From: Russ Cox <rsc@golang.org>
Date: Wed, 29 Nov 2017 21:31:47 +0000 (-0500)
Subject: testing: remove claim that b.Run is safe for concurrent use
X-Git-Tag: go1.10beta1~79
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=f3b24b9f0766351fc8b3d43c4ea03f948a460e75;p=gostls13.git

testing: remove claim that b.Run is safe for concurrent use

It's not safe (it crashes), and it's also useless: if you run
multiple benchmarks in parallel you will not get reliable
timing results from any of them.

Fixes #18603.

Change-Id: I00e5a72f7c98151543cf7d5573c38383276e391a
Reviewed-on: https://go-review.googlesource.com/80841
Reviewed-by: Ian Lance Taylor <iant@golang.org>
---

diff --git a/src/testing/benchmark.go b/src/testing/benchmark.go
index 2d0de180d7..4d569b7971 100644
--- a/src/testing/benchmark.go
+++ b/src/testing/benchmark.go
@@ -475,9 +475,6 @@ func (ctx *benchContext) processBench(b *B) {
 //
 // A subbenchmark is like any other benchmark. A benchmark that calls Run at
 // least once will not be measured itself and will be called once with N=1.
-//
-// Run may be called simultaneously from multiple goroutines, but all such
-// calls must return before the outer benchmark function for b returns.
 func (b *B) Run(name string, f func(b *B)) bool {
 	// Since b has subbenchmarks, we will no longer run it as a benchmark itself.
 	// Release the lock and acquire it on exit to ensure locks stay paired.