From 483c082d2eae839c4a55061264d1972c2acc62e4 Mon Sep 17 00:00:00 2001
From: Diego Ximenes <dxmendes1@gmail.com>
Date: Thu, 2 Jan 2025 21:01:28 -0300
Subject: [PATCH] ExecutionClient.Start and ExecutionClient.StopAndWait return
 promises

---
 arbnode/inbox_test.go      |  8 ++++----
 arbnode/node.go            |  7 +++++--
 execution/gethexec/node.go | 14 ++++++++------
 execution/interface.go     |  4 ++--
 4 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/arbnode/inbox_test.go b/arbnode/inbox_test.go
index 0c8f00a3d4..2207e47b4e 100644
--- a/arbnode/inbox_test.go
+++ b/arbnode/inbox_test.go
@@ -90,12 +90,12 @@ func (w *execClientWrapper) ResultAtPos(pos arbutil.MessageIndex) containers.Pro
 	return containers.NewReadyPromise(w.ExecutionEngine.ResultAtPos(pos))
 }
 
-func (w *execClientWrapper) Start(ctx context.Context) error {
-	return nil
+func (w *execClientWrapper) Start(ctx context.Context) containers.PromiseInterface[struct{}] {
+	return containers.NewReadyPromise(struct{}{}, nil)
 }
 
-func (w *execClientWrapper) StopAndWait() {
-	return
+func (w *execClientWrapper) StopAndWait() containers.PromiseInterface[struct{}] {
+	return containers.NewReadyPromise(struct{}{}, nil)
 }
 
 func NewTransactionStreamerForTest(t *testing.T, ownerAddress common.Address) (*gethexec.ExecutionEngine, *TransactionStreamer, ethdb.Database, *core.BlockChain) {
diff --git a/arbnode/node.go b/arbnode/node.go
index b5742524c9..a0f8f02e6c 100644
--- a/arbnode/node.go
+++ b/arbnode/node.go
@@ -1243,7 +1243,7 @@ func (n *Node) Start(ctx context.Context) error {
 	if execClient != nil {
 		execClient.SetConsensusClient(n)
 	}
-	err = n.ExecutionClient.Start(ctx)
+	_, err = n.ExecutionClient.Start(ctx).Await(ctx)
 	if err != nil {
 		return fmt.Errorf("error starting exec client: %w", err)
 	}
@@ -1414,7 +1414,10 @@ func (n *Node) StopAndWait() {
 		n.DASLifecycleManager.StopAndWaitUntil(2 * time.Second)
 	}
 	if n.ExecutionClient != nil {
-		n.ExecutionClient.StopAndWait()
+		_, err := n.ExecutionClient.StopAndWait().Await(n.ctx)
+		if err != nil {
+			log.Error("error stopping execution client", "err", err)
+		}
 	}
 	if err := n.Stack.Close(); err != nil {
 		log.Error("error on stack close", "err", err)
diff --git a/execution/gethexec/node.go b/execution/gethexec/node.go
index 5b78a73c73..9ee0bcc896 100644
--- a/execution/gethexec/node.go
+++ b/execution/gethexec/node.go
@@ -347,9 +347,9 @@ func (n *ExecutionNode) Initialize(ctx context.Context) error {
 }
 
 // not thread safe
-func (n *ExecutionNode) Start(ctx context.Context) error {
+func (n *ExecutionNode) Start(ctx context.Context) containers.PromiseInterface[struct{}] {
 	if n.started.Swap(true) {
-		return errors.New("already started")
+		return containers.NewReadyPromise(struct{}{}, errors.New("already started"))
 	}
 	// TODO after separation
 	// err := n.Stack.Start()
@@ -359,17 +359,17 @@ func (n *ExecutionNode) Start(ctx context.Context) error {
 	n.ExecEngine.Start(ctx)
 	err := n.TxPublisher.Start(ctx)
 	if err != nil {
-		return fmt.Errorf("error starting transaction puiblisher: %w", err)
+		return containers.NewReadyPromise(struct{}{}, fmt.Errorf("error starting transaction puiblisher: %w", err))
 	}
 	if n.ParentChainReader != nil {
 		n.ParentChainReader.Start(ctx)
 	}
-	return nil
+	return containers.NewReadyPromise(struct{}{}, nil)
 }
 
-func (n *ExecutionNode) StopAndWait() {
+func (n *ExecutionNode) StopAndWait() containers.PromiseInterface[struct{}] {
 	if !n.started.Load() {
-		return
+		return containers.NewReadyPromise(struct{}{}, nil)
 	}
 	// TODO after separation
 	// n.Stack.StopRPC() // does nothing if not running
@@ -391,6 +391,8 @@ func (n *ExecutionNode) StopAndWait() {
 	// if err := n.Stack.Close(); err != nil {
 	// 	log.Error("error on stak close", "err", err)
 	// }
+
+	return containers.NewReadyPromise(struct{}{}, nil)
 }
 
 func (n *ExecutionNode) DigestMessage(num arbutil.MessageIndex, msg *arbostypes.MessageWithMetadata, msgForPrefetch *arbostypes.MessageWithMetadata) containers.PromiseInterface[*execution.MessageResult] {
diff --git a/execution/interface.go b/execution/interface.go
index 51de32a685..dcf6fec72a 100644
--- a/execution/interface.go
+++ b/execution/interface.go
@@ -37,8 +37,8 @@ type ExecutionClient interface {
 
 	Maintenance() containers.PromiseInterface[struct{}]
 
-	Start(ctx context.Context) error
-	StopAndWait()
+	Start(ctx context.Context) containers.PromiseInterface[struct{}]
+	StopAndWait() containers.PromiseInterface[struct{}]
 }
 
 // needed for validators / stakers