tree 5a2978611182106bb7f9ca0ff3388588a1f72804
parent c979f9254a9be60d4e53e9d55534fc5211b079a1
author Rob Findley <rfindley@google.com> 1617985239 -0400
committer Robert Findley <rfindley@google.com> 1625774154 +0000

internal/lsp: add a setting to batch didChangeWatchedFile notifications

Gopls's serial processing of didChangeWatchedFile notifications has
historically been a pain point for clients that don't batch file events,
when branch switching or running go generate.

It's "not that tricky" for us to debounce and batch up watched file
notifications on our end, so this CL introduces this functionality as a
new experimental setting. Truth be told it ended up being harder than
expected, due to (1) our requirement for regtests to be able to
determine when diagnostics have completed, and (2) our reliance on
jsonrpc2 for sequencing changes to the server.

To address (1), I factored out the actual processing of change
notifications into a separate method (thus increasing our surprisingly
long chain of method calls). To address (2), I guarded the processing of
file changes with a mutex.

I also guarded some places where views and snapshots were accessed in
potentially racy ways. Our interaction with session.views was rather
complicated, so I had to switch session.viewsMu to a RWMutex.

Add this to the experimental regtest mode, and more generally enable all
experimental features in this mode, rather than just the experimental
workspace module.

Fixes golang/go#41691

Change-Id: Ifccdbdf86263dbe2e37ffe9f7bbf2a2cd74218b4
Reviewed-on: https://go-review.googlesource.com/c/tools/+/309269
Trust: Robert Findley <rfindley@google.com>
Trust: Rebecca Stambler <rstambler@golang.org>
Run-TryBot: Robert Findley <rfindley@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>