From 765cc726b64044a55fb37d10a8bec1c153b06be5 Mon Sep 17 00:00:00 2001 From: miller Date: Sun, 5 Dec 2021 16:39:20 +0000 Subject: [PATCH] src/cmd/go/internal/work: lock Builder output mutex consistently To prevent interleaving of output when 'go build' compiles several packages in parallel, the output mutex in the Builder struct must be locked around any calls to Builder.Print which could generate arbitrary amounts of text (ie more than is guaranteed to be written atomically to a pipe). Fixes #49987 For #49338 Change-Id: I7947df57667deeff3f03f231824298d823f8a943 Reviewed-on: https://go-review.googlesource.com/c/go/+/369018 Reviewed-by: Bryan Mills Run-TryBot: Bryan Mills TryBot-Result: Gopher Robot Trust: Russ Cox --- src/cmd/go/internal/work/buildid.go | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/src/cmd/go/internal/work/buildid.go b/src/cmd/go/internal/work/buildid.go index 4e9189a36320a..76335e9bb170b 100644 --- a/src/cmd/go/internal/work/buildid.go +++ b/src/cmd/go/internal/work/buildid.go @@ -570,6 +570,8 @@ func showStdout(b *Builder, c *cache.Cache, actionID cache.ActionID, key string) b.Showcmd("", "%s # internal", joinUnambiguously(str.StringList("cat", c.OutputFile(stdoutEntry.OutputID)))) } if !cfg.BuildN { + b.output.Lock() + defer b.output.Unlock() b.Print(string(stdout)) } } @@ -578,6 +580,8 @@ func showStdout(b *Builder, c *cache.Cache, actionID cache.ActionID, key string) // flushOutput flushes the output being queued in a. func (b *Builder) flushOutput(a *Action) { + b.output.Lock() + defer b.output.Unlock() b.Print(string(a.output)) a.output = nil }