.wg.Done()
+
 		for {
 			select {
 			case <-time.After(blocktime):
 			case <-ctx.Done():
 				return
-			case ch := <-bm.stopCh:
-				close(ch)
-				close(bm.stopCh)
-				return
 			}
 
 			nulls := atomic.SwapInt64(&bm.nextNulls, 0)
-			if err := bm.miner.MineOne(ctx, miner.MineReq{
+			err := bm.miner.MineOne(ctx, miner.MineReq{
 				InjectNulls: abi.ChainEpoch(nulls),
 				Done:        func(bool, abi.ChainEpoch, error) {},
-			}); err != nil {
+			})
+			switch {
+			case err == nil: // wrap around
+			case ctx.Err() != nil: // context fired.
+				return
+			default: // log error
 				bm.t.Error(err)
 			}
 		}
@@ -110,11 +119,6 @@ func (bm *BlockMiner) MineUntilBlock(ctx context.Context, fn TestFullNode, cb fu
 // Stop stops the block miner.
 func (bm *BlockMiner) Stop() {
 	bm.t.Log("shutting down mining")
-	if _, ok := <-bm.stopCh; ok {
-		// already stopped
-		return
-	}
-	ch := make(chan struct{})
-	bm.stopCh <- ch
-	<-ch
+	bm.cancel()
+	bm.wg.Wait()
 }

itests/kit/node_builder.go

@@ -370,6 +370,7 @@ func mockBuilderOpts(t *testing.T, fullOpts []FullNodeOpts, storage []StorageMin
 		wait.Lock()
 
 		bm := NewBlockMiner(t, miners[0])
+		t.Cleanup(bm.Stop)
 
 		bm.MineUntilBlock(ctx, fulls[0], func(epoch abi.ChainEpoch) {
 			wait.Unlock()