tree 52ab2c372ccdbf8705e611a2a553681c15f2d49d
parent 9c9572d6f9fbce5c24ffad71aec97df56f4aae5f
author Heschi Kreinick <heschi@google.com> 1594149511 -0400
committer Heschi Kreinick <heschi@google.com> 1594160492 +0000

internal/lsp/cache: fix race in RunProcessEnvFunc

Changing build flags (-modfile) while work is happening in the
background causes races. Explicitly detect relevant configuration
changes and only modify the ProcessEnv then, when the resolver is
inactive after the call to ClearForNewMod.

This still leaves a very small window for a race: if refreshProcessEnv
has already captured env but not yet started priming the cache, it may
race with the modification. But I don't expect it to be a problem in
practice.

Fixes golang/go#39865.

Change-Id: I31c79f39be55975fee14aa0e548b060c46cdd882
Reviewed-on: https://go-review.googlesource.com/c/tools/+/241317
Run-TryBot: Heschi Kreinick <heschi@google.com>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>