Add shared-memory support to Activity Tracker.
This is to aid access to non-persistent breadcrumbs created by
subprocesses.
Turns out that the analyzer required read/write access to take
snapshots because of the "unchanged" indicator. That's undesirable
(and sometimes simply infeasible) so I've changed "unchanged" in
favor of a "data version" that is incremented. Comparing before/after
versions will indicate if anything has changed without requiring write
ability by the analyzer.
If the data-version increments 4B times during an analyzer copy, we
have an ABA problem but I think that can be safely discounted.
Bug: 620813
Change-Id: Ic2455dcd3a70f8ec92c4878d7680ce890f16c071
Reviewed-on: https://chromium-review.googlesource.com/773159
Commit-Queue: Brian White <bcwhite@chromium.org>
Reviewed-by: Sigurður Ásgeirsson <siggi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#518963}
CrOS-Libchrome-Original-Commit: 32db29f8dcdc46834c45153f92c5cc9fca7916ec
6 files changed