From 75a38151cd832304c3eec4c002d59d644e597534 Mon Sep 17 00:00:00 2001
From: Sam Batschelet <sam.batschelet@avalabs.org>
Date: Fri, 24 Feb 2023 16:32:32 -0500
Subject: [PATCH] Simplfy subprocess `Stop` & remove useless test (#2652)

---
 utils/ulimit/ulimit_test.go                  | 18 ------------------
 vms/rpcchainvm/runtime/subprocess/stopper.go | 19 +++++--------------
 2 files changed, 5 insertions(+), 32 deletions(-)
 delete mode 100644 utils/ulimit/ulimit_test.go

diff --git a/utils/ulimit/ulimit_test.go b/utils/ulimit/ulimit_test.go
deleted file mode 100644
index 0ffe3aa11934..000000000000
--- a/utils/ulimit/ulimit_test.go
+++ /dev/null
@@ -1,18 +0,0 @@
-// Copyright (C) 2019-2022, Ava Labs, Inc. All rights reserved.
-// See the file LICENSE for licensing terms.
-
-package ulimit
-
-import (
-	"testing"
-
-	"github.com/ava-labs/avalanchego/utils/logging"
-)
-
-// Test_SetDefault performs sanity checks for the os default.
-func Test_SetDefault(t *testing.T) {
-	err := Set(DefaultFDLimit, logging.NoLog{})
-	if err != nil {
-		t.Skipf("default fd-limit failed %v", err)
-	}
-}
diff --git a/vms/rpcchainvm/runtime/subprocess/stopper.go b/vms/rpcchainvm/runtime/subprocess/stopper.go
index 616f9c473c83..5f432bd416fd 100644
--- a/vms/rpcchainvm/runtime/subprocess/stopper.go
+++ b/vms/rpcchainvm/runtime/subprocess/stopper.go
@@ -20,22 +20,13 @@ func NewStopper(logger logging.Logger, cmd *exec.Cmd) runtime.Stopper {
 }
 
 type stopper struct {
-	lock     sync.Mutex
-	cmd      *exec.Cmd
-	shutdown bool
-
+	once   sync.Once
+	cmd    *exec.Cmd
 	logger logging.Logger
 }
 
 func (s *stopper) Stop(ctx context.Context) {
-	s.lock.Lock()
-	defer s.lock.Unlock()
-
-	// subsequent calls to this method are a no-op
-	if s.shutdown || s.cmd.Process == nil {
-		return
-	}
-
-	s.shutdown = true
-	stop(ctx, s.logger, s.cmd)
+	s.once.Do(func() {
+		stop(ctx, s.logger, s.cmd)
+	})
 }