[dev.fuzz] internal/fuzz: add mutex to workerClient

This prevents workerClient.Close from closing fuzzIn while
workerClient.fuzz is writing to it concurrently. It also prevents
multiple callers from writing to fuzzIn concurrently, though there's
nothing that does that yet.

This should prevent most "broken pipe" errors, though they may still
be possible if worker.stop is called and it needs to kill the process
due to a timeout. In the future, we should detect and ignore those
errors, but for now, they're useful for debugging.

Also, improve documentation on workerClient and workerServer.

Change-Id: Ie2c870392d5e91674d3b1e32b2fa4f9de9ac3eb0
Reviewed-on: https://go-review.googlesource.com/c/go/+/275173
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Jay Conrod <jayconrod@google.com>
Reviewed-by: Katie Hockman <katie@golang.org>

0 files changed, 0 insertions, 0 deletions