Use same infrastructure for VFS retention and continuous build

[lptr]

We are now detecting changes on the file system in two different ways. Consolidate this.

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cc: @gradle/build-cache

[lptr]

Are we going to stop supporting continuous mode for platforms unsupported by our own native file watching, or are we going to add some proxy for the JDK's polling perhaps?

[wolfs]

We could keep the JDK watcher backend around. I am also fine with dropping support for continuous build on platforms not supported by our native file watching.

[lptr]

See thread about problematic timeouts wrt continuous mode (especially macOS): https://gradle.slack.com/archives/C0WTFHWT1/p1583943879064600

We need to update these. Searching for \b2000\b in the codebase turns them up usually.

[wolfs]

Currently, most of the continuous build integration tests don't work on Java > 8 on macOS, since we don't set HIGH_FREQUENCY on the JDK watchers. See ☝️ .

[wolfs]

ChangesDuringBuildContinuousIntegrationTest should be changed so it actually checks if the detected changes are picked up by the tasks which are executed.

[wolfs]

Using the native infrastructure for continuous build will also fix #3427.

[graemerocher]

Could this be prioritized for 6.6? continuous build is a great feature but can be slow on Mac

[graemerocher]

Any news?

[lptr]

We are also frustrated with this issue, and will address it in the foreseeable future. It's non-trivial, though. Give us a bit more time.

[avanwieringen-sensus]

Any progress on this issue? I know it is a difficult one, but just wondering :-)

[lptr]

Not for 7.0, but keep watching this space! :)