From 828d0d759e577040f219154cd67cc8b01d1c26ea Mon Sep 17 00:00:00 2001
From: Peter Ebden <peter.ebden@gmail.com>
Date: Tue, 17 Oct 2023 07:29:32 -0400
Subject: [PATCH] Use errgroup limiter where appropriate (#2926)

* make use of errgroup.SetLimit

* here too

* gofmt
---
 src/format/fmt.go   | 4 +---
 src/run/run_step.go | 5 +----
 2 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/src/format/fmt.go b/src/format/fmt.go
index 80acbb9f49..cd15c50c9e 100644
--- a/src/format/fmt.go
+++ b/src/format/fmt.go
@@ -41,12 +41,10 @@ func Format(config *core.Configuration, filenames []string, rewrite, quiet bool)
 func formatAll(filenames <-chan string, parallelism int, rewrite, quiet bool) (bool, error) {
 	var changed int64
 	var g errgroup.Group
-	limiter := make(chan struct{}, parallelism)
+	g.SetLimit(parallelism)
 	for filename := range filenames {
 		filename := filename
 		g.Go(func() error {
-			limiter <- struct{}{}
-			defer func() { <-limiter }()
 			c, err := format(filename, rewrite, quiet)
 			if c {
 				atomic.AddInt64(&changed, 1)
diff --git a/src/run/run_step.go b/src/run/run_step.go
index e17bebb51a..fe24d4b6c5 100644
--- a/src/run/run_step.go
+++ b/src/run/run_step.go
@@ -38,14 +38,11 @@ func Run(state *core.BuildState, label core.AnnotatedOutputLabel, args []string,
 func Parallel(ctx context.Context, state *core.BuildState, labels []core.AnnotatedOutputLabel, args []string, numTasks int, outputMode process.OutputMode, remote, env, detach, inTmp bool, dir string) int {
 	prepareRun()
 
-	limiter := make(chan struct{}, numTasks)
 	var g errgroup.Group
+	g.SetLimit(numTasks)
 	for _, label := range labels {
 		label := label // capture locally
 		g.Go(func() error {
-			limiter <- struct{}{}
-			defer func() { <-limiter }()
-
 			err := runWithOutput(ctx, state, label, args, outputMode, remote, env, detach, inTmp, dir)
 			if err != nil && ctx.Err() == nil {
 				log.Error("Command failed: %s", err)