From 396f3a06ea2a49eb410f12e244c0dd77095d0de9 Mon Sep 17 00:00:00 2001
From: Sean Liao <sean@liao.dev>
Date: Fri, 21 Mar 2025 19:51:13 +0000
Subject: [PATCH] errgroup: document calling Go before Wait
Fixes golang/go#70284
Change-Id: I31d60ea182226c032b0ffbddcbb5b53675dfd5e6
Reviewed-on: https://go-review.googlesource.com/c/sync/+/660075
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Alan Donovan <adonovan@google.com>
Auto-Submit: Damien Neil <dneil@google.com>
Reviewed-by: Damien Neil <dneil@google.com>
---
errgroup/errgroup.go | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/errgroup/errgroup.go b/errgroup/errgroup.go
index a4ea5d1..f8c3c09 100644
--- a/errgroup/errgroup.go
+++ b/errgroup/errgroup.go
@@ -18,7 +18,7 @@ import (
type token struct{}
// A Group is a collection of goroutines working on subtasks that are part of
-// the same overall task.
+// the same overall task. A Group should not be reused for different tasks.
//
// A zero Group is valid, has no limit on the number of active goroutines,
// and does not cancel on error.
@@ -61,6 +61,7 @@ func (g *Group) Wait() error {
}
// Go calls the given function in a new goroutine.
+// The first call to Go must happen before a Wait.
// It blocks until the new goroutine can be added without the number of
// active goroutines in the group exceeding the configured limit.
//